<?php

namespace Luracast\Restler;

use Exception;
use Luracast\Restler\Data\Text;

/**
 * Parses the PHPDoc comments for metadata. Inspired by `Documentor` code base.
 *
 * @category   Framework
 * @package    Restler
 * @subpackage Helper
 * @author     R.Arul Kumaran <arul@luracast.com>
 * @copyright  2010 Luracast
 * @license    http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link       http://luracast.com/products/restler/
 *
 */
class CommentParser
{
	/**
	 * name for the embedded data
	 *
	 * @var string
	 */
	public static $embeddedDataName = 'properties';
	/**
	 * Regular Expression pattern for finding the embedded data and extract
	 * the inner information. It is used with preg_match.
	 *
	 * @var string
	 */
	public static $embeddedDataPattern
		= '/```(\w*)[\s]*(([^`]*`{0,2}[^`]+)*)```/ms';
	/**
	 * Pattern will have groups for the inner details of embedded data
	 * this index is used to locate the data portion.
	 *
	 * @var int
	 */
	public static $embeddedDataIndex = 2;
	/**
	 * Delimiter used to split the array data.
	 *
	 * When the name portion is of the embedded data is blank auto detection
	 * will be used and if URLEncodedFormat is detected as the data format
	 * the character specified will be used as the delimiter to find split
	 * array data.
	 *
	 * @var string
	 */
	public static $arrayDelimiter = ',';

	/**
	 * @var array annotations that support array value
	 */
	public static $allowsArrayValue = array(
		'choice'     => true,
		'select'     => true,
		'properties' => true,
	);

	/**
	 * character sequence used to escape \@
	 */
	const escapedAtChar = '\\@';

	/**
	 * character sequence used to escape end of comment
	 */
	const escapedCommendEnd = '{@*}';

	/**
	 * Instance of Restler class injected at runtime.
	 *
	 * @var Restler
	 */
	public $restler;
	/**
	 * Comment information is parsed and stored in to this array.
	 *
	 * @var array
	 */
	private $_data = array();

	/**
	 * Parse the comment and extract the data.
	 *
	 * @static
	 *
	 * @param      $comment
	 * @param bool $isPhpDoc
	 *
	 * @return array associative array with the extracted values
	 */
	public static function parse($comment, $isPhpDoc = true)
	{
		$p = new self();
		if (empty($comment)) {
			return $p->_data;
		}

		if ($isPhpDoc) {
			$comment = self::removeCommentTags($comment);
		}

		$p->extractData($comment);
		return $p->_data;
	}

	/**
	 * Removes the comment tags from each line of the comment.
	 *
	 * @static
	 *
	 * @param string $comment PhpDoc style comment
	 *
	 * @return string comments with out the tags
	 */
	public static function removeCommentTags($comment)
	{
		$pattern = '/(^\/\*\*)|(^\s*\**[ \/]?)|\s(?=@)|\s\*\//m';
		return preg_replace($pattern, '', $comment);
	}

	/**
	 * Extracts description and long description, uses other methods to get
	 * parameters.
	 *
	 * @param $comment
	 *
	 * @return array
	 */
	private function extractData($comment)
	{
		//to use @ as part of comment we need to
		$comment = str_replace(
			array(self::escapedCommendEnd, self::escapedAtChar),
			array('*/', '@'),
			$comment);

		$description = array();
		$longDescription = array();
		$params = array();

		$mode = 0; // extract short description;
		$comments = preg_split("/(\r?\n)/", $comment);
		// remove first blank line;
		array_shift($comments);
		$addNewline = false;
		foreach ($comments as $line) {
			$line = trim($line);
			$newParam = false;
			if (empty($line)) {
				if ($mode == 0) {
					$mode++;
				} else {
					$addNewline = true;
				}
				continue;
			} elseif ($line[0] == '@') {
				$mode = 2;
				$newParam = true;
			}
			switch ($mode) {
				case 0 :
					$description[] = $line;
					if (count($description) > 3) {
						// if more than 3 lines take only first line
						$longDescription = $description;
						$description[] = array_shift($longDescription);
						$mode = 1;
					} elseif (substr($line, -1) == '.') {
						$mode = 1;
					}
					break;
				case 1 :
					if ($addNewline) {
						$line = ' ' . $line;
					}
					$longDescription[] = $line;
					break;
				case 2 :
					$newParam
						? $params[] = $line
						: $params[count($params) - 1] .= ' ' . $line;
			}
			$addNewline = false;
		}
		$description = implode(' ', $description);
		$longDescription = implode(' ', $longDescription);
		$description = preg_replace('/\s+/msu', ' ', $description);
		$longDescription = preg_replace('/\s+/msu', ' ', $longDescription);
		list($description, $d1)
			= $this->parseEmbeddedData($description);
		list($longDescription, $d2)
			= $this->parseEmbeddedData($longDescription);
		$this->_data = compact('description', 'longDescription');
		$d2 += $d1;
		if (!empty($d2)) {
			$this->_data[self::$embeddedDataName] = $d2;
		}
		foreach ($params as $key => $line) {
			list(, $param, $value) = preg_split('/\@|\s/', $line, 3)
			+ array('', '', '');
			list($value, $embedded) = $this->parseEmbeddedData($value);
			$value = array_filter(preg_split('/\s+/msu', $value), 'strlen');
			$this->parseParam($param, $value, $embedded);
		}
		return $this->_data;
	}

	/**
	 * Parse parameters that begin with (at)
	 *
	 * @param       $param
	 * @param array $value
	 * @param array $embedded
	 */
	private function parseParam($param, array $value, array $embedded)
	{
		$data = &$this->_data;
		$allowMultiple = false;
		switch ($param) {
			case 'param' :
			case 'property' :
			case 'property-read' :
			case 'property-write' :
				$value = $this->formatParam($value);
				$allowMultiple = true;
				break;
			case 'var' :
				$value = $this->formatVar($value);
				break;
			case 'return' :
				$value = $this->formatReturn($value);
				break;
			case 'class' :
				$data = &$data[$param];
				list ($param, $value) = $this->formatClass($value);
				break;
			case 'access' :
				$value = reset($value);
				break;
			case 'expires' :
			case 'status' :
				$value = intval(reset($value));
				break;
			case 'throws' :
				$value = $this->formatThrows($value);
				$allowMultiple = true;
				break;
			case 'author':
				$value = $this->formatAuthor($value);
				$allowMultiple = true;
				break;
			case 'header' :
			case 'link':
			case 'example':
			case 'todo':
				$allowMultiple = true;
				//don't break, continue with code for default:
			default :
				$value = implode(' ', $value);
		}
		if (!empty($embedded)) {
			if (is_string($value)) {
				$value = array('description' => $value);
			}
			$value[self::$embeddedDataName] = $embedded;
		}
		if (empty($data[$param])) {
			if ($allowMultiple) {
				$data[$param] = array(
					$value
				);
			} else {
				$data[$param] = $value;
			}
		} elseif ($allowMultiple) {
			$data[$param][] = $value;
		} elseif ($param == 'param') {
			$arr = array(
				$data[$param],
				$value
			);
			$data[$param] = $arr;
		} else {
			if (!is_string($value) && isset($value[self::$embeddedDataName])
				&& isset($data[$param][self::$embeddedDataName])
			) {
				$value[self::$embeddedDataName]
					+= $data[$param][self::$embeddedDataName];
			}
			if (!is_array($data[$param])) {
				$data[$param] = array('description' => (string) $data[$param]);
			}
			if (is_array($value)) {
				$data[$param] = $value + $data[$param];
			}
		}
	}

	/**
	 * Parses the inline php doc comments and embedded data.
	 *
	 * @param $subject
	 *
	 * @return array
	 * @throws Exception
	 */
	private function parseEmbeddedData($subject)
	{
		$data = array();

		//parse {@pattern } tags specially
		while (preg_match('|(?s-m)({@pattern (/.+/[imsxuADSUXJ]*)})|', $subject, $matches)) {
			$subject = str_replace($matches[0], '', $subject);
			$data['pattern'] = $matches[2];
		}
		while (preg_match('/{@(\w+)\s?([^}]*)}/ms', $subject, $matches)) {
			$name = $matches[1];
			$value = $matches[2];
			$subject = str_replace($matches[0], '', $subject);
			if ($name == 'pattern') {
				throw new Exception('Inline pattern tag should follow {@pattern /REGEX_PATTERN_HERE/} format and can optionally include PCRE modifiers following the ending `/`');
			} elseif (isset(static::$allowsArrayValue[$name])) {
				$value = explode(static::$arrayDelimiter, $value);
			} elseif ($value == 'true' || $value == 'false') {
				$value = $value == 'true';
			} elseif ($value == '') {
				$value = true;
			} elseif ($name == 'required') {
				$value = explode(static::$arrayDelimiter, $value);
			}
			if (defined('Luracast\\Restler\\UI\\HtmlForm::'.$name)) {
				$value = constant($value);
			}
			$data[$name] = $value;
		}

		while (preg_match(self::$embeddedDataPattern, $subject, $matches)) {
			$subject = str_replace($matches[0], '', $subject);
			$str = $matches[self::$embeddedDataIndex];
			if (isset($this->restler)
				&& self::$embeddedDataIndex > 1
				&& !empty($name)
			) {
				$extension = $name;
				$formatMap = $this->restler->getFormatMap();
				if (isset($formatMap[$extension])) {
					/**
					 * @var \Luracast\Restler\Format\iFormat
					 */
					$format = $formatMap[$extension];
					$format = new $format();
					$data = $format->decode($str);
				}
			} else { // auto detect
				if ($str[0] == '{') {
					$d = json_decode($str, true);
					if (json_last_error() != JSON_ERROR_NONE) {
						throw new Exception('Error parsing embedded JSON data'
							. " $str");
					}
					$data = $d + $data;
				} else {
					parse_str($str, $d);
					//clean up
					$d = array_filter($d);
					foreach ($d as $key => $val) {
						$kt = trim($key);
						if ($kt != $key) {
							unset($d[$key]);
							$key = $kt;
							$d[$key] = $val;
						}
						if (is_string($val)) {
							if ($val == 'true' || $val == 'false') {
								$d[$key] = $val == 'true' ? true : false;
							} else {
								$val = explode(self::$arrayDelimiter, $val);
								if (count($val) > 1) {
									$d[$key] = $val;
								} else {
									$d[$key] =
										preg_replace('/\s+/msu', ' ',
											$d[$key]);
								}
							}
						}
					}
					$data = $d + $data;
				}
			}
		}
		return array($subject, $data);
	}

	private function formatThrows(array $value)
	{
		$code = 500;
		$exception = 'Exception';
		if (count($value) > 1) {
			$v1 = empty($value[0]) ? null : $value[0];
			$v2 = empty($value[1]) ? null : $value[1];
			if (is_numeric($v1)) {
				$code = $v1;
				$exception = $v2;
				array_shift($value);
				array_shift($value);
			} elseif (is_numeric($v2)) {
				$code = $v2;
				$exception = $v1;
				array_shift($value);
				array_shift($value);
			} else {
				$exception = $v1;
				array_shift($value);
			}
		} elseif (count($value) && isset($value[0]) && is_numeric($value[0])) {
			$code = $value[0];
			array_shift($value);
		}
		$message = implode(' ', $value);
		if (!isset(RestException::$codes[$code])) {
			$code = 500;
		} elseif (empty($message)) {
			$message = RestException::$codes[$code];
		}
		return compact('code', 'message', 'exception');
	}

	private function formatClass(array $value)
	{
		$param = array_shift($value);

		if (empty($param)) {
			$param = 'Unknown';
		}
		$value = implode(' ', $value);
		return array(
			ltrim($param, '\\'),
			array('description' => $value)
		);
	}

	private function formatAuthor(array $value)
	{
		$r = array();
		$email = end($value);
		if ($email[0] == '<') {
			$email = substr($email, 1, -1);
			array_pop($value);
			$r['email'] = $email;
		}
		$r['name'] = implode(' ', $value);
		return $r;
	}

	private function formatReturn(array $value)
	{
		$data = explode('|', array_shift($value));
		$r = array(
			'type' => count($data) == 1 ? $data[0] : $data
		);
		$r['description'] = implode(' ', $value);
		return $r;
	}

	private function formatParam(array $value)
	{
		$r = array();
		$data = array_shift($value);
		if (empty($data)) {
			$r['type'] = 'mixed';
		} elseif ($data[0] == '$') {
			$r['name'] = substr($data, 1);
			$r['type'] = 'mixed';
		} else {
			$data = explode('|', $data);
			$r['type'] = count($data) == 1 ? $data[0] : $data;

			$data = array_shift($value);
			if (!empty($data) && $data[0] == '$') {
				$r['name'] = substr($data, 1);
			}
		}
		if (isset($r['type']) && is_string($r['type']) && Text::endsWith($r['type'], '[]')) {
			$r[static::$embeddedDataName]['type'] = substr($r['type'], 0, -2);
			$r['type'] = 'array';
		}
		if ($value) {
			$r['description'] = implode(' ', $value);
		}
		return $r;
	}

	private function formatVar(array $value)
	{
		$r = array();
		$data = array_shift($value);
		if (empty($data)) {
			$r['type'] = 'mixed';
		} elseif ($data[0] == '$') {
			$r['name'] = substr($data, 1);
			$r['type'] = 'mixed';
		} else {
			$data = explode('|', $data);
			$r['type'] = count($data) == 1 ? $data[0] : $data;
		}
		if (isset($r['type']) && Text::endsWith($r['type'], '[]')) {
			$r[static::$embeddedDataName]['type'] = substr($r['type'], 0, -2);
			$r['type'] = 'array';
		}
		if ($value) {
			$r['description'] = implode(' ', $value);
		}
		return $r;
	}
}