const {
    EmbedBuilder,
    AttachmentBuilder,
    GuildScheduledEventEntityType,
    GuildScheduledEventPrivacyLevel,
    PermissionFlagsBits,
    MessageFlags
} = require("discord.js");

const { ObjectId } = require("mongodb");
const path = require("node:path");
const { mClient } = require("..");




/*
 * CONFIG
 */

const DATABASE = "neo-db";
const DUTY_COLLECTION = "items_duties";

const RAID_PLANNER_CHANNEL_ID =
    process.env.RAID_PLANNER_CHANNEL_ID;

const RAID_TIMEZONE =
    process.env.RAID_TIMEZONE || "Europe/Berlin";


/*
 * LOCAL DUTY ASSETS
 */

const dutyIconDirectory = path.resolve(
    __dirname,
    "../assets/duties"
);


const DUTY_ICONS = {
    Guildhest: "Guildhest.png",
    Dungeon: "Dungeon.png",
    Trial: "Trial.png",
    Raid: "Raid.png",
    AllianceRaid: "Raid.png",

    VariantDungeon:
        "Variant_and_criterion_dungeons_icon1.png",

    Criterion:
        "Variant_and_criterion_dungeons_icon1.png"
};


const DUTY_DIFFICULTY_ICONS = {
    Ultimate: "Ultimate_Raid.png",
    Chaotic: "Chaotic_Alliance_Raid.png"
};


/*
 * RAID SIGNUP EMOJIS
 */

const RAID_EMOJIS = {
    Tank: {
        id: "1537931883369726042",
        display:
            "<:TankRole:1537931883369726042>"
    },

    Healer: {
        id: "1537931880756805704",
        display:
            "<:HealerRole:1537931880756805704>"
    },

    DPS: {
        id: "1537931878668050442",
        display:
            "<:DPSRole:1537931878668050442>"
    }
};


/*
 * MODAL EXPORT
 *
 * Your modal handler should use the base customId:
 * raidPlan:<dutyObjectId>
 *
 * and resolve "raidPlan".
 */

module.exports = {
    customId: "raidPlan",

    async execute(interaction) {
        return handleRaidPlan(interaction);
    }
};


/*
 * MAIN HANDLER
 */

async function handleRaidPlan(interaction) {
    await interaction.deferReply({
        flags: MessageFlags.Ephemeral
    });


    if (!interaction.guild) {
        return interaction.editReply({
            content:
                "Raid planning can only be used inside a server."
        });
    }


    if (!RAID_PLANNER_CHANNEL_ID) {
        return interaction.editReply({
            content:
                "RAID_PLANNER_CHANNEL_ID is not configured."
        });
    }


    /*
     * customId:
     *
     * raidPlan:<ObjectId>
     */
    const [
        prefix,
        dutyId
    ] = interaction.customId.split(":");


    if (
        prefix !== "raidPlan" ||
        !ObjectId.isValid(dutyId)
    ) {
        return interaction.editReply({
            content:
                "Invalid raid planner data."
        });
    }


    /*
     * Fetch selected duty.
     */

    const collection = mClient
        .db(DATABASE)
        .collection(DUTY_COLLECTION);


    const duty =
        await collection.findOne({
            _id: new ObjectId(dutyId)
        });


    if (!duty) {
        return interaction.editReply({
            content:
                "The selected duty could not be found."
        });
    }


    /*
     * Read modal fields.
     */

    const name =
        interaction.fields
            .getTextInputValue(
                "raid-name"
            )
            .trim();


    const description =
        interaction.fields
            .getTextInputValue(
                "raid-description"
            )
            .trim();


    const enteredDuty =
        interaction.fields
            .getTextInputValue(
                "raid-duty"
            )
            .trim();


    const date =
        interaction.fields
            .getTextInputValue(
                "raid-date"
            )
            .trim();


    const timeRange =
        interaction.fields
            .getTextInputValue(
                "raid-time"
            )
            .trim();


    /*
     * Duty field is display-only in practice.
     * Verify user didn't modify it.
     */

    if (
        enteredDuty !==
        duty.Name
    ) {
        return interaction.editReply({
            content:
                "The Duty field was changed. Please create the raid again."
        });
    }


    /*
     * Validate date.
     */

    if (
        !isValidDateString(
            date
        )
    ) {
        return interaction.editReply({
            content:
                "Invalid date. Use `DD-MM-YYYY`, for example `22-08-2026`."
        });
    }


    /*
     * Validate time range.
     */

    const parsedTimeRange =
        parseTimeRange(
            timeRange
        );


    if (!parsedTimeRange) {
        return interaction.editReply({
            content:
                "Invalid time. Use the 24-hour format `HH:mm - HH:mm`, for example `20:00 - 23:00`."
        });
    }


    const {
        startTime,
        endTime
    } = parsedTimeRange;


    /*
     * Convert configured timezone to JS Date.
     */

    const startDate =
        zonedDateTimeToDate(
            date,
            startTime,
            RAID_TIMEZONE
        );


    let endDate =
        zonedDateTimeToDate(
            date,
            endTime,
            RAID_TIMEZONE
        );


    if (
        !startDate ||
        !endDate
    ) {
        return interaction.editReply({
            content:
                "I couldn't understand that date and time."
        });
    }


    /*
     * If the end time is before/equal to the start,
     * assume the raid crosses midnight.
     *
     * Example:
     * 23:00 - 02:00
     */

    if (
        endDate <=
        startDate
    ) {
        endDate =
            new Date(
                endDate.getTime() +
                24 * 60 * 60 * 1000
            );
    }


    /*
     * Start must be in the future.
     */

    if (
        startDate.getTime() <=
        Date.now()
    ) {
        return interaction.editReply({
            content:
                "The raid must be scheduled for a future date and time."
        });
    }


    /*
     * Fetch planner channel.
     */

    const channel =
        await interaction.guild
            .channels
            .fetch(
                RAID_PLANNER_CHANNEL_ID
            );


    if (
        !channel ||
        !channel.isTextBased() ||
        typeof channel.send !==
            "function"
    ) {
        return interaction.editReply({
            content:
                "The configured raid planner channel could not be found or is not a text channel."
        });
    }


    /*
     * Bot member.
     */

    const me =
        interaction.guild.members.me;


    if (!me) {
        return interaction.editReply({
            content:
                "I couldn't determine my server permissions."
        });
    }


    /*
     * Event permission.
     */

    if (
        !me.permissions.has(
            PermissionFlagsBits.CreateEvents
        )
    ) {
        return interaction.editReply({
            content:
                "I need the **Create Events** permission."
        });
    }


    /*
     * Destination channel permissions.
     */

    const channelPermissions =
        channel.permissionsFor(me);


    if (
        !channelPermissions ||
        !channelPermissions.has([
            PermissionFlagsBits.ViewChannel,
            PermissionFlagsBits.SendMessages,
            PermissionFlagsBits.EmbedLinks,
            PermissionFlagsBits.AddReactions
        ])
    ) {
        return interaction.editReply({
            content:
                "I need **View Channel**, **Send Messages**, **Embed Links**, and **Add Reactions** in the raid planner channel."
        });
    }


    /*
     * Create scheduled event.
     */

    let event;


    try {
        event =
            await createRaidEvent(
                interaction,
                {
                    name,
                    description,
                    duty,
                    startDate,
                    endDate
                }
            );

    } catch (error) {
        console.error(
            "Raid event creation failed:",
            error
        );


        return interaction.editReply({
            content:
                "I couldn't create the scheduled event."
        });
    }


    /*
     * Create planner embed/message.
     */

    let message;


    try {
        message =
            await createRaidMessage(
                interaction,
                channel,
                {
                    name,
                    description,
                    duty,
                    startDate,
                    endDate
                },
                event
            );

    } catch (error) {
        console.error(
            "Raid planner message failed:",
            error
        );


        /*
         * Remove event if planner post fails.
         */
        try {
            await event.delete(
                "Raid planner message failed"
            );

        } catch (cleanupError) {
            console.error(
                "Raid event cleanup failed:",
                cleanupError
            );
        }


        return interaction.editReply({
            content:
                "I couldn't publish the raid planner."
        });
    }


    /*
     * Confirmation to raid creator.
     */

    return interaction.editReply({
        content:
            `Raid created successfully!\n${message.url}`
    });
}


/*
 * CREATE DISCORD SCHEDULED EVENT
 */

async function createRaidEvent(
    interaction,
    data
) {
    const eventDescription = [
        data.description,
        "",
        `Duty: ${data.duty.Name}`,
        `Difficulty: ${data.duty.Difficulty}`,
        `Organized by: ${interaction.user.displayName}`
    ]
        .join("\n")
        .slice(
            0,
            1000
        );


    return interaction.guild
        .scheduledEvents
        .create({

            name:
                data.name.slice(
                    0,
                    100
                ),

            description:
                eventDescription,

            scheduledStartTime:
                data.startDate,

            scheduledEndTime:
                data.endDate,

            privacyLevel:
                GuildScheduledEventPrivacyLevel
                    .GuildOnly,

            entityType:
                GuildScheduledEventEntityType
                    .External,

            entityMetadata: {
                location:
                    `Final Fantasy XIV — ${data.duty.Name}`
                        .slice(
                            0,
                            100
                        )
            },

            reason:
                `Raid planned by ${interaction.user.tag}`
        });
}


/*
 * CREATE RAID PLANNER MESSAGE
 */

async function createRaidMessage(
    interaction,
    channel,
    data,
    event
) {
    const startUnix =
        Math.floor(
            data.startDate
                .getTime() /
            1000
        );


    const endUnix =
        Math.floor(
            data.endDate
                .getTime() /
            1000
        );


    const eventUrl =
        `https://discord.com/events/${interaction.guildId}/${event.id}`;


    const icon =
        getDutyIconFile(
            data.duty
        );


    const embed =
        new EmbedBuilder()

            .setTitle(
                "Shaiwase Raid Planner"
            )

            .setDescription(
                [
                    `## ${data.name}`,
                    data.description
                ].join(
                    "\n\n"
                )
            )

            .addFields(

                {
                    name:
                        "Duty",

                    value:
                        `**${data.duty.Name}**\n` +
                        `${formatDutyType(data.duty.Type)} • ${data.duty.Difficulty}`,

                    inline:
                        false
                },

                {
                    name:
                        "Date",

                    value:
                        `<t:${startUnix}:D>`,

                    inline:
                        true
                },

                {
                    name:
                        "Time",

                    value:
                        `<t:${startUnix}:t> - <t:${endUnix}:t>`,

                    inline:
                        true
                },

                {
                    name:
                        "Starts",

                    value:
                        `<t:${startUnix}:R>`,

                    inline:
                        true
                },

                {
                    name:
                        "Discord Event",

                    value:
                        `[View Event](${eventUrl})`,

                    inline:
                        false
                },

                {
                    name:
                        "Sign Up",

                    value:
                        `${RAID_EMOJIS.Tank.display} Tank\n` +
                        `${RAID_EMOJIS.Healer.display} Healer\n` +
                        `${RAID_EMOJIS.DPS.display} DPS`,

                    inline:
                        false
                }
            )

            .setFooter({
                text:
                    `Created by ${interaction.user.displayName}`
            })

            .setTimestamp();


    /*
     * Local duty icon attachment.
     */

    const files = [];


    if (icon) {
        const attachmentName =
            "duty-icon.png";


        files.push(
            new AttachmentBuilder(
                icon.path,
                {
                    name:
                        attachmentName
                }
            )
        );


        embed.setThumbnail(
            `attachment://${attachmentName}`
        );
    }


    /*
     * Send only into raid planner channel.
     */

    const message =
        await channel.send({
            embeds: [
                embed
            ],

            files
        });


    /*
     * Signup reactions.
     */

    await message.react(
        RAID_EMOJIS.Tank.id
    );


    await message.react(
        RAID_EMOJIS.Healer.id
    );


    await message.react(
        RAID_EMOJIS.DPS.id
    );


    return message;
}


/*
 * GET DUTY ICON
 */

function getDutyIconFile(duty) {
    const fileName =
        DUTY_DIFFICULTY_ICONS[
            duty.Difficulty
        ]
        ??
        DUTY_ICONS[
            duty.Type
        ];


    if (!fileName)
        return null;


    return {
        fileName,

        path:
            path.join(
                dutyIconDirectory,
                fileName
            )
    };
}


/*
 * FORMAT DUTY TYPE
 */

function formatDutyType(type) {
    switch (type) {
        case "AllianceRaid":
            return "Alliance Raid";

        case "VariantDungeon":
            return "Variant Dungeon";

        default:
            return type;
    }
}


/*
 * VALIDATE DD-MM-YYYY
 */

function isValidDateString(value) {
    const match =
        /^(\d{2})-(\d{2})-(\d{4})$/
            .exec(value);


    if (!match)
        return false;


    const day =
        Number(
            match[1]
        );


    const month =
        Number(
            match[2]
        );


    const year =
        Number(
            match[3]
        );


    const date =
        new Date(
            Date.UTC(
                year,
                month - 1,
                day
            )
        );


    return (
        date.getUTCFullYear() ===
            year
        &&
        date.getUTCMonth() ===
            month - 1
        &&
        date.getUTCDate() ===
            day
    );
}


/*
 * PARSE:
 *
 * 20:00 - 23:00
 *
 * 24-hour clock
 */

function parseTimeRange(value) {
    const match =
        /^(\d{2}):(\d{2})\s*-\s*(\d{2}):(\d{2})$/
            .exec(value);


    if (!match)
        return null;


    const startHour =
        Number(
            match[1]
        );


    const startMinute =
        Number(
            match[2]
        );


    const endHour =
        Number(
            match[3]
        );


    const endMinute =
        Number(
            match[4]
        );


    if (
        startHour < 0 ||
        startHour > 23 ||
        startMinute < 0 ||
        startMinute > 59 ||
        endHour < 0 ||
        endHour > 23 ||
        endMinute < 0 ||
        endMinute > 59
    ) {
        return null;
    }


    return {
        startTime:
            `${String(startHour).padStart(2, "0")}:${String(startMinute).padStart(2, "0")}`,

        endTime:
            `${String(endHour).padStart(2, "0")}:${String(endMinute).padStart(2, "0")}`
    };
}


/*
 * CONVERT DD-MM-YYYY + HH:mm FROM
 * CONFIGURED TIMEZONE INTO JS DATE.
 */

function zonedDateTimeToDate(
    dateString,
    timeString,
    timeZone
) {
    const [
        day,
        month,
        year
    ] =
        dateString
            .split("-")
            .map(Number);


    const [
        hour,
        minute
    ] =
        timeString
            .split(":")
            .map(Number);


    let timestamp =
        Date.UTC(
            year,
            month - 1,
            day,
            hour,
            minute,
            0
        );


    /*
     * Two passes helps account for DST.
     */

    for (
        let i = 0;
        i < 2;
        i++
    ) {
        const offset =
            getTimeZoneOffset(
                new Date(
                    timestamp
                ),
                timeZone
            );


        timestamp =
            Date.UTC(
                year,
                month - 1,
                day,
                hour,
                minute,
                0
            )
            -
            offset;
    }


    const result =
        new Date(
            timestamp
        );


    return Number.isNaN(
        result.getTime()
    )
        ? null
        : result;
}


/*
 * GET UTC OFFSET OF IANA TIMEZONE
 */

function getTimeZoneOffset(
    date,
    timeZone
) {
    const formatter =
        new Intl.DateTimeFormat(
            "en-US",
            {
                timeZone,

                year:
                    "numeric",

                month:
                    "2-digit",

                day:
                    "2-digit",

                hour:
                    "2-digit",

                minute:
                    "2-digit",

                second:
                    "2-digit",

                hourCycle:
                    "h23"
            }
        );


    const parts =
        formatter
            .formatToParts(
                date
            )
            .reduce(
                (
                    result,
                    part
                ) => {

                    if (
                        part.type !==
                        "literal"
                    ) {
                        result[
                            part.type
                        ] =
                            Number(
                                part.value
                            );
                    }


                    return result;
                },
                {}
            );


    const asUTC =
        Date.UTC(
            parts.year,
            parts.month - 1,
            parts.day,
            parts.hour,
            parts.minute,
            parts.second
        );


    return (
        asUTC -
        date.getTime()
    );
}