/**
 * bot.ts
 * Scans the chat for reactions and updates the leaderboard database.
 */

import {
    Attachment,
    AttachmentBuilder,
    Client,
    Collection,
    Events,
    GatewayIntentBits,
    Interaction,
    Message,
    MessageFlags,
    MessageReaction,
    MessageType,
    PartialMessageReaction,
    Partials, SlashCommandBuilder,
    TextChannel,
    User
} from 'discord.js';
import fs = require('node:fs');
import path = require('node:path');
import fetch from 'node-fetch';
import FormData = require('form-data');
import tmp = require('tmp');
import { JSDOM } from 'jsdom';
import { logError, logInfo, logWarn } from '../logging';
import {
    db,
    openDb,
    reactionEmojis,
    recordReaction,
    requestTTSResponse,
    sync
} from './util';
import 'dotenv/config';

const config = {};

interface CommandClient extends Client {
    commands?: Collection<string, { data: SlashCommandBuilder, execute: (interaction: Interaction) => Promise<void> }>
}

const client: CommandClient = new Client({
    intents: [GatewayIntentBits.Guilds, GatewayIntentBits.GuildMessages, GatewayIntentBits.GuildMessageReactions, GatewayIntentBits.MessageContent],
    partials: [Partials.Message, Partials.Channel, Partials.Reaction],
});
client.commands = new Collection();

client.once(Events.ClientReady, async () => {
    logInfo('[bot] Ready.');
    for (let i = 0; i < reactionEmojis.length; ++i)
        logInfo(`[bot] config: reaction_${i + 1} = ${reactionEmojis[i]}`);
});


async function onMessageReactionChanged(reaction: MessageReaction | PartialMessageReaction, user: User)
{
    // When a reaction is received, check if the structure is partial
    if (reaction.partial) {
        // If the message this reaction belongs to was removed, the fetching might result in an API error which should be handled
        try {
            await reaction.fetch();
        } catch (error) {
            logError('[bot] Something went wrong when fetching the reaction:', error);
            // Return as `reaction.message.author` may be undefined/null
            return;
        }
    }
    if (reaction.message.partial) {
        // If the message this reaction belongs to was removed, the fetching might result in an API error which should be handled
        try {
            await reaction.message.fetch();
        } catch (error) {
            logError('[bot] Something went wrong when fetching the message:', error);
            // Return as `reaction.message.author` may be undefined/null
            return;
        }
    }

    // Now the message has been cached and is fully available
    logInfo(`[bot] ${reaction.message.author.id}'s message reaction count changed: ${reaction.emoji.name}x${reaction.count}`);
    await recordReaction(<MessageReaction> reaction);
}

function textOnlyMessages(message: Message)
{
    return message.cleanContent.length > 0 &&
        (message.type === MessageType.Default || message.type === MessageType.Reply);
}

function isGoodResponse(response: string)
{
    return response.length > 0 && !(response in [
        '@Today Man-San(1990)🍁🍂',
        '@1981 Celical Man🍁🍂',
        '@Exiled Sammy 🔒🏝⏱'
    ]);
}

async function onNewMessage(message: Message)
{
    if (message.author.bot) {
        return;
    }

    /** First, handle audio messages */
    if (message.flags.has(MessageFlags.IsVoiceMessage)) {
        try {
            const audio = await requestRVCResponse(message.attachments.first());
            const audioBuf = await audio.arrayBuffer();
            const audioFile = new AttachmentBuilder(Buffer.from(audioBuf)).setName('mikuified.wav');
            await message.reply({
                files: [audioFile]
            });
        } catch (err) {
            logError(`[bot] Failed to generate audio message reply: ${err}`);
        }
    }

    /** Text messages */
    if (!textOnlyMessages(message)) {
        return;
    }

    // Miku must reply when spoken to
    const mustReply = message.mentions.has(process.env.CLIENT) || message.cleanContent.toLowerCase().includes('miku');

    const history = await message.channel.messages.fetch({
        limit: config["llmconf"].llmSettings.msg_context-1,
        before: message.id
    });

    // change Miku's message probability depending on current message frequency
    const historyMessages = [...history.values()].reverse();
    //const historyTimes = historyMessages.map((m: Message) => m.createdAt.getTime());
    //const historyAvgDelayMins = (historyTimes[historyTimes.length - 1] - historyTimes[0]) / 60000;
    const replyChance = Math.floor(Math.random() * 1/Number(process.env.REPLY_CHANCE)) === 0;
    const willReply = mustReply || replyChance;

    if (!willReply) {
        return;
    }

    const cleanHistory = historyMessages.filter(textOnlyMessages);
    const cleanHistoryList = [
        ...cleanHistory,
        message
    ];

    await message.channel.sendTyping();

    try {
        const response = await requestLLMResponse(cleanHistoryList);
        // evaluate response
        if (!isGoodResponse(response)) {
            logWarn(`[bot] Burning bad response: "${response}"`);
            return;
        }
        await message.reply(response);
    } catch (err) {
        logError(`[bot] Error while generating LLM response: ${err}`);
    }
}

async function fetchMotd()
{
    try {
	    const res = await fetch(process.env.MOTD_HREF);
	    const xml = await res.text();
	    const parser = new JSDOM(xml);
	    const doc = parser.window.document;
	    const el = doc.querySelector(process.env.MOTD_QUERY);
	    return el ? el.textContent : null;
    } catch (err) {
	    logWarn('[bot] Failed to fetch MOTD; is the booru down?');
    }
}

async function requestRVCResponse(src: Attachment): Promise<Blob>
{
    logInfo(`[bot] Downloading audio message ${src.url}`);
    const srcres = await fetch(src.url);
    const srcbuf = await srcres.arrayBuffer();
    const tmpFile = tmp.fileSync();
    const tmpFileName = tmpFile.name;
    fs.writeFileSync(tmpFileName, Buffer.from(srcbuf));
    logInfo(`[bot] Got audio file: ${srcbuf.size} bytes`);

    const queryParams = new URLSearchParams();
    queryParams.append("token", process.env.LLM_TOKEN);

    const fd = new FormData();
    fd.append('file', fs.readFileSync(tmpFileName), 'voice-message.ogg');

    const rvcEndpoint = `${process.env.LLM_HOST}/rvc?${queryParams.toString()}`;
    logInfo(`[bot] Requesting RVC response for ${src.id}`);
    const res = await fetch(rvcEndpoint, {
        method: 'POST',
        body: fd
    });
    const resContents = await res.blob();
    return resContents;
}

async function requestLLMResponse(messages)
{
    const queryParams = new URLSearchParams();
    queryParams.append("token", process.env.LLM_TOKEN);
    for (const field of Object.keys(config["llmconf"].llmSettings)) {
        queryParams.append(field, config["llmconf"].llmSettings[field]);
    }
    const llmEndpoint = `${process.env.LLM_HOST}/?${queryParams.toString()}`;
    const messageList = messages.map((m: Message) => ({
        role: m.author.bot ? "assistant" : "user",
        content: m.cleanContent,
    }));
    const reqBody = [
        {
            "role": "system",
            "content": config["llmconf"].sys_prompt
        },
        ...messageList
    ];
    logInfo("[bot] Requesting LLM response with message list: " + reqBody.map(m => m.content));
    const res = await fetch(llmEndpoint, {
        method: 'POST',
        headers: {
            'Content-Type': 'application/json',
        },
        body: JSON.stringify(reqBody)
    });
    const txt = await res.json();
    const txtRaw: string = txt["raw"][0];
    // Depends on chat template used
    const prefix = "<|start_header_id|>assistant<|end_header_id|>\n\n";
    const suffix = "<|reserved_special_token_";
    const txtStart = txtRaw.lastIndexOf(prefix);
    const txtEnd = txtRaw.slice(txtStart + prefix.length);
    const txtStop = txtEnd.indexOf(suffix) !== -1 ? txtEnd.indexOf(suffix) : txtEnd.length;
    return txtEnd.slice(0, txtStop);
}

async function scheduleRandomMessage(firstTime = false)
{
    if (!firstTime) {
        const channel = <TextChannel> await client.channels.fetch(process.env.MOTD_CHANNEL);
        if (!channel) {
            logWarn(`[bot] Channel ${process.env.MOTD_CHANNEL} not found, disabling MOTD.`);
            return;
        }
        const randomMessage = await fetchMotd();
        if (randomMessage) {
            try {
                const audio = await requestTTSResponse(randomMessage);
                const audioBuf = await audio.arrayBuffer();
                const audioFile = new AttachmentBuilder(Buffer.from(audioBuf)).setName('mikuified.wav');
                await channel.send({
                    content: randomMessage,
                    files: [audioFile]
                });
                logInfo(`[bot] Sent MOTD + TTS: ${randomMessage}`);
            } catch (err) {
                await channel.send(randomMessage);
                logWarn(`[bot] Could not fetch MOTD TTS: ${err}`);
                logInfo(`[bot] Send text MOTD: ${randomMessage}`);
            }
        } else {
            logWarn(`[bot] Could not fetch MOTD.`);
        }
    }
    // wait between 2-8 hours
    const timeoutMins = Math.random() * 360 + 120;
    const scheduledTime = new Date();
    scheduledTime.setMinutes(scheduledTime.getMinutes() + timeoutMins);
    logInfo(`[bot] Next MOTD: ${scheduledTime.toLocaleTimeString()}`);
    setTimeout(scheduleRandomMessage, timeoutMins * 60 * 1000);
}

client.on(Events.InteractionCreate, async interaction => {
    if (!interaction.isChatInputCommand()) return;
});

client.on(Events.MessageCreate, onNewMessage);
client.on(Events.MessageReactionAdd, onMessageReactionChanged);
client.on(Events.MessageReactionRemove, onMessageReactionChanged);
client.on(Events.InteractionCreate, async interaction => {
    if (!interaction.isChatInputCommand()) return;

    const client: CommandClient = interaction.client;
    const command = client.commands.get(interaction.commandName);

    if (!command) {
        logError(`[bot] No command matching ${interaction.commandName} was found.`);
        return;
    }

    try {
        await command.execute(interaction);
    } catch (error) {
        logError(error);
        if (interaction.replied || interaction.deferred) {
            await interaction.followUp({ content: 'There was an error while executing this command!', ephemeral: true });
        } else {
            await interaction.reply({ content: 'There was an error while executing this command!', ephemeral: true });
        }
    }
});

// startup
(async () => {
    tmp.setGracefulCleanup();
    logInfo("[db] Opening...");
    await openDb();
    logInfo("[db] Migrating...");
    await db.migrate();
    logInfo("[db] Ready.");

    logInfo("[bot] Loading commands...");
    const foldersPath = path.join(__dirname, 'commands');
    const commandFolders = fs.readdirSync(foldersPath);
    for (const folder of commandFolders) {
        const commandsPath = path.join(foldersPath, folder);
        const commandFiles = fs.readdirSync(commandsPath).filter(file => file.endsWith('.js'));
        for (const file of commandFiles) {
            const filePath = path.join(commandsPath, file);
            const command = require(filePath);
            client.commands.set(command.data.name, command);
            config[command.data.name] = command.config;
            logInfo(`[bot] Found command: /${command.data.name}`);
        }
    }

    logInfo("[bot] Logging in...");
    await client.login(process.env.TOKEN);
    await sync(client.guilds);
    if (process.env.ENABLE_MOTD) {
        await scheduleRandomMessage(true);
    }
})();