const {
    EmbedBuilder,
    ActionRowBuilder,
    ButtonBuilder,
    ButtonStyle,
    MessageFlags
} = require("discord.js");

const {
    getCollections,
    getCookieBalance,
    transferCookies,
    temporaryEphemeralReply,
    temporaryEphemeralFollowUp,
    getUnixTime,
    randomInteger
} = require("./cookieEconomy");


const EVENT_COLLECTION =
    "items_events";


/*
 * ============================================================
 * GENERAL CONFIG
 * ============================================================
 */

const BATTLE_DURATION =
    60 * 60;

const BOSS_ACTION_THRESHOLD =
    10;

const LIMIT_GAUGE_MAX =
    100;


/*
 * ============================================================
 * ACTION CONFIG
 * ============================================================
 *
 * Roles / Jobs can override these values later.
 */

const ACTIONS = {
    Strike: {
        cooldown:
            8,

        energyGain:
            12,

        limitGain:
            5,

        powerMultiplier:
            1.0
    },


    Defend: {
        cooldown:
            20,

        energyCost:
            5,

        limitGain:
            2,

        reduction:
            0.25,

        charges:
            2
    },


    Heal: {
        cooldown:
            25,

        energyCost:
            10,

        limitGain:
            3,

        powerMultiplier:
            1.0
    }
};


/*
 * ============================================================
 * JOBS
 * ============================================================
 *
 * Every job uses the same buttons.
 *
 * Job modifiers simply make certain actions
 * more efficient.
 */

const JOBS = {
    DPS: {
        BlackMage: {
            name:
                "Black Mage",

            class:
                "Thaumaturge",

            emoji:
                "🔥",

            strikeMultiplier:
                1.40,

            strikeEnergy:
                10,

            strikeLimit:
                5
        },


        Dragoon: {
            name:
                "Dragoon",

            class:
                "Lancer",

            emoji:
                "🐉",

            strikeMultiplier:
                1.30,

            strikeEnergy:
                12,

            strikeLimit:
                7
        },


        Bard: {
            name:
                "Bard",

            class:
                "Archer",

            emoji:
                "🏹",

            strikeMultiplier:
                1.15,

            strikeEnergy:
                14,

            strikeLimit:
                9
        }
    },


    Tank: {
        Paladin: {
            name:
                "Paladin",

            class:
                "Gladiator",

            emoji:
                "⚔️",

            strikeMultiplier:
                0.90,

            defendCost:
                2,

            defendReduction:
                0.55,

            defendCharges:
                3
        },


        Warrior: {
            name:
                "Warrior",

            class:
                "Marauder",

            emoji:
                "🪓",

            strikeMultiplier:
                1.05,

            defendCost:
                3,

            defendReduction:
                0.45,

            defendCharges:
                2
        },


        DarkKnight: {
            name:
                "Dark Knight",

            class:
                null,

            emoji:
                "🌑",

            strikeMultiplier:
                1.10,

            defendCost:
                3,

            defendReduction:
                0.50,

            defendCharges:
                2
        }
    },


    Healer: {
        WhiteMage: {
            name:
                "White Mage",

            class:
                "Conjurer",

            emoji:
                "✨",

            strikeMultiplier:
                0.75,

            healCost:
                5,

            healMultiplier:
                1.55,

            healLimit:
                3
        },


        Scholar: {
            name:
                "Scholar",

            class:
                "Arcanist",

            emoji:
                "📖",

            strikeMultiplier:
                0.80,

            healCost:
                6,

            healMultiplier:
                1.35,

            healLimit:
                4
        },


        Astrologian: {
            name:
                "Astrologian",

            class:
                null,

            emoji:
                "🌟",

            strikeMultiplier:
                0.80,

            healCost:
                6,

            healMultiplier:
                1.25,

            healLimit:
                6
        }
    }
};


/*
 * ============================================================
 * INVESTMENT TIERS
 * ============================================================
 */

const TIERS = {
    Sprout: {
        name:
            "Sprout",

        emoji:
            "🌱",

        cost:
            100,

        health:
            180,

        power:
            20
    },


    Adventurer: {
        name:
            "Adventurer",

        emoji:
            "⚔️",

        cost:
            500,

        health:
            280,

        power:
            35
    },


    WarriorOfLight: {
        name:
            "Warrior of Light",

        emoji:
            "✨",

        cost:
            1000,

        health:
            380,

        power:
            50
    }
};


/*
 * ============================================================
 * ROLE SELECTION
 * ============================================================
 *
 * Joining is allowed both during recruitment
 * and during an active battle.
 */

async function chooseCrumbleStrikeRole(
    interaction,
    role
) {
    const event =
        await getCrumbleStrikeFromPublicMessage(
            interaction
        );


    if (!event) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    "This Crumble Strike encounter no longer exists."
            }
        );
    }


    if (
        ![
            "Joining",
            "Active"
        ].includes(
            event.state
        )
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    "This encounter can no longer be joined."
            }
        );
    }


    /*
     * Recruitment timer only matters before
     * combat has started.
     */

    if (
        event.state ===
        "Joining"
        &&
        event.joinUntil <=
        getUnixTime()
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    "Recruitment has already expired."
            }
        );
    }


    const participant =
        event.participants?.[
        interaction.user.id
        ];


    if (participant) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    `You're already participating as **${participant.job}**.`
            }
        );
    }


    if (!JOBS[role]) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    "That role doesn't exist."
            }
        );
    }


    return interaction.reply({
        embeds: [
            buildJobSelectionEmbed(
                event,
                interaction.user,
                role
            )
        ],

        components:
            buildJobButtons(
                role
            ),

        flags:
            MessageFlags.Ephemeral
    });
}


/*
 * ============================================================
 * JOB SELECTION
 * ============================================================
 */

async function chooseCrumbleStrikeJob(
    interaction,
    role,
    jobKey
) {
    const metadata =
        parseSelectionFooter(
            interaction
        );


    if (
        metadata.type !==
        "crumbleStrikeJob"
        ||
        metadata.userId !==
        interaction.user.id
        ||
        metadata.role !==
        role
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    "This character selection is no longer valid."
            }
        );
    }


    const job =
        JOBS[role]?.[
        jobKey
        ];


    if (!job) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    "That Job isn't available."
            }
        );
    }


    const event =
        await getCrumbleStrikeByEventId(
            metadata.eventId
        );


    if (
        !event
        ||
        ![
            "Joining",
            "Active"
        ].includes(
            event.state
        )
    ) {
        return interaction.update({
            embeds: [
                new EmbedBuilder()
                    .setTitle(
                        "🍪 Entry Closed"
                    )
                    .setDescription(
                        "This encounter is no longer accepting adventurers."
                    )
            ],

            components: []
        });
    }


    return interaction.update({
        embeds: [
            buildTierSelectionEmbed(
                event,
                interaction.user,
                role,
                jobKey,
                job
            )
        ],

        components:
            buildTierButtons()
    });
}


/*
 * ============================================================
 * CONFIRM JOIN
 * ============================================================
 */

async function confirmCrumbleStrikeJoin(
    interaction,
    tierKey
) {
    const metadata =
        parseSelectionFooter(
            interaction
        );


    if (
        metadata.type !==
        "crumbleStrikeTier"
        ||
        metadata.userId !==
        interaction.user.id
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    "This character selection is no longer valid."
            }
        );
    }


    const role =
        metadata.role;

    const jobKey =
        metadata.job;

    const job =
        JOBS[role]?.[
        jobKey
        ];

    const tier =
        TIERS[
        tierKey
        ];


    if (
        !job ||
        !tier
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    "That character setup is invalid."
            }
        );
    }


    const {
        db
    } =
        getCollections();


    const events =
        db.collection(
            EVENT_COLLECTION
        );


    const event =
        await events.findOne({
            eventId:
                metadata.eventId,

            eventType:
                "CrumbleStrike"
        });


    if (
        !event
        ||
        ![
            "Joining",
            "Active"
        ].includes(
            event.state
        )
    ) {
        return interaction.update({
            embeds: [
                new EmbedBuilder()
                    .setTitle(
                        "🍪 Entry Closed"
                    )
                    .setDescription(
                        "The battle can no longer be joined."
                    )
            ],

            components: []
        });
    }


    if (
        event.participants?.[
        interaction.user.id
        ]
    ) {
        return interaction.update({
            embeds: [
                new EmbedBuilder()
                    .setTitle(
                        "🍪 Already Joined"
                    )
                    .setDescription(
                        "You're already participating."
                    )
            ],

            components: []
        });
    }


    const balance =
        await getCookieBalance(
            interaction.user.id
        );


    if (
        balance <
        tier.cost
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    `You need **${tier.cost.toLocaleString()} Cookies** to join as a ${tier.name}.`
            }
        );
    }


    try {
        await transferCookies(
            interaction.user.id,
            event.escrowId,
            tier.cost
        );

    } catch (error) {
        if (
            error.message ===
            "INSUFFICIENT_COOKIES"
        ) {
            return temporaryEphemeralReply(
                interaction,
                {
                    content:
                        "Your Cookie balance changed before you could join."
                }
            );
        }


        throw error;
    }


    const now =
        getUnixTime();


    const participant = {
        role,

        job:
            job.name,

        jobKey,

        class:
            job.class,

        tier:
            tierKey,

        investment:
            tier.cost,

        health:
            tier.health,

        maxHealth:
            tier.health,

        power:
            tier.power,

        energy:
            0,

        maxEnergy:
            100,

        damage:
            0,

        healing:
            0,

        mitigation:
            0,

        defense: {
            charges:
                0,

            reduction:
                0
        },

        knockedOut:
            false,

        joinedAt:
            now,

        cooldowns: {
            Strike:
                0,

            Defend:
                0,

            Heal:
                0
        }
    };


    const result =
        await events.updateOne(
            {
                eventId:
                    event.eventId,

                eventType:
                    "CrumbleStrike",

                state: {
                    $in: [
                        "Joining",
                        "Active"
                    ]
                },

                [`participants.${interaction.user.id}`]: {
                    $exists:
                        false
                }
            },
            {
                $set: {
                    [`participants.${interaction.user.id}`]:
                        participant
                },

                $inc: {
                    rewardPool:
                        tier.cost
                }
            }
        );


    /*
     * Race-condition protection.
     */

    if (
        result.modifiedCount !==
        1
    ) {
        await safeTransfer(
            event.escrowId,
            interaction.user.id,
            tier.cost
        );


        return interaction.update({
            embeds: [
                new EmbedBuilder()
                    .setTitle(
                        "🍪 Unable to Join"
                    )
                    .setDescription(
                        "Your entry could not be registered. Your Cookies were refunded."
                    )
            ],

            components: []
        });
    }


    await refreshCrumbleStrikeMessage(
        interaction.client,
        event.eventId
    );


    const lateJoin =
        event.state ===
        "Active";


    return interaction.update({
        embeds: [
            new EmbedBuilder()
                .setTitle(
                    lateJoin
                        ? "⚔️ Reinforcements Arrive!"
                        : "⚔️ You Joined Crumble Strike!"
                )

                .setDescription(
                    [
                        `### ${job.emoji} ${formatJobProgression(job)}`,
                        "",
                        `${getRoleEmoji(role)} **${role}**`,
                        `${tier.emoji} **${tier.name}**`,
                        "",
                        `🍪 Investment: **${tier.cost.toLocaleString()}**`,
                        `❤️ HP: **${tier.health}**`,
                        `💪 Power: **${tier.power}**`,
                        `⚡ Energy: **0/100**`,
                        "",
                        lateJoin
                            ? "You've joined the battle already in progress."
                            : "You're ready for battle."
                    ].join("\n")
                )
        ],

        components: []
    });
}


/*
 * ============================================================
 * START BATTLE
 * ============================================================
 */

async function startCrumbleStrikeBattle(
    interaction
) {
    const event =
        await getCrumbleStrikeFromPublicMessage(
            interaction
        );


    if (!event) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    "This encounter no longer exists."
            }
        );
    }


    if (
        interaction.user.id !==
        event.creatorId
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    "Only the player who summoned the boss can start the battle early."
            }
        );
    }


    const participantCount =
        Object.keys(
            event.participants ??
            {}
        ).length;


    if (
        participantCount <
        event.minimumParticipants
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    `You need at least **${event.minimumParticipants} players**. Currently **${participantCount}/${event.minimumParticipants}**.`
            }
        );
    }


    await interaction.deferUpdate();


    return activateCrumbleStrike(
        interaction.client,
        event.eventId
    );
}


/*
 * ============================================================
 * ACTIVATE BATTLE
 * ============================================================
 */

async function activateCrumbleStrike(
    client,
    eventId
) {
    const {
        db
    } =
        getCollections();


    const events =
        db.collection(
            EVENT_COLLECTION
        );


    const event =
        await events.findOne({
            eventId,

            eventType:
                "CrumbleStrike"
        });


    if (
        !event ||
        event.state !==
        "Joining"
    ) {
        return false;
    }


    const participantCount =
        Object.keys(
            event.participants ??
            {}
        ).length;


    if (
        participantCount <
        event.minimumParticipants
    ) {
        return false;
    }


    const now =
        getUnixTime();


    /*
     * HP is locked when the battle begins.
     *
     * Late joiners do NOT increase boss HP.
     */

    const maxHealth =
        12000 +
        (
            participantCount *
            4000
        );


    const result =
        await events.updateOne(
            {
                eventId,

                eventType:
                    "CrumbleStrike",

                state:
                    "Joining"
            },
            {
                $set: {
                    state:
                        "Active",

                    battleStartedAt:
                        now,

                    battleEndsAt:
                        now +
                        BATTLE_DURATION,

                    "boss.health":
                        maxHealth,

                    "boss.maxHealth":
                        maxHealth,

                    "boss.limitGauge":
                        0,

                    "boss.actionGauge":
                        0
                }
            }
        );


    if (
        result.modifiedCount !==
        1
    ) {
        return false;
    }


    await refreshCrumbleStrikeMessage(
        client,
        eventId
    );


    return true;
}


/*
 * ============================================================
 * COMBAT ACTION
 * ============================================================
 */
async function performRevive(
    interaction,
    event,
    player
) {
    const now =
        getUnixTime();


    const cooldown =
        player.cooldowns?.Revive ??
        0;


    if (
        cooldown >
        now
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    `🌟 Revive is ready <t:${cooldown}:R>.`
            }
        );
    }


    const knockedOutPlayers =
        Object.entries(
            event.participants ??
            {}
        )
            .filter(
                (
                    [
                        ,
                        participant
                    ]
                ) =>
                    participant.knockedOut
            );


    if (
        !knockedOutPlayers.length
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    "🌟 Nobody currently needs reviving."
            }
        );
    }


    const revivePower =
        player.role ===
            "Healer"
            ? 2
            : 1;


    await interaction.deferUpdate();


    const {
        db
    } =
        getCollections();


    const events =
        db.collection(
            EVENT_COLLECTION
        );


    /*
     * Re-fetch immediately before applying
     * the party-wide revival pulse.
     */

    const latest =
        await events.findOne({
            eventId:
                event.eventId,

            eventType:
                "CrumbleStrike",

            state:
                "Active"
        });


    if (!latest) {
        return;
    }


    const setOperations = {
        [`participants.${interaction.user.id}.cooldowns.Revive`]:
            now +
            ACTIONS.Revive.cooldown
    };


    const incOperations = {
        "boss.actionGauge":
            1,

        "boss.limitGauge":
            ACTIONS.Revive.limitGain,

        [`participants.${interaction.user.id}.reviveAssists`]:
            0
    };


    let revivedCount =
        0;

    let assistedCount =
        0;

    let totalProgress =
        0;


    const resultLines =
        [];


    for (
        const [
            targetId,
            target
        ]
        of Object.entries(
            latest.participants ??
            {}
        )
    ) {
        if (
            !target.knockedOut
        ) {
            continue;
        }


        const currentProgress =
            target.revive?.progress ??
            0;


        const appliedProgress =
            Math.min(
                revivePower,
                REVIVE_REQUIRED -
                currentProgress
            );


        const newProgress =
            Math.min(
                REVIVE_REQUIRED,
                currentProgress +
                revivePower
            );


        totalProgress +=
            appliedProgress;


        /*
         * Completed revival.
         */

        if (
            newProgress >=
            REVIVE_REQUIRED
        ) {
            const revivePercent =
                REVIVE_HP[
                target.role
                ]
                ??
                0.75;


            const restoredHealth =
                Math.max(
                    1,

                    Math.floor(
                        target.maxHealth *
                        revivePercent
                    )
                );


            setOperations[
                `participants.${targetId}.health`
            ] =
                restoredHealth;


            setOperations[
                `participants.${targetId}.knockedOut`
            ] =
                false;


            setOperations[
                `participants.${targetId}.energy`
            ] =
                0;


            setOperations[
                `participants.${targetId}.defense`
            ] = {
                charges:
                    0,

                reduction:
                    0
            };


            setOperations[
                `participants.${targetId}.revive.progress`
            ] =
                0;


            revivedCount++;


            resultLines.push(
                `🌟 <@${targetId}> — **REVIVED** (${restoredHealth}/${target.maxHealth} HP)`
            );
        }


        /*
         * Still needs more revival progress.
         */

        else {
            setOperations[
                `participants.${targetId}.revive.progress`
            ] =
                newProgress;


            assistedCount++;


            resultLines.push(
                `💫 <@${targetId}> — **${newProgress}/${REVIVE_REQUIRED}**`
            );
        }
    }


    /*
     * Reward contribution according to the
     * actual amount of progress applied.
     */

    incOperations[
        `participants.${interaction.user.id}.reviveAssists`
    ] =
        totalProgress;


    if (
        revivedCount >
        0
    ) {
        incOperations[
            `participants.${interaction.user.id}.revives`
        ] =
            revivedCount;
    }


    const updateResult =
        await events.updateOne(
            {
                eventId:
                    event.eventId,

                eventType:
                    "CrumbleStrike",

                state:
                    "Active",

                [`participants.${interaction.user.id}.knockedOut`]:
                    false,

                [`participants.${interaction.user.id}.cooldowns.Revive`]: {
                    $lte:
                        now
                }
            },
            {
                $set:
                    setOperations,

                $inc:
                    incOperations
            }
        );


    if (
        updateResult.modifiedCount !==
        1
    ) {
        return temporaryEphemeralFollowUp(
            interaction,
            {
                content:
                    "That revival action could not be resolved."
            }
        );
    }


    await clampBossGauges(
        event.eventId
    );


    const bossAttack =
        await resolveBossTurnIfReady(
            interaction.client,
            event.eventId
        );


    await refreshCrumbleStrikeMessage(
        interaction.client,
        event.eventId
    );


    const embed =
        new EmbedBuilder()
            .setTitle(
                "🌟 Party Revive"
            )

            .setDescription(
                [
                    `${getJobEmoji(player)} **${player.job}** sends out a wave of revival energy.`,
                    "",
                    ...resultLines
                ].join("\n")
            )

            .addFields(
                {
                    name:
                        "Revival Power",

                    value:
                        `**+${revivePower}** per KO'd player`,

                    inline:
                        true
                },

                {
                    name:
                        "Revived",

                    value:
                        `**${revivedCount}**`,

                    inline:
                        true
                },

                {
                    name:
                        "Progress Applied",

                    value:
                        `**${totalProgress}**`,

                    inline:
                        true
                }
            );


    if (bossAttack) {
        embed.addFields({
            name:
                "👹 Boss Turn",

            value:
                bossAttack.summary
        });
    }


    return temporaryEphemeralFollowUp(
        interaction,
        {
            embeds: [
                embed
            ]
        },
        9000
    );
}

async function performCrumbleStrikeAction(
    interaction,
    actionName
) {
    const event =
        await getCrumbleStrikeFromPublicMessage(
            interaction
        );


    if (
        !event ||
        event.state !==
        "Active"
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    "There is no active battle here."
            }
        );
    }


    const player =
        event.participants?.[
        interaction.user.id
        ];


    if (!player) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    "You haven't joined this Crumble Strike yet."
            }
        );
    }


    if (player.knockedOut) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    "💀 You're knocked out and can no longer act."
            }
        );
    }


    switch (actionName) {
        case "Strike":
            return performStrike(
                interaction,
                event,
                player
            );

        case "Defend":
            return performDefend(
                interaction,
                event,
                player
            );

        case "Heal":
            return performHeal(
                interaction,
                event,
                player
            );

        case "Revive":
            return performRevive(
                interaction,
                event,
                player
            );

        case "LimitBreak":
            return performLimitBreak(
                interaction,
                event,
                player
            );
    }
}


/*
 * ============================================================
 * STRIKE
 * ============================================================
 */

async function performStrike(
    interaction,
    event,
    player
) {
    const now =
        getUnixTime();


    const cooldown =
        player.cooldowns?.Strike ??
        0;


    if (
        cooldown >
        now
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    `⚔️ Strike is ready <t:${cooldown}:R>.`
            }
        );
    }


    const job =
        getParticipantJob(
            player
        );


    const multiplier =
        job?.strikeMultiplier ??
        ACTIONS.Strike.powerMultiplier;


    const variance =
        randomInteger(
            90,
            110
        ) /
        100;


    const damage =
        Math.max(
            1,

            Math.floor(
                player.power *
                multiplier *
                variance
            )
        );


    const energyGain =
        job?.strikeEnergy ??
        ACTIONS.Strike.energyGain;


    const limitGain =
        job?.strikeLimit ??
        ACTIONS.Strike.limitGain;


    const newEnergy =
        Math.min(
            player.maxEnergy,
            player.energy +
            energyGain
        );


    await interaction.deferUpdate();


    const {
        db
    } =
        getCollections();


    const events =
        db.collection(
            EVENT_COLLECTION
        );


    const result =
        await events.updateOne(
            {
                eventId:
                    event.eventId,

                state:
                    "Active",

                "boss.health": {
                    $gt:
                        0
                },

                [`participants.${interaction.user.id}.cooldowns.Strike`]: {
                    $lte:
                        now
                }
            },
            {
                $inc: {
                    "boss.health":
                        -damage,

                    "boss.actionGauge":
                        1,

                    "boss.limitGauge":
                        limitGain,

                    [`participants.${interaction.user.id}.damage`]:
                        damage
                },

                $set: {
                    [`participants.${interaction.user.id}.energy`]:
                        newEnergy,

                    [`participants.${interaction.user.id}.cooldowns.Strike`]:
                        now +
                        ACTIONS.Strike.cooldown
                }
            }
        );


    if (
        result.modifiedCount !==
        1
    ) {
        return temporaryEphemeralFollowUp(
            interaction,
            {
                content:
                    "That action could not be resolved."
            }
        );
    }


    await clampBossGauges(
        event.eventId
    );


    const bossAttack =
        await resolveBossTurnIfReady(
            interaction.client,
            event.eventId
        );


    const victory =
        await checkForVictory(
            interaction.client,
            event.eventId
        );


    if (!victory) {
        await refreshCrumbleStrikeMessage(
            interaction.client,
            event.eventId
        );
    }


    const resultEmbed =
        new EmbedBuilder()
            .setTitle(
                "⚔️ Strike"
            )

            .setDescription(
                `${getJobEmoji(player)} **${player.job}** attacks the Crumbbound Behemoth!`
            )

            .addFields(
                {
                    name:
                        "Damage",

                    value:
                        `**${damage.toLocaleString()}**`,

                    inline:
                        true
                },

                {
                    name:
                        "Energy",

                    value:
                        `**${newEnergy}/${player.maxEnergy}**`,

                    inline:
                        true
                },

                {
                    name:
                        "Limit Generated",

                    value:
                        `**+${limitGain}**`,

                    inline:
                        true
                }
            );


    if (bossAttack) {
        resultEmbed.addFields({
            name:
                "👹 Boss Turn",

            value:
                bossAttack.summary
        });
    }


    return temporaryEphemeralFollowUp(
        interaction,
        {
            embeds: [
                resultEmbed
            ]
        },
        8000
    );
}


/*
 * ============================================================
 * DEFEND
 * ============================================================
 */

async function performDefend(
    interaction,
    event,
    player
) {
    const now =
        getUnixTime();


    const cooldown =
        player.cooldowns?.Defend ??
        0;


    if (
        cooldown >
        now
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    `🛡️ Defend is ready <t:${cooldown}:R>.`
            }
        );
    }


    const job =
        getParticipantJob(
            player
        );


    const energyCost =
        job?.defendCost ??
        ACTIONS.Defend.energyCost;


    const reduction =
        job?.defendReduction ??
        ACTIONS.Defend.reduction;


    const charges =
        job?.defendCharges ??
        ACTIONS.Defend.charges;


    if (
        player.energy <
        energyCost
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    `🛡️ Defend requires **${energyCost} Energy**. You currently have **${player.energy}**.`
            }
        );
    }


    await interaction.deferUpdate();


    const {
        db
    } =
        getCollections();


    const events =
        db.collection(
            EVENT_COLLECTION
        );


    const result =
        await events.updateOne(
            {
                eventId:
                    event.eventId,

                state:
                    "Active",

                [`participants.${interaction.user.id}.energy`]: {
                    $gte:
                        energyCost
                },

                [`participants.${interaction.user.id}.cooldowns.Defend`]: {
                    $lte:
                        now
                }
            },
            {
                $inc: {
                    "boss.actionGauge":
                        1,

                    "boss.limitGauge":
                        ACTIONS.Defend.limitGain,

                    [`participants.${interaction.user.id}.energy`]:
                        -energyCost
                },

                $set: {
                    [`participants.${interaction.user.id}.defense`]:
                    {
                        charges,
                        reduction
                    },

                    [`participants.${interaction.user.id}.cooldowns.Defend`]:
                        now +
                        ACTIONS.Defend.cooldown
                }
            }
        );


    if (
        result.modifiedCount !==
        1
    ) {
        return temporaryEphemeralFollowUp(
            interaction,
            {
                content:
                    "That defensive action could not be resolved."
            }
        );
    }


    await clampBossGauges(
        event.eventId
    );


    const bossAttack =
        await resolveBossTurnIfReady(
            interaction.client,
            event.eventId
        );


    await refreshCrumbleStrikeMessage(
        interaction.client,
        event.eventId
    );


    const energyAfter =
        player.energy -
        energyCost;


    const resultEmbed =
        new EmbedBuilder()
            .setTitle(
                "🛡️ Defend"
            )

            .setDescription(
                `${getJobEmoji(player)} **${player.job}** prepares for the next attack.`
            )

            .addFields(
                {
                    name:
                        "Damage Reduction",

                    value:
                        `**${Math.round(reduction * 100)}%**`,

                    inline:
                        true
                },

                {
                    name:
                        "Charges",

                    value:
                        `**${charges}** incoming attack${charges === 1 ? "" : "s"}`,

                    inline:
                        true
                },

                {
                    name:
                        "Energy",

                    value:
                        `**${energyAfter}/${player.maxEnergy}**`,

                    inline:
                        true
                }
            );


    if (bossAttack) {
        resultEmbed.addFields({
            name:
                "👹 Boss Turn",

            value:
                bossAttack.summary
        });
    }


    return temporaryEphemeralFollowUp(
        interaction,
        {
            embeds: [
                resultEmbed
            ]
        },
        8000
    );
}


/*
 * ============================================================
 * PARTY HEAL
 * ============================================================
 */

async function performHeal(
    interaction,
    event,
    player
) {
    const now =
        getUnixTime();


    const cooldown =
        player.cooldowns?.Heal ??
        0;


    if (
        cooldown >
        now
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    `❤️ Heal is ready <t:${cooldown}:R>.`
            }
        );
    }


    const job =
        getParticipantJob(
            player
        );


    const energyCost =
        job?.healCost ??
        ACTIONS.Heal.energyCost;


    const multiplier =
        job?.healMultiplier ??
        ACTIONS.Heal.powerMultiplier;


    const limitGain =
        job?.healLimit ??
        ACTIONS.Heal.limitGain;


    if (
        player.energy <
        energyCost
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    `❤️ Heal requires **${energyCost} Energy**. You currently have **${player.energy}**.`
            }
        );
    }


    const healPerPlayer =
        Math.max(
            1,

            Math.floor(
                player.power *
                multiplier
            )
        );


    await interaction.deferUpdate();


    const {
        db
    } =
        getCollections();


    const events =
        db.collection(
            EVENT_COLLECTION
        );


    /*
     * Re-fetch immediately before healing.
     */

    const latest =
        await events.findOne({
            eventId:
                event.eventId,

            state:
                "Active"
        });


    if (!latest) {
        return;
    }


    let totalHealing =
        0;

    let healedPlayers =
        0;


    const setOperations = {};


    for (
        const [
            userId,
            target
        ]
        of Object.entries(
            latest.participants ??
            {}
        )
    ) {
        /*
         * Heal does not revive KO'd players.
         */

        if (
            target.knockedOut ||
            target.health <= 0 ||
            target.health >=
            target.maxHealth
        ) {
            continue;
        }


        const newHealth =
            Math.min(
                target.maxHealth,
                target.health +
                healPerPlayer
            );


        const actualHealing =
            newHealth -
            target.health;


        if (
            actualHealing <=
            0
        ) {
            continue;
        }


        setOperations[
            `participants.${userId}.health`
        ] =
            newHealth;


        totalHealing +=
            actualHealing;

        healedPlayers++;
    }


    setOperations[
        `participants.${interaction.user.id}.cooldowns.Heal`
    ] =
        now +
        ACTIONS.Heal.cooldown;


    const result =
        await events.updateOne(
            {
                eventId:
                    event.eventId,

                state:
                    "Active",

                [`participants.${interaction.user.id}.energy`]: {
                    $gte:
                        energyCost
                }
            },
            {
                $set:
                    setOperations,

                $inc: {
                    "boss.actionGauge":
                        1,

                    "boss.limitGauge":
                        limitGain,

                    [`participants.${interaction.user.id}.energy`]:
                        -energyCost,

                    [`participants.${interaction.user.id}.healing`]:
                        totalHealing
                }
            }
        );


    if (
        result.modifiedCount !==
        1
    ) {
        return temporaryEphemeralFollowUp(
            interaction,
            {
                content:
                    "That heal could not be resolved."
            }
        );
    }


    await clampBossGauges(
        event.eventId
    );


    const bossAttack =
        await resolveBossTurnIfReady(
            interaction.client,
            event.eventId
        );


    await refreshCrumbleStrikeMessage(
        interaction.client,
        event.eventId
    );


    const resultEmbed =
        new EmbedBuilder()
            .setTitle(
                "❤️ Party Heal"
            )

            .setDescription(
                `${getJobEmoji(player)} **${player.job}** restores the party.`
            )

            .addFields(
                {
                    name:
                        "Healing",

                    value:
                        `**${totalHealing.toLocaleString()} HP**`,

                    inline:
                        true
                },

                {
                    name:
                        "Players Restored",

                    value:
                        `**${healedPlayers}**`,

                    inline:
                        true
                },

                {
                    name:
                        "Energy",

                    value:
                        `**${player.energy - energyCost}/${player.maxEnergy}**`,

                    inline:
                        true
                },

                {
                    name:
                        "Limit Generated",

                    value:
                        `**+${limitGain}**`,

                    inline:
                        true
                }
            );


    if (bossAttack) {
        resultEmbed.addFields({
            name:
                "👹 Boss Turn",

            value:
                bossAttack.summary
        });
    }


    return temporaryEphemeralFollowUp(
        interaction,
        {
            embeds: [
                resultEmbed
            ]
        },
        8000
    );
}


/*
 * ============================================================
 * LIMIT BREAK
 * ============================================================
 */

async function performLimitBreak(
    interaction,
    event,
    player
) {
    if (
        event.boss.limitGauge <
        LIMIT_GAUGE_MAX
    ) {
        return temporaryEphemeralReply(
            interaction,
            {
                content:
                    `✨ The Limit Gauge is only **${event.boss.limitGauge}/${LIMIT_GAUGE_MAX}**.`
            }
        );
    }


    const livingPlayers =
        Object.values(
            event.participants ??
            {}
        )
            .filter(
                participant =>
                    !participant.knockedOut
            );


    const totalPartyPower =
        livingPlayers.reduce(
            (
                total,
                participant
            ) =>
                total +
                participant.power,

            0
        );


    /*
     * Huge scaling hit:
     *
     * 8% boss max HP
     * +
     * 8x total living party Power
     */

    const damage =
        Math.floor(
            (
                event.boss.maxHealth *
                0.08
            )
            +
            (
                totalPartyPower *
                8
            )
        );


    await interaction.deferUpdate();


    const {
        db
    } =
        getCollections();


    const events =
        db.collection(
            EVENT_COLLECTION
        );


    /*
     * Gauge check is repeated atomically.
     *
     * Only one player can successfully spend it.
     */

    const result =
        await events.updateOne(
            {
                eventId:
                    event.eventId,

                state:
                    "Active",

                "boss.limitGauge": {
                    $gte:
                        LIMIT_GAUGE_MAX
                },

                "boss.health": {
                    $gt:
                        0
                }
            },
            {
                $inc: {
                    "boss.health":
                        -damage,

                    "boss.actionGauge":
                        1,

                    [`participants.${interaction.user.id}.damage`]:
                        damage
                },

                $set: {
                    "boss.limitGauge":
                        0
                }
            }
        );


    if (
        result.modifiedCount !==
        1
    ) {
        return temporaryEphemeralFollowUp(
            interaction,
            {
                content:
                    "Someone else used the Limit Break first!"
            }
        );
    }


    const bossAttack =
        await resolveBossTurnIfReady(
            interaction.client,
            event.eventId
        );


    const victory =
        await checkForVictory(
            interaction.client,
            event.eventId
        );


    if (!victory) {
        await refreshCrumbleStrikeMessage(
            interaction.client,
            event.eventId
        );
    }


    const resultEmbed =
        new EmbedBuilder()
            .setTitle(
                "✨ LIMIT BREAK!"
            )

            .setDescription(
                [
                    `${getJobEmoji(player)} **${player.job}** unleashes`,
                    "",
                    "## ULTIMATE COOKIE CALAMITY",
                    "",
                    `💥 **${damage.toLocaleString()} DAMAGE!**`
                ].join("\n")
            );


    if (bossAttack) {
        resultEmbed.addFields({
            name:
                "👹 Boss Turn",

            value:
                bossAttack.summary
        });
    }


    return temporaryEphemeralFollowUp(
        interaction,
        {
            embeds: [
                resultEmbed
            ]
        },
        10000
    );
}


/*
 * ============================================================
 * BOSS TURN
 * ============================================================
 */

async function resolveBossTurnIfReady(
    client,
    eventId
) {
    const {
        db
    } =
        getCollections();


    const events =
        db.collection(
            EVENT_COLLECTION
        );


    const event =
        await events.findOne({
            eventId,

            eventType:
                "CrumbleStrike",

            state:
                "Active",

            "boss.actionGauge": {
                $gte:
                    BOSS_ACTION_THRESHOLD
            }
        });


    if (!event) {
        return null;
    }


    /*
     * Claim the boss turn.
     */

    const claim =
        await events.updateOne(
            {
                eventId,

                state:
                    "Active",

                "boss.actionGauge": {
                    $gte:
                        BOSS_ACTION_THRESHOLD
                }
            },
            {
                $inc: {
                    "boss.actionGauge":
                        -BOSS_ACTION_THRESHOLD
                }
            }
        );


    if (
        claim.modifiedCount !==
        1
    ) {
        return null;
    }


    const latest =
        await events.findOne({
            eventId
        });


    const setOperations = {};
    const incOperations = {};

    let totalDamage =
        0;

    let totalMitigated =
        0;

    let knockedOut =
        0;


    const baseDamage =
        randomInteger(
            45,
            75
        );


    for (
        const [
            userId,
            participant
        ]
        of Object.entries(
            latest.participants ??
            {}
        )
    ) {
        if (
            participant.knockedOut
        ) {
            continue;
        }


        let damage =
            baseDamage;


        const defense =
            participant.defense ??
            {
                charges: 0,
                reduction: 0
            };


        if (
            defense.charges >
            0
        ) {
            const reduced =
                Math.floor(
                    damage *
                    defense.reduction
                );


            damage -=
                reduced;


            totalMitigated +=
                reduced;


            incOperations[
                `participants.${userId}.mitigation`
            ] =
                reduced;


            setOperations[
                `participants.${userId}.defense.charges`
            ] =
                Math.max(
                    0,
                    defense.charges -
                    1
                );
        }


        const health =
            Math.max(
                0,
                participant.health -
                damage
            );


        setOperations[
            `participants.${userId}.health`
        ] =
            health;


        if (
            health <=
            0
        ) {
            setOperations[
                `participants.${userId}.knockedOut`
            ] =
                true;

            knockedOut++;
        }


        totalDamage +=
            damage;
    }


    const update = {
        $set:
            setOperations
    };


    if (
        Object.keys(
            incOperations
        ).length
    ) {
        update.$inc =
            incOperations;
    }


    await events.updateOne(
        {
            eventId,

            state:
                "Active"
        },
        update
    );


    /*
     * If everybody is KO'd we don't immediately
     * fail the whole event.
     *
     * Late reinforcements may still join.
     */


    return {
        damage:
            totalDamage,

        mitigation:
            totalMitigated,

        knockedOut,

        summary:
            [
                `💥 **Crumbquake!**`,
                `Party Damage: **${totalDamage.toLocaleString()}**`,
                totalMitigated > 0
                    ? `Mitigated: **${totalMitigated.toLocaleString()}**`
                    : null,
                knockedOut > 0
                    ? `💀 Knocked Out: **${knockedOut}**`
                    : null
            ]
                .filter(Boolean)
                .join("\n")
    };
}


/*
 * ============================================================
 * LIMIT GAUGE CLAMP
 * ============================================================
 */

async function clampBossGauges(
    eventId
) {
    const {
        db
    } =
        getCollections();


    const events =
        db.collection(
            EVENT_COLLECTION
        );


    await events.updateOne(
        {
            eventId,

            "boss.limitGauge": {
                $gt:
                    LIMIT_GAUGE_MAX
            }
        },
        {
            $set: {
                "boss.limitGauge":
                    LIMIT_GAUGE_MAX
            }
        }
    );
}


/*
 * ============================================================
 * VICTORY CHECK
 * ============================================================
 */

async function checkForVictory(
    client,
    eventId
) {
    const {
        db
    } =
        getCollections();


    const events =
        db.collection(
            EVENT_COLLECTION
        );


    const event =
        await events.findOne({
            eventId,

            eventType:
                "CrumbleStrike",

            state:
                "Active"
        });


    if (
        !event ||
        event.boss.health >
        0
    ) {
        return false;
    }


    await events.updateOne(
        {
            eventId,

            state:
                "Active"
        },
        {
            $set: {
                "boss.health":
                    0
            }
        }
    );


    return resolveCrumbleStrikeVictory(
        client,
        eventId
    );
}


/*
 * ============================================================
 * VICTORY + REWARDS
 * ============================================================
 */

async function resolveCrumbleStrikeVictory(
    client,
    eventId
) {
    const {
        db
    } =
        getCollections();


    const events =
        db.collection(
            EVENT_COLLECTION
        );


    /*
     * Atomically claim resolution.
     */

    const event =
        await events.findOneAndUpdate(
            {
                eventId,

                eventType:
                    "CrumbleStrike",

                state:
                    "Active"
            },
            {
                $set: {
                    state:
                        "Resolving",

                    "boss.health":
                        0
                }
            },
            {
                returnDocument:
                    "after"
            }
        );


    if (!event) {
        return false;
    }


    const participants =
        Object.entries(
            event.participants ??
            {}
        );


    const rewardPool =
        await getCookieBalance(
            event.escrowId
        );


    /*
     * 30% evenly distributed.
     * 70% based on combat contribution.
     */

    const participationPool =
        Math.floor(
            rewardPool *
            0.30
        );


    const contributionPool =
        rewardPool -
        participationPool;


    const evenShare =
        participants.length
            ? Math.floor(
                participationPool /
                participants.length
            )

            : 0;


    const scored =
        participants.map(
            (
                [
                    userId,
                    participant
                ]
            ) => {
                const contribution =
                    getContributionScore(
                        participant
                    );


                return {
                    userId,
                    participant,
                    contribution
                };
            }
        );


    const totalContribution =
        scored.reduce(
            (
                total,
                player
            ) =>
                total +
                player.contribution,

            0
        );


    const rewards =
        [];

    let distributed =
        0;


    for (
        const player
        of scored
    ) {
        const contributionReward =
            totalContribution >
                0
                ? Math.floor(
                    contributionPool *
                    (
                        player.contribution /
                        totalContribution
                    )
                )

                : 0;


        const reward =
            evenShare +
            contributionReward;


        if (
            reward >
            0
        ) {
            const paid =
                await safeTransfer(
                    event.escrowId,
                    player.userId,
                    reward
                );


            if (paid) {
                distributed +=
                    reward;
            }
        }


        rewards.push({
            userId:
                player.userId,

            job:
                player.participant.job,

            role:
                player.participant.role,

            damage:
                player.participant.damage ??
                0,

            healing:
                player.participant.healing ??
                0,

            mitigation:
                player.participant.mitigation ??
                0,

            contribution:
                player.contribution,

            reward
        });
    }


    /*
     * Rounding remainder goes to highest
     * contribution.
     */

    const remaining =
        await getCookieBalance(
            event.escrowId
        );


    if (
        remaining >
        0 &&
        rewards.length
    ) {
        const top =
            rewards
                .slice()
                .sort(
                    (
                        a,
                        b
                    ) =>
                        b.contribution -
                        a.contribution
                )[0];


        const paid =
            await safeTransfer(
                event.escrowId,
                top.userId,
                remaining
            );


        if (paid) {
            top.reward +=
                remaining;
        }
    }


    await events.updateOne(
        {
            eventId,

            state:
                "Resolving"
        },
        {
            $set: {
                state:
                    "Defeated",

                defeatedAt:
                    getUnixTime(),

                rewards
            }
        }
    );


    await refreshCrumbleStrikeMessage(
        client,
        eventId
    );


    return true;
}


function getContributionScore(
    participant
) {
    return Math.floor(
        (
            participant.damage ??
            0
        )
        +
        (
            (
                participant.healing ??
                0
            )
            *
            0.80
        )
        +
        (
            (
                participant.mitigation ??
                0
            )
            *
            0.80
        )
    );
}


/*
 * ============================================================
 * FAILURE
 * ============================================================
 */

async function failCrumbleStrike(
    client,
    eventId
) {
    const {
        db
    } =
        getCollections();


    const events =
        db.collection(
            EVENT_COLLECTION
        );


    const event =
        await events.findOneAndUpdate(
            {
                eventId,

                eventType:
                    "CrumbleStrike",

                state:
                    "Active"
            },
            {
                $set: {
                    state:
                        "Failed",

                    failedAt:
                        getUnixTime()
                }
            },
            {
                returnDocument:
                    "after"
            }
        );


    if (!event)
        return false;


    const escrow =
        await getCookieBalance(
            event.escrowId
        );


    if (
        escrow >
        0
    ) {
        await safeTransfer(
            event.escrowId,
            client.user.id,
            escrow
        );
    }


    await refreshCrumbleStrikeMessage(
        client,
        eventId
    );


    return true;
}


/*
 * ============================================================
 * CANCEL + REFUND
 * ============================================================
 */

async function cancelCrumbleStrikeAndRefund(
    client,
    eventId
) {
    const {
        db
    } =
        getCollections();


    const events =
        db.collection(
            EVENT_COLLECTION
        );


    const event =
        await events.findOneAndUpdate(
            {
                eventId,

                eventType:
                    "CrumbleStrike",

                state:
                    "Joining"
            },
            {
                $set: {
                    state:
                        "Cancelled",

                    cancelledAt:
                        getUnixTime()
                }
            },
            {
                returnDocument:
                    "after"
            }
        );


    if (!event)
        return false;


    for (
        const [
            userId,
            participant
        ]
        of Object.entries(
            event.participants ??
            {}
        )
    ) {
        if (
            participant.investment >
            0
        ) {
            await safeTransfer(
                event.escrowId,
                userId,
                participant.investment
            );
        }
    }


    const remaining =
        await getCookieBalance(
            event.escrowId
        );


    if (
        remaining >
        0
    ) {
        await safeTransfer(
            event.escrowId,
            event.creatorId,
            remaining
        );
    }


    await refreshCrumbleStrikeMessage(
        client,
        eventId
    );


    return true;
}


/*
 * ============================================================
 * PUBLIC MESSAGE REFRESH
 * ============================================================
 */

async function refreshCrumbleStrikeMessage(
    client,
    eventId
) {
    const event =
        await getCrumbleStrikeByEventId(
            eventId
        );


    if (!event)
        return;


    let channel;


    try {
        channel =
            await client.channels.fetch(
                event.channelId
            );

    } catch {
        return;
    }


    if (!channel)
        return;


    let message;


    try {
        message =
            await channel.messages.fetch(
                event.messageId
            );

    } catch {
        return;
    }


    const {
        embed,
        components
    } =
        buildCrumbleStrikeMessage(
            event
        );


    await message.edit({
        embeds: [
            embed
        ],

        components
    });
}


/*
 * ============================================================
 * PUBLIC EMBED
 * ============================================================
 */

function buildCrumbleStrikeMessage(
    event
) {
    const participants =
        Object.values(
            event.participants ??
            {}
        );


    const participantCount =
        participants.length;


    const roleCounts =
        getRoleCounts(
            participants
        );


    /*
     * RECRUITMENT
     */

    if (
        event.state ===
        "Joining"
    ) {
        return {
            embed:
                new EmbedBuilder()
                    .setTitle(
                        "🍪 Crumble Strike"
                    )

                    .setDescription(
                        [
                            "## The Crumbbound Behemoth",
                            "",
                            "*A creature of hunger, crumbs, and extremely questionable dietary choices.*",
                            "",
                            `**Recruitment ends:** <t:${event.joinUntil}:R>`,
                            `**Participants:** ${participantCount}/${event.minimumParticipants} required`,
                            `**Reward Pool:** ${event.rewardPool.toLocaleString()} 🍪`,
                            "",
                            `⚔️ DPS: **${roleCounts.DPS}**`,
                            `🛡️ Tanks: **${roleCounts.Tank}**`,
                            `❤️ Healers: **${roleCounts.Healer}**`,
                            "",
                            participantCount >=
                                event.minimumParticipants
                                ? "✅ The summoner may start the battle early."
                                : "Choose your role below to join."
                        ].join("\n")
                    )

                    .setFooter({
                        text:
                            `crumbleStrike:${event.eventId}`
                    }),

            components:
                buildRecruitmentButtons()
        };
    }


    /*
     * ACTIVE
     */

    if (
        event.state ===
        "Active"
    ) {
        const hp =
            Math.max(
                0,
                event.boss.health
            );


        const limit =
            Math.min(
                LIMIT_GAUGE_MAX,
                event.boss.limitGauge ??
                0
            );


        const bossGauge =
            event.boss.actionGauge ??
            0;


        return {
            embed:
                new EmbedBuilder()
                    .setTitle(
                        "⚔️ Crumble Strike"
                    )

                    .setDescription(
                        [
                            "## The Crumbbound Behemoth",
                            "",
                            buildBar(
                                hp,
                                event.boss.maxHealth,
                                20
                            ),
                            `**${hp.toLocaleString()} / ${event.boss.maxHealth.toLocaleString()} HP**`,
                            "",
                            "### ✨ Limit Break",
                            buildBar(
                                limit,
                                LIMIT_GAUGE_MAX,
                                20
                            ),
                            `**${limit}/${LIMIT_GAUGE_MAX}**`,
                            "",
                            `👹 **Boss Turn:** ${bossGauge}/${BOSS_ACTION_THRESHOLD}`,
                            "",
                            `**Participants:** ${participantCount}`,
                            `⚔️ ${roleCounts.DPS} DPS • 🛡️ ${roleCounts.Tank} Tanks • ❤️ ${roleCounts.Healer} Healers`,
                            `**Reward Pool:** ${event.rewardPool.toLocaleString()} 🍪`,
                            `**Battle ends:** <t:${event.battleEndsAt}:R>`,
                            "",
                            "### ⚔️ Battle Actions",
                            "**⚔️ Strike**",
                            "Low damage • Generates Energy and Limit Gauge • 8s cooldown",
                            "",
                            "**🛡️ Defend**",
                            "Reduces damage from upcoming boss attacks • Base cost: 5 Energy",
                            "",
                            "**❤️ Heal**",
                            "Restores HP to all living party members • Base cost: 10 Energy",
                            "",
                            "**✨ Limit Break**",
                            "Massive shared attack • Requires a full 100-point Limit Gauge",
                            "",
                            "*Your Job modifies how effective these actions are.*"
                        ].join("\n")
                    )

                    .setFooter({
                        text:
                            `crumbleStrike:${event.eventId}`
                    }),

            /*
             * Combat + late joining.
             */

            components: [
                ...buildCombatButtons(),
                ...buildLateJoinButtons()
            ]
        };
    }


    /*
     * DEFEATED
     */

    if (
        event.state ===
        "Defeated"
    ) {
        const rewards =
            (
                event.rewards ??
                []
            )
                .slice()
                .sort(
                    (
                        a,
                        b
                    ) =>
                        b.contribution -
                        a.contribution
                );


        const leaderboard =
            rewards
                .slice(
                    0,
                    10
                )
                .map(
                    (
                        player,
                        index
                    ) =>
                        [
                            `**${index + 1}.** <@${player.userId}> — ${player.job}`,
                            `⚔️ ${player.damage.toLocaleString()} • ❤️ ${player.healing.toLocaleString()} • 🛡️ ${player.mitigation.toLocaleString()}`,
                            `🍪 **${player.reward.toLocaleString()}**`
                        ].join("\n")
                )
                .join("\n\n");


        return {
            embed:
                new EmbedBuilder()
                    .setTitle(
                        "🏆 Crumble Strike Complete!"
                    )

                    .setDescription(
                        [
                            "## The Crumbbound Behemoth Has Fallen!",
                            "",
                            leaderboard ||
                            "The beast was defeated."
                        ].join("\n")
                    )

                    .setFooter({
                        text:
                            `crumbleStrike:${event.eventId}`
                    }),

            components: []
        };
    }


    /*
     * FAILED
     */

    if (
        event.state ===
        "Failed"
    ) {
        return {
            embed:
                new EmbedBuilder()
                    .setTitle(
                        "💀 Crumble Strike Failed"
                    )

                    .setDescription(
                        [
                            "The Crumbbound Behemoth survived.",
                            "",
                            `The committed **${event.rewardPool.toLocaleString()} Cookies** were claimed by the ShaiBot Vault.`
                        ].join("\n")
                    )

                    .setFooter({
                        text:
                            `crumbleStrike:${event.eventId}`
                    }),

            components: []
        };
    }


    /*
     * CANCELLED
     */

    if (
        event.state ===
        "Cancelled"
    ) {
        return {
            embed:
                new EmbedBuilder()
                    .setTitle(
                        "🍪 Crumble Strike Cancelled"
                    )

                    .setDescription(
                        "Not enough adventurers joined during recruitment. All committed Cookies were refunded."
                    )

                    .setFooter({
                        text:
                            `crumbleStrike:${event.eventId}`
                    }),

            components: []
        };
    }


    return {
        embed:
            new EmbedBuilder()
                .setTitle(
                    "🍪 Crumble Strike"
                )
                .setDescription(
                    `Encounter state: **${event.state}**`
                ),

        components: []
    };
}


/*
 * ============================================================
 * COMBAT BUTTONS
 * ============================================================
 */

function buildCombatButtons() {
    return [
        new ActionRowBuilder()
            .addComponents(
                new ButtonBuilder()
                    .setCustomId(
                        "crumbleStrikeStrike"
                    )
                    .setLabel(
                        "Strike"
                    )
                    .setEmoji(
                        "⚔️"
                    )
                    .setStyle(
                        ButtonStyle.Danger
                    ),

                new ButtonBuilder()
                    .setCustomId(
                        "crumbleStrikeDefend"
                    )
                    .setLabel(
                        "Defend"
                    )
                    .setEmoji(
                        "🛡️"
                    )
                    .setStyle(
                        ButtonStyle.Primary
                    ),

                new ButtonBuilder()
                    .setCustomId(
                        "crumbleStrikeHeal"
                    )
                    .setLabel(
                        "Heal"
                    )
                    .setEmoji(
                        "❤️"
                    )
                    .setStyle(
                        ButtonStyle.Success
                    ),

                new ButtonBuilder()
                    .setCustomId(
                        "crumbleStrikeLimitBreak"
                    )
                    .setLabel(
                        "Limit Break"
                    )
                    .setEmoji(
                        "✨"
                    )
                    .setStyle(
                        ButtonStyle.Secondary
                    )
            )
    ];
}


/*
 * ============================================================
 * LATE JOIN BUTTONS
 * ============================================================
 */

function buildLateJoinButtons() {
    return [
        new ActionRowBuilder()
            .addComponents(
                new ButtonBuilder()
                    .setCustomId(
                        "crumbleStrikeRoleDPS"
                    )
                    .setLabel(
                        "Join DPS"
                    )
                    .setEmoji(
                        "⚔️"
                    )
                    .setStyle(
                        ButtonStyle.Danger
                    ),

                new ButtonBuilder()
                    .setCustomId(
                        "crumbleStrikeRoleTank"
                    )
                    .setLabel(
                        "Join Tank"
                    )
                    .setEmoji(
                        "🛡️"
                    )
                    .setStyle(
                        ButtonStyle.Primary
                    ),

                new ButtonBuilder()
                    .setCustomId(
                        "crumbleStrikeRoleHealer"
                    )
                    .setLabel(
                        "Join Healer"
                    )
                    .setEmoji(
                        "❤️"
                    )
                    .setStyle(
                        ButtonStyle.Success
                    )
            )
    ];
}


/*
 * ============================================================
 * RECRUITMENT BUTTONS
 * ============================================================
 */

function buildRecruitmentButtons() {
    return [
        new ActionRowBuilder()
            .addComponents(
                new ButtonBuilder()
                    .setCustomId(
                        "crumbleStrikeRoleDPS"
                    )
                    .setLabel(
                        "DPS"
                    )
                    .setEmoji(
                        "⚔️"
                    )
                    .setStyle(
                        ButtonStyle.Danger
                    ),

                new ButtonBuilder()
                    .setCustomId(
                        "crumbleStrikeRoleTank"
                    )
                    .setLabel(
                        "Tank"
                    )
                    .setEmoji(
                        "🛡️"
                    )
                    .setStyle(
                        ButtonStyle.Primary
                    ),

                new ButtonBuilder()
                    .setCustomId(
                        "crumbleStrikeRoleHealer"
                    )
                    .setLabel(
                        "Healer"
                    )
                    .setEmoji(
                        "❤️"
                    )
                    .setStyle(
                        ButtonStyle.Success
                    )
            ),

        new ActionRowBuilder()
            .addComponents(
                new ButtonBuilder()
                    .setCustomId(
                        "crumbleStrikeStart"
                    )
                    .setLabel(
                        "Start Battle"
                    )
                    .setEmoji(
                        "⚔️"
                    )
                    .setStyle(
                        ButtonStyle.Secondary
                    )
            )
    ];
}


/*
 * ============================================================
 * JOB SELECTION
 * ============================================================
 */

function buildJobSelectionEmbed(
    event,
    user,
    role
) {
    const jobs =
        JOBS[
        role
        ];


    const description =
        Object.values(
            jobs
        )
            .map(
                job =>
                    `${job.emoji} **${formatJobProgression(job)}**`
            )
            .join("\n");


    return new EmbedBuilder()
        .setTitle(
            `${getRoleEmoji(role)} Choose Your ${role} Job`
        )

        .setDescription(
            [
                description,
                "",
                "Choose the Job you want to bring into battle."
            ].join("\n")
        )

        .setFooter({
            text:
                `crumbleStrikeJob:${event.eventId}:${user.id}:${role}`
        });
}


function buildJobButtons(
    role
) {
    return [
        new ActionRowBuilder()
            .addComponents(
                ...Object.entries(
                    JOBS[
                    role
                    ]
                )
                    .map(
                        (
                            [
                                key,
                                job
                            ]
                        ) =>
                            new ButtonBuilder()
                                .setCustomId(
                                    `crumbleStrikeJob${key}`
                                )
                                .setLabel(
                                    job.name
                                )
                                .setEmoji(
                                    job.emoji
                                )
                                .setStyle(
                                    ButtonStyle.Primary
                                )
                    )
            )
    ];
}


/*
 * ============================================================
 * TIER SELECTION
 * ============================================================
 */

function buildTierSelectionEmbed(
    event,
    user,
    role,
    jobKey,
    job
) {
    return new EmbedBuilder()
        .setTitle(
            `${job.emoji} ${formatJobProgression(job)}`
        )

        .setDescription(
            [
                `${getRoleEmoji(role)} **${role}**`,
                "",
                "Choose your commitment.",
                "",
                "🌱 **Sprout — 100 🍪**",
                "Entry-level HP and Power.",
                "",
                "⚔️ **Adventurer — 500 🍪**",
                "Improved HP and Power.",
                "",
                "✨ **Warrior of Light — 1,000 🍪**",
                "Highest starting HP and Power."
            ].join("\n")
        )

        .setFooter({
            text:
                `crumbleStrikeTier:${event.eventId}:${user.id}:${role}:${jobKey}`
        });
}


function buildTierButtons() {
    return [
        new ActionRowBuilder()
            .addComponents(
                new ButtonBuilder()
                    .setCustomId(
                        "crumbleStrikeTierSprout"
                    )
                    .setLabel(
                        "Sprout — 100"
                    )
                    .setEmoji(
                        "🌱"
                    )
                    .setStyle(
                        ButtonStyle.Secondary
                    ),

                new ButtonBuilder()
                    .setCustomId(
                        "crumbleStrikeTierAdventurer"
                    )
                    .setLabel(
                        "Adventurer — 500"
                    )
                    .setEmoji(
                        "⚔️"
                    )
                    .setStyle(
                        ButtonStyle.Primary
                    ),

                new ButtonBuilder()
                    .setCustomId(
                        "crumbleStrikeTierWarriorOfLight"
                    )
                    .setLabel(
                        "Warrior of Light — 1,000"
                    )
                    .setEmoji(
                        "✨"
                    )
                    .setStyle(
                        ButtonStyle.Success
                    )
            )
    ];
}


/*
 * ============================================================
 * EVENT LOOKUPS
 * ============================================================
 */

async function getCrumbleStrikeFromPublicMessage(
    interaction
) {
    const footer =
        interaction.message
            .embeds[0]
            ?.footer
            ?.text;


    const [
        type,
        eventId
    ] =
        footer?.split(":")
        ?? [];


    if (
        type !==
        "crumbleStrike"
        ||
        !eventId
    ) {
        return null;
    }


    return getCrumbleStrikeByEventId(
        eventId
    );
}


async function getCrumbleStrikeByEventId(
    eventId
) {
    const {
        db
    } =
        getCollections();


    return db
        .collection(
            EVENT_COLLECTION
        )
        .findOne({
            eventId,

            eventType:
                "CrumbleStrike"
        });
}


/*
 * ============================================================
 * SELECTION FOOTER
 * ============================================================
 */

function parseSelectionFooter(
    interaction
) {
    const footer =
        interaction.message
            .embeds[0]
            ?.footer
            ?.text;


    const parts =
        footer?.split(":")
        ?? [];


    if (
        parts[0] ===
        "crumbleStrikeJob"
    ) {
        return {
            type:
                parts[0],

            eventId:
                parts[1],

            userId:
                parts[2],

            role:
                parts[3]
        };
    }


    if (
        parts[0] ===
        "crumbleStrikeTier"
    ) {
        return {
            type:
                parts[0],

            eventId:
                parts[1],

            userId:
                parts[2],

            role:
                parts[3],

            job:
                parts[4]
        };
    }


    return {};
}


/*
 * ============================================================
 * JOB HELPERS
 * ============================================================
 */

function getParticipantJob(
    participant
) {
    if (
        participant.jobKey &&
        JOBS[
        participant.role
        ]?.[
        participant.jobKey
        ]
    ) {
        return JOBS[
            participant.role
        ][
            participant.jobKey
        ];
    }


    /*
     * Compatibility with participants created
     * before jobKey was stored.
     */

    return Object.values(
        JOBS[
        participant.role
        ]
        ??
        {}
    )
        .find(
            job =>
                job.name ===
                participant.job
        )
        ??
        null;
}


function getJobEmoji(
    participant
) {
    return (
        getParticipantJob(
            participant
        )?.emoji
        ??
        getRoleEmoji(
            participant.role
        )
    );
}


function formatJobProgression(
    job
) {
    if (
        job.class
    ) {
        return (
            `${job.class} → ${job.name}`
        );
    }


    return job.name;
}


/*
 * ============================================================
 * DISPLAY HELPERS
 * ============================================================
 */

function getRoleEmoji(
    role
) {
    switch (role) {
        case "DPS":
            return "⚔️";

        case "Tank":
            return "🛡️";

        case "Healer":
            return "❤️";

        default:
            return "🍪";
    }
}


function getRoleCounts(
    participants
) {
    const counts = {
        DPS: 0,
        Tank: 0,
        Healer: 0
    };


    for (
        const participant
        of participants
    ) {
        if (
            counts[
            participant.role
            ]
            !==
            undefined
        ) {
            counts[
                participant.role
            ]++;
        }
    }


    return counts;
}


function buildBar(
    current,
    max,
    size = 20
) {
    if (
        max <=
        0
    ) {
        return "░".repeat(
            size
        );
    }


    const ratio =
        Math.max(
            0,

            Math.min(
                1,
                current /
                max
            )
        );


    const filled =
        Math.round(
            ratio *
            size
        );


    return (
        "█".repeat(
            filled
        )
        +
        "░".repeat(
            size -
            filled
        )
    );
}


/*
 * ============================================================
 * SAFE TRANSFER
 * ============================================================
 */

async function safeTransfer(
    from,
    to,
    amount
) {
    try {
        await transferCookies(
            from,
            to,
            amount
        );


        return true;

    } catch (error) {
        console.error(
            `Crumble Strike Cookie transfer failed (${from} -> ${to}, ${amount}):`,
            error
        );


        return false;
    }
}


/*
 * ============================================================
 * EXPORTS
 * ============================================================
 */

module.exports = {
    JOBS,
    TIERS,

    chooseCrumbleStrikeRole,
    chooseCrumbleStrikeJob,
    confirmCrumbleStrikeJoin,

    startCrumbleStrikeBattle,
    activateCrumbleStrike,

    performCrumbleStrikeAction,

    resolveCrumbleStrikeVictory,
    failCrumbleStrike,
    cancelCrumbleStrikeAndRefund,

    refreshCrumbleStrikeMessage
};