<?php

/**
 * Parser output with source map
 *
 * @package Less
 * @subpackage Output
 */
class Less_Output_Mapped extends Less_Output {

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

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

    /**
     * Current column
     *
     * @var integer
     */
    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 string  $fileInfo
     * @param integer $index
     * @param mixed   $mapLines
     */
    public function add($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);
    }

}