<?php
/**
 * ZAP image search class
 */
class ImgSearch {
	private $hitPosition;

	private $numberResults = 16;

	private $folder;

	private $word;

	private $engine;

	private $allowedFileTypes = array('image/jpeg','image/gif','image/png');
	
	private $log;

	/**
	 * Constructor
	 * @param string $imgFolder path to save images to
	 * @param string $word keyword to search for
	 */
	public function __construct($imgFolder, $word) {
		$this->folder = $imgFolder;
		$this->word = $word;

		$this->hitPosition = (int) rand(0,10);

		if (ZAP_LOG == true) {
			$this->log = new Log($this->folder);
		}

		$config = Config::getInstance();
		$engines = $config->retrieve('engines');
		$this->engine = $engines[array_rand($engines)];
	}

	/**
	 * download image that corresponds to $keyWord
	 * returns filename of image if downloaded succeeded, or false if failed
	 * @return string $localUrl / boolean
	 */
	public function getImage() {
		$imgData = $this->getImageData();
		if ($imgData == false) {
			$this->addLog('error','Search: ', 'bad search data received' );
			return false;
		}
		$this->addLog('ok', 'Engine: ', $imgData['engine']);

		$localUrl = $this->imageToTmp($imgData['results'], $this->folder);

		return $localUrl;
	}

	/**
	 * Returns an array that contains searchdata for $word
	 * @return array $searchData or false
	 */
	public function getImageData() {
		$clazz = ucfirst($this->engine);
		$search = new $clazz();
		$search->setQuery(urlencode($this->word));
		$search->setParam('start', $this->hitPosition);
		$search->setParam('size', $this->numberResults);

		$searchData = $search->getData();

		return $searchData['result'] == false ? false : $searchData;
	}

	/**
	 * Saves image or returns false
	 * @param array $results
	 * @param string $tmpDir
	 * @param integer $hit
	 * @return mixed
	 */
	private function imageToTmp($results, $tmpDir, $hit = 0) {
		$first = $results[$hit]['clickurl'];
		$imageName = $tmpDir . DIRECTORY_SEPARATOR . $this->filename($first);

		$myCurl = new ZAPCurl($first, true);
		$imageData = $myCurl->fetchCurlData();

    	if($imageData == false) {
			$this->addLog('error', 'Search: ', 'received empty file' . PHP_EOL);
			return false;
		}

		if(file_put_contents($imageName, $imageData)) {
			if($this->imageTypeOk($imageName)) {
				$this->addLog('ok', 'Search: ', "downloaded to $imageName");
				$this->addLog('ok', 'Search: ', 'source: ' . $results[$hit]['referer']);
				$this->addLog('ok', 'Search: ', 'thumb: ' . $results[$hit]['thumb'] . PHP_EOL);
				return $imageName;
			} else {
				$this->addLog('error', 'Search: ', 'wrong file type: image removed');
				unlink($imageName);

				$nextHit = $hit + 1;
				return $this->imageToTmp($results, $tmpDir, $nextHit);
			}
		} else {
			$this->addLog('error', 'Search: ', 'failed saving image');
			return false;
		}
	}

	/**
	 * Check mime type of image
	 * @param string $fileUri
	 * @return boolean
	 */
    private function imageTypeOk($fileUri) {
		$mimeType = mime_content_type($fileUri);
		return in_array($mimeType, $this->allowedFileTypes);
    }

	/**
	 * Gets filename from a url
	 * @param string $urlString
	 * @return string
	 */
    private function filename($urlString) {
    	$ar = explode('/', $urlString);
    	$filename = array_pop($ar);
    	// Strip query string so the saved file has a real extension
    	$filename = explode('?', $filename)[0];
    	return $filename;
    }

	/**
	 * Log messages
	 */
	private function addLog($type, $head, $message) {
		if (ZAP_LOG == true) {
			$this->log->addToLog($type, $head, $message);
		}
		return;
	}
}
?>