const fs = require("fs");
const os = require("os");
const path = require("path");
const { spawnSync } = require("child_process");
const args = process.argv.slice(2);
const THIRDPARTY_DIR = __dirname;

function findArg(argname, isBoolean) {
	let prefix = `--${argname}`;
	let idx = args.findIndex(arg => arg == prefix);
	if (idx >= 0) {
		if (isBoolean) return true;
		else return args[idx + 1];
	}
	idx = args.findIndex(arg => arg.startsWith(prefix))
	if (idx >= 0) return args[idx].substring(prefix.length + 1);
	return null;
}

function assert(cond, message) {
	if (!cond) {
		console.error(message);
		process.exit(1);
	}
}

const buildOptions = {
	withOpenCV: findArg("with-opencv", true) ?? false,
	buildType: findArg("build-type", false) ?? "Release",
	proxy: findArg("proxy"),
	generator: findArg("generator"),
}

const spawnOption = {
	stdio: "inherit", env: {
		...process.env, ...buildOptions.proxy ? {
			"http_proxy": buildOptions.proxy,
			"https_proxy": buildOptions.proxy,
		} : {}
	}
};

function P(path) { return path.replace(/\\/g, "/"); }

function checkFile(...items) {
	return fs.existsSync(path.resolve(...items));
}

function downloadSource(name, repo, branch, recursive, checkedFile) {
	const sourceRootDir = path.join(THIRDPARTY_DIR, "_source");
	fs.mkdirSync(sourceRootDir, { recursive: true });
	const sourceDir = path.join(sourceRootDir, name);
	if (checkFile(sourceDir, checkedFile)) return sourceDir;

	console.log(`${name}源代码不存在，正在下载...`);
	assert(spawnSync("git", [
		"clone",
		...recursive ? ["--recursive"] : [],
		repo, "-b", branch,
		sourceDir
	], { ...spawnOption }).status == 0, `下载${name}源代码失败`);

	return sourceDir;
}

function cmakeBuildFromSource(name, repo, branch, downloader, buildArgs, cmakeCreator) {
	const sourceDir = downloader ? downloader(name, repo, branch) : downloadSource(name, repo, branch, false, "CMakeLists.txt");
	const buildDir = path.join(sourceDir, "build", buildOptions.buildType);
	const installDir = path.join(THIRDPARTY_DIR, name, buildOptions.buildType);
	const configFile = path.join(installDir, "config.cmake");

	if (typeof buildArgs == "function") buildArgs = buildArgs(sourceDir, buildDir, installDir);

	//编译源代码
	if (checkFile(configFile)) return
	console.log(`${name}目标不存在，正在编译...`);
	fs.rmSync(buildDir, { recursive: true, force: true });
	fs.mkdirSync(buildDir, { recursive: true });

	assert(spawnSync("cmake", [
		"-G", buildOptions.generator ?? "Ninja", sourceDir,
		"-DCMAKE_BUILD_TYPE=" + buildOptions.buildType,
		"-DCMAKE_INSTALL_PREFIX=" + installDir,
		...(buildArgs ?? []).map(arg => arg.startsWith("-D") ? arg : `-D${arg}`),
	], { ...spawnOption, cwd: buildDir }).status == 0, `配置${name}失败`);

	assert(spawnSync("cmake", [
		"--build", ".",
		"--parallel", os.cpus().length.toString(),
		"--config", buildOptions.buildType,
		"--target", "install",
	], { ...spawnOption, cwd: buildDir }).status == 0, `编译${name}失败`);

	fs.writeFileSync(configFile, cmakeCreator(installDir));
}

async function downloadFromURL(name, url, resolver) {
	const cacheDir = path.join(THIRDPARTY_DIR, "_cache");
	fs.mkdirSync(cacheDir, { recursive: true });
	const saveName = path.join(cacheDir, path.basename(url));
	const outputDir = path.join(cacheDir, name);
	fs.rmSync(outputDir, { force: true, recursive: true });

	if (!checkFile(saveName)) {
		console.log(`开始下载${name}, 地址:${url}`);
		await fetch(url).then(res => {
			console.log(res.status)
		})
		const result = spawnSync("curl", ["-o", saveName + ".cache", "-L", url, "-s", "-w", "%{http_code}"], { ...spawnOption, stdio: "pipe" });
		assert(result.status == 0 && result.stdout.toString() == "200", `下载${name}失败`);
		fs.renameSync(saveName + ".cache", saveName);
	}
	let currentName = saveName;

	if (saveName.endsWith(".bz2")) {
		currentName = saveName.substring(0, saveName.length - 4);
		const input = fs.createReadStream(saveName);
		const out = fs.createWriteStream(currentName);
		const bz2 = require("unbzip2-stream")();
		await new Promise((resolve, reject) => {
			input.pipe(bz2).pipe(out);
			out.on("close", resolve);
			input.on("error", reject);
			bz2.on("error", reject);
			out.on("error", reject);
		});
	}

	const format = path.extname(currentName);
	assert([".tar", ".gz", ".tgz", ".zip"].includes(format), "仅支持.tar, .gz, .tgz, .zip格式的压缩文件");
	const method = {
		".tar": require("compressing").tar,
		".gz": require("compressing").gzip,
		".tgz": require("compressing").tgz,
		".zip": require("compressing").zip,
	}[format];
	await method.uncompress(currentName, outputDir);

	await resolver(outputDir);

	fs.rmSync(outputDir, { recursive: true, force: true });
}


async function main() {
	//OpenCV
	if (buildOptions.withOpenCV) cmakeBuildFromSource("OpenCV", "https://github.com/opencv/opencv.git", "4.11.0", null, [
		"-DBUILD_SHARED_LIBS=OFF",
		"-DBUILD_opencv_apps=OFF",
		"-DBUILD_opencv_js=OFF",
		"-DBUILD_opencv_python2=OFF",
		"-DBUILD_opencv_python3=OFF",
		"-DBUILD_ANDROID_PROJECTS=OFF",
		"-DBUILD_ANDROID_EXAMPLES=OFF",
		"-DBUILD_TESTS=OFF",
		"-DBUILD_FAT_JAVA_LIB=OFF",
		"-DBUILD_ANDROID_SERVICE=OFF",
		"-DBUILD_JAVA=OFF",
		"-DBUILD_PERF_TESTS=OFF"
	], (root) => [
		`set(OpenCV_STATIC ON)`,
		os.platform() == "win32" ?
			`include(${JSON.stringify(P(path.join(root, "OpenCVConfig.cmake")))})` :
			`include(${JSON.stringify(P(path.join(root, "lib/cmake/opencv4/OpenCVConfig.cmake")))})`,
		`set(OpenCV_INCLUDE_DIR \${OpenCV_INCLUDE_DIRS})`,
		os.platform() == "win32" ?
			"set(OpenCV_LIB_DIR ${OpenCV_LIB_PATH})" :
			`set(OpenCV_LIB_DIR ${JSON.stringify(P(path.join(root, "lib")))})`,
		// `set(OpenCV_LIBS OpenCV_LIBS)`,
	].join("\n"));
}

main();