<?php
// Own namespace
namespace Org\Mxchange\CoreFramework\Filesystem\Input\Csv;

// Import framework stuff
use Org\Mxchange\CoreFramework\Filesystem\Text\BaseInputTextFile;
use Org\Mxchange\CoreFramework\Generic\FrameworkInterface;
use Org\Mxchange\CoreFramework\Stream\Filesystem\CsvInputStreamer;

// Import SPL stuff
use \InvalidArgumentException;
use \SplFileInfo;
use \UnexpectedValueException;

/**
 * A CSV file input class for writing CSV files
 *
 * @author		Roland Haeder <webmaster@ship-simu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2023 Core 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 CsvInputFile extends BaseInputTextFile implements CsvInputStreamer {
	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	private function __construct () {
		// Call parent constructor
		parent::__construct(__CLASS__);
	}

	/**
	 * Creates an instance of this File class and prepares it for usage
	 *
	 * @param	$infoInstance	An instance of a SplFileInfo class
	 * @return	$fileInstance	An instance of this File class
	 */
	public final static function createCsvInputFile (SplFileInfo $infoInstance) {
		// Get a new instance
		$fileInstance = new CsvInputFile();

		// Init this abstract file
		$fileInstance->initFile($infoInstance);

		// Return the prepared instance
		return $fileInstance;
	}

	/**
	 * Reads a line from CSV file and returns it as an indexed array. Please
	 * note that strings *must* be always in double-quotes, else any found
	 * column separators will be parsed or they may be interpreted incorrectly.
	 *
	 * @param	$columnSeparator	Character to use separting columns
	 * @param	$expectedMatches	Expected matches, 0 is default and means flexible
	 * @return	$lineArray			An indexed array with the read line
	 * @throws	InvalidArgumentException	If a parameter is invalid
	 * @throws	UnexpectedValueException	If the array count is not matching expected count
	 */
	public function readCsvFileLine (string $columnSeparator, int $expectedMatches = 0) {
		// Validate parameter
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] columnSeparator=%s,expectedMatches=%d - CALLED!', __METHOD__, __LINE__, $columnSeparator, $expectedMatches));
		if (strlen($columnSeparator) === 0) {
			// No empty column separator
			throw new InvalidArgumentException('Parameter "columnSeparator" is empty', FrameworkInterface::EXCEPTION_INVALID_ARGUMENT);
		} elseif ($expectedMatches < 0) {
			// Below zero is not valid
			throw new InvalidArgumentException(sprintf('expectedMatches=%d is below zero', $expectedMatches));
		}

		// Read raw line and trim anything unwanted away
		$data = trim($this->getPointerInstance()->readLine());

		// Is the line empty?
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] data(%d)=%s', __METHOD__, __LINE__, strlen($data), $data));
		if (empty($data)) {
			// Yes, then skip below code
			/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Read data is an empty line - EXIT!', __METHOD__, __LINE__));
			return;
		}

		// Parse data
		$lineArray = $this->parseDataToIndexedArray($data, $columnSeparator);

		// Is the expected count found?
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] expectedMatches=%d,lineArray()=%d', __METHOD__, __LINE__, $expectedMatches, count($lineArray)));
		if (($expectedMatches > 0) && (count($lineArray) !== $expectedMatches)) {
			// Invalid line found as strict count matching is requested
			throw new UnexpectedValueException(sprintf('lineArray()=%d has not expected count %d', count($lineArray), $expectedMatches), FrameworkInterface::EXCEPTION_UNEXPECTED_VALUE);
		}

		// Return it
		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] lineArray()=%d - EXIT!', __METHOD__, __LINE__, count($lineArray)));
		return $lineArray;
	}

	/**
	 * Parses given data into an array
	 *
	 * @param	$data				Raw data e.g. returned from readLine()
	 * @param	$columnSeparator	Character to use separting columns
	 * @return	$lineArray			An indexed array with the read line
	 */
	private function parseDataToIndexedArray (string $data, string $columnSeparator) {
		// Init return array
		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] data()=%d,columnSeparator=%s - CALLED!', __METHOD__, __LINE__, strlen($data), $columnSeparator));
		$lineArray = [];

		// Whether the parser reads a quoted string (which may contain the column separator again)
		$isInQuotes = false;

		// Init column data
		$column = '';

		// Now parse the line
		for ($idx = 0; $idx < strlen($data); $idx++) {
			// "Cache" char
			$char = substr($data, $idx, 1);

			// Is the column separator found and not within quotes?
			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] idx=%d,char=%s ...', __METHOD__, __LINE__, $idx, $char));
			if (($isInQuotes === false) && ($char == $columnSeparator)) {
				// Add this line to the array
				//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Adding column=%s ...', __METHOD__, __LINE__, $column));
				array_push($lineArray, $column);

				// Clear variable ...
				//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] line[]=%d - After add!', __METHOD__, __LINE__, count($lineArray)));
				$column = '';

				// ... and skip it
				continue;
			} elseif ($char == chr(34)) {
				// $column must be empty at this point if we are at starting quote
				//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] column=%s ...', __METHOD__, __LINE__, $column));
				assert(($isInQuotes === true) || (empty($column)));

				// Double-quote found, so flip variable
				$isInQuotes = (!$isInQuotes);

				// Skip double-quote (escaping of them is not yet supported)
				//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] isInQuotes=%d ...', __METHOD__, __LINE__, intval($isInQuotes)));
				continue;
			}

			// Add char to column
			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Adding char=%s ...', __METHOD__, __LINE__, $idx, $char));
			$column .= $char;
		}

		// Is there something outstanding?
		if (!empty($column)) {
			// Then don't forget this. :-)
			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Adding column=%s ...', __METHOD__, __LINE__, $column));
			array_push($lineArray, $column);

			// Debug message
			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] line[]=%d - After add!', __METHOD__, __LINE__, count($lineArray)));
		}

		// Return it
		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] line[]=%d - EXIT!', __METHOD__, __LINE__, count($lineArray)));
		return $lineArray;
	}

}