<?php
/**
 * TJavaScript class file
 *
 * @author Wei Zhuo<weizhuo[at]gmail[dot]com>
 * @link https://github.com/pradosoft/prado
 * @license https://github.com/pradosoft/prado/blob/master/LICENSE
 */

namespace Prado\Web\Javascripts;

use Prado\Web\THttpUtility;
use Prado\Prado;

/**
 * TJavaScript class.
 *
 * TJavaScript is a utility class containing commonly-used javascript-related
 * functions.
 *
 * @author Wei Zhuo<weizhuo[at]gmail[dot]com>
 * @since 3.0
 */
class TJavaScript
{
	/**
	 * Renders a list of javascript files
	 * @param array $files URLs to the javascript files
	 * @return string rendering result
	 */
	public static function renderScriptFiles($files)
	{
		$str = '';
		foreach ($files as $file) {
			$str .= self::renderScriptFile($file);
		}
		return $str;
	}

	/**
	 * Renders a javascript file
	 * @param \Prado\Web\Javascripts\TJavaScriptAsset|string $asset URL to the javascript file or TJavaScriptAsset
	 * @return string rendering result
	 */
	public static function renderScriptFile($asset)
	{
		if (is_object($asset) && ($asset instanceof TJavaScriptAsset)) {
			return $asset->__toString() . "\n";
		}
		return '<script src="' . THttpUtility::htmlEncode($asset) . "\"></script>\n";
	}

	/**
	 * Renders a list of javascript blocks
	 * @param array $scripts javascript blocks
	 * @return string rendering result
	 */
	public static function renderScriptBlocks($scripts)
	{
		if (count($scripts)) {
			return "<script>\n/*<![CDATA[*/\n" . implode("\n", $scripts) . "\n/*]]>*/\n</script>\n";
		} else {
			return '';
		}
	}

	/**
	 * Renders a list of javascript code
	 * @param array $scripts javascript blocks
	 * @return string rendering result
	 */
	public static function renderScriptBlocksCallback($scripts)
	{
		if (count($scripts)) {
			return implode("\n", $scripts) . "\n";
		} else {
			return '';
		}
	}

	/**
	 * Renders javascript block
	 * @param string $script javascript block
	 * @return string rendering result
	 */
	public static function renderScriptBlock($script)
	{
		return "<script>\n/*<![CDATA[*/\n{$script}\n/*]]>*/\n</script>\n";
	}

	/**
	 * Quotes a javascript string.
	 * After processing, the string is safely enclosed within a pair of
	 * quotation marks and can serve as a javascript string.
	 * @param string $js string to be quoted
	 * @return string the quoted string
	 */
	public static function quoteString($js)
	{
		return self::jsonEncode($js, JSON_HEX_QUOT | JSON_HEX_APOS | JSON_HEX_TAG);
	}

	/**
	 * @param mixed $js
	 * @return TJavaScriptLiteral Marks a string as a javascript function. Once marke, the string is considered as a
	 * raw javascript function that is not supposed to be encoded by {@link encode}
	 */
	public static function quoteJsLiteral($js)
	{
		if ($js instanceof TJavaScriptLiteral) {
			return $js;
		} else {
			return new TJavaScriptLiteral($js);
		}
	}

	/**
	 * @param mixed $js
	 * @return bool true if the parameter is marked as a javascript function, i.e. if it's considered as a
	 * raw javascript function that is not supposed to be encoded by {@link encode}
	 */
	public static function isJsLiteral($js)
	{
		return ($js instanceof TJavaScriptLiteral);
	}

	/**
	 * Encodes a PHP variable into javascript representation.
	 *
	 * Example:
	 * <code>
	 * $options['onLoading'] = "doit";
	 * $options['onComplete'] = "more";
	 * echo TJavaScript::encode($options);
	 * //expects the following javascript code
	 * // {'onLoading':'doit','onComplete':'more'}
	 * </code>
	 *
	 * For higher complexity data structures use {@link jsonEncode} and {@link jsonDecode}
	 * to serialize and unserialize.
	 *
	 * @param mixed $value PHP variable to be encoded
	 * @param bool $toMap whether the output is a map or a list.
	 * @since 3.1.5
	 * @param bool $encodeEmptyStrings wether to encode empty strings too. Default to false for BC.
	 * @return string the encoded string
	 */
	public static function encode($value, $toMap = true, $encodeEmptyStrings = false)
	{
		if (is_string($value)) {
			return self::quoteString($value);
		} elseif (is_bool($value)) {
			return $value ? 'true' : 'false';
		} elseif (is_array($value)) {
			$results = '';
			if (($n = count($value)) > 0 && array_keys($value) !== range(0, $n - 1)) {
				foreach ($value as $k => $v) {
					if ($v !== '' || $encodeEmptyStrings) {
						if ($results !== '') {
							$results .= ',';
						}
						$results .= "'$k':" . self::encode($v, $toMap, $encodeEmptyStrings);
					}
				}
				return '{' . $results . '}';
			} else {
				foreach ($value as $v) {
					if ($v !== '' || $encodeEmptyStrings) {
						if ($results !== '') {
							$results .= ',';
						}
						$results .= self::encode($v, $toMap, $encodeEmptyStrings);
					}
				}
				return '[' . $results . ']';
			}
		} elseif (is_int($value)) {
			return "$value";
		} elseif (is_float($value)) {
			switch ($value) {
				case -INF:
					return 'Number.NEGATIVE_INFINITY';
					break;
				case INF:
					return 'Number.POSITIVE_INFINITY';
					break;
				default:
					$locale = localeConv();
					if ($locale['decimal_point'] == '.') {
						return "$value";
					} else {
						return str_replace($locale['decimal_point'], '.', "$value");
					}
					break;
			}
		} elseif (is_object($value)) {
			if ($value instanceof TJavaScriptLiteral) {
				return $value->toJavaScriptLiteral();
			} else {
				return self::encode(get_object_vars($value), $toMap);
			}
		} elseif ($value === null) {
			return 'null';
		} else {
			return '';
		}
	}
	/**
	 * Encodes a PHP variable into javascript string.
	 * This method invokes json_encode to perform the encoding.
	 * @param mixed $value variable to be encoded
	 * @param mixed $options
	 * @return string encoded string
	 */
	public static function jsonEncode($value, $options = 0)
	{
		if (($g = Prado::getApplication()->getGlobalization(false)) !== null &&
			strtoupper($enc = $g->getCharset()) != 'UTF-8') {
			self::convertToUtf8($value, $enc);
		}

		$s = @json_encode($value, $options);
		self::checkJsonError();
		return $s;
	}

	/**
	 * Encodes an string or the content of an array to UTF8
	 * @param array|mixed|string $value
	 * @param string $sourceEncoding
	 */
	private static function convertToUtf8(&$value, $sourceEncoding)
	{
		if (is_string($value)) {
			$value = iconv($sourceEncoding, 'UTF-8', $value);
		} elseif (is_array($value)) {
			foreach ($value as &$element) {
				self::convertToUtf8($element, $sourceEncoding);
			}
		}
	}

	/**
	 * Decodes a javascript string into PHP variable.
	 * This method invokes json_decode to perform the decoding.
	 * @param string $value string to be decoded
	 * @param bool $assoc whether to convert returned objects to associative arrays
	 * @param int $depth recursion depth
	 * @return mixed decoded variable
	 */
	public static function jsonDecode($value, $assoc = false, $depth = 512)
	{
		$s = @json_decode($value, $assoc, $depth);
		self::checkJsonError();
		return $s;
	}

	private static function checkJsonError()
	{
		switch ($err = json_last_error()) {
			case JSON_ERROR_NONE:
				return;
				break;
			case JSON_ERROR_DEPTH:
				$msg = 'Maximum stack depth exceeded';
				break;
			case JSON_ERROR_STATE_MISMATCH:
				$msg = 'Underflow or the modes mismatch';
				break;
			case JSON_ERROR_CTRL_CHAR:
				$msg = 'Unexpected control character found';
				break;
			case JSON_ERROR_SYNTAX:
				$msg = 'Syntax error, malformed JSON';
				break;
			case JSON_ERROR_UTF8:
				$msg = 'Malformed UTF-8 characters, possibly incorrectly encoded';
				break;
			default:
				$msg = 'Unknown error';
				break;
		}
		throw new \Exception("JSON error ($err): $msg");
	}

	/**
	 * Minimize the size of a javascript script.
	 * This method is based on Douglas Crockford's JSMin.
	 * @param string $code code that you want to minimzie
	 * @return string minimized version of the code
	 */
	public static function JSMin($code)
	{
		return \JSMin\JSMin::minify($code);
	}
}