const Client = require('./index');

const fetch = require('node-fetch');

const LISTEN_ON = '5fcbf598b39160080e797ad6';
const PREFIX = '::';
const ADMIN_ID = '5fc828ea4e96e00725c17fd7';

const joined = [];
const selected = [];

// https://stackoverflow.com/questions/17619741/randomly-generating-unique-number-in-pairs-multiple-times

const randomPairs = (players) => {
    const pairs = [];
    while(players.length) {
        pairs.push([
            pluckRandomElement(players),
            pluckRandomElement(players)
        ]);
    }
    return pairs;
};

const pluckRandomElement = (array) => {
    const i = randomInt(array.length);
    return array.splice(i, 1)[0];
};

const randomInt = (limit) => {
    return Math.floor(Math.random() * limit);
};

const getRandomUser = (self, count=0) => {
    if (count > 3) return joined[0];
    count++;

    let final;

    let chosen = joined[Math.floor(Math.random() * joined.length)];
    final = chosen;
    if (chosen._id === self._id) return final = getRandomUser(self, count);
    if ((selected.indexOf(chosen)) !== 1) return final = getRandomUser(self, count);
    if (!final) return final = getRandomUser(self, count);

    

    return final || null;
};

const main = async () => {
    const client = new Client('https://b.hippoz.xyz', {
        throwErrors: true
    });

    const res = await fetch(`${client.url}/api/v1/users/token/create`, {
        method: 'POST',
        headers: {
            'Accept': 'application/json',
            'Content-Type': 'application/json'
        },
        body: JSON.stringify({
            username: 'D',
            password: 'D'
        })
    });

    const json = await res.json();

    if (!res.ok || json.error) throw new Error('Failed to generate token from API endpoint');

    await client.setToken(json.token);
    await client.gatewayConnect();
    
    client.gateway.on('connect', () => {
        const category = client.gateway.subscribeToCategoryChat(LISTEN_ON);

        client.gateway.on('message', (e) => {
            if (e.author._id === client.user._id) return;
            if (!e.content.startsWith(PREFIX)) return;
            if (e.category._id !== category) return;

            const cmdString = e.content.substring(PREFIX.length);
            const cmdFull = cmdString.split(' ');
            const cmd = cmdFull[0] || 'NO_CMD';

            console.log(cmdFull);

            switch (cmd) {
                case 'join': {
                    const existing = joined.findIndex((o) => {
                        return o._id === e.author._id;
                    });

                    if (existing !== -1) {
                        client.gateway.sendMessage(category, 'Already joined', {
                            nickAuthor: { username: 'Error' },
                            destUser: { _id: e.author._id }
                        });
                        break;
                    }

                    joined.push(e.author);
                    console.log(`[*] User joined`, e.author);
                    client.gateway.sendMessage(category, `${e.author.username} joined!`, {
                        nickAuthor: { username: 'New join!' }
                    });
                    break;
                }
                case 'roll': {
                    if (e.author._id !== ADMIN_ID) {
                        client.gateway.sendMessage(category, 'Access denied', {
                            nickAuthor: { username: 'Error' },
                            destUser: { _id: e.author._id }
                        });
                        break;
                    }
                    client.gateway.sendMessage(category, 'Rolling...', {
                        nickAuthor: { username: 'Woo' }
                    });

                    const pairs = randomPairs(joined);
                    
                    for (const pair of pairs) {
                        const p1 = pair[0];
                        const p2 = pair[1];
                        if (!p1 || !p2) continue;
                        for (const player of pair) {
                            client.gateway.sendMessage(category, `${p1.username} with ${p2.username}`, {
                                nickAuthor: { username: 'Your result' },
                                destUser: { _id: player._id }
                            });
                        }
                    }
                    break;
                }
            }
        });
    });
};

main();