<?php
/**
 * Generates the styles for the frontend.
 * Handles the 'output' argument of fields
 *
 * @package     Kirki
 * @category    Core
 * @author      Aristeides Stathopoulos
 * @copyright   Copyright (c) 2016, Aristeides Stathopoulos
 * @license     http://opensource.org/licenses/gpl-2.0.php GNU Public License
 * @since       1.0
 */

// Exit if accessed directly
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

if ( ! class_exists( 'Kirki_Styles_Output_CSS' ) ) {
	final class Kirki_Styles_Output_CSS {

		public static $instance = null;

		public static $settings    = null;
		public static $output      = array();
		public static $callback    = null;
		public static $option_name = null;
		public static $field_type  = null;

		public static $google_fonts = null;
		public static $backup_fonts = null;

		public static $css;

		public static $value = null;

		/**
		 * The class constructor.
		 */
		private function __construct() {
			if ( is_null( self::$google_fonts ) ) {
				self::$google_fonts = Kirki_Fonts::get_google_fonts();
			}
			if ( is_null( self::$backup_fonts ) ) {
				self::$backup_fonts = Kirki_Fonts::get_backup_fonts();
			}
		}

		/**
		 * Get a single instance of this class
		 *
		 * @return object
		 */
		public static function get_instance() {
			if ( null === self::$instance ) {
				self::$instance = new Kirki_Styles_Output_CSS();
			}
			return self::$instance;
		}

		/**
		 * get the CSS for a field
		 *
		 * @var 	string		the setting ID.
		 * @var 	string		theme_mod / option
		 * @var 	array 		an array of arrays of the output arguments.
		 * @var 	mixed		a callable function.
		 */
		public static function css( $field ) {
			/**
			 * Set class vars
			 */
			self::$settings   = $field['settings'];
			self::$callback   = $field['sanitize_callback'];
			self::$field_type = $field['type'];
			self::$output     = $field['output'];
			if ( ! is_array( self::$output ) ) {
				self::$output = array(
					array(
						'element'           => self::$output,
						'sanitize_callback' => null,
					),
				);
			}
			/**
			 * Get the value of this field
			 */
			self::$value = Kirki_Values::get_sanitized_field_value( $field );
			/**
			 * Returns the styles
			 */
			return self::styles();

		}

		/**
		 * Gets the array of generated styles and creates the minimized, inline CSS
		 *
		 * @param array
		 * @return string	the generated CSS.
		 */
		public static function styles_parse( $css = array() ) {

			/**
			 * Process the array of CSS properties and produce the final CSS
			 */
			$final_css = '';
			if ( ! is_array( $css ) || empty( $css ) ) {
				return '';
			}
			foreach ( $css as $media_query => $styles ) {

				$final_css .= ( 'global' != $media_query ) ? $media_query . '{' : '';

				foreach ( $styles as $style => $style_array ) {
					$final_css .= $style . '{';
						foreach ( $style_array as $property => $value ) {
							$value = ( is_string( $value ) ) ? $value : '';
							// Take care of formatting the URL for background-image statements.
							if ( 'background-image' == $property || 'background' == $property && false !== filter_var( $value, FILTER_VALIDATE_URL, FILTER_FLAG_PATH_REQUIRED ) ) {
								$value = 'url("' . $value . '")';
							}
							// Make sure the background-position property is properly formatted
							if ( 'background-position' == $property ) {
								$value = str_replace( array( '_', '-' ), ' ', $value );
							}
							$final_css .= $property . ':' . $value . ';';
						}
					$final_css .= '}';
				}

				$final_css .= ( 'global' != $media_query ) ? '}' : '';

			}

			return $final_css;

		}

		/**
		 * Get the styles as an array.
		 */
		public static function styles() {

			$google_fonts_array = self::$google_fonts;
			$backup_fonts       = self::$backup_fonts;

			$styles = array();

			foreach ( self::$output as $output ) {

				if ( ! isset( $output['element'] ) ) {
					continue;
				}
				/**
				 * Do we have units?
				 */
				$units = ( isset( $output['units'] ) ) ? $output['units'] : '';
				/**
				 * Do we have a prefix?
				 */
				$prefix = ( isset( $output['prefix'] ) ) ? $output['prefix'] : '';
				/**
				 * Do we have a suffix?
				 */
				$suffix = ( isset( $output['suffix'] ) ) ? $output['suffix'] : '';
				/**
				 * Accept "callback" as short for "sanitize_callback".
				 */
				if ( ! isset( $output['sanitize_callback'] ) && isset( $output['callback'] ) ) {
					$output['sanitize_callback'] = $output['callback'];
				}
				/**
				 * Do we have a "media_query" defined?
				 */
				if ( ! isset( $output['media_query'] ) ) {
					$output['media_query'] = 'global';
				} else {
					$output['media_query'] = esc_attr( $output['media_query'] );
				}
				/**
				 * Do we need to run this through a callback action?
				 */
				$value = ( '' != self::$callback ) ? call_user_func( self::$callback, self::$value ) : self::$value;
				if ( isset( $output['sanitize_callback'] ) && null !== $output['sanitize_callback'] ) {
					$value = call_user_func( $output['sanitize_callback'], $value );
				}
				/**
				 * Make sure the value is a string before proceeding
				 * If all is ok, then populate the array.
				 */
				$element = $output['element'];
				/**
				 * Allow using an array of elements
				 */
				if ( is_array( $output['element'] ) ) {
					/**
					 * Make sure our values are unique
					 */
					$elements = array_unique( $element );
					/**
					 * Sort elements alphabetically.
					 * This way all duplicate items will be merged in the final CSS array.
					 */
					sort( $elements );
					/**
					 * Implode items
					 */
					$element = implode( ',', $elements );
				}
				if ( ! is_array( $value ) ) {
					if ( ! isset( $output['property'] ) ) {
						continue;
					}
					if ( 'font-family' == $output['property'] ) {
						// Add backup font
						if ( Kirki_Fonts::is_google_font( $value ) ) {
							if ( isset( $google_fonts_array[ $value ] ) && isset( $google_fonts_array[ $value ]['category'] ) ) {
								if ( isset( $backup_fonts[ $google_fonts_array[ $value ]['category'] ] ) ) {
									// add double quotes if needed
									if ( false !== strpos( $value, ' ' ) && false === strpos( $value, '"' ) ) {
										$value = '"' . $value . '", ' . $backup_fonts[ $google_fonts_array[ $value ]['category'] ];
									} else {
										$value .= ', ' . $backup_fonts[ $google_fonts_array[ $value ]['category'] ];
									}
								}
							}
						}
					}
					$styles[ $output['media_query'] ][ $element ][ $output['property'] ] = $prefix . $value . $units . $suffix;
				} else {
					/**
					 * Take care of typography controls output
					 */
					if ( 'typography' == self::$field_type ) {
						if ( isset( $value['bold'] ) && $value['bold'] ) {
							$styles[ $output['media_query'] ][ $element ]['font-weight'] = 'bold';
						}
						if ( isset( $value['italic'] ) && $value['italic'] ) {
							$styles[ $output['media_query'] ][ $element ]['font-style'] = 'italic';
						}
						if ( isset( $value['underline'] ) && $value['underline'] ) {
							$styles[ $output['media_query'] ][ $element ]['text-decoration'] = 'underline';
						}
						if ( isset( $value['strikethrough'] ) && $value['strikethrough'] ) {
							$styles[ $output['media_query'] ][ $element ]['text-decoration'] = 'strikethrough';
						}
						if ( isset( $value['font-family'] ) ) {
							// add double quotes if needed
							if ( false !== strpos( $value['font-family'], ' ' ) && false === strpos( $value['font-family'], '"' ) ) {
								$styles[ $output['media_query'] ][ $element ]['font-family'] = '"' . $value['font-family'] . '"';
							} else {
								$styles[ $output['media_query'] ][ $element ]['font-family'] = $value['font-family'];
							}
							// Add backup font
							if ( Kirki_Fonts::is_google_font( $value['font-family'] ) ) {
								if ( isset( $google_fonts_array[ $value['font-family'] ] ) && isset( $google_fonts_array[ $value['font-family'] ]['category'] ) ) {
									if ( isset( $backup_fonts[ $google_fonts_array[ $value['font-family'] ]['category'] ] ) ) {
										// add double quotes if needed
										if ( false !== strpos( $value['font-family'], ' ' ) && false === strpos( $value['font-family'], '"' ) ) {
											$styles[ $output['media_query'] ][ $element ]['font-family'] = '"' . $value['font-family'] . '", ' . $backup_fonts[ $google_fonts_array[ $value['font-family'] ]['category'] ];
										} else {
											$styles[ $output['media_query'] ][ $element ]['font-family'] = $value['font-family'] . ', ' . $backup_fonts[ $google_fonts_array[ $value['font-family'] ]['category'] ];
										}
									}
								}
							}
						}
						foreach ( $value as $key => $sub_value ) {
							$styles[ $output['media_query'] ][ $element ][ $key ] = $sub_value;
						}
					}
					/**
					 * Take care of "spacing" controls output
					 */
					if ( 'spacing' == self::$field_type && isset( $output['property'] ) ) {
						foreach ( $value as $key => $sub_value ) {
							if ( false !== strpos( $output['property'], '%%' ) ) {
								$property = str_replace( '%%', $key, $output['property'] );
							} else {
								$property = $output['property'] . '-' . $key;
							}
							$styles[ $output['media_query'] ][ $element ][ $property ] = $sub_value;
						}
					}
				}
			}

			return $styles;

		}

		/**
		 * Add prefixes if necessary.
		 *
		 * @param  $css array
		 * @return  array
		 */
		public static function add_prefixes( $css ) {

			if ( is_array( $css ) ) {
				foreach ( $css as $media_query => $elements ) {
					foreach ( $elements as $element => $style_array ) {
						foreach ( $style_array as $property => $value ) {
							/**
							 * border-radius
							 */
							if ( 'border-radius' == $property ) {
								$css[ $media_query ][ $element ]['-webkit-border-radius'] = $value;
								$css[ $media_query ][ $element ]['-moz-border-radius'] = $value;
							}
							/**
							 * box-shadow
							 */
							if ( 'box-shadow' == $property ) {
								$css[ $media_query ][ $element ]['-webkit-box-shadow'] = $value;
								$css[ $media_query ][ $element ]['-moz-box-shadow']    = $value;
							}
							/**
							 * box-sizing
							 */
							elseif ( 'box-sizing' == $property ) {
								$css[ $media_query ][ $element ]['-webkit-box-sizing'] = $value;
								$css[ $media_query ][ $element ]['-moz-box-sizing']    = $value;
							}
							/**
							 * text-shadow
							 */
							elseif ( 'text-shadow' == $property ) {
								$css[ $media_query ][ $element ]['-webkit-text-shadow'] = $value;
								$css[ $media_query ][ $element ]['-moz-text-shadow']    = $value;
							}
							/**
							 * transform
							 */
							elseif ( 'transform' == $property ) {
								$css[ $media_query ][ $element ]['-webkit-transform'] = $value;
								$css[ $media_query ][ $element ]['-moz-transform']    = $value;
								$css[ $media_query ][ $element ]['-ms-transform']     = $value;
								$css[ $media_query ][ $element ]['-o-transform']      = $value;
							}
							/**
							 * background-size
							 */
							elseif ( 'background-size' == $property ) {
								$css[ $media_query ][ $element ]['-webkit-background-size'] = $value;
								$css[ $media_query ][ $element ]['-moz-background-size']    = $value;
								$css[ $media_query ][ $element ]['-ms-background-size']     = $value;
								$css[ $media_query ][ $element ]['-o-background-size']      = $value;
							}
							/**
							 * transition
							 */
							elseif ( 'transition' == $property ) {
								$css[ $media_query ][ $element ]['-webkit-transition'] = $value;
								$css[ $media_query ][ $element ]['-moz-transition']    = $value;
								$css[ $media_query ][ $element ]['-ms-transition']     = $value;
								$css[ $media_query ][ $element ]['-o-transition']      = $value;
							}
							/**
							 * transition-property
							 */
							elseif ( 'transition-property' == $property ) {
								$css[ $media_query ][ $element ]['-webkit-transition-property'] = $value;
								$css[ $media_query ][ $element ]['-moz-transition-property']    = $value;
								$css[ $media_query ][ $element ]['-ms-transition-property']     = $value;
								$css[ $media_query ][ $element ]['-o-transition-property']      = $value;
							}
						}
					}
				}
			}

			return $css;

		}

	}
}