matrix-quotes-bot/index.js

import * as dotenv from 'dotenv';
import { MatrixClient } from 'matrix-js-sdk';
import fs from 'fs';

dotenv.config();

console.log('🚀 Starting Ancestor Quote Bot...\n');

const deviceId = process.env.MATRIX_DEVICE_ID || 'ANCESTORBOT';

const client = new MatrixClient({
    accessToken: process.env.MATRIX_ACCESS_TOKEN,
    baseUrl: process.env.MATRIX_HOME_SERVER,
    deviceId,
});

// The Rust crypto backend uses an in-memory store here (no IndexedDB in Node),
// so after a restart it 'forgets' one-time keys it already uploaded. Re-uploading
// an existing OTK id makes Synapse reject the request with a 400, the SDK never
// marks it as sent, and it retries forever — which blocks decryption entirely.
// Rewrite that specific 400 into a synthetic success: the empty count makes the
// Rust machine mint fresh OTK ids on the next tick, which then upload cleanly.
function installOtkCollisionWorkaround(client) {
    const http = client.http;
    const authedRequest = http.authedRequest.bind(http);
    http.authedRequest = async function (method, path, queryParams, body, opts) {
        try {
            return await authedRequest(method, path, queryParams, body, opts);
        } catch (err) {
            if (
                method === 'POST' &&
                /\/keys\/upload$/.test(path) &&
                err?.httpStatus === 400 &&
                /already exists/.test(err?.message || '')
            ) {
                console.warn('⚙️ One-time-key collision on keys/upload; telling Rust crypto to mint fresh keys');
                return '{"one_time_key_counts":{}}';
            }
            throw err;
        }
    };
}
installOtkCollisionWorkaround(client);

function loadQuotes() {
    try {
        const quotesFile = './quotes.json';
        if (fs.existsSync(quotesFile)) {
            return JSON.parse(fs.readFileSync(quotesFile, 'utf8'));
        }
    } catch (err) {
        console.error('Error loading quotes:', err.message);
    }
    return [];
}

(async () => {
    const quotes = loadQuotes();
    
    if (quotes.length === 0) {
        console.error('❌ No quotes found! Please ensure quotes.json is present.');
        process.exit(1);
    }

    console.log(`✅ Loaded ${quotes.length} Ancestor quotes`);
    
    const token = process.env.MATRIX_ACCESS_TOKEN;
    const server = process.env.MATRIX_HOME_SERVER;
    
    if (!token || !server) {
        console.error('❌ Missing required environment variables!');
        console.error('   Required: MATRIX_ACCESS_TOKEN, MATRIX_HOME_SERVER');
        console.error('   See .env.example for guidance.');
        process.exit(1);
    }
    console.log(`🏠 Server: ${server}`);
    
    try {
        const whoami = await client.whoami();
        const userId = whoami.user_id;

        if (!userId || !userId.startsWith('@')) {
            console.error(`❌ whoami returned invalid user ID: ${userId}`);
            process.exit(1);
        }

        client.credentials.userId = userId;
        console.log(`👤 Bot Identity: ${userId} (device ${deviceId})`);

        // Enable end-to-end encryption so the bot can read and reply in
        // encrypted rooms. The Rust/Olm WASM backend needs no native
        // compile. useIndexedDB=false keeps everything in memory (no
        // IndexedDB in Node).
        await client.initRustCrypto({ useIndexedDB: false });
        console.log('🔐 E2EE crypto initialised (Rust/Olm WASM)');

        await client.startClient();
        console.log('✅ MatrixClient connected and authenticated\n');

        const joinedRooms = client.getRooms();
        console.log(`🏠 Current rooms: ${joinedRooms.length}`);
        joinedRooms.forEach((r) => {
            console.log(`   - ${r.roomId} membership="${r.getMyMembership()}"`);
        });
        console.log('');

        const cmd = (process.env.BOT_COMMAND || '!quote').toLowerCase();

        // Auto-accept invites so the bot can be invited into rooms.
        client.on('RoomMember.membership', (event, member) => {
            if (member.userId === userId && member.membership === 'invite') {
                const roomId = event.getRoomId();
                console.log(`📩 Invited to ${roomId}, joining...`);
                client.joinRoom(roomId).catch((err) => {
                    console.error('Failed to join room:', err.message);
                });
            }
        });

        // Respond to messages in any room this bot is a member of.
        client.on('event', (event) => {
            const type = event.getType();

            // If an event still arrives encrypted, decryption failed — the
            // room is likely set to only share keys with verified sessions.
            if (type === 'm.room.encrypted') {
                console.log(`🔒 [${event.getRoomId()}] could not decrypt message. ` +
                    `The room may be set to share keys only with verified sessions; ` +
                    `change room encryption settings to include this bot's device, or verify it.`);
                return;
            }

            if (type !== 'm.room.message') return;

            const sender = event.getSender();
            if (sender === userId) return;

            const room = client.getRoom(event.getRoomId());
            if (!room) return;

            const membership = room.getMyMembership();
            if (membership !== 'join') return;

            const content = event.getContent();
            if (!content || typeof content.body !== 'string') return;

            const lower = content.body.toLowerCase().trim();
            if (lower === cmd || lower.startsWith(cmd + ' ')) {
                const quote = quotes[Math.floor(Math.random() * quotes.length)];
                client.sendTextMessage(room.roomId, quote)
                    .then(() => console.log(`🎃 [${room.roomId}] ${quote}`))
                    .catch((err) => console.error('Failed to send quote:', err.message));
            }
        });

        console.log('🤖 Bot is running!');
        console.log(`   Invite this bot to a room and type ${process.env.BOT_COMMAND || '!quote'} to get an Ancestor quote.\n`);

    } catch (err) {
        console.error('❌ Fatal error starting bot:', err.message);
        console.error(err.stack);
        process.exit(1);
    }
    
    process.on('unhandledRejection', (reason, promise) => {
        console.error('🚨 Unhandled rejection:', reason?.message || reason);
        process.exit(1);
    });
    
    setInterval(() => {}, 60000);
})();