/**
 * sync.ts
 * Syncs the message reactions in chat with the database, for when the bot is not running.
 */

import {
    Client,
    Collection,
    Events,
    GatewayIntentBits,
    GuildTextBasedChannel,
    IntentsBitField,
    Message,
    MessageReaction,
    Partials
} from 'discord.js';
import { db, clearDb, openDb, reactionEmojis, recordReaction } from './util';

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

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

async function startup() {
    console.log("[db] Clearing database...");
    clearDb();
    console.log("[db] Opening...");
    await openDb();
    console.log("[db] Migrating...");
    await db.migrate();
    console.log("[db] Ready.");
    console.log("[bot] Logging in...");
    await client.login(process.env.TOKEN);

    const guild = await client.guilds.fetch(process.env.GUILD);
    if (!guild) {
        console.error(`[bot] FATAL: guild ${guild.id} not found!`);
        return 1;
    }
    console.log(`[bot] Entered guild ${guild.id}`);
    const channels = await guild.channels.fetch();
    const textChannels = <Collection<string, GuildTextBasedChannel>> channels.filter(c => c && 'messages' in c && c.isTextBased);
    for (const [id, textChannel] of textChannels) {
        console.log(`[bot] Found text channel ${id}`);
        let before: string = undefined;
        let messages = new Collection<string, Message<true>>();
        let newMessages: Collection<string, Message<true>>;
        try {
            do {
                newMessages = await textChannel.messages.fetch({before, limit: 100});
                messages = messages.concat(newMessages);
                console.log(`[bot] [${id}] Fetched ${messages.size} messages (+${newMessages.size})`);
                if (messages.size > 0)
                    before = messages.last().id;
            } while (newMessages.size > 0);
            console.log(`[bot] [${id}] Fetched all messages.`);
            const reactions = messages.flatMap<MessageReaction>(m => m.reactions.cache);
            console.log(`[bot] Found ${reactions.size} reactions`);
            for (const [_, reaction] of reactions) {
                await recordReaction(reaction);
            }
            console.log(`[bot] [${id}] Finished recording reactions.`);
        } catch (err) {
            console.warn(`[bot] [${id}] Failed to fetch messages and reactions: ${err}`);
        }
    }
    process.exit(0);
}

startup();