<?php
require 'Reader.php';
require 'Preprocessor.php';

/**
 * Class handling access to data-files(original and preprocessed) for webgrind.
 * @author Jacob Oettinger
 * @author Joakim Nygård
 */
class Webgrind_FileHandler
{

    private static $singleton = null;


    /**
     * @return Singleton instance of the filehandler
     */
    public static function getInstance() {
        if (self::$singleton==null)
            self::$singleton = new self();
        return self::$singleton;
    }

    private function __construct() {
        // Get list of files matching the defined format
        $files = $this->getFiles(Webgrind_Config::xdebugOutputFormat(), Webgrind_Config::xdebugOutputDir());

        // Get list of preprocessed files
        $prepFiles = $this->getPrepFiles('/\\'.Webgrind_Config::$preprocessedSuffix.'$/', Webgrind_Config::storageDir());
        // Loop over the preprocessed files.
        foreach ($prepFiles as $fileName=>$prepFile) {
            $fileName = str_replace(Webgrind_Config::$preprocessedSuffix,'',$fileName);

            // If it is older than its corrosponding original: delete it.
            // If it's original does not exist: delete it
            if (!isset($files[$fileName]) || $files[$fileName]['mtime']>$prepFile['mtime'])
                unlink($prepFile['absoluteFilename']);
            else
                $files[$fileName]['preprocessed'] = true;
        }
        // Sort by mtime
        uasort($files,array($this,'mtimeCmp'));

        $this->files = $files;
    }

    /**
     * Get the value of the cmd header in $file
     *
     * @return void string
     */
    private function getInvokeUrl($file) {
        if (preg_match('/\.webgrind$/', $file))
            return 'Webgrind internal';

        // Grab name of invoked file.
        $fp = fopen($file, 'r');
        $invokeUrl = '';
        while ((($line = fgets($fp)) !== FALSE) && !strlen($invokeUrl)) {
            if (preg_match('/^cmd: (.*)$/', $line, $parts)) {
                $invokeUrl = isset($parts[1]) ? $parts[1] : '';
            }
        }
        fclose($fp);
        if (!strlen($invokeUrl))
            $invokeUrl = 'Unknown!';

        return $invokeUrl;
    }

    /**
     * List of files in $dir whose filename has the format $format
     *
     * @return array Files
     */
    private function getFiles($format, $dir) {
        $list = preg_grep($format,scandir($dir));
        $files = array();

        # Moved this out of loop to run faster
        if (function_exists('xdebug_get_profiler_filename'))
            $selfFile = realpath(xdebug_get_profiler_filename());
        else
            $selfFile = '';

        foreach ($list as $file) {
            $absoluteFilename = $dir.$file;

            // Exclude webgrind preprocessed files
            if (false !== strstr($absoluteFilename, Webgrind_Config::$preprocessedSuffix))
                continue;

            // Make sure that script never parses the profile currently being generated. (infinite loop)
            if ($selfFile == realpath($absoluteFilename))
                continue;

            $invokeUrl = rtrim($this->getInvokeUrl($absoluteFilename));
            if (Webgrind_Config::$hideWebgrindProfiles && $invokeUrl == dirname(dirname(__FILE__)).DIRECTORY_SEPARATOR.'index.php')
                continue;

            $files[$file] = array('absoluteFilename' => $absoluteFilename,
                                  'mtime' => filemtime($absoluteFilename),
                                  'preprocessed' => false,
                                  'invokeUrl' => $invokeUrl,
                                  'filesize' => $this->bytestostring(filesize($absoluteFilename))
                            );
        }
        return $files;
    }

    /**
     * List of files in $dir whose filename has the format $format
     *
     * @return array Files
     */
    private function getPrepFiles($format, $dir) {
        $list = preg_grep($format,scandir($dir));
        $files = array();

        foreach ($list as $file) {
            $absoluteFilename = $dir.$file;

            // Make sure that script does not include the profile currently being generated. (infinite loop)
            if (function_exists('xdebug_get_profiler_filename') && realpath(xdebug_get_profiler_filename())==realpath($absoluteFilename))
                continue;

            $files[$file] = array('absoluteFilename' => $absoluteFilename,
                                  'mtime' => filemtime($absoluteFilename),
                                  'preprocessed' => true,
                                  'filesize' => $this->bytestostring(filesize($absoluteFilename))
                            );
        }
        return $files;
    }
    /**
     * Get list of available trace files. Optionally including traces of the webgrind script it self
     *
     * @return array Files
     */
    public function getTraceList() {
        $result = array();
        foreach ($this->files as $fileName=>$file) {
            $result[] = array('filename'  => $fileName,
                              'invokeUrl' => str_replace($_SERVER['DOCUMENT_ROOT'].'/', '', $file['invokeUrl']),
                              'filesize'  => $file['filesize'],
                              'mtime'     => date(Webgrind_Config::$dateFormat, $file['mtime'])
                        );
        }
        return $result;
    }

    /**
     * Get a trace reader for the specific file.
     *
     * If the file has not been preprocessed yet this will be done first.
     *
     * @param string File to read
     * @param Cost format for the reader
     * @return Webgrind_Reader Reader for $file
     */
    public function getTraceReader($file, $costFormat) {
        $prepFile = Webgrind_Config::storageDir().$file.Webgrind_Config::$preprocessedSuffix;
        try {
            $r = new Webgrind_Reader($prepFile, $costFormat);
        } catch (Exception $e) {
            // Preprocessed file does not exist or other error
            Webgrind_Preprocessor::parse(Webgrind_Config::xdebugOutputDir().$file, $prepFile);
            $r = new Webgrind_Reader($prepFile, $costFormat);
        }
        return $r;
    }

    /**
     * Comparison function for sorting
     *
     * @return boolean
     */
    private function mtimeCmp($a, $b) {
        if ($a['mtime'] == $b['mtime'])
            return 0;

        return ($a['mtime'] > $b['mtime']) ? -1 : 1;
    }

    /**
     * Present a size (in bytes) as a human-readable value
     *
     * @param int    $size        size (in bytes)
     * @param int    $precision    number of digits after the decimal point
     * @return string
     */
    private function bytestostring($size, $precision = 0) {
        $sizes = array('YB', 'ZB', 'EB', 'PB', 'TB', 'GB', 'MB', 'KB', 'B');
        $total = count($sizes);

        while ($total-- && $size > 1024) {
            $size /= 1024;
        }
        return round($size, $precision).$sizes[$total];
    }
}