<?php

/**
 * Parser Exception
 *
 * @package Less
 * @subpackage exception
 */
class Less_Exception_Parser extends Exception {

    /**
     * The current file
     *
     * @var Less_ImportedFile
     */
    public $currentFile;

    /**
     * The current parser index
     *
     * @var integer
     */
    public $index;

    protected $input;

    protected $details = [];


    /**
     * Constructor
     *
     * @param string               $message
     * @param Exception            $previous Previous exception
     * @param integer              $index The current parser index
     * @param Less_FileInfo|string $currentFile The file
     * @param integer              $code The exception code
     */
    public function __construct($message = NULL, Exception $previous = NULL, $index = NULL, $currentFile = NULL, $code = 0) {

        if (PHP_VERSION_ID < 50300) {
            $this->previous = $previous;
            parent::__construct($message, $code);
        } else {
            parent::__construct($message, $code, $previous);
        }

        $this->currentFile = $currentFile;
        $this->index = $index;

        $this->genMessage();
    }

    /**
     * Converts the exception to string
     *
     * @return string
     */
    public function genMessage() {

        if ($this->currentFile && $this->currentFile['filename']) {
            $this->message .= ' in '.basename($this->currentFile['filename']);
        }

        if ($this->index !== NULL) {
            $this->getInput();
            if ($this->input) {
                $line = self::getLineNumber();
                $this->message .= ' on line '.$line.', column '.self::getColumn();

                $lines = explode("\n", $this->input);

                $count = count($lines);
                $start_line = max(0, $line - 3);
                $last_line = min($count, $start_line + 6);
                $num_len = strlen($last_line);
                for ($i = $start_line; $i < $last_line; $i++) {
                    $this->message .= "\n".str_pad($i + 1, $num_len, '0', STR_PAD_LEFT).'| '.$lines[$i];
                }
            }
        }

    }

    protected function getInput() {

        if (!$this->input && $this->currentFile && $this->currentFile['filename']) {
            $this->input = file_get_contents($this->currentFile['filename']);
        }
    }

    /**
     * Returns the line number the error was encountered
     *
     * @return integer
     */
    public function getLineNumber() {
        if ($this->index) {
            // https://bugs.php.net/bug.php?id=49790
            if (ini_get("mbstring.func_overload")) {
                return substr_count(substr($this->input, 0, $this->index), "\n") + 1;
            } else {
                return substr_count($this->input, "\n", 0, $this->index) + 1;
            }
        }

        return 1;
    }


    /**
     * Returns the column the error was encountered
     *
     * @return integer
     */
    public function getColumn() {

        $part = substr($this->input, 0, $this->index);
        $pos = strrpos($part, "\n");

        return $this->index - $pos;
    }

}