@periskope/baileys/lib/WAM/encode.js

WhatsApp API

import { BinaryInfo } from './BinaryInfo.js';
import { FLAG_BYTE, FLAG_EVENT, FLAG_EXTENDED, FLAG_FIELD, FLAG_GLOBAL, WEB_EVENTS, WEB_GLOBALS } from './constants.js';
const getHeaderBitLength = (key) => (key < 256 ? 2 : 3);
export const encodeWAM = (binaryInfo) => {
    binaryInfo.buffer = [];
    encodeWAMHeader(binaryInfo);
    encodeEvents(binaryInfo);
    console.log(binaryInfo.buffer);
    const totalSize = binaryInfo.buffer.map(a => a.length).reduce((a, b) => a + b);
    const buffer = Buffer.alloc(totalSize);
    let offset = 0;
    for (const buffer_ of binaryInfo.buffer) {
        buffer_.copy(buffer, offset);
        offset += buffer_.length;
    }
    return buffer;
};
function encodeWAMHeader(binaryInfo) {
    const headerBuffer = Buffer.alloc(8); // starting buffer
    headerBuffer.write('WAM', 0, 'utf8');
    headerBuffer.writeUInt8(binaryInfo.protocolVersion, 3);
    headerBuffer.writeUInt8(1, 4); //random flag
    headerBuffer.writeUInt16BE(binaryInfo.sequence, 5);
    headerBuffer.writeUInt8(0, 7); // regular channel
    binaryInfo.buffer.push(headerBuffer);
}
function encodeGlobalAttributes(binaryInfo, globals) {
    for (const [key, _value] of Object.entries(globals)) {
        const id = WEB_GLOBALS.find(a => a?.name === key).id;
        let value = _value;
        if (typeof value === 'boolean') {
            value = value ? 1 : 0;
        }
        binaryInfo.buffer.push(serializeData(id, value, FLAG_GLOBAL));
    }
}
function encodeEvents(binaryInfo) {
    for (const [name, { props, globals }] of binaryInfo.events.map(a => Object.entries(a)[0])) {
        encodeGlobalAttributes(binaryInfo, globals);
        const event = WEB_EVENTS.find(a => a.name === name);
        const props_ = Object.entries(props);
        let extended = false;
        for (const [, value] of props_) {
            extended || (extended = value !== null);
        }
        const eventFlag = extended ? FLAG_EVENT : FLAG_EVENT | FLAG_EXTENDED;
        binaryInfo.buffer.push(serializeData(event.id, -event.weight, eventFlag));
        for (let i = 0; i < props_.length; i++) {
            const [key, _value] = props_[i];
            const id = event.props[key]?.[0];
            extended = i < props_.length - 1;
            let value = _value;
            if (typeof value === 'boolean') {
                value = value ? 1 : 0;
            }
            const fieldFlag = extended ? FLAG_EVENT : FLAG_FIELD | FLAG_EXTENDED;
            binaryInfo.buffer.push(serializeData(id, value, fieldFlag));
        }
    }
}
function serializeData(key, value, flag) {
    const bufferLength = getHeaderBitLength(key);
    let buffer;
    let offset = 0;
    if (value === null) {
        if (flag === FLAG_GLOBAL) {
            buffer = Buffer.alloc(bufferLength);
            offset = serializeHeader(buffer, offset, key, flag);
            return buffer;
        }
    }
    else if (typeof value === 'number' && Number.isInteger(value)) {
        // is number
        if (value === 0 || value === 1) {
            buffer = Buffer.alloc(bufferLength);
            offset = serializeHeader(buffer, offset, key, flag | ((value + 1) << 4));
            return buffer;
        }
        else if (-128 <= value && value < 128) {
            buffer = Buffer.alloc(bufferLength + 1);
            offset = serializeHeader(buffer, offset, key, flag | (3 << 4));
            buffer.writeInt8(value, offset);
            return buffer;
        }
        else if (-32768 <= value && value < 32768) {
            buffer = Buffer.alloc(bufferLength + 2);
            offset = serializeHeader(buffer, offset, key, flag | (4 << 4));
            buffer.writeInt16LE(value, offset);
            return buffer;
        }
        else if (-2147483648 <= value && value < 2147483648) {
            buffer = Buffer.alloc(bufferLength + 4);
            offset = serializeHeader(buffer, offset, key, flag | (5 << 4));
            buffer.writeInt32LE(value, offset);
            return buffer;
        }
        else {
            buffer = Buffer.alloc(bufferLength + 8);
            offset = serializeHeader(buffer, offset, key, flag | (7 << 4));
            buffer.writeDoubleLE(value, offset);
            return buffer;
        }
    }
    else if (typeof value === 'number') {
        // is float
        buffer = Buffer.alloc(bufferLength + 8);
        offset = serializeHeader(buffer, offset, key, flag | (7 << 4));
        buffer.writeDoubleLE(value, offset);
        return buffer;
    }
    else if (typeof value === 'string') {
        // is string
        const utf8Bytes = Buffer.byteLength(value, 'utf8');
        if (utf8Bytes < 256) {
            buffer = Buffer.alloc(bufferLength + 1 + utf8Bytes);
            offset = serializeHeader(buffer, offset, key, flag | (8 << 4));
            buffer.writeUint8(utf8Bytes, offset++);
        }
        else if (utf8Bytes < 65536) {
            buffer = Buffer.alloc(bufferLength + 2 + utf8Bytes);
            offset = serializeHeader(buffer, offset, key, flag | (9 << 4));
            buffer.writeUInt16LE(utf8Bytes, offset);
            offset += 2;
        }
        else {
            buffer = Buffer.alloc(bufferLength + 4 + utf8Bytes);
            offset = serializeHeader(buffer, offset, key, flag | (10 << 4));
            buffer.writeUInt32LE(utf8Bytes, offset);
            offset += 4;
        }
        buffer.write(value, offset, 'utf8');
        return buffer;
    }
    throw 'missing';
}
function serializeHeader(buffer, offset, key, flag) {
    if (key < 256) {
        buffer.writeUInt8(flag, offset);
        offset += 1;
        buffer.writeUInt8(key, offset);
        offset += 1;
    }
    else {
        buffer.writeUInt8(flag | FLAG_BYTE, offset);
        offset += 1;
        buffer.writeUInt16LE(key, offset);
        offset += 2;
    }
    return offset;
}
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