<?php
  /**
   * Copyright (c) 2013 Frank Karlitschek frank@owncloud.org
   * Copyright (c) 2013 Georg Ehrke georg@ownCloud.com
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   */
  namespace OC\Preview;
  
  function findBinaryPath($program) {

  	exec('command -v ' . escapeshellarg($program) . ' 2> /dev/null', $output, $returnCode);

  	if ($returnCode === 0 && count($output) > 0) {
  		return escapeshellcmd($output[0]);
  	}
  	return null;
  }
  
  // movie preview is currently not supported on Windows
  if (!\OC_Util::runningOnWindows()) {

  	$isExecEnabled = \OC_Helper::is_function_enabled('exec');

  	$ffmpegBinary = null;
  	$avconvBinary = null;
  
  	if ($isExecEnabled) {
  		$avconvBinary = findBinaryPath('avconv');
  		if (!$avconvBinary) {
  			$ffmpegBinary = findBinaryPath('ffmpeg');
  		}
  	}
  
  	if($isExecEnabled && ( $avconvBinary || $ffmpegBinary )) {
  
  		class Movie extends Provider {
  			public static $avconvBinary;
  			public static $ffmpegBinary;
  
  			public function getMimeType() {
  				return '/video\/.*/';
  			}
  
  			public function getThumbnail($path, $maxX, $maxY, $scalingup, $fileview) {
  				// TODO: use proc_open() and stream the source file ?

  				$fileInfo = $fileview->getFileInfo($path);
  				$useFileDirectly = (!$fileInfo->isEncrypted() && !$fileInfo->isMounted());
  
  				if ($useFileDirectly) {
  					$absPath = $fileview->getLocalFile($path);
  				} else {
  					$absPath = \OC_Helper::tmpFile();
  
  					$handle = $fileview->fopen($path, 'rb');
  
  					// we better use 5MB (1024 * 1024 * 5 = 5242880) instead of 1MB.
  					// in some cases 1MB was no enough to generate thumbnail
  					$firstmb = stream_get_contents($handle, 5242880);
  					file_put_contents($absPath, $firstmb);
  				}
  
  				$result = $this->generateThumbNail($maxX, $maxY, $absPath, 5);
  				if ($result === false) {
  					$result = $this->generateThumbNail($maxX, $maxY, $absPath, 1);
  					if ($result === false) {
  						$result = $this->generateThumbNail($maxX, $maxY, $absPath, 0);
  					}
  				}
  
  				if (!$useFileDirectly) {
  					unlink($absPath);
  				}

  				return $result;
  			}
  
  			/**
  			 * @param int $maxX
  			 * @param int $maxY
  			 * @param string $absPath
  			 * @param string $tmpPath
  			 * @param int $second
  			 * @return bool|\OC_Image
  			 */
  			private function generateThumbNail($maxX, $maxY, $absPath, $second)
  			{
  				$tmpPath = \OC_Helper::tmpFile();

  
  				if (self::$avconvBinary) {

  					$cmd = self::$avconvBinary . ' -an -y -ss ' . escapeshellarg($second) .

  						' -i ' . escapeshellarg($absPath) .
  						' -f mjpeg -vframes 1 -vsync 1 ' . escapeshellarg($tmpPath) .
  						' > /dev/null 2>&1';

  				} else {
  					$cmd = self::$ffmpegBinary . ' -y -ss ' . escapeshellarg($second) .

  						' -i ' . escapeshellarg($absPath) .
  						' -f mjpeg -vframes 1' .
  						' -s ' . escapeshellarg($maxX) . 'x' . escapeshellarg($maxY) .
  						' ' . escapeshellarg($tmpPath) .
  						' > /dev/null 2>&1';
  				}
  
  				exec($cmd, $output, $returnCode);

  				if ($returnCode === 0) {
  					$image = new \OC_Image();
  					$image->loadFromFile($tmpPath);
  					unlink($tmpPath);
  					return $image->valid() ? $image : false;
  				}

  				unlink($tmpPath);

  				return false;
  			}
  		}
  
  		// a bit hacky but didn't want to use subclasses
  		Movie::$avconvBinary = $avconvBinary;
  		Movie::$ffmpegBinary = $ffmpegBinary;
  
  		\OC\Preview::registerProvider('OC\Preview\Movie');
  	}
  }