/**
 * util.ts
 * Common helper functions
 */

import { MessageReaction, User } from 'discord.js';
import { createWriteStream, existsSync, unlinkSync } from 'fs';
import { get as httpGet } from 'https';
import { Database, open } from 'sqlite';
import { Database as Database3 } from 'sqlite3';
import 'dotenv/config';
import { ScoreboardMessageRow } from '../models';


const reactionEmojis: string[] = process.env.REACTIONS.split(',');
let db: Database = null;

async function openDb() {
    db = await open({
        filename: 'db.sqlite',
        driver: Database3
    })
}

function clearDb() {
    unlinkSync('db.sqlite');
}

function messageLink(message: ScoreboardMessageRow)
{
    return `https://discord.com/channels/${message.guild}/${message.channel}/${message.id}`;
}

function userAvatarPath(user: User)
{
    return `../public/avatars/${user.id}.webp`;
}

async function downloadUserAvatar(user: User)
{
    console.log(`[bot] Downloading ${user.id}'s avatar...`);
    const file = createWriteStream(userAvatarPath(user));
    return new Promise<void>(resolve => {
        httpGet(user.avatarURL(), res => {
            res.pipe(file);
            file.on('finish', () => {
                file.close();
                console.log(`[bot] Finished downloading ${user.id}'s avatar.`);
                resolve();
            });
        });
    });
}

async function refreshUserReactionTotalCount(user: User, emoji_idx: number)
{
    const result = await db.get<{sum: number}>(
        `SELECT sum(reaction_${emoji_idx}_count) AS sum FROM messages WHERE author = ?`,
        user.id
    );
    const emojiTotal = result.sum;
    await db.run(
        `INSERT INTO users(id, username, reaction_${emoji_idx}_total) VALUES(?, ?, ?) ON CONFLICT(id) DO
        UPDATE SET reaction_${emoji_idx}_total = ?, username = ? WHERE id = ?`,
        user.id,
        user.displayName,
        emojiTotal,
        emojiTotal,
        user.displayName,
        user.id
    );
    if (!existsSync(userAvatarPath(user))) {
        await downloadUserAvatar(user);
    }
    console.log(`[bot] Refreshed ${user.id}'s ${reactionEmojis[emoji_idx - 1]} count.`);
}

async function recordReaction(reaction: MessageReaction)
{
    const emojiIdx = reactionEmojis.indexOf(reaction.emoji.name) + 1;
    if (emojiIdx === 0) {
        return;
    }
    try {
        await db.run(
            `INSERT INTO messages(id, guild, channel, author, content, reaction_${emojiIdx}_count) VALUES(?, ?, ?, ?, ?, 1)
            ON CONFLICT(id) DO UPDATE SET reaction_${emojiIdx}_count = ? WHERE id = ?`,
            reaction.message.id,
            reaction.message.guildId,
            reaction.message.channelId,
            reaction.message.author.id,
            reaction.message.content,
            reaction.count,
            reaction.message.id
        );
        await refreshUserReactionTotalCount(reaction.message.author, emojiIdx);
        console.log(`[bot] Recorded ${reaction.emoji.name}x${reaction.count} in database.`);
    } catch (error) {
        console.error('[bot] Something went wrong when updating the database:', error);
        return;
    }
}

export { db, clearDb, openDb, reactionEmojis, recordReaction };