<?php
/**
 * A UploadedList URL source class for crawlers
 *
 * @author		Roland Haeder <webmaster@ship-simu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2014 Crawler Developer Team
 * @license		GNU GPL 3.0 or any newer version
 * @link		http://www.ship-simu.org
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
class CrawlerUploadedListUrlSource extends BaseUrlSource implements UrlSource, Registerable {
	/**
	 * Cached path of CSV files
	 */
	private $csvFilesPath = '';

	/**
	 * Last found CSV file
	 */
	private $lastCsvFile = '';

	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	protected function __construct () {
		// Call parent constructor
		parent::__construct(__CLASS__);

		// Set CSV files path
		$this->csvFilesPath = $this->getConfigInstance()->getConfigEntry('base_path') . '/' . $this->getConfigInstance()->getConfigEntry('crawler_csv_file_path');

		// Get directory instance
		$directoryInstance = ObjectFactory::createObjectByConfiguredName('directory_class', array($this->csvFilesPath));

		// Set it here
		$this->setDirectoryInstance($directoryInstance);
	}

	/**
	 * Checks whether a CSV file is found in configured path
	 *
	 * @return	$isFound	Whether a CSV file is found
	 */
	private function isCsvFileFound () {
		// Is it valid?
		if (!$this->getDirectoryInstance()->getDirectoryIteratorInstance()->valid()) {
			// Rewind to start
			$this->getDirectoryInstance()->getDirectoryIteratorInstance()->rewind();
		} // END - if

		// Read next entry
		$directoryEntry = $this->getDirectoryInstance()->readDirectoryExcept(array('.htaccess', '.', '..'));

		// Debug message
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('SOURCE[' . __METHOD__ . ':' . __LINE__ . '] directoryEntry(' . strlen($directoryEntry) . ')=' . $directoryEntry);

		// Is it empty or wrong file extension?
		if ((empty($directoryEntry)) || (substr($directoryEntry, -4, 4) != '.csv')) {
			// Skip further processing
			/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('SOURCE[' . __METHOD__ . ':' . __LINE__ . '] directoryEntry(' . strlen($directoryEntry) . ')=' . $directoryEntry . ' - SKIPPED!');
			return FALSE;
		} // END - if

		// Initialize CSV instance
		$csvFileInstance = ObjectFactory::createObjectByConfiguredName('csv_file_class', array($this->csvFilesPath . '/' . $directoryEntry));

		// Set it here
		$this->setCsvFileInstance($csvFileInstance);

		// Found a file
		return TRUE;
	}

	/**
	 * Creates an instance of this class
	 *
	 * @return	$sourceInstance		An instance of a Source class
	 */
	public final static function createCrawlerUploadedListUrlSource () {
		// Get new instance
		$sourceInstance = new CrawlerUploadedListUrlSource();

		// Init source
		$sourceInstance->initSource('crawler', 'uploaded_list');

		// Get a ??? @TODO

		// Return the prepared instance
		return $sourceInstance;
	}

	/**
	 * Processes entries in the stack.
	 *
	 * @return	void
	 * @todo	~10% done
	 */
	public function processStack () {
		// Does the stack have some entries left?
		if (!$this->isUrlStackEmpty()) {
			/*
			 * Handle next entry. This method will be called very often, so need
			 * to process more than one entry at a time.
			 */
			$this->processNextEntry();
		} elseif ($this->isCsvFileFound()) {
			/*
			 * A file containing an URL list is found. Please note the format is
			 * CSV-like as you may wish to provide meta data such as crawl
			 * depth, handling of 3rd-party URLs and such.
			 */
			$this->importCsvFile();
		}

		$this->partialStub('Please implement this method.');
	}
}

// [EOF]
?>