<?php
/**
 * Parser output with source map
 *
 * @private
 */
class Less_Output_Mapped extends Less_Output {

	/**
	 * The source map generator
	 *
	 * @var Less_SourceMap_Generator
	 */
	protected $generator;

	/**
	 * Current line
	 *
	 * @var int
	 */
	protected $lineNumber = 0;

	/**
	 * Current column
	 *
	 * @var int
	 */
	protected $column = 0;

	/**
	 * Array of contents map (file and its content)
	 *
	 * @var array
	 */
	protected $contentsMap = [];

	/**
	 * Constructor
	 *
	 * @param array $contentsMap Array of filename to contents map
	 * @param Less_SourceMap_Generator $generator
	 */
	public function __construct( array $contentsMap, $generator ) {
		$this->contentsMap = $contentsMap;
		$this->generator = $generator;
	}

	/**
	 * Adds a chunk to the stack
	 * The $index for less.php may be different from less.js since less.php does not chunkify inputs
	 *
	 * @param string $chunk
	 * @param array|null $fileInfo
	 * @param int $index
	 * @param bool|null $mapLines
	 */
	public function add( $chunk, $fileInfo = null, $index = 0, $mapLines = null ) {
		// ignore adding empty strings
		if ( $chunk === '' ) {
			return;
		}

		$sourceLines = [];
		$sourceColumns = ' ';

		if ( $fileInfo ) {

			$url = $fileInfo['currentUri'];

			if ( isset( $this->contentsMap[$url] ) ) {
				$inputSource = substr( $this->contentsMap[$url], 0, $index );
				$sourceLines = explode( "\n", $inputSource );
				$sourceColumns = end( $sourceLines );
			} else {
				throw new Exception( 'Filename ' . $url . ' not in contentsMap' );
			}

		}

		$lines = explode( "\n", $chunk );
		$columns = end( $lines );

		if ( $fileInfo ) {

			if ( !$mapLines ) {
				$this->generator->addMapping(
						$this->lineNumber + 1, // generated_line
						$this->column, // generated_column
						count( $sourceLines ), // original_line
						strlen( $sourceColumns ), // original_column
						$fileInfo
				);
			} else {
				for ( $i = 0, $count = count( $lines ); $i < $count; $i++ ) {
					$this->generator->addMapping(
						$this->lineNumber + $i + 1, // generated_line
						$i === 0 ? $this->column : 0, // generated_column
						count( $sourceLines ) + $i, // original_line
						$i === 0 ? strlen( $sourceColumns ) : 0, // original_column
						$fileInfo
					);
				}
			}
		}

		if ( count( $lines ) === 1 ) {
			$this->column += strlen( $columns );
		} else {
			$this->lineNumber += count( $lines ) - 1;
			$this->column = strlen( $columns );
		}

		// add only chunk
		parent::add( $chunk );
	}

}
