"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.computeHashes = computeHashes;
exports.computeHashesFromStream = computeHashesFromStream;
/**
 * Servicio: checksumService
 *
 * Calcula sumas y metadatos de un fichero de forma eficiente usando streams.
 * Las funciones principales procesan el archivo en streaming para producir:
 * - `md5` (hex)
 * - `sha1` (hex)
 * - `crc32` (hex, 8 caracteres)
 * - `size` (bytes)
 *
 * `computeHashes(filePath)` devuelve un objeto con los valores anteriores y
 * está pensado para usarse durante la importación/normalización de ROMs.
 */
const fs_1 = __importDefault(require("fs"));
const crypto_1 = require("crypto");
function makeCRCTable() {
    const table = new Uint32Array(256);
    for (let n = 0; n < 256; n++) {
        let c = n;
        for (let k = 0; k < 8; k++) {
            if (c & 1)
                c = 0xedb88320 ^ (c >>> 1);
            else
                c = c >>> 1;
        }
        table[n] = c >>> 0;
    }
    return table;
}
const CRC_TABLE = makeCRCTable();
function updateCrc(crc, buf) {
    let c = crc >>> 0;
    for (let i = 0; i < buf.length; i++) {
        c = (CRC_TABLE[(c ^ buf[i]) & 0xff] ^ (c >>> 8)) >>> 0;
    }
    return c >>> 0;
}
async function computeHashes(filePath) {
    return new Promise((resolve, reject) => {
        const md5 = (0, crypto_1.createHash)('md5');
        const sha1 = (0, crypto_1.createHash)('sha1');
        let size = 0;
        let crc = 0xffffffff >>> 0;
        const rs = fs_1.default.createReadStream(filePath);
        rs.on('error', (err) => reject(err));
        rs.on('data', (chunk) => {
            md5.update(chunk);
            sha1.update(chunk);
            size += chunk.length;
            crc = updateCrc(crc, chunk);
        });
        rs.on('end', () => {
            const md5sum = md5.digest('hex');
            const sha1sum = sha1.digest('hex');
            const final = (crc ^ 0xffffffff) >>> 0;
            const crcHex = final.toString(16).padStart(8, '0').toLowerCase();
            resolve({ size, md5: md5sum, sha1: sha1sum, crc32: crcHex });
        });
    });
}
async function computeHashesFromStream(rs) {
    return new Promise((resolve, reject) => {
        const md5 = (0, crypto_1.createHash)('md5');
        const sha1 = (0, crypto_1.createHash)('sha1');
        let size = 0;
        let crc = 0xffffffff >>> 0;
        let settled = false;
        const cleanup = () => {
            try {
                rs.removeListener('error', onError);
                rs.removeListener('data', onData);
                rs.removeListener('end', onEnd);
                rs.removeListener('close', onClose);
            }
            catch (e) { }
        };
        const finalize = () => {
            if (settled)
                return;
            settled = true;
            cleanup();
            const md5sum = md5.digest('hex');
            const sha1sum = sha1.digest('hex');
            const final = (crc ^ 0xffffffff) >>> 0;
            const crcHex = final.toString(16).padStart(8, '0').toLowerCase();
            resolve({ size, md5: md5sum, sha1: sha1sum, crc32: crcHex });
        };
        const onError = (err) => {
            if (settled)
                return;
            settled = true;
            cleanup();
            reject(err);
        };
        const onData = (chunk) => {
            md5.update(chunk);
            sha1.update(chunk);
            size += chunk.length;
            crc = updateCrc(crc, chunk);
        };
        const onEnd = () => finalize();
        const onClose = () => finalize();
        rs.on('error', onError);
        rs.on('data', onData);
        rs.on('end', onEnd);
        rs.on('close', onClose);
    });
}
exports.default = computeHashes;