path: root/src/api/messages.js

import fs from 'node:fs';
import path from 'node:path';
import mime from 'mime';
import wweb from 'whatsapp-web.js';
import * as ser from '../serialize.js';

const { MessageMedia } = wweb;

const msgParam = { type: 'string', required: true, description: 'Serialized message ID (the "id" field)' };
const chatParam = { type: 'chat', required: true, description: 'Chat: JID (549...@c.us, ...@g.us), phone number or exact name' };
const MSG_COLUMNS = ['date', 'senderName', 'type', 'body', 'id'];

// Content parameters shared by send and reply.
const contentParams = {
    body: { type: 'string', description: 'Text (or caption when there is media)' },
    media: { type: 'path', description: 'File to attach' },
    mediaUrl: { type: 'string', description: 'URL of a file to attach' },
    asDocument: { type: 'boolean', description: 'Send the media as a document' },
    asVoice: { type: 'boolean', description: 'Send audio as a voice note' },
    asSticker: { type: 'boolean', description: 'Send an image as a sticker' },
    viewOnce: { type: 'boolean', description: 'View once' },
    linkPreview: { type: 'boolean', description: 'Generate link previews (default true)' },
    mentions: { type: 'array', description: 'JIDs to mention (the text must include @number)' },
};

async function buildContent(ctx, p) {
    let media;
    if (p.media) media = MessageMedia.fromFilePath(p.media);
    else if (p.mediaUrl) media = await MessageMedia.fromUrl(p.mediaUrl, { unsafeMime: true });
    if (!media && !p.body) throw new ctx.WaError('EINVAL', 'nothing to send: "body", "media" or "mediaUrl" is missing');
    const opts = {};
    if (media && p.body) opts.caption = p.body;
    if (p.asDocument) opts.sendMediaAsDocument = true;
    if (p.asVoice) opts.sendAudioAsVoice = true;
    if (p.asSticker) opts.sendMediaAsSticker = true;
    if (p.viewOnce) opts.isViewOnce = true;
    if (p.linkPreview !== undefined) opts.linkPreview = p.linkPreview;
    if (p.mentions) opts.mentions = p.mentions;
    return [media ?? p.body, opts];
}

// Adds media.data (base64) to the serialized messages that have media.
async function attachMedia(pairs) {
    for (const [msg, out] of pairs) {
        if (!msg.hasMedia) continue;
        try {
            const m = await msg.downloadMedia();
            if (m) Object.assign(out.media, { mimetype: m.mimetype, filename: m.filename || out.media.filename, data: m.data });
        } catch (e) {
            out.media.error = e.message;
        }
    }
}

function uniquePath(p) {
    if (!fs.existsSync(p)) return p;
    const { dir, name, ext } = path.parse(p);
    for (let i = 1; ; i++) {
        const c = path.join(dir, `${name}-${i}${ext}`);
        if (!fs.existsSync(c)) return c;
    }
}

export default {
    'messages.list': {
        description: 'Messages of a chat, in chronological order (the last `limit`).',
        params: {
            chatId: chatParam,
            limit: { type: 'integer', default: 50, description: 'Maximum count (from the most recent backwards)' },
            since: { type: 'integer', description: 'Only messages with timestamp >= since (epoch s). Loads history until covered' },
            until: { type: 'integer', description: 'Only messages with timestamp < until (epoch s)' },
            fromMe: { type: 'boolean', description: 'true: sent only; false: received only' },
            includeMedia: { type: 'boolean', default: false, description: 'Download media and include it as base64 (media.data)' },
        },
        columns: MSG_COLUMNS,
        handler: async (ctx, p) => {
            const chat = await ctx.getChat(p.chatId);
            const search = p.fromMe === undefined ? {} : { fromMe: p.fromMe };
            let limit = p.limit;
            let msgs = await chat.fetchMessages({ ...search, limit });
            // With `since`, keep loading history until past that date (or exhausted).
            if (p.since !== undefined) {
                const oldest = () => msgs.reduce((min, m) => Math.min(min, m.timestamp), Infinity);
                while (msgs.length >= limit && oldest() >= p.since && limit < 20000) {
                    limit *= 2;
                    msgs = await chat.fetchMessages({ ...search, limit });
                }
                msgs = msgs.filter((m) => m.timestamp >= p.since);
            }
            if (p.until !== undefined) msgs = msgs.filter((m) => m.timestamp < p.until);
            const pairs = msgs.map((m) => [m, ser.message(m, ctx.ser)]);
            if (p.includeMedia) await attachMedia(pairs);
            return pairs.map(([, out]) => out);
        },
    },

    'messages.get': {
        description: 'A message by ID.',
        params: {
            messageId: msgParam,
            includeMedia: { type: 'boolean', default: false, description: 'Download media and include it as base64 (media.data)' },
        },
        columns: MSG_COLUMNS,
        handler: async (ctx, p) => {
            const m = await ctx.getMessage(p.messageId);
            const out = ser.message(m, ctx.ser);
            if (p.includeMedia) await attachMedia([[m, out]]);
            return out;
        },
    },

    'messages.search': {
        description: 'Searches messages by text (in all chats or in one).',
        params: {
            query: { type: 'string', required: true, description: 'Text to search for' },
            chatId: { ...chatParam, required: false },
            page: { type: 'integer', description: 'Results page' },
            limit: { type: 'integer', description: 'Results per page' },
        },
        columns: ['date', 'chatId', 'senderName', 'body', 'id'],
        handler: async (ctx, p) => {
            const { query, ...opts } = p;
            const msgs = await ctx.client.searchMessages(query, opts);
            return msgs.map((m) => ser.message(m, ctx.ser));
        },
    },

    'messages.send': {
        description: 'Sends a text message or a file.',
        params: {
            chatId: chatParam,
            ...contentParams,
            quotedMessageId: { type: 'string', description: 'ID of the message to quote (reply to)' },
        },
        columns: MSG_COLUMNS,
        handler: async (ctx, p) => {
            const [content, opts] = await buildContent(ctx, p);
            if (p.quotedMessageId) opts.quotedMessageId = p.quotedMessageId;
            const m = await ctx.client.sendMessage(p.chatId, content, opts);
            return ser.message(m, ctx.ser);
        },
    },

    'messages.reply': {
        description: 'Replies quoting a message, in the same chat.',
        params: { messageId: msgParam, ...contentParams },
        columns: MSG_COLUMNS,
        handler: async (ctx, p) => {
            const orig = await ctx.getMessage(p.messageId);
            const [content, opts] = await buildContent(ctx, p);
            const m = await orig.reply(content, undefined, opts);
            return ser.message(m, ctx.ser);
        },
    },

    'messages.forward': {
        description: 'Forwards a message to another chat.',
        params: { messageId: msgParam, chatId: chatParam },
        handler: async (ctx, p) => {
            await (await ctx.getMessage(p.messageId)).forward(p.chatId);
            return { ok: true