"use strict";
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
    return new (P || (P = Promise))(function (resolve, reject) {
        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
        step((generator = generator.apply(thisArg, _arguments || [])).next());
    });
};
Object.defineProperty(exports, "__esModule", { value: true });
const fs = require("fs");
const util_1 = require("util");
const statAsync = util_1.promisify(fs.stat);
const openAsync = util_1.promisify(fs.open);
const closeAsync = util_1.promisify(fs.close);
const MAX_BYTES = 512;
function isBinaryFile(file, size) {
    return __awaiter(this, void 0, void 0, function* () {
        if (isString(file)) {
            const stat = yield statAsync(file);
            isStatFile(stat);
            const fileDescriptor = yield openAsync(file, 'r');
            const allocBuffer = Buffer.alloc(MAX_BYTES);
            // Read the file with no encoding for raw buffer access.
            // NB: something is severely wrong with promisify, had to construct my own Promise
            return new Promise((fulfill, reject) => {
                fs.read(fileDescriptor, allocBuffer, 0, MAX_BYTES, 0, (err, bytesRead, _) => {
                    closeAsync(fileDescriptor);
                    if (err) {
                        reject(err);
                    }
                    else {
                        fulfill(isBinaryCheck(allocBuffer, bytesRead));
                    }
                });
            });
        }
        else {
            if (size === undefined) {
                size = file.length;
            }
            return isBinaryCheck(file, size);
        }
    });
}
exports.isBinaryFile = isBinaryFile;
function isBinaryFileSync(file, size) {
    if (isString(file)) {
        const stat = fs.statSync(file);
        isStatFile(stat);
        const fileDescriptor = fs.openSync(file, 'r');
        const allocBuffer = Buffer.alloc(MAX_BYTES);
        const bytesRead = fs.readSync(fileDescriptor, allocBuffer, 0, MAX_BYTES, 0);
        fs.closeSync(fileDescriptor);
        return isBinaryCheck(allocBuffer, bytesRead);
    }
    else {
        if (size === undefined) {
            size = file.length;
        }
        return isBinaryCheck(file, size);
    }
}
exports.isBinaryFileSync = isBinaryFileSync;
function isBinaryCheck(fileBuffer, bytesRead) {
    // empty file. no clue what it is.
    if (bytesRead === 0) {
        return false;
    }
    let suspiciousBytes = 0;
    const totalBytes = Math.min(bytesRead, MAX_BYTES);
    // UTF-8 BOM
    if (bytesRead >= 3 && fileBuffer[0] === 0xef && fileBuffer[1] === 0xbb && fileBuffer[2] === 0xbf) {
        return false;
    }
    // UTF-32 BOM
    if (bytesRead >= 4 && fileBuffer[0] === 0x00 && fileBuffer[1] === 0x00 && fileBuffer[2] === 0xfe && fileBuffer[3] === 0xff) {
        return false;
    }
    // UTF-32 LE BOM
    if (bytesRead >= 4 && fileBuffer[0] === 0xff && fileBuffer[1] === 0xfe && fileBuffer[2] === 0x00 && fileBuffer[3] === 0x00) {
        return false;
    }
    // GB BOM
    if (bytesRead >= 4 && fileBuffer[0] === 0x84 && fileBuffer[1] === 0x31 && fileBuffer[2] === 0x95 && fileBuffer[3] === 0x33) {
        return false;
    }
    if (totalBytes >= 5 && fileBuffer.slice(0, 5).toString() === '%PDF-') {
        /* PDF. This is binary. */
        return true;
    }
    // UTF-16 BE BOM
    if (bytesRead >= 2 && fileBuffer[0] === 0xfe && fileBuffer[1] === 0xff) {
        return false;
    }
    // UTF-16 LE BOM
    if (bytesRead >= 2 && fileBuffer[0] === 0xff && fileBuffer[1] === 0xfe) {
        return false;
    }
    for (let i = 0; i < totalBytes; i++) {
        if (fileBuffer[i] === 0) {
            // NULL byte--it's binary!
            return true;
        }
        else if ((fileBuffer[i] < 7 || fileBuffer[i] > 14) && (fileBuffer[i] < 32 || fileBuffer[i] > 127)) {
            // UTF-8 detection
            if (fileBuffer[i] > 193 && fileBuffer[i] < 224 && i + 1 < totalBytes) {
                i++;
                if (fileBuffer[i] > 127 && fileBuffer[i] < 192) {
                    continue;
                }
            }
            else if (fileBuffer[i] > 223 && fileBuffer[i] < 240 && i + 2 < totalBytes) {
                i++;
                if (fileBuffer[i] > 127 && fileBuffer[i] < 192 && fileBuffer[i + 1] > 127 && fileBuffer[i + 1] < 192) {
                    i++;
                    continue;
                }
            }
            suspiciousBytes++;
            // Read at least 32 fileBuffer before making a decision
            if (i > 32 && (suspiciousBytes * 100) / totalBytes > 10) {
                return true;
            }
        }
    }
    if ((suspiciousBytes * 100) / totalBytes > 10) {
        return true;
    }
    return false;
}
function isString(x) {
    return typeof x === "string";
}
function isStatFile(stat) {
    if (!stat.isFile()) {
        throw new Error(`Path provided was not a file!`);
    }
}