<?php
/**
 * A class for reading files
 *
 * @author		Roland Haeder <webmaster@mxchange.org>
 * @version		0.3.0
 * @copyright	Copyright(c) 2007, 2008 Roland Haeder, this is free software
 * @license		GNU GPL 3.0 or any newer version
 * @link 		http://www.mxchange.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 FrameworkFileInputPointer extends BaseFrameworkSystem {
	/**
	 * The current file we are working in
	 */
	private $fileName = "";

	/**
	 * The file pointer
	 */
	private $filePointer = null;

	/**
	 * Private constructor
	 */
	private final function __construct () {
		// Call parent constructor
		parent::constructor(__CLASS__);

		// Set part description
		$this->setObjectDescription("Dateiausgabe-Handler");

		// Create unique ID
		$this->createUniqueID();

		// Clean-up a little
		$this->removeNumberFormaters();
	}

	/**
	 * Destructor for cleaning purposes, etc
	 */
	public final function __destruct() {
		// Is there a resource pointer? Then we have to close the file here!
		if (is_resource($this->getPointer())) {
			// Try to close a file
			$this->closeFile();
		}

		// Call the parent destructor
		parent::__destruct();
	}

	/**
	 * Create a file pointer based on the given file. The file will also
	 * be verified here.
	 *
	 * @param		$fileName				The file name we shall pass
	 *								to fopen()
	 * @throws	FileIsEmptyException	If the provided file name is empty.
	 * @throws	FilePointerNotOpenedException		If fopen() returns not a
	 *										file resource
	 * @return	void
	 */
	public final static function createFrameworkFileInputPointer ($fileName) {
		// Some pre-sanity checks...
		if (is_null($fileName)) {
			// No filename given
			throw new FileIsEmptyException(null, self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
		}

		// Try to open a handler
		$filePointer = @fopen($fileName, 'rb');
		if (($filePointer === null) || ($filePointer === false)) {
			// Something bad happend
			throw new FilePointerNotOpenedException ($fileName, self::EXCEPTION_FILE_POINTER_INVALID);
		}

		// Create new instance
		$pointerInstance = new FrameworkFileInputPointer();

		// Set file pointer and file name
		$pointerInstance->setPointer($filePointer);
		$pointerInstance->setFileName($fileName);

		// Return the instance
		return $pointerInstance;
	}

	/**
	 * Read data a file pointer
	 *
	 * @return	mixed	The result of fread()
	 * @throws	NullPointerException	If the file pointer instance
	 *								is not set by setPointer()
	 * @throws	InvalidFileResourceException	If there is being set
	 *									an invalid file resource
	 */
	public function readFromFile () {
		if (is_null($this->getPointer())) {
			// Pointer not initialized
			throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
		} elseif (!is_resource($this->getPointer())) {
			// Pointer is not a valid resource!
			throw new InvalidFileResourceException($this, self::EXCEPTION_INVALID_DIRECTORY_POINTER);
		}

		// Read data from the file pointer and return it
		return fread($this->getPointer(), 1024);
	}

	/**
	 * Read lines from a file pointer
	 *
	 * @return	mixed	The result of fread()
	 * @throws	NullPointerException	If the file pointer instance
	 *								is not set by setPointer()
	 * @throws	InvalidFileResourceException	If there is being set
	 *									an invalid file resource
	 */
	public function readLinesFromFile () {
		if (is_null($this->getPointer())) {
			// Pointer not initialized
			throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
		} elseif (!is_resource($this->getPointer())) {
			// Pointer is not a valid resource!
			throw new InvalidFileResourceException($this, self::EXCEPTION_INVALID_DIRECTORY_POINTER);
		}

		// Read data from the file pointer and return it
		return fgets($this->getPointer(), 1024);
	}

	/**
	 * Close a file source and set it's instance to null and the file name
	 * to empty
	 *
	 * @return	void
	 * @throws	NullPointerException	If the file pointer instance
	 *								is not set by setPointer()
	 * @throws	InvalidFileResourceException	If there is being set
	 */
	public function closeFile () {
		if (is_null($this->getPointer())) {
			// Pointer not initialized
			throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
		} elseif (!is_resource($this->getPointer())) {
			// Pointer is not a valid resource!
			throw new InvalidFileResourceException($this, self::EXCEPTION_INVALID_DIRECTORY_POINTER);
		}

		// Close the file pointer and reset the instance variable
		@fclose($this->getPointer());
		$this->setPointer(null);
		$this->setFileName("");
	}

	/**
	 * Setter for the file pointer
	 *
	 * @param		$filePointer	File resource
	 * @return	void
	 */
	public final function setPointer ($filePointer) {
		// Sanity-check if the pointer is a valid file resource
		if (is_resource($filePointer) || is_null($filePointer)) {
			// Is a valid resource
			$this->filePointer = $filePointer;
		} else {
			// Throw exception
			throw new InvalidFileResourceException($this, self::EXCEPTION_INVALID_DIRECTORY_POINTER);
		}
	}

	/**
	 * Getter for the file pointer
	 *
	 * @return	$filePointer	The file pointer which shall be a valid
	 *						file resource
	 */
	public final function getPointer () {
		return $this->filePointer;
	}

	/**
	 * Setter for file name
	 *
	 * @param		$fileName		The new file name
	 * @return	void
	 */
	public final function setFileName ($fileName) {
		$fileName = (string) $fileName;
		$this->fileName = $fileName;
	}

	/**
	 * Getter for file name
	 *
	 * @return	$fileName		The current file name
	 */
	public final function getFileName () {
		return $this->fileName;
	}
}

// [EOF]
?>