<?php

/**

 * Style Engine: WP_Style_Engine_Processor class

 *

 * @package WordPress

 * @subpackage StyleEngine

 * @since 6.1.0

 */

/**

 * Core class used to compile styles from stores or collection of CSS rules.

 *

 * @since 6.1.0

 */

#[AllowDynamicProperties]

class WP_Style_Engine_Processor {

	/**

	 * A collection of Style Engine Store objects.

	 *

	 * @since 6.1.0

	 * @var WP_Style_Engine_CSS_Rules_Store[]

	 */

	protected $stores = array();

	/**

	 * The set of CSS rules that this processor will work on.

	 *

	 * @since 6.1.0

	 * @var WP_Style_Engine_CSS_Rule[]

	 */

	protected $css_rules = array();

	/**

	 * Adds a store to the processor.

	 *

	 * @since 6.1.0

	 *

	 * @param WP_Style_Engine_CSS_Rules_Store $store The store to add.

	 * @return WP_Style_Engine_Processor Returns the object to allow chaining methods.

	 */

	public function add_store( $store ) {

		if ( ! $store instanceof WP_Style_Engine_CSS_Rules_Store ) {

			_doing_it_wrong(

				__METHOD__,

				__( '$store must be an instance of WP_Style_Engine_CSS_Rules_Store' ),

				'6.1.0'

			);

			return $this;

		}

		$this->stores[ $store->get_name() ] = $store;

		return $this;

	}

	/**

	 * Adds rules to be processed.

	 *

	 * @since 6.1.0

	 * @since 6.6.0 Added support for rules_group.

	 *

	 * @param WP_Style_Engine_CSS_Rule|WP_Style_Engine_CSS_Rule[] $css_rules A single, or an array of,

	 *                                                                       WP_Style_Engine_CSS_Rule objects

	 *                                                                       from a store or otherwise.

	 * @return WP_Style_Engine_Processor Returns the object to allow chaining methods.

	 */

	public function add_rules( $css_rules ) {

		if ( ! is_array( $css_rules ) ) {

			$css_rules = array( $css_rules );

		}

		foreach ( $css_rules as $rule ) {

			$selector    = $rule->get_selector();

			$rules_group = $rule->get_rules_group();

			/**

			 * If there is a rules_group and it already exists in the css_rules array,

			 * add the rule to it.

			 * Otherwise, create a new entry for the rules_group.

			 */

			if ( ! empty( $rules_group ) ) {

				if ( isset( $this->css_rules[ "$rules_group $selector" ] ) ) {

					$this->css_rules[ "$rules_group $selector" ]->add_declarations( $rule->get_declarations() );

					continue;

				}

				$this->css_rules[ "$rules_group $selector" ] = $rule;

				continue;

			}

			// If the selector already exists, add the declarations to it.

			if ( isset( $this->css_rules[ $selector ] ) ) {

				$this->css_rules[ $selector ]->add_declarations( $rule->get_declarations() );

				continue;

			}

			$this->css_rules[ $rule->get_selector() ] = $rule;

		}

		return $this;

	}

	/**

	 * Gets the CSS rules as a string.

	 *

	 * @since 6.1.0

	 * @since 6.4.0 The Optimization is no longer the default.

	 *

	 * @param array $options   {

	 *     Optional. An array of options. Default empty array.

	 *

	 *     @type bool $optimize Whether to optimize the CSS output, e.g. combine rules.

	 *                          Default false.

	 *     @type bool $prettify Whether to add new lines and indents to output.

	 *                          Defaults to whether the `SCRIPT_DEBUG` constant is defined.

	 * }

	 * @return string The computed CSS.

	 */

	public function get_css( $options = array() ) {

		$defaults = array(

			'optimize' => false,

			'prettify' => defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG,

		);

		$options  = wp_parse_args( $options, $defaults );

		// If we have stores, get the rules from them.

		foreach ( $this->stores as $store ) {

			$this->add_rules( $store->get_all_rules() );

		}

		// Combine CSS selectors that have identical declarations.

		if ( true === $options['optimize'] ) {

			$this->combine_rules_selectors();

		}

		// Build the CSS.

		$css = '';

		foreach ( $this->css_rules as $rule ) {

			// See class WP_Style_Engine_CSS_Rule for the get_css method.

			$css .= $rule->get_css( $options['prettify'] );

			$css .= $options['prettify'] ? "\n" : '';

		}

		return $css;

	}

	/**

	 * Combines selectors from the rules store when they have the same styles.

	 *

	 * @since 6.1.0

	 */

	private function combine_rules_selectors() {

		// Build an array of selectors along with the JSON-ified styles to make comparisons easier.

		$selectors_json = array();

		foreach ( $this->css_rules as $rule ) {

			$declarations = $rule->get_declarations()->get_declarations();

			ksort( $declarations );

			$selectors_json[ $rule->get_selector() ] = wp_json_encode( $declarations );

		}

		// Combine selectors that have the same styles.

		foreach ( $selectors_json as $selector => $json ) {

			// Get selectors that use the same styles.

			$duplicates = array_keys( $selectors_json, $json, true );

			// Skip if there are no duplicates.

			if ( 1 >= count( $duplicates ) ) {

				continue;

			}

			$declarations = $this->css_rules[ $selector ]->get_declarations();

			foreach ( $duplicates as $key ) {

				// Unset the duplicates from the $selectors_json array to avoid looping through them as well.

				unset( $selectors_json[ $key ] );

				// Remove the rules from the rules collection.

				unset( $this->css_rules[ $key ] );

			}

			// Create a new rule with the combined selectors.

			$duplicate_selectors                     = implode( ',', $duplicates );

			$this->css_rules[ $duplicate_selectors ] = new WP_Style_Engine_CSS_Rule( $duplicate_selectors, $declarations );

		}

	}

}