<?php

/**
 * The context object handles the current configuration file and different
 * useful functions associated to the current view state.
 */
class FreshRSS_Context {
	public static $user_conf = null;
	public static $system_conf = null;
	public static $categories = array();

	public static $name = '';

	public static $total_unread = 0;
	public static $total_starred = array(
		'all' => 0,
		'read' => 0,
		'unread' => 0,
	);

	public static $get_unread = 0;
	public static $current_get = array(
		'all' => false,
		'starred' => false,
		'feed' => false,
		'category' => false,
	);
	public static $next_get = 'a';

	public static $state = 0;
	public static $order = 'DESC';
	public static $number = 0;
	public static $search = '';
	public static $first_id = '';
	public static $next_id = '';
	public static $id_max = '';

	/**
	 * Initialize the context.
	 *
	 * Set the correct configurations and $categories variables.
	 */
	public static function init() {
		// Init configuration.
		self::$system_conf = Minz_Configuration::get('system');
		self::$user_conf = Minz_Configuration::get('user');

		$catDAO = new FreshRSS_CategoryDAO();
		self::$categories = $catDAO->listCategories();
	}

	/**
	 * Returns if the current state includes $state parameter.
	 */
	public static function isStateEnabled($state) {
		return self::$state & $state;
	}

	/**
	 * Returns the current state with or without $state parameter.
	 */
	public static function getRevertState($state) {
		if (self::$state & $state) {
			return self::$state & ~$state;
		} else {
			return self::$state | $state;
		}
	}

	/**
	 * Return the current get as a string or an array.
	 *
	 * If $array is true, the first item of the returned value is 'f' or 'c' and
	 * the second is the id.
	 */
	public static function currentGet($array = false) {
		if (self::$current_get['all']) {
			return 'a';
		} elseif (self::$current_get['starred']) {
			return 's';
		} elseif (self::$current_get['feed']) {
			if ($array) {
				return array('f', self::$current_get['feed']);
			} else {
				return 'f_' . self::$current_get['feed'];
			}
		} elseif (self::$current_get['category']) {
			if ($array) {
				return array('c', self::$current_get['category']);
			} else {
				return 'c_' . self::$current_get['category'];
			}
		}
	}

	/**
	 * Return true if $get parameter correspond to the $current_get attribute.
	 */
	public static function isCurrentGet($get) {
		$type = $get[0];
		$id = substr($get, 2);

		switch($type) {
		case 'a':
			return self::$current_get['all'];
		case 's':
			return self::$current_get['starred'];
		case 'f':
			return self::$current_get['feed'] == $id;
		case 'c':
			return self::$current_get['category'] == $id;
		default:
			return false;
		}
	}

	/**
	 * Set the current $get attribute.
	 *
	 * Valid $get parameter are:
	 *   - a
	 *   - s
	 *   - f_<feed id>
	 *   - c_<category id>
	 *
	 * $name and $get_unread attributes are also updated as $next_get
	 * Raise an exception if id or $get is invalid.
	 */
	public static function _get($get) {
		$type = $get[0];
		$id = substr($get, 2);
		$nb_unread = 0;

		switch($type) {
		case 'a':
			self::$current_get['all'] = true;
			self::$name = _t('index.feed.title');
			self::$get_unread = self::$total_unread;
			break;
		case 's':
			self::$current_get['starred'] = true;
			self::$name = _t('index.feed.title_fav');
			self::$get_unread = self::$total_starred['unread'];

			// Update state if favorite is not yet enabled.
			self::$state = self::$state | FreshRSS_Entry::STATE_FAVORITE;
			break;
		case 'f':
			// We try to find the corresponding feed.
			$feed = FreshRSS_CategoryDAO::findFeed(self::$categories, $id);
			if ($feed === null) {
				$feedDAO = FreshRSS_Factory::createFeedDao();
				$feed = $feedDAO->searchById($id);

				if (!$feed) {
					throw new FreshRSS_Context_Exception('Invalid feed: ' . $id);
				}
			}

			self::$current_get['feed'] = $id;
			self::$current_get['category'] = $feed->category();
			self::$name = $feed->name();
			self::$get_unread = $feed->nbNotRead();
			break;
		case 'c':
			// We try to find the corresponding category.
			self::$current_get['category'] = $id;
			if (!isset(self::$categories[$id])) {
				$catDAO = new FreshRSS_CategoryDAO();
				$cat = $catDAO->searchById($id);

				if (!$cat) {
					throw new FreshRSS_Context_Exception('Invalid category: ' . $id);
				}
			} else {
				$cat = self::$categories[$id];
			}

			self::$name = $cat->name();
			self::$get_unread = $cat->nbNotRead();
			break;
		default:
			throw new FreshRSS_Context_Exception('Invalid getter: ' . $get);
		}

		self::_nextGet();
	}

	/**
	 * Set the value of $next_get attribute.
	 */
	public static function _nextGet() {
		$get = self::currentGet();
		// By default, $next_get == $get
		self::$next_get = $get;

		if (self::$user_conf->onread_jump_next && strlen($get) > 2) {
			$another_unread_id = '';
			$found_current_get = false;
			switch ($get[0]) {
			case 'f':
				// We search the next feed with at least one unread article in
				// same category as the currend feed.
				foreach (self::$categories as $cat) {
					if ($cat->id() != self::$current_get['category']) {
						// We look into the category of the current feed!
						continue;
					}

					foreach ($cat->feeds() as $feed) {
						if ($feed->id() == self::$current_get['feed']) {
							// Here is our current feed! Fine, the next one will
							// be a potential candidate.
							$found_current_get = true;
							continue;
						}

						if ($feed->nbNotRead() > 0) {
							$another_unread_id = $feed->id();
							if ($found_current_get) {
								// We have found our current feed and now we
								// have an feed with unread articles. Leave the
								// loop!
								break;
							}
						}
					}
					break;
				}

				// If no feed have been found, next_get is the current category.
				self::$next_get = empty($another_unread_id) ?
				                  'c_' . self::$current_get['category'] :
				                  'f_' . $another_unread_id;
				break;
			case 'c':
				// We search the next category with at least one unread article.
				foreach (self::$categories as $cat) {
					if ($cat->id() == self::$current_get['category']) {
						// Here is our current category! Next one could be our
						// champion if it has unread articles.
						$found_current_get = true;
						continue;
					}

					if ($cat->nbNotRead() > 0) {
						$another_unread_id = $cat->id();
						if ($found_current_get) {
							// Unread articles and the current category has
							// already been found? Leave the loop!
							break;
						}
					}
				}

				// No unread category? The main stream will be our destination!
				self::$next_get = empty($another_unread_id) ?
				                  'a' :
				                  'c_' . $another_unread_id;
				break;
			}
		}
	}

	/**
	 * Determine if the auto remove is available in the current context.
	 * This feature is available if:
	 *   - it is activated in the configuration
	 *   - the "read" state is not enable
	 *   - the "unread" state is enable
	 *
	 * @return boolean
	 */
	public static function isAutoRemoveAvailable() {
		if (!self::$user_conf->auto_remove_article) {
			return false;
		}
		if (self::isStateEnabled(FreshRSS_Entry::STATE_READ)) {
			return false;
		}
		if (!self::isStateEnabled(FreshRSS_Entry::STATE_NOT_READ)) {
			return false;
		}
		return true;
	}

	/**
	 * Determine if the "sticky post" option is enabled. It can be enable
	 * by the user when it is selected in the configuration page or by the
	 * application when the context allows to auto-remove articles when they
	 * are read.
	 *
	 * @return boolean
	 */
	public static function isStickyPostEnabled() {
		if (self::$user_conf->sticky_post) {
			return true;
		}
		if (self::isAutoRemoveAvailable()) {
			return true;
		}
		return false;
	}

	/**
	 * Parse search string to extract the different keywords.
	 *
	 * @return array
	 */
	public function parseSearch() {
		$search = self::$search;
		$intitle = $this->parseIntitleSearch($search);
		$author = $this->parseAuthorSearch($intitle['string']);
		$inurl = $this->parseInurlSearch($author['string']);
		$pubdate = $this->parsePubdateSearch($inurl['string']);
		$date = $this->parseDateSearch($pubdate['string']);

		$remaining = array();
		$remaining_search = trim($date['string']);
		if (strcmp($remaining_search, '') != 0) {
			$remaining['search'] = $remaining_search;
		}

		return array_merge($intitle['search'], $author['search'], $inurl['search'], $date['search'], $pubdate['search'], $remaining);
	}

	/**
	 * Parse the search string to find intitle keyword and the search related
	 * to it.
	 * The search is the first word following the keyword.
	 * It returns an array containing the matched string and the search.
	 *
	 * @param string $search
	 * @return array
	 */
	private function parseIntitleSearch($search) {
		if (preg_match('/intitle:(?P<delim>[\'"])(?P<search>.*)(?P=delim)/U', $search, $matches)) {
			return array(
			    'string' => str_replace($matches[0], '', $search),
			    'search' => array('intitle' => $matches['search']),
			);
		}
		if (preg_match('/intitle:(?P<search>\w*)/', $search, $matches)) {
			return array(
			    'string' => str_replace($matches[0], '', $search),
			    'search' => array('intitle' => $matches['search']),
			);
		}
		return array(
		    'string' => $search,
		    'search' => array(),
		);
	}

	/**
	 * Parse the search string to find author keyword and the search related
	 * to it.
	 * The search is the first word following the keyword except when using
	 * a delimiter. Supported delimiters are single quote (') and double
	 * quotes (").
	 * It returns an array containing the matched string and the search.
	 *
	 * @param string $search
	 * @return array
	 */
	private function parseAuthorSearch($search) {
		if (preg_match('/author:(?P<delim>[\'"])(?P<search>.*)(?P=delim)/U', $search, $matches)) {
			return array(
			    'string' => str_replace($matches[0], '', $search),
			    'search' => array('author' => $matches['search']),
			);
		}
		if (preg_match('/author:(?P<search>\w*)/', $search, $matches)) {
			return array(
			    'string' => str_replace($matches[0], '', $search),
			    'search' => array('author' => $matches['search']),
			);
		}
		return array(
		    'string' => $search,
		    'search' => array(),
		);
	}

	/**
	 * Parse the search string to find inurl keyword and the search related
	 * to it.
	 * The search is the first word following the keyword except.
	 * It returns an array containing the matched string and the search.
	 *
	 * @param string $search
	 * @return array
	 */
	private function parseInurlSearch($search) {
		if (preg_match('/inurl:(?P<search>[^\s]*)/', $search, $matches)) {
			return array(
			    'string' => str_replace($matches[0], '', $search),
			    'search' => array('inurl' => $matches['search']),
			);
		}
		return array(
		    'string' => $search,
		    'search' => array(),
		);
	}

	/**
	 * Parse the search string to find date keyword and the search related
	 * to it.
	 * The search is the first word following the keyword.
	 * It returns an array containing the matched string and the search.
	 *
	 * @param string $search
	 * @return array
	 */
	private function parseDateSearch($search) {
		if (preg_match('/date:(?P<search>[^\s]*)/', $search, $matches)) {
			list($min_date, $max_date) = parseDateInterval($matches['search']);
			return array(
			    'string' => str_replace($matches[0], '', $search),
			    'search' => array('min_date' => $min_date, 'max_date' => $max_date),
			);
		}
		return array(
		    'string' => $search,
		    'search' => array(),
		);
	}

	/**
	 * Parse the search string to find pubdate keyword and the search related
	 * to it.
	 * The search is the first word following the keyword.
	 * It returns an array containing the matched string and the search.
	 *
	 * @param string $search
	 * @return array
	 */
	private function parsePubdateSearch($search) {
		if (preg_match('/pubdate:(?P<search>[^\s]*)/', $search, $matches)) {
			list($min_date, $max_date) = parseDateInterval($matches['search']);
			return array(
			    'string' => str_replace($matches[0], '', $search),
			    'search' => array('min_pubdate' => $min_date, 'max_pubdate' => $max_date),
			);
		}
		return array(
		    'string' => $search,
		    'search' => array(),
		);
	}

}