Clean up and documentation in photo_drive.

1 files changed, 271 insertions, 242 deletions

diff --git a/include/photo/photo_driver.php b/include/photo/photo_driver.php
index 5c8ed9bdc..718bf875b 100644
--- a/include/photo/photo_driver.php
+++ b/include/photo/photo_driver.php
@@ -1,18 +1,30 @@
-<?php /** @file */
+<?php
 
+/**
+ * @brief Return a photo_driver object.
+ *
+ * Use this factory when manipulating images.
+ *
+ * Return a photo driver object implementing ImageMagick or GD.
+ *
+ * @param string $data Image data
+ * @param string $type
+ * @return null|photo_driver
+ *   NULL if unsupported image type or failure, otherwise photo driver object
+ */
 function photo_factory($data, $type = null) {
 	$ph = null;
+	$m = null;
 
-
-	$unsupported_types = array(
+	$unsupported_types = [
 		'image/bmp',
 		'image/vnd.microsoft.icon',
 		'image/tiff',
-		'image/svg+xml'
-	);
+		'image/svg+xml',
+	];
 
-	if($type && in_array(strtolower($type),$unsupported_types)) {
-		logger('photo_factory: unsupported image type');
+	if($type && in_array(strtolower($type), $unsupported_types)) {
+		logger('Unsupported image type ' . $type);
 		return null;
 	}
 
@@ -21,29 +33,30 @@ function photo_factory($data, $type = null) {
 	if(class_exists('Imagick') && !$ignore_imagick) {
 		$v = Imagick::getVersion();
 		preg_match('/ImageMagick ([0-9]+\.[0-9]+\.[0-9]+)/', $v['versionString'], $m);
-		if(version_compare($m[1],'6.6.7') >= 0) {
+		if(version_compare($m[1], '6.6.7') >= 0) {
 			require_once('include/photo/photo_imagick.php');
-			$ph = new photo_imagick($data,$type);
-		}
-		else {
+			$ph = new photo_imagick($data, $type);
+		} else {
 			// earlier imagick versions have issues with scaling png's
 			// don't log this because it will just fill the logfile.
-			// leave this note here so those who are looking for why 
+			// leave this note here so those who are looking for why
 			// we aren't using imagick can find it
 		}
 	}
 
 	if(! $ph) {
 		require_once('include/photo/photo_gd.php');
-		$ph = new photo_gd($data,$type);
+		$ph = new photo_gd($data, $type);
 	}
 
 	return $ph;
 }
 
 
-
-
+/**
+ * @brief Abstract photo driver class.
+ *
+ */
 abstract class photo_driver {
 
 	protected $image;
@@ -79,12 +92,12 @@ abstract class photo_driver {
 
 	public function __construct($data, $type='') {
 		$this->types = $this->supportedTypes();
-		if (! array_key_exists($type,$this->types)){
-			$type='image/jpeg';
+		if (! array_key_exists($type, $this->types)){
+			$type = 'image/jpeg';
 		}
 		$this->type = $type;
 		$this->valid = false;
-		$this->load($data,$type);
+		$this->load($data, $type);
 	}
 
 	public function __destruct() {
@@ -99,12 +112,14 @@ abstract class photo_driver {
 	public function getWidth() {
 		if(!$this->is_valid())
 			return FALSE;
+
 		return $this->width;
 	}
 
 	public function getHeight() {
 		if(!$this->is_valid())
 			return FALSE;
+
 		return $this->height;
 	}
 
@@ -112,6 +127,7 @@ abstract class photo_driver {
 	public function saveImage($path) {
 		if(!$this->is_valid())
 			return FALSE;
+
 		return (file_put_contents($path, $this->imageString()) ? true : false);
 	}
 
@@ -131,12 +147,14 @@ abstract class photo_driver {
 	}
 
 	/**
-	 * @brief scale image
-	 * int $max maximum pixel size in either dimension
-	 * boolean $float_height - if true allow height to float to any length on tall images, 
-	 *     constraining only the width
+	 * @brief Scale image to max pixel size in either dimension.
+	 *
+	 * @param int $max maximum pixel size in either dimension
+	 * @param boolean $float_height (optional)
+	 *   if true allow height to float to any length on tall images, constraining
+	 *   only the width
+	 *  @return boolean|void false on failure, otherwise void
 	 */
-
 	public function scaleImage($max, $float_height = true) {
 		if(!$this->is_valid())
 			return FALSE;
@@ -203,7 +221,6 @@ abstract class photo_driver {
 		if(!$this->is_valid())
 			return FALSE;
 
-
 		$width = $this->width;
 		$height = $this->height;
 
@@ -241,33 +258,39 @@ abstract class photo_driver {
 		$this->doScaleImage($dest_width,$dest_height);
 	}
 
-
+	/**
+	 * @brief Scales image to a square.
+	 *
+	 * @param int $dim Pixel of squre image
+	 * @return boolean|void false on failure, otherwise void
+	 */
 	public function scaleImageSquare($dim) {
 		if(!$this->is_valid())
 			return FALSE;
-		$this->doScaleImage($dim,$dim);
-	}
 
+		$this->doScaleImage($dim, $dim);
+	}
 
 	/**
-	 * @brief reads exif data from filename
+	 * @brief reads exif data from filename.
+	 *
+	 * @param string $filename
+	 * @return boolean|array
 	 */
-
 	public function exif($filename) {
 
-
-		if((! function_exists('exif_read_data')) 
+		if((! function_exists('exif_read_data'))
 			|| (! in_array($this->getType(), [ 'image/jpeg' , 'image/tiff'] ))) {
 			return false;
 		}
 
 		/*
 		 * PHP 7.2 allows you to use a stream resource, which should reduce/avoid
-		 * memory exhaustion on large images. 
+		 * memory exhaustion on large images.
 		 */
 
-		if(version_compare(PHP_VERSION,'7.2.0') >= 0) {
-			$f = @fopen($filename,'rb');
+		if(version_compare(PHP_VERSION, '7.2.0') >= 0) {
+			$f = @fopen($filename, 'rb');
 		}
 		else {
 			$f = $filename;
@@ -281,21 +304,23 @@ abstract class photo_driver {
 	}
 
 	/**
-	 * @brief orients current image based on exif orientation information
+	 * @brief Orients current image based on exif orientation information.
+	 *
+	 * @param array $exif
+	 * @return boolean true if oriented, otherwise false
 	 */
-
 	public function orient($exif) {
 
 		if(! ($this->is_valid() && $exif)) {
 			return false;
 		}
 
-		$ort = ((array_key_exists('IFD0',$exif)) ? $exif['IFD0']['Orientation'] : $exif['Orientation']);
+		$ort = ((array_key_exists('IFD0', $exif)) ? $exif['IFD0']['Orientation'] : $exif['Orientation']);
 
 		if(! $ort) {
 			return false;
 		}
-		
+
 		switch($ort) {
 			case 1: // nothing
 				break;
@@ -319,7 +344,7 @@ abstract class photo_driver {
 				$this->flip();
 				$this->rotate(-90);
 				break;
-			case 8:	// 90 rotate left
+			case 8: // 90 rotate left
 				$this->rotate(90);
 				break;
 			default:
@@ -329,15 +354,21 @@ abstract class photo_driver {
 		return true;
 	}
 
-
+	/**
+	 * @brief Save photo to database.
+	 *
+	 * @param array $arr
+	 * @param boolean $skipcheck (optional) default false
+	 * @return boolean|array
+	 */
 	public function save($arr, $skipcheck = false) {
 
 		if(! ($skipcheck || $this->is_valid())) {
-			logger('attempt to store invalid photo.');
+			logger('Attempt to store invalid photo.');
 			return false;
 		}
 
-		$p = array();
+		$p = [];
 
 		$p['aid'] = ((intval($arr['aid'])) ? intval($arr['aid']) : 0);
 		$p['uid'] = ((intval($arr['uid'])) ? intval($arr['uid']) : 0);
@@ -351,11 +382,11 @@ abstract class photo_driver {
 		$p['allow_gid'] = (($arr['allow_gid']) ? $arr['allow_gid'] : '');
 		$p['deny_cid'] = (($arr['deny_cid']) ? $arr['deny_cid'] : '');
 		$p['deny_gid'] = (($arr['deny_gid']) ? $arr['deny_gid'] : '');
-		$p['edited'] = (($arr['edited']) ? $arr['edited'] : datetime_convert()); 
+		$p['edited'] = (($arr['edited']) ? $arr['edited'] : datetime_convert());
 		$p['title'] = (($arr['title']) ? $arr['title'] : '');
 		$p['description'] = (($arr['description']) ? $arr['description'] : '');
 		$p['photo_usage'] = intval($arr['photo_usage']);
-		$p['os_storage'] = intval($arr['os_storage']);			
+		$p['os_storage'] = intval($arr['os_storage']);
 		$p['os_path'] = $arr['os_path'];
 		$p['os_syspath'] = ((array_key_exists('os_syspath',$arr)) ? $arr['os_syspath'] : '');
 		$p['display_path'] = (($arr['display_path']) ? $arr['display_path'] : '');
@@ -364,7 +395,7 @@ abstract class photo_driver {
 		$p['expires'] = (($arr['expires']) ? $arr['expires'] : gmdate('Y-m-d H:i:s', time() + get_config('system','photo_cache_time', 86400)));
 
 		if(! intval($p['imgscale']))
-			logger('save: ' . print_r($arr,true), LOGGER_DATA);
+			logger('save: ' . print_r($arr, true), LOGGER_DATA);
 
 		$x = q("select id, created from photo where resource_id = '%s' and uid = %d and xchan = '%s' and imgscale = %d limit 1",
 				dbesc($p['resource_id']),
@@ -372,7 +403,7 @@ abstract class photo_driver {
 				dbesc($p['xchan']),
 				intval($p['imgscale'])
 		);
-		
+
 		if($x) {
 			$p['created'] = (($x['created']) ? $x['created'] : $p['edited']);
 			$r = q("UPDATE photo set
@@ -388,7 +419,7 @@ abstract class photo_driver {
 				height = %d,
 				width = %d,
 				content = '%s',
-				os_storage = %d, 
+				os_storage = %d,
 				filesize = %d,
 				imgscale = %d,
 				photo_usage = %d,
@@ -463,33 +494,36 @@ abstract class photo_driver {
 				dbescdate($p['expires'])
 			);
 		}
-		logger('photo save ' . $p['imgscale'] . ' returned ' . intval($r));
+		logger('Photo save ' . $p['imgscale'] . ' returned ' . intval($r));
+
 		return $r;
 	}
 
 }
 
-
-
 /**
- * Guess image mimetype from filename or from Content-Type header
+ * @brief Guess image mimetype from filename or from Content-Type header.
  *
- * @arg $filename string Image filename
- * @arg $headers string Headers to check for Content-Type (from curl request)
+ * @param string $filename
+ *   Image filename
+ * @param string $headers (optional)
+ *   Headers to check for Content-Type (from curl request)
+ * @return null|string Guessed mimetype
  */
-
 function guess_image_type($filename, $headers = '') {
 //	logger('Photo: guess_image_type: '.$filename . ($headers?' from curl headers':''), LOGGER_DEBUG);
 	$type = null;
-	if ($headers) {
-		$hdrs=array();
-		$h = explode("\n",$headers);
+	$m = null;
+
+	if($headers) {
+		$hdrs = [];
+		$h = explode("\n", $headers);
 		foreach ($h as $l) {
-			list($k,$v) = array_map("trim", explode(":", trim($l), 2));
+			list($k,$v) = array_map('trim', explode(':', trim($l), 2));
 			$hdrs[strtolower($k)] = $v;
 		}
-		logger('Curl headers: '.var_export($hdrs, true), LOGGER_DEBUG);
-		if (array_key_exists('content-type', $hdrs)) {
+		logger('Curl headers: ' .var_export($hdrs, true), LOGGER_DEBUG);
+		if(array_key_exists('content-type', $hdrs)) {
 			$ph = photo_factory('');
 			$types = $ph->supportedTypes();
 
@@ -498,13 +532,13 @@ function guess_image_type($filename, $headers = '') {
 		}
 	}
 
-	if (is_null($type)){
+	if(is_null($type)){
 		$ignore_imagick = get_config('system', 'ignore_imagick');
 		// Guessing from extension? Isn't that... dangerous?
 		if(class_exists('Imagick') && file_exists($filename) && is_readable($filename) && !$ignore_imagick) {
 			$v = Imagick::getVersion();
 			preg_match('/ImageMagick ([0-9]+\.[0-9]+\.[0-9]+)/', $v['versionString'], $m);
-			if(version_compare($m[1],'6.6.7') >= 0) {
+			if(version_compare($m[1], '6.6.7') >= 0) {
 				/**
 				 * Well, this not much better,
 				 * but at least it comes from the data inside the image,
@@ -516,7 +550,7 @@ function guess_image_type($filename, $headers = '') {
 			else {
 				// earlier imagick versions have issues with scaling png's
 				// don't log this because it will just fill the logfile.
-				// leave this note here so those who are looking for why 
+				// leave this note here so those who are looking for why
 				// we aren't using imagick can find it
 			}
 		}
@@ -551,33 +585,36 @@ function guess_image_type($filename, $headers = '') {
 
 	}
 	logger('Photo: guess_image_type: filename = ' . $filename . ' type = ' . $type, LOGGER_DEBUG);
-	return $type;
 
+	return $type;
 }
 
-
-function delete_thing_photo($url,$ob_hash) {
+/**
+ * @brief Delete thing photo from database.
+ *
+ * @param string $url
+ * @param string $ob_hash
+ * @return void
+ */
+function delete_thing_photo($url, $ob_hash) {
 
 	$hash = basename($url);
-	$hash = substr($hash,0,strpos($hash,'-'));
+	$hash = substr($hash, 0, strpos($hash, '-'));
 
-	// hashes should be 32 bytes. 
+	// hashes should be 32 bytes.
 
 	if((! $ob_hash) || (strlen($hash) < 16))
-		return;	
+		return;
 
-	$r = q("delete from photo where xchan = '%s' and photo_usage = %d and resource_id = '%s'",
+	q("delete from photo where xchan = '%s' and photo_usage = %d and resource_id = '%s'",
 		dbesc($ob_hash),
 		intval(PHOTO_THING),
 		dbesc($hash)
 	);
-	
 }
 
-
-
 /**
- * @brief fetches an photo from external site and prepares its miniatures.
+ * @brief Fetches a photo from external site and prepares its miniatures.
  *
  * @param string $photo
  *    external URL to fetch base image
@@ -596,223 +633,215 @@ function delete_thing_photo($url,$ob_hash) {
  * * \e boolean \b 4 => TRUE if fetch failure
  * * \e string \b 5 => modification date
  */
+function import_xchan_photo($photo, $xchan, $thing = false, $force = false) {
+	$modified = '';
+	$o = null;
+
+	$flags = (($thing) ? PHOTO_THING : PHOTO_XCHAN);
+	$album = (($thing) ? 'Things' : 'Contact Photos');
+
+	logger('Updating channel photo from ' . $photo . ' for ' . $xchan, LOGGER_DEBUG);
+
+	if($thing) {
+		$hash = photo_new_resource();
+	} else {
+		$r = q("select resource_id, edited, mimetype from photo where xchan = '%s' and photo_usage = %d and imgscale = 4 limit 1", dbesc($xchan), intval(PHOTO_XCHAN));
+		if($r) {
+			$hash = $r[0]['resource_id'];
+			$modified = $r[0]['edited'];
+			$type = $r[0]['mimetype'];
+		} else {
+			$hash = photo_new_resource();
+		}
+	}
 
-function import_xchan_photo($photo,$xchan,$thing = false,$force = false) {
-
-        $modified = '';
-
-        $flags = (($thing) ? PHOTO_THING : PHOTO_XCHAN);
-        $album = (($thing) ? 'Things' : 'Contact Photos');
-
-        logger('import_xchan_photo: updating channel photo from ' . $photo . ' for ' . $xchan, LOGGER_DEBUG);
-
-        if($thing) {
-                $hash = photo_new_resource();
-        }
-        else {
-                $r = q("select resource_id, edited, mimetype from photo where xchan = '%s' and photo_usage = %d and imgscale = 4 limit 1",
-                        dbesc($xchan),
-                        intval(PHOTO_XCHAN)
-                );
-                if($r) {
-                        $hash = $r[0]['resource_id'];
-                        $modified = $r[0]['edited'];
-                        $type = $r[0]['mimetype'];
-                }
-                else {
-                        $hash = photo_new_resource();
-                }
-        }
-
-        $photo_failure = false;
-        $img_str = '';
-
-        if($photo) {
-                $filename = basename($photo);
-
-                if($force || $modified == '') {
-                        $result = z_fetch_url($photo,true);
-                }
-                else {
-                        $h = array('headers' => array("If-Modified-Since: " . gmdate("D, d M Y H:i:s", strtotime($modified . "Z")) . " GMT"));
-                        $result = z_fetch_url($photo,true,0,$h);
-                }
-
-                if($result['success']) {
-                        $img_str = $result['body'];
-                        $type = guess_image_type($photo, $result['header']);
-                        $modified = gmdate('Y-m-d H:i:s', (preg_match('/last-modified: (.+) \S+/i', $result['header'], $o) ? strtotime($o[1] . 'Z') : time()));
-                        if(is_null($type))
-                                $photo_failure = true;
-                }
-                elseif($result['return_code'] == 304) {
-                        $photo = z_root() . '/photo/' . $hash . '-4';
-                        $thumb = z_root() . '/photo/' . $hash . '-5';
-                        $micro = z_root() . '/photo/' . $hash . '-6';
-                }
-                else {
-                        $photo_failure = true;
-                }
-
-        }
-        else
-                $photo_failure = true;
-
-        if(! $photo_failure && $result['return_code'] != 304) {
-                $img = photo_factory($img_str, $type);
-                if($img->is_valid()) {
-                        $width = $img->getWidth();
-                        $height = $img->getHeight();
-
-                        if($width && $height) {
-                                if(($width / $height) > 1.2) {
-                                        // crop out the sides
-                                        $margin = $width - $height;
-                                        $img->cropImage(300,($margin / 2),0,$height,$height);
-                                }
-                                elseif(($height / $width) > 1.2) {
-                                        // crop out the bottom
-                                        $margin = $height - $width;
-                                        $img->cropImage(300,0,0,$width,$width);
-
-                                }
-                                else {
-                                        $img->scaleImageSquare(300);
-                                }
-
-                        }
-                        else
-                                $photo_failure = true;
-
-                        $p = array(
-							'xchan' => $xchan,
-							'resource_id' => $hash,
-							'filename' => basename($photo),
-							'album' => $album,
-							'photo_usage' => $flags,
-							'imgscale' => 4,
-							'edited' => $modified
-						);
-
-                        $r = $img->save($p);
-
-                        if($r === false)
-                                $photo_failure = true;
-
-                        $img->scaleImage(80);
-                        $p['imgscale'] = 5;
-
-                        $r = $img->save($p);
-
-                        if($r === false)
-                                $photo_failure = true;
-
-                        $img->scaleImage(48);
-                        $p['imgscale'] = 6;
-
-                        $r = $img->save($p);
-
-                        if($r === false)
-                                $photo_failure = true;
-
-                        $photo = z_root() . '/photo/' . $hash . '-4';
-                        $thumb = z_root() . '/photo/' . $hash . '-5';
-                        $micro = z_root() . '/photo/' . $hash . '-6';
-                }
-                else {
-                        logger('import_xchan_photo: invalid image from ' . $photo);
-                        $photo_failure = true;
-                }
-        }
-        if($photo_failure) {
-                $default = get_default_profile_photo();
-                $photo = z_root() . '/' . $default;
-                $thumb = z_root() . '/' . get_default_profile_photo(80);
-                $micro = z_root() . '/' . get_default_profile_photo(48);
-                $type = 'image/png';
-                $modified = gmdate('Y-m-d H:i:s', filemtime($default));
-        }
-
-		logger('HTTP code: ' . $result['return_code'] . '; modified: ' . $modified . '; failure: ' . ($photo_failure ? 'yes' : 'no') . '; URL: ' . $photo, LOGGER_DEBUG);
-        return(array($photo,$thumb,$micro,$type,$photo_failure,$modified));
-
-}
-
-function import_channel_photo_from_url($photo,$aid,$uid) {
+	$photo_failure = false;
+	$img_str = '';
 
 	if($photo) {
-		$filename = basename($photo);
 
-		$result = z_fetch_url($photo,true);
+		if($force || $modified == '') {
+			$result = z_fetch_url($photo, true);
+		} else {
+			$h = [
+					'headers' => [
+							'If-Modified-Since: ' . gmdate('D, d M Y H:i:s', strtotime($modified . 'Z')) . ' GMT'
+					]
+			];
+			$result = z_fetch_url($photo, true, 0, $h);
+		}
 
 		if($result['success']) {
 			$img_str = $result['body'];
 			$type = guess_image_type($photo, $result['header']);
+			$modified = gmdate('Y-m-d H:i:s', (preg_match('/last-modified: (.+) \S+/i', $result['header'], $o) ? strtotime($o[1] . 'Z') : time()));
+			if(is_null($type))
+				$photo_failure = true;
+		} elseif($result['return_code'] == 304) {
+			$photo = z_root() . '/photo/' . $hash . '-4';
+			$thumb = z_root() . '/photo/' . $hash . '-5';
+			$micro = z_root() . '/photo/' . $hash . '-6';
+		} else {
+			$photo_failure = true;
+		}
+	} else {
+		$photo_failure = true;
+	}
 
-            if(is_null($type))
-                    $photo_failure = true;
+	if(!$photo_failure && $result['return_code'] != 304) {
+		$img = photo_factory($img_str, $type);
+		if($img->is_valid()) {
+			$width = $img->getWidth();
+			$height = $img->getHeight();
+
+			if($width && $height) {
+				if(($width / $height) > 1.2) {
+					// crop out the sides
+					$margin = $width - $height;
+					$img->cropImage(300, ($margin / 2), 0, $height, $height);
+				} elseif(($height / $width) > 1.2) {
+					// crop out the bottom
+					$margin = $height - $width;
+					$img->cropImage(300, 0, 0, $width, $width);
+				} else {
+					$img->scaleImageSquare(300);
+				}
+			} else {
+				$photo_failure = true;
+			}
+
+			$p = [
+					'xchan' => $xchan,
+					'resource_id' => $hash,
+					'filename' => basename($photo),
+					'album' => $album,
+					'photo_usage' => $flags,
+					'imgscale' => 4,
+					'edited' => $modified,
+			];
+
+			$r = $img->save($p);
+			if($r === false)
+				$photo_failure = true;
+
+			$img->scaleImage(80);
+			$p['imgscale'] = 5;
+			$r = $img->save($p);
+			if($r === false)
+				$photo_failure = true;
+
+			$img->scaleImage(48);
+			$p['imgscale'] = 6;
+			$r = $img->save($p);
+			if($r === false)
+				$photo_failure = true;
+
+			$photo = z_root() . '/photo/' . $hash . '-4';
+			$thumb = z_root() . '/photo/' . $hash . '-5';
+			$micro = z_root() . '/photo/' . $hash . '-6';
+		} else {
+			logger('Invalid image from ' . $photo);
+			$photo_failure = true;
 		}
 	}
-	else {
-		$photo_failure = true;
+	if($photo_failure) {
+		$default = get_default_profile_photo();
+		$photo = z_root() . '/' . $default;
+		$thumb = z_root() . '/' . get_default_profile_photo(80);
+		$micro = z_root() . '/' . get_default_profile_photo(48);
+		$type = 'image/png';
+		$modified = gmdate('Y-m-d H:i:s', filemtime($default));
 	}
 
-	import_channel_photo($img_str,$type,$aid,$uid);
+	logger('HTTP code: ' . $result['return_code'] . '; modified: ' . $modified
+			. '; failure: ' . ($photo_failure ? 'yes' : 'no') . '; URL: ' . $photo, LOGGER_DEBUG);
 
-	return $type;
+	return(array($photo,$thumb,$micro,$type,$photo_failure,$modified));
 }
 
+/**
+  * @brief Import channel photo from a URL.
+ *
+ * @param string $photo URL to a photo
+ * @param int $aid
+ * @param int $uid channel_id
+ * @return null|string Guessed image mimetype or null.
+ */
+function import_channel_photo_from_url($photo, $aid, $uid) {
+	$type = null;
 
-function import_channel_photo($photo,$type,$aid,$uid) {
+	if($photo) {
+		$result = z_fetch_url($photo, true);
+
+		if($result['success']) {
+			$img_str = $result['body'];
+			$type = guess_image_type($photo, $result['header']);
 
-	logger('import_channel_photo: importing channel photo for ' . $uid, LOGGER_DEBUG);
+			import_channel_photo($img_str, $type, $aid, $uid);
+		}
+	}
 
-	$hash = photo_new_resource();
+	return $type;
+}
 
-	$photo_failure = false;
+/**
+ * @brief Import a channel photo and prepare its miniatures.
+ *
+ * @param string $photo Image data
+ * @param string $type
+ * @param int $aid
+ * @param int $uid channel_id
+ * @return boolean|string false on failure, otherwise resource_id of photo
+ */
+function import_channel_photo($photo, $type, $aid, $uid) {
 
+	logger('Importing channel photo for ' . $uid, LOGGER_DEBUG);
 
+	$photo_failure = false;
+	$hash = photo_new_resource();
 	$filename = $hash;
 
 	$img = photo_factory($photo, $type);
 	if($img->is_valid()) {
 
+		// config array for image save method
+		$p = [
+				'aid' => $aid,
+				'uid' => $uid,
+				'resource_id' => $hash,
+				'filename' => $filename,
+				'album' => t('Profile Photos'),
+				'photo_usage' => PHOTO_PROFILE,
+				'imgscale' => 4,
+		];
+
+		// photo size
 		$img->scaleImageSquare(300);
-
-		$p = array('aid' => $aid, 'uid' => $uid, 'resource_id' => $hash, 'filename' => $filename, 'album' => t('Profile Photos'), 'photo_usage' => PHOTO_PROFILE, 'imgscale' => 4);
-
 		$r = $img->save($p);
-
 		if($r === false)
 			$photo_failure = true;
 
+		// thumb size
 		$img->scaleImage(80);
 		$p['imgscale'] = 5;
-
 		$r = $img->save($p);
-
 		if($r === false)
 			$photo_failure = true;
 
+		// micro size
 		$img->scaleImage(48);
 		$p['imgscale'] = 6;
-
 		$r = $img->save($p);
-
 		if($r === false)
 			$photo_failure = true;
 
-	}
-	else {
-		logger('import_channel_photo: invalid image.');
+	} else {
+		logger('Invalid image.');
 		$photo_failure = true;
 	}
 
-	//return(($photo_failure)? false : true);
-
 	if($photo_failure)
 		return false;
 	else
 		return $hash;
-
 }