<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\console\controllers;

use Yii;
use yii\console\Exception;
use yii\console\Controller;

/**
 * This command allows you to combine and compress your JavaScript and CSS files.
 *
 * Usage:
 * 1. Create a configuration file using 'template' action:
 *    yii asset/template /path/to/myapp/config.php
 * 2. Edit the created config file, adjusting it for your web application needs.
 * 3. Run the 'compress' action, using created config:
 *    yii asset /path/to/myapp/config.php /path/to/myapp/config/assets_compressed.php
 * 4. Adjust your web application config to use compressed assets.
 *
 * Note: in the console environment some path aliases like '@webroot' and '@web' may not exist,
 * so corresponding paths inside the configuration should be specified directly.
 *
 * Note: by default this command relies on an external tools to perform actual files compression,
 * check [[jsCompressor]] and [[cssCompressor]] for more details.
 *
 * @property \yii\web\AssetManager $assetManager Asset manager instance. Note that the type of this property
 * differs in getter and setter. See [[getAssetManager()]] and [[setAssetManager()]] for details.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0
 */
class AssetController extends Controller
{
	/**
	 * @var string controller default action ID.
	 */
	public $defaultAction = 'compress';
	/**
	 * @var array list of asset bundles to be compressed.
	 */
	public $bundles = [];
	/**
	 * @var array list of asset bundles, which represents output compressed files.
	 * You can specify the name of the output compressed file using 'css' and 'js' keys:
	 * For example:
	 *
	 * ~~~
	 * 'app\config\AllAsset' => [
	 *     'js' => 'js/all-{ts}.js',
	 *     'css' => 'css/all-{ts}.css',
	 *     'depends' => [ ... ],
	 * ]
	 * ~~~
	 *
	 * File names can contain placeholder "{ts}", which will be filled by current timestamp, while
	 * file creation.
	 */
	public $targets = [];
	/**
	 * @var string|callback JavaScript file compressor.
	 * If a string, it is treated as shell command template, which should contain
	 * placeholders {from} - source file name - and {to} - output file name.
	 * Otherwise, it is treated as PHP callback, which should perform the compression.
	 *
	 * Default value relies on usage of "Closure Compiler"
	 * @see https://developers.google.com/closure/compiler/
	 */
	public $jsCompressor = 'java -jar compiler.jar --js {from} --js_output_file {to}';
	/**
	 * @var string|callback CSS file compressor.
	 * If a string, it is treated as shell command template, which should contain
	 * placeholders {from} - source file name - and {to} - output file name.
	 * Otherwise, it is treated as PHP callback, which should perform the compression.
	 *
	 * Default value relies on usage of "YUI Compressor"
	 * @see https://github.com/yui/yuicompressor/
	 */
	public $cssCompressor = 'java -jar yuicompressor.jar {from} -o {to}';

	/**
	 * @var array|\yii\web\AssetManager [[yii\web\AssetManager]] instance or its array configuration, which will be used
	 * for assets processing.
	 */
	private $_assetManager = [];

	/**
	 * Returns the asset manager instance.
	 * @throws \yii\console\Exception on invalid configuration.
	 * @return \yii\web\AssetManager asset manager instance.
	 */
	public function getAssetManager()
	{
		if (!is_object($this->_assetManager)) {
			$options = $this->_assetManager;
			if (!isset($options['class'])) {
				$options['class'] = 'yii\\web\\AssetManager';
			}
			if (!isset($options['basePath'])) {
				throw new Exception("Please specify 'basePath' for the 'assetManager' option.");
			}
			if (!isset($options['baseUrl'])) {
				throw new Exception("Please specify 'baseUrl' for the 'assetManager' option.");
			}
			$this->_assetManager = Yii::createObject($options);
		}
		return $this->_assetManager;
	}

	/**
	 * Sets asset manager instance or configuration.
	 * @param \yii\web\AssetManager|array $assetManager asset manager instance or its array configuration.
	 * @throws \yii\console\Exception on invalid argument type.
	 */
	public function setAssetManager($assetManager)
	{
		if (is_scalar($assetManager)) {
			throw new Exception('"' . get_class($this) . '::assetManager" should be either object or array - "' . gettype($assetManager) . '" given.');
		}
		$this->_assetManager = $assetManager;
	}

	/**
	 * Combines and compresses the asset files according to the given configuration.
	 * During the process new asset bundle configuration file will be created.
	 * You should replace your original asset bundle configuration with this file in order to use compressed files.
	 * @param string $configFile configuration file name.
	 * @param string $bundleFile output asset bundles configuration file name.
	 */
	public function actionCompress($configFile, $bundleFile)
	{
		$this->loadConfiguration($configFile);
		$bundles = $this->loadBundles($this->bundles);
		$targets = $this->loadTargets($this->targets, $bundles);
		$timestamp = time();
		foreach ($targets as $name => $target) {
			echo "Creating output bundle '{$name}':\n";
			if (!empty($target->js)) {
				$this->buildTarget($target, 'js', $bundles, $timestamp);
			}
			if (!empty($target->css)) {
				$this->buildTarget($target, 'css', $bundles, $timestamp);
			}
			echo "\n";
		}

		$targets = $this->adjustDependency($targets, $bundles);
		$this->saveTargets($targets, $bundleFile);
	}

	/**
	 * Applies configuration from the given file to self instance.
	 * @param string $configFile configuration file name.
	 * @throws \yii\console\Exception on failure.
	 */
	protected function loadConfiguration($configFile)
	{
		echo "Loading configuration from '{$configFile}'...\n";
		foreach (require($configFile) as $name => $value) {
			if (property_exists($this, $name) || $this->canSetProperty($name)) {
				$this->$name = $value;
			} else {
				throw new Exception("Unknown configuration option: $name");
			}
		}

		$this->getAssetManager(); // check if asset manager configuration is correct
	}

	/**
	 * Creates full list of source asset bundles.
	 * @param string[] $bundles list of asset bundle names
	 * @return \yii\web\AssetBundle[] list of source asset bundles.
	 */
	protected function loadBundles($bundles)
	{
		echo "Collecting source bundles information...\n";

		$am = $this->getAssetManager();
		$result = [];
		foreach ($bundles as $name) {
			$result[$name] = $am->getBundle($name);
		}
		foreach ($result as $bundle) {
			$this->loadDependency($bundle, $result);
		}

		return $result;
	}

	/**
	 * Loads asset bundle dependencies recursively.
	 * @param \yii\web\AssetBundle $bundle bundle instance
	 * @param array $result already loaded bundles list.
	 * @throws Exception on failure.
	 */
	protected function loadDependency($bundle, &$result)
	{
		$am = $this->getAssetManager();
		foreach ($bundle->depends as $name) {
			if (!isset($result[$name])) {
				$dependencyBundle = $am->getBundle($name);
				$result[$name] = false;
				$this->loadDependency($dependencyBundle, $result);
				$result[$name] = $dependencyBundle;
			} elseif ($result[$name] === false) {
				throw new Exception("A circular dependency is detected for bundle '$name'.");
			}
		}
	}

	/**
	 * Creates full list of output asset bundles.
	 * @param array $targets output asset bundles configuration.
	 * @param \yii\web\AssetBundle[] $bundles list of source asset bundles.
	 * @return \yii\web\AssetBundle[] list of output asset bundles.
	 * @throws Exception on failure.
	 */
	protected function loadTargets($targets, $bundles)
	{
		// build the dependency order of bundles
		$registered = [];
		foreach ($bundles as $name => $bundle) {
			$this->registerBundle($bundles, $name, $registered);
		}
		$bundleOrders = array_combine(array_keys($registered), range(0, count($bundles) - 1));

		// fill up the target which has empty 'depends'.
		$referenced = [];
		foreach ($targets as $name => $target) {
			if (empty($target['depends'])) {
				if (!isset($all)) {
					$all = $name;
				} else {
					throw new Exception("Only one target can have empty 'depends' option. Found two now: $all, $name");
				}
			} else {
				foreach ($target['depends'] as $bundle) {
					if (!isset($referenced[$bundle])) {
						$referenced[$bundle] = $name;
					} else {
						throw new Exception("Target '{$referenced[$bundle]}' and '$name' cannot contain the bundle '$bundle' at the same time.");
					}
				}
			}
		}
		if (isset($all)) {
			$targets[$all]['depends'] = array_diff(array_keys($registered), array_keys($referenced));
		}

		// adjust the 'depends' order for each target according to the dependency order of bundles
		// create an AssetBundle object for each target
		foreach ($targets as $name => $target) {
			if (!isset($target['basePath'])) {
				throw new Exception("Please specify 'basePath' for the '$name' target.");
			}
			if (!isset($target['baseUrl'])) {
				throw new Exception("Please specify 'baseUrl' for the '$name' target.");
			}
			usort($target['depends'], function ($a, $b) use ($bundleOrders) {
				if ($bundleOrders[$a] == $bundleOrders[$b]) {
					return 0;
				} else {
					return $bundleOrders[$a] > $bundleOrders[$b] ? 1 : -1;
				}
			});
			$target['class'] = $name;
			$targets[$name] = Yii::createObject($target);
		}
		return $targets;
	}

	/**
	 * Builds output asset bundle.
	 * @param \yii\web\AssetBundle $target output asset bundle
	 * @param string $type either 'js' or 'css'.
	 * @param \yii\web\AssetBundle[] $bundles source asset bundles.
	 * @param integer $timestamp current timestamp.
	 * @throws Exception on failure.
	 */
	protected function buildTarget($target, $type, $bundles, $timestamp)
	{
		$outputFile = strtr($target->$type, [
			'{ts}' => $timestamp,
		]);
		$inputFiles = [];

		foreach ($target->depends as $name) {
			if (isset($bundles[$name])) {
				foreach ($bundles[$name]->$type as $file) {
					$inputFiles[] = $bundles[$name]->basePath . '/' . $file;
				}
			} else {
				throw new Exception("Unknown bundle: '{$name}'");
			}
		}
		if ($type === 'js') {
			$this->compressJsFiles($inputFiles, $target->basePath . '/' . $outputFile);
		} else {
			$this->compressCssFiles($inputFiles, $target->basePath . '/' . $outputFile);
		}
		$target->$type = [$outputFile];
	}

	/**
	 * Adjust dependencies between asset bundles in the way source bundles begin to depend on output ones.
	 * @param \yii\web\AssetBundle[] $targets output asset bundles.
	 * @param \yii\web\AssetBundle[] $bundles source asset bundles.
	 * @return \yii\web\AssetBundle[] output asset bundles.
	 */
	protected function adjustDependency($targets, $bundles)
	{
		echo "Creating new bundle configuration...\n";

		$map = [];
		foreach ($targets as $name => $target) {
			foreach ($target->depends as $bundle) {
				$map[$bundle] = $name;
			}
		}

		foreach ($targets as $name => $target) {
			$depends = [];
			foreach ($target->depends as $bn) {
				foreach ($bundles[$bn]->depends as $bundle) {
					$depends[$map[$bundle]] = true;
				}
			}
			unset($depends[$name]);
			$target->depends = array_keys($depends);
		}

		// detect possible circular dependencies
		foreach ($targets as $name => $target) {
			$registered = [];
			$this->registerBundle($targets, $name, $registered);
		}

		foreach ($map as $bundle => $target) {
			$targets[$bundle] = Yii::createObject([
				'class' => 'yii\\web\\AssetBundle',
				'depends' => [$target],
			]);
		}
		return $targets;
	}

	/**
	 * Registers asset bundles including their dependencies.
	 * @param \yii\web\AssetBundle[] $bundles asset bundles list.
	 * @param string $name bundle name.
	 * @param array $registered stores already registered names.
	 * @throws Exception if circular dependency is detected.
	 */
	protected function registerBundle($bundles, $name, &$registered)
	{
		if (!isset($registered[$name])) {
			$registered[$name] = false;
			$bundle = $bundles[$name];
			foreach ($bundle->depends as $depend) {
				$this->registerBundle($bundles, $depend, $registered);
			}
			unset($registered[$name]);
			$registered[$name] = true;
		} elseif ($registered[$name] === false) {
			throw new Exception("A circular dependency is detected for target '$name'.");
		}
	}

	/**
	 * Saves new asset bundles configuration.
	 * @param \yii\web\AssetBundle[] $targets list of asset bundles to be saved.
	 * @param string $bundleFile output file name.
	 * @throws \yii\console\Exception on failure.
	 */
	protected function saveTargets($targets, $bundleFile)
	{
		$array = [];
		foreach ($targets as $name => $target) {
			foreach (['js', 'css', 'depends', 'basePath', 'baseUrl'] as $prop) {
				if (!empty($target->$prop)) {
					$array[$name][$prop] = $target->$prop;
				}
			}
		}
		$array = var_export($array, true);
		$version = date('Y-m-d H:i:s', time());
		$bundleFileContent = <<<EOD
<?php
/**
 * This file is generated by the "yii {$this->id}" command.
 * DO NOT MODIFY THIS FILE DIRECTLY.
 * @version {$version}
 */
return {$array};
EOD;
		if (!file_put_contents($bundleFile, $bundleFileContent)) {
			throw new Exception("Unable to write output bundle configuration at '{$bundleFile}'.");
		}
		echo "Output bundle configuration created at '{$bundleFile}'.\n";
	}

	/**
	 * Compresses given JavaScript files and combines them into the single one.
	 * @param array $inputFiles list of source file names.
	 * @param string $outputFile output file name.
	 * @throws \yii\console\Exception on failure
	 */
	protected function compressJsFiles($inputFiles, $outputFile)
	{
		if (empty($inputFiles)) {
			return;
		}
		echo "  Compressing JavaScript files...\n";
		if (is_string($this->jsCompressor)) {
			$tmpFile = $outputFile . '.tmp';
			$this->combineJsFiles($inputFiles, $tmpFile);
			echo shell_exec(strtr($this->jsCompressor, [
				'{from}' => escapeshellarg($tmpFile),
				'{to}' => escapeshellarg($outputFile),
			]));
			@unlink($tmpFile);
		} else {
			call_user_func($this->jsCompressor, $this, $inputFiles, $outputFile);
		}
		if (!file_exists($outputFile)) {
			throw new Exception("Unable to compress JavaScript files into '{$outputFile}'.");
		}
		echo "  JavaScript files compressed into '{$outputFile}'.\n";
	}

	/**
	 * Compresses given CSS files and combines them into the single one.
	 * @param array $inputFiles list of source file names.
	 * @param string $outputFile output file name.
	 * @throws \yii\console\Exception on failure
	 */
	protected function compressCssFiles($inputFiles, $outputFile)
	{
		if (empty($inputFiles)) {
			return;
		}
		echo "  Compressing CSS files...\n";
		if (is_string($this->cssCompressor)) {
			$tmpFile = $outputFile . '.tmp';
			$this->combineCssFiles($inputFiles, $tmpFile);
			echo shell_exec(strtr($this->cssCompressor, [
				'{from}' => escapeshellarg($tmpFile),
				'{to}' => escapeshellarg($outputFile),
			]));
			@unlink($tmpFile);
		} else {
			call_user_func($this->cssCompressor, $this, $inputFiles, $outputFile);
		}
		if (!file_exists($outputFile)) {
			throw new Exception("Unable to compress CSS files into '{$outputFile}'.");
		}
		echo "  CSS files compressed into '{$outputFile}'.\n";
	}

	/**
	 * Combines JavaScript files into a single one.
	 * @param array $inputFiles source file names.
	 * @param string $outputFile output file name.
	 * @throws \yii\console\Exception on failure.
	 */
	public function combineJsFiles($inputFiles, $outputFile)
	{
		$content = '';
		foreach ($inputFiles as $file) {
			$content .= "/*** BEGIN FILE: $file ***/\n"
				. file_get_contents($file)
				. "/*** END FILE: $file ***/\n";
		}
		if (!file_put_contents($outputFile, $content)) {
			throw new Exception("Unable to write output JavaScript file '{$outputFile}'.");
		}
	}

	/**
	 * Combines CSS files into a single one.
	 * @param array $inputFiles source file names.
	 * @param string $outputFile output file name.
	 * @throws \yii\console\Exception on failure.
	 */
	public function combineCssFiles($inputFiles, $outputFile)
	{
		$content = '';
		foreach ($inputFiles as $file) {
			$content .= "/*** BEGIN FILE: $file ***/\n"
				. $this->adjustCssUrl(file_get_contents($file), dirname($file), dirname($outputFile))
				. "/*** END FILE: $file ***/\n";
		}
		if (!file_put_contents($outputFile, $content)) {
			throw new Exception("Unable to write output CSS file '{$outputFile}'.");
		}
	}

	/**
	 * Adjusts CSS content allowing URL references pointing to the original resources.
	 * @param string $cssContent source CSS content.
	 * @param string $inputFilePath input CSS file name.
	 * @param string $outputFilePath output CSS file name.
	 * @return string adjusted CSS content.
	 */
	protected function adjustCssUrl($cssContent, $inputFilePath, $outputFilePath)
	{
		$sharedPathParts = [];
		$inputFilePathParts = explode('/', $inputFilePath);
		$inputFilePathPartsCount = count($inputFilePathParts);
		$outputFilePathParts = explode('/', $outputFilePath);
		$outputFilePathPartsCount = count($outputFilePathParts);
		for ($i =0; $i < $inputFilePathPartsCount && $i < $outputFilePathPartsCount; $i++) {
			if ($inputFilePathParts[$i] == $outputFilePathParts[$i]) {
				$sharedPathParts[] = $inputFilePathParts[$i];
			} else {
				break;
			}
		}
		$sharedPath = implode('/', $sharedPathParts);

		$inputFileRelativePath = trim(str_replace($sharedPath, '', $inputFilePath), '/');
		$outputFileRelativePath = trim(str_replace($sharedPath, '', $outputFilePath), '/');
		$inputFileRelativePathParts = explode('/', $inputFileRelativePath);
		$outputFileRelativePathParts = explode('/', $outputFileRelativePath);

		$callback = function ($matches) use ($inputFileRelativePathParts, $outputFileRelativePathParts) {
			$fullMatch = $matches[0];
			$inputUrl = $matches[1];

			if (preg_match('/https?:\/\//is', $inputUrl)) {
				return $fullMatch;
			}

			$outputUrlParts = array_fill(0, count($outputFileRelativePathParts), '..');
			$outputUrlParts = array_merge($outputUrlParts, $inputFileRelativePathParts);

			if (strpos($inputUrl, '/') !== false) {
				$inputUrlParts = explode('/', $inputUrl);
				foreach ($inputUrlParts as $key => $inputUrlPart) {
					if ($inputUrlPart == '..') {
						array_pop($outputUrlParts);
						unset($inputUrlParts[$key]);
					}
				}
				$outputUrlParts[] = implode('/', $inputUrlParts);
			} else {
				$outputUrlParts[] = $inputUrl;
			}
			$outputUrl = implode('/', $outputUrlParts);

			return str_replace($inputUrl, $outputUrl, $fullMatch);
		};

		$cssContent = preg_replace_callback('/url\(["\']?([^"]*)["\']?\)/is', $callback, $cssContent);

		return $cssContent;
	}

	/**
	 * Creates template of configuration file for [[actionCompress]].
	 * @param string $configFile output file name.
	 * @throws \yii\console\Exception on failure.
	 */
	public function actionTemplate($configFile)
	{
		$template = <<<EOD
<?php
/**
 * Configuration file for the "yii asset" console command.
 * Note that in the console environment, some path aliases like '@webroot' and '@web' may not exist.
 * Please define these missing path aliases.
 */
return [
	// The list of asset bundles to compress:
	'bundles' => [
		// 'yii\web\YiiAsset',
		// 'yii\web\JqueryAsset',
	],
	// Asset bundle for compression output:
	'targets' => [
		'app\config\AllAsset' => [
			'basePath' => 'path/to/web',
			'baseUrl' => '',
			'js' => 'js/all-{ts}.js',
			'css' => 'css/all-{ts}.css',
		],
	],
	// Asset manager configuration:
	'assetManager' => [
		'basePath' => __DIR__,
		'baseUrl' => '',
	],
);
EOD;
		if (file_exists($configFile)) {
			if (!$this->confirm("File '{$configFile}' already exists. Do you wish to overwrite it?")) {
				return;
			}
		}
		if (!file_put_contents($configFile, $template)) {
			throw new Exception("Unable to write template file '{$configFile}'.");
		} else {
			echo "Configuration file template created at '{$configFile}'.\n\n";
		}
	}
}