<?php
/**
 * Base WordPress Image Editor
 *
 * @package WordPress
 * @subpackage Image_Editor
 */

/**
 * Base WordPress Image Editor class for which Editor implementations extend
 *
 * @since 3.5.0
 */
abstract class WP_Image_Editor {
	protected $file = null;
	protected $size = null;
	protected $mime_type  = null;
	protected $default_mime_type = 'image/jpeg';
	protected $quality = 90;

	protected function __construct( $filename ) {
		$this->file = $filename;
	}

	/**
	 * Returns a WP_Image_Editor instance and loads file into it.
	 *
	 * @since 3.5.0
	 * @access public
	 *
	 * @param string $path Path to File to Load
	 * @param array $required_methods Methods to require in implementation
	 * @return WP_Image_Editor|WP_Error
	 */
	public final static function get_instance( $path = null, $required_methods = null ) {
		$implementation = apply_filters( 'wp_image_editor_class', self::choose_implementation( $required_methods ), $path );

		if ( $implementation ) {
			$editor = new $implementation( $path );
			$loaded = $editor->load();

			if ( is_wp_error( $loaded ) )
				return $loaded;

			return $editor;
		}

		return new WP_Error( 'no_editor', __('No editor could be selected') );
	}

	/**
	 * Tests which editors are capable of supporting the request.
	 *
	 * @since 3.5.0
	 * @access private
	 *
	 * @param array $required_methods String array of all methods required for implementation returned.
	 * @return string|bool Class name for the first editor that claims to support the request. False if no editor claims to support the request.
	 */
	private final static function choose_implementation( $required_methods = null ) {
		$request_order = apply_filters( 'wp_image_editors',
			array( 'WP_Image_Editor_Imagick', 'WP_Image_Editor_GD' ) );

		if ( ! $required_methods )
			$required_methods = apply_filters( 'wp_image_editor_default_methods',
				array( 'resize', 'multi_resize', 'crop', 'rotate', 'flip', 'stream' ) );

		// Loop over each editor on each request looking for one which will serve this request's needs
		foreach ( $request_order as $editor ) {
			// Check to see if this editor is a possibility, calls the editor statically
			if ( ! call_user_func( array( $editor, 'test' ) ) )
				continue;

			// Make sure that all methods are supported by editor.
			if ( array_diff( $required_methods, get_class_methods( $editor ) ) )
				continue;

			return $editor;
		}
		return false;
	}

	abstract protected function load(); // returns bool|WP_Error
	abstract public function save( $destfilename = null, $mime_type = null );

	/**
	 * Implement all of the below to support natively used functions:
	 *
	 * public function resize( $max_w, $max_h, $crop = false )
	 * public function multi_resize( $sizes )
	 * public function crop( $src_x, $src_y, $src_w, $src_h, $dst_w = null, $dst_h = null, $src_abs = false )
	 * public function rotate( $angle )
	 * public function flip( $horz, $vert )
	 * public function stream( $mime_type = null )
	 */

	/**
	 * Checks to see if current environment supports the editor chosen.
	 * Must be overridden in a sub-class.
	 *
	 * @since 3.5.0
	 * @access public
	 * @abstract
	 *
	 * @param array $args
	 * @return boolean
	 */
	public static function test( $args = null ) {
		return false;
	}

	/**
	 * Checks to see if editor supports mime-type specified
	 * Must be overridden in a sub-class.
	 *
	 * @since 3.5.0
	 * @access public
	 * @abstract
	 *
	 * @param string $mime_type
	 * @return boolean
	 */
	public static function supports_mime_type( $mime_type ) {
		return false;
	}

	/**
	 * Gets dimensions of image
	 *
	 * @since 3.5.0
	 * @access public
	 *
	 * @return array {'width'=>int, 'height'=>int}
	 */
	public function get_size() {
		return $this->size;
	}

	/**
	 * Sets current image size
	 *
	 * @since 3.5.0
	 * @access protected
	 *
	 * @param int $width
	 * @param int $height
	 */
	protected function update_size( $width = null, $height = null ) {
		$this->size = array(
			'width' => $width,
			'height' => $height
		);
		return true;
	}

	/**
	 * Sets Image Compression quality on a 1-100% scale.
	 *
	 * @since 3.5.0
	 * @access public
	 *
	 * @param int $quality Compression Quality. Range: [1,100]
	 * @return boolean
	 */
	public function set_quality( $quality ) {
		$this->quality = apply_filters( 'wp_editor_set_quality', $quality );

		return ( (bool) $this->quality );
	}

	/**
	 * Returns preferred mime-type and extension based on provided
	 * file's extension and mime, or current file's extension and mime.
	 *
	 * Will default to $this->default_mime_type if requested is not supported.
	 *
	 * Provides corrected filename only if filename is provided.
	 *
	 * @since 3.5.0
	 * @access protected
	 *
	 * @param string $filename
	 * @param string $mime_type
	 * @return array { filename|null, extension, mime-type }
	 */
	protected function get_output_format( $filename = null, $mime_type = null ) {
		$new_ext = $file_ext = null;
		$file_mime = null;

		// By default, assume specified type takes priority
		if ( $mime_type ) {
			$new_ext = $this->get_extension( $mime_type );
		}

		if ( $filename ) {
			$file_ext = strtolower( pathinfo( $filename, PATHINFO_EXTENSION ) );
			$file_mime = $this->get_mime_type( $file_ext );
		}
		else {
			// If no file specified, grab editor's current extension and mime-type.
			$file_ext = strtolower( pathinfo( $this->file, PATHINFO_EXTENSION ) );
			$file_mime = $this->mime_type;
		}

		// Check to see if specified mime-type is the same as type implied by
		// file extension.  If so, prefer extension from file.
		if ( ! $mime_type || ( $file_mime == $mime_type ) ) {
			$mime_type = $file_mime;
			$new_ext = $file_ext;
		}

		// Double-check that the mime-type selected is supported by the editor.
		// If not, choose a default instead.
		if ( ! $this->supports_mime_type( $mime_type ) ) {
			$mime_type = apply_filters( 'image_editor_default_mime_type', $this->default_mime_type );
			$new_ext = $this->get_extension( $mime_type );
		}

		if ( $filename ) {
			$ext = '';
			$info = pathinfo( $filename );
			$dir  = $info['dirname'];

			if( isset( $info['extension'] ) )
				$ext = $info['extension'];

			$filename = trailingslashit( $dir ) . wp_basename( $filename, ".$ext" ) . ".{$new_ext}";
		}

		return array( $filename, $new_ext, $mime_type );
	}

	/**
	 * Builds an output filename based on current file, and adding proper suffix
	 *
	 * @since 3.5.0
	 * @access public
	 *
	 * @param string $suffix
	 * @param string $dest_path
	 * @param string $extension
	 * @return string filename
	 */
	public function generate_filename( $suffix = null, $dest_path = null, $extension = null ) {
		// $suffix will be appended to the destination filename, just before the extension
		if ( ! $suffix )
			$suffix = $this->get_suffix();

		$info = pathinfo( $this->file );
		$dir  = $info['dirname'];
		$ext  = $info['extension'];

		$name = wp_basename( $this->file, ".$ext" );
		$new_ext = strtolower( $extension ? $extension : $ext );

		if ( ! is_null( $dest_path ) && $_dest_path = realpath( $dest_path ) )
			$dir = $_dest_path;

		return trailingslashit( $dir ) . "{$name}-{$suffix}.{$new_ext}";
	}

	/**
	 * Builds and returns proper suffix for file based on height and width.
	 *
	 * @since 3.5.0
	 * @access public
	 *
	 * @return string suffix
	 */
	public function get_suffix() {
		if ( ! $this->get_size() )
			return false;

		return "{$this->size['width']}x{$this->size['height']}";
	}

	/**
	 * Either calls editor's save function or handles file as a stream.
	 *
	 * @since 3.5.0
	 * @access protected
	 *
	 * @param string|stream $filename
	 * @param callable $function
	 * @param array $arguments
	 * @return boolean
	 */
	protected function make_image( $filename, $function, $arguments ) {
		$dst_file = $filename;

		if ( $stream = wp_is_stream( $filename ) ) {
			$filename = null;
			ob_start();
		}

		$result = call_user_func_array( $function, $arguments );

		if ( $result && $stream ) {
			$contents = ob_get_contents();

			$fp = fopen( $dst_file, 'w' );

			if ( ! $fp )
				return false;

			fwrite( $fp, $contents );
			fclose( $fp );
		}

		if ( $stream ) {
			ob_end_clean();
		}

		return $result;
	}

	/**
	 * Returns first matched mime-type from extension,
	 * as mapped from wp_get_mime_types()
	 *
	 * @since 3.5.0
	 * @access protected
	 *
	 * @param string $extension
	 * @return string|boolean
	 */
	protected static function get_mime_type( $extension = null ) {
		if ( ! $extension )
			return false;

		$mime_types = wp_get_mime_types();
		$extensions = array_keys( $mime_types );

		foreach( $extensions as $_extension ) {
			if ( preg_match( "/{$extension}/i", $_extension ) ) {
				return $mime_types[$_extension];
			}
		}

		return false;
	}

	/**
	 * Returns first matched extension from Mime-type,
	 * as mapped from wp_get_mime_types()
	 *
	 * @since 3.5.0
	 * @access protected
	 *
	 * @param string $mime_type
	 * @return string|boolean
	 */
	protected static function get_extension( $mime_type = null ) {
		$extensions = explode( '|', array_search( $mime_type, wp_get_mime_types() ) );

		if ( empty( $extensions[0] ) )
			return false;

		return $extensions[0];
	}
}
