"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.streamLineByLineAsync = exports.streamFileLineByLineAsync = exports.lineReaderAsync = exports.readFile = void 0;
// cSpell:ignore curr
// cSpell:words zlib iconv
const fs = require("fs");
const iconv = require("iconv-lite");
const zlib = require("zlib");
const readline = require("readline");
const defaultEncoding = 'utf8';
function readFile(filename, encoding = defaultEncoding) {
    return new Promise((resolve, reject) => {
        const data = [];
        const stream = prepareFileStream(filename, encoding, reject);
        let resolved = false;
        function complete() {
            resolve(data.join(''));
            resolved = resolved || (resolve(data.join('')), true);
        }
        stream.on('error', reject);
        stream.on('data', (d) => data.push(d));
        stream.on('close', complete);
        stream.on('end', complete);
    });
}
exports.readFile = readFile;
/**
 * Reads a file line by line. The last value emitted by the Observable is always an empty string.
 * @param filename
 * @param encoding defaults to 'utf8'
 */
function lineReaderAsync(filename, encoding = defaultEncoding) {
    return streamFileLineByLineAsync(filename, encoding);
}
exports.lineReaderAsync = lineReaderAsync;
function prepareFileStream(filename, encoding, fnError) {
    const pipes = [];
    if (filename.match(/\.gz$/i)) {
        pipes.push(zlib.createGunzip());
    }
    pipes.push(iconv.decodeStream(encoding));
    const fileStream = fs.createReadStream(filename);
    fileStream.on('error', fnError);
    const stream = pipes.reduce((s, p) => s.pipe(p).on('error', fnError), fileStream);
    return stream;
}
/**
 * Emit a file line by line
 * @param filename full path to the file to read.
 * @param encoding defaults to 'utf8'
 */
function streamFileLineByLineAsync(filename, encoding = defaultEncoding) {
    const fnError = (e) => {
        iter.throw && iter.throw(e);
    };
    const stream = prepareFileStream(filename, encoding, fnError);
    const iter = streamLineByLineAsync(stream);
    return iter;
}
exports.streamFileLineByLineAsync = streamFileLineByLineAsync;
/**
 * Emit a file line by line
 * @param filename full path to the file to read.
 * @param encoding defaults to 'utf8'
 */
function streamLineByLineAsync(stream, encoding = defaultEncoding) {
    let data = '.';
    let done = false;
    let error;
    const buffer = [];
    const pending = [];
    const fnError = (e) => {
        error = e;
    };
    const fnComplete = () => {
        // readline will consume the last newline without emitting an empty last line.
        // If the last data read contains a new line, then emit an empty string.
        if (data.match(/(?:(?:\r?\n)|(?:\r))$/)) {
            buffer.push('');
        }
        processBuffer();
        done = true;
    };
    // We want to capture the last line.
    stream.on('data', (d) => (data = dataToString(d, encoding)));
    stream.on('error', fnError);
    const rl = readline.createInterface({
        input: stream,
        terminal: false,
    });
    rl.on('close', fnComplete);
    rl.on('line', (text) => {
        buffer.push(text);
        processBuffer();
    });
    function registerPromise(resolve, reject) {
        pending.push({ resolve, reject });
        processBuffer();
    }
    function processBuffer() {
        if (error && pending.length && !buffer.length) {
            const p = pending.shift();
            p === null || p === void 0 ? void 0 : p.reject(error);
            return;
        }
        while (pending.length && buffer.length) {
            const p = pending.shift();
            const b = buffer.shift();
            if (b !== undefined && p) {
                p.resolve({ done: false, value: b });
            }
        }
        if (!done) {
            pending.length ? rl.resume() : rl.pause();
        }
        if (done && pending.length && !buffer.length) {
            const p = pending.shift();
            p === null || p === void 0 ? void 0 : p.resolve({ done, value: undefined });
        }
    }
    const iter = {
        [Symbol.asyncIterator]: () => iter,
        next() {
            return new Promise(registerPromise);
        },
        throw(e) {
            fnError(e);
            return new Promise(registerPromise);
        },
    };
    return iter;
}
exports.streamLineByLineAsync = streamLineByLineAsync;
function dataToString(data, encoding = 'utf8') {
    if (typeof data === 'string') {
        return data;
    }
    return data.toString(encoding);
}
//# sourceMappingURL=fileReader.js.map