/**
 * @license
 * Copyright 2019 Balena Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { run as oclifRun } from '@oclif/dev-cli';
import * as archiver from 'archiver';
import * as Bluebird from 'bluebird';
import { execFile, spawn } from 'child_process';
import { stripIndent } from 'common-tags';
import * as filehound from 'filehound';
import * as fs from 'fs-extra';
import * as path from 'path';
import { exec as execPkg } from 'pkg';
import * as rimraf from 'rimraf';
import * as semver from 'semver';
import * as shellEscape from 'shell-escape';
import * as util from 'util';

export const ROOT = path.join(__dirname, '..');
// Note: the following 'tslint disable' line was only required to
// satisfy ts-node under Appveyor's MSYS2 on Windows -- oddly specific.
// Maybe something to do with '/' vs '\' in paths in some tslint file.
// tslint:disable-next-line:no-var-requires
export const packageJSON = require(path.join(ROOT, 'package.json'));
export const version = 'v' + packageJSON.version;
const arch = process.arch;

function dPath(...paths: string[]) {
	return path.join(ROOT, 'dist', ...paths);
}

interface PathByPlatform {
	[platform: string]: string;
}

const standaloneZips: PathByPlatform = {
	linux: dPath(`balena-cli-${version}-linux-${arch}-standalone.zip`),
	darwin: dPath(`balena-cli-${version}-macOS-${arch}-standalone.zip`),
	win32: dPath(`balena-cli-${version}-windows-${arch}-standalone.zip`),
};

const oclifInstallers: PathByPlatform = {
	darwin: dPath('macos', `balena-${version}.pkg`),
	win32: dPath('win', `balena-${version}-${arch}.exe`),
};

const renamedOclifInstallers: PathByPlatform = {
	darwin: dPath(`balena-cli-${version}-macOS-${arch}-installer.pkg`),
	win32: dPath(`balena-cli-${version}-windows-${arch}-installer.exe`),
};

export const finalReleaseAssets: { [platform: string]: string[] } = {
	win32: [standaloneZips['win32'], renamedOclifInstallers['win32']],
	darwin: [standaloneZips['darwin'], renamedOclifInstallers['darwin']],
	linux: [standaloneZips['linux']],
};

const MSYS2_BASH = 'C:\\msys64\\usr\\bin\\bash.exe';

/**
 * Run the MSYS2 bash.exe shell in a child process (child_process.spawn()).
 * The given argv arguments are escaped using the 'shell-escape' package,
 * so that backslashes in Windows paths, and other bash-special characters,
 * are preserved. If argv is not provided, defaults to process.argv, to the
 * effect that this current (parent) process is re-executed under MSYS2 bash.
 * This is useful to change the default shell from cmd.exe to MSYS2 bash on
 * Windows.
 * @param argv Arguments to be shell-escaped and given to MSYS2 bash.exe.
 */
export async function runUnderMsys(argv?: string[]) {
	const newArgv = argv || process.argv;
	await new Promise((resolve, reject) => {
		const args = ['-lc', shellEscape(newArgv)];
		const child = spawn(MSYS2_BASH, args, { stdio: 'inherit' });
		child.on('close', code => {
			if (code) {
				console.log(`runUnderMsys: child process exited with code ${code}`);
				reject(code);
			} else {
				resolve();
			}
		});
	});
}

/**
 * Use the 'pkg' module to create a single large executable file with
 * the contents of 'node_modules' and the CLI's javascript code.
 * Also copy a number of native modules (binary '.node' files) that are
 * compiled during 'npm install' to the 'build-bin' folder, alongside
 * the single large executable file created by pkg. (This is necessary
 * because of a pkg limitation that does not allow binary executables
 * to be directly executed from inside another binary executable.)
 */
async function buildPkg() {
	const args = [
		'--target',
		'host',
		'--output',
		'build-bin/balena',
		'package.json',
	];
	console.log('=======================================================');
	console.log(`execPkg ${args.join(' ')}`);
	console.log(`cwd="${process.cwd()}" ROOT="${ROOT}"`);
	console.log('=======================================================');

	await execPkg(args);

	const xpaths: Array<[string, string[]]> = [
		// [platform, [path, to, file]]
		['*', ['opn', 'xdg-open']],
		['darwin', ['denymount', 'bin', 'denymount']],
	];
	await Bluebird.map(xpaths, ([platform, xpath]) => {
		if (platform === '*' || platform === process.platform) {
			// eg copy from node_modules/opn/xdg-open to build-bin/xdg-open
			return fs.copy(
				path.join(ROOT, 'node_modules', ...xpath),
				path.join(ROOT, 'build-bin', xpath.pop()!),
			);
		}
	});
	const nativeExtensionPaths: string[] = await filehound
		.create()
		.paths(path.join(ROOT, 'node_modules'))
		.ext(['node', 'dll'])
		.find();

	console.log(`\nCopying to build-bin:\n${nativeExtensionPaths.join('\n')}`);

	await Bluebird.map(nativeExtensionPaths, extPath =>
		fs.copy(
			extPath,
			extPath.replace(
				path.join(ROOT, 'node_modules'),
				path.join(ROOT, 'build-bin'),
			),
		),
	);
}

/**
 * Run some basic tests on the built pkg executable.
 * TODO: test more than just `balena version -j`; integrate with the
 * existing mocha/chai CLI command testing.
 */
async function testPkg() {
	type JsonVersions = import('../lib/actions-oclif/version').JsonVersions;
	const pkgBalenaPath = path.join(
		ROOT,
		'build-bin',
		process.platform === 'win32' ? 'balena.exe' : 'balena',
	);
	console.log(`Testing standalone package "${pkgBalenaPath}"...`);
	// Run `balena version -j`, parse its stdout as JSON, and check that the
	// reported Node.js major version matches semver.major(process.version)
	const stdout = await getSubprocessStdout(pkgBalenaPath, ['version', '-j']);
	let pkgNodeVersion = '';
	let pkgNodeMajorVersion = 0;
	try {
		const balenaVersions: JsonVersions = JSON.parse(stdout);
		pkgNodeVersion = balenaVersions['Node.js'];
		pkgNodeMajorVersion = semver.major(pkgNodeVersion);
	} catch (err) {
		throw new Error(stripIndent`
			Error parsing JSON output of "balena version -j": ${err}
			Original output: "${stdout}"`);
	}
	if (semver.major(process.version) !== pkgNodeMajorVersion) {
		throw new Error(
			`Mismatched major version: built-in pkg Node version="${pkgNodeVersion}" vs process.version="${
				process.version
			}"`,
		);
	}
	console.log('Success! (standalone package test successful)');
}

/**
 * Create the zip file for the standalone 'pkg' bundle previously created
 * by the buildPkg() function in 'build-bin.ts'.
 */
async function zipPkg() {
	const outputFile = standaloneZips[process.platform];
	if (!outputFile) {
		throw new Error(
			`Standalone installer unavailable for platform "${process.platform}"`,
		);
	}
	await fs.mkdirp(path.dirname(outputFile));
	await new Promise((resolve, reject) => {
		console.log(`Zipping standalone package to "${outputFile}"...`);

		const archive = archiver('zip', {
			zlib: { level: 7 },
		});
		archive.directory(path.join(ROOT, 'build-bin'), 'balena-cli');

		const outputStream = fs.createWriteStream(outputFile);

		outputStream.on('close', resolve);
		outputStream.on('error', reject);

		archive.on('error', reject);
		archive.on('warning', console.warn);

		archive.pipe(outputStream);
		archive.finalize();
	});
}

export async function buildStandaloneZip() {
	console.log(`Building standalone zip package for CLI ${version}`);
	try {
		await buildPkg();
		await testPkg();
		await zipPkg();
	} catch (error) {
		console.log(`Error creating or testing standalone zip package:\n ${error}`);
		process.exit(1);
	}
	console.log(`Standalone zip package build completed`);
}

async function renameInstallerFiles() {
	if (await fs.pathExists(oclifInstallers[process.platform])) {
		await fs.rename(
			oclifInstallers[process.platform],
			renamedOclifInstallers[process.platform],
		);
	}
}

/**
 * If the CSC_LINK and CSC_KEY_PASSWORD env vars are set, digitally sign the
 * executable installer by running the balena-io/scripts/shared/sign-exe.sh
 * script (which must be in the PATH) using a MSYS2 bash shell.
 */
async function signWindowsInstaller() {
	if (process.env.CSC_LINK && process.env.CSC_KEY_PASSWORD) {
		const exeName = renamedOclifInstallers[process.platform];
		const execFileAsync = util.promisify<string, string[], void>(execFile);

		console.log(`Signing installer "${exeName}"`);
		await execFileAsync(MSYS2_BASH, [
			'sign-exe.sh',
			'-f',
			exeName,
			'-d',
			`balena-cli ${version}`,
		]);
	} else {
		console.log(
			'Skipping installer signing step because CSC_* env vars are not set',
		);
	}
}

/**
 * Run the `oclif-dev pack:win` or `pack:macos` command (depending on the value
 * of process.platform) to generate the native installers (which end up under
 * the 'dist' folder). There are some harcoded options such as selecting only
 * 64-bit binaries under Windows.
 */
export async function buildOclifInstaller() {
	let packOS = '';
	let packOpts = ['-r', ROOT];
	if (process.platform === 'darwin') {
		packOS = 'macos';
	} else if (process.platform === 'win32') {
		packOS = 'win';
		packOpts = packOpts.concat('-t', 'win32-x64');
	}
	if (packOS) {
		console.log(`Building oclif installer for CLI ${version}`);
		const packCmd = `pack:${packOS}`;
		const dirs = [path.join(ROOT, 'dist', packOS)];
		if (packOS === 'win') {
			dirs.push(path.join(ROOT, 'tmp', 'win*'));
		}
		for (const dir of dirs) {
			console.log(`rimraf(${dir})`);
			await Bluebird.fromCallback(cb => rimraf(dir, cb));
		}
		console.log('=======================================================');
		console.log(`oclif-dev "${packCmd}" "${packOpts.join('" "')}"`);
		console.log(`cwd="${process.cwd()}" ROOT="${ROOT}"`);
		console.log('=======================================================');
		await oclifRun([packCmd].concat(...packOpts));
		await renameInstallerFiles();
		// The Windows installer is explicitly signed here (oclif doesn't do it).
		// The macOS installer is automatically signed by oclif (which runs the
		// `pkgbuild` tool), using the certificate name given in package.json
		// (`oclif.macos.sign` section).
		if (process.platform === 'win32') {
			await signWindowsInstaller();
		}
		console.log(`oclif installer build completed`);
	}
}

/**
 * Convert e.g. 'C:\myfolder' -> '/C/myfolder' so that the path can be given
 * as argument to "unix tools" like 'tar' under MSYS or MSYS2 on Windows.
 */
export function fixPathForMsys(p: string): string {
	return p.replace(/\\/g, '/').replace(/^([a-zA-Z]):/, '/$1');
}

/**
 * Run the executable at execPath as a child process, and resolve a promise
 * to the executable's stdout output as a string. Reject the promise if
 * anything is printed to stderr, or if the child process exits with a
 * non-zero exit code.
 * @param execPath Executable path
 * @param args Command-line argument for the executable
 */
async function getSubprocessStdout(
	execPath: string,
	args: string[],
): Promise<string> {
	const child = spawn(execPath, args);
	return new Promise((resolve, reject) => {
		let stdout = '';
		child.stdout.on('error', reject);
		child.stderr.on('error', reject);
		child.stdout.on('data', (data: Buffer) => {
			try {
				stdout = data.toString();
			} catch (err) {
				reject(err);
			}
		});
		child.stderr.on('data', (data: Buffer) => {
			try {
				const stderr = data.toString();
				reject(new Error(`"${execPath}": non-empty stderr "${stderr}"`));
			} catch (err) {
				reject(err);
			}
		});
		child.on('exit', (code: number) => {
			if (code) {
				reject(new Error(`"${execPath}": non-zero exit code "${code}"`));
			} else {
				resolve(stdout);
			}
		});
	});
}