<?php
/**
 * Addifect SSR Engine
 *
 * Handles Server-Side Rendering (SSR) for the Addifect interactive design tool,
 * hydrating JSON trees and replacing HTML template tokens with live WordPress data.
 *
 * @package    Addifect
 * @subpackage Core
 * @since      1.0.4
 */

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

/**
 * Addifect SSR Engine
 *
 * Handles Server-Side Rendering (SSR) for this specialized interactive design tool,
 * hydrating JSON trees and replacing HTML template tokens with live WordPress data.
 *
 * @since 1.0.4
 */
class Addifect_SSR_Engine {
	/**
	 * The Master Bootloader.
	 * Pass your saved React HTML and Addifect JSON in here before rendering the page.
	 *
	 * @param string       $raw_html The raw HTML string generated by React.
	 * @param string|array $raw_json The Addifect JSON tree as a string or array.
	 * @return array Array containing the hydrated 'html' and 'json'.
	 */
	public static function process_page( $raw_html, $raw_json ) {
		$tree         = is_string( $raw_json ) ? json_decode( $raw_json, true ) : $raw_json;
		$queries_data = array();

		// 1. HYDRATE JSON & FETCH POSTS
		self::hydrate_tree_recursive( $tree, $queries_data );

		// 2. HYDRATE HTML (If there are dynamic queries and saved HTML)
		if ( ! empty( $queries_data ) && ! empty( $raw_html ) ) {
			$raw_html = self::render_html_templates( $raw_html, $queries_data );
		}

		return array(
			'html' => $raw_html,
			'json' => $tree,
		);
	}

	/**
	 * Recursively scans the JSON for 'data-store' blocks with a 'query',
	 * fetches the WordPress data, and saves it for HTML injection.
	 *
	 * @param array $node         The current node in the JSON tree being processed. Passed by reference.
	 * @param array $queries_data Reference to the array holding fetched WordPress data.
	 * @return void
	 */
	private static function hydrate_tree_recursive( &$node, &$queries_data ) {
		if ( isset( $node['mode'] ) && 'data-store' === $node['mode'] && ! empty( $node['query'] ) ) {

			$args = array(
				'post_type'      => isset( $node['query']['post_type'] ) ? sanitize_text_field( $node['query']['post_type'] ) : 'post',
				'posts_per_page' => isset( $node['query']['posts_per_page'] ) ? intval( $node['query']['posts_per_page'] ) : 10,
				'orderby'        => isset( $node['query']['orderby'] ) ? sanitize_text_field( $node['query']['orderby'] ) : 'date',
				'order'          => isset( $node['query']['order'] ) ? sanitize_text_field( $node['query']['order'] ) : 'DESC',
				'post_status'    => 'publish',
				'no_found_rows'  => true,
			);

			$posts   = get_posts( $args );
			$records = array();

			foreach ( $posts as $index => $post ) {
				$categories    = get_the_category( $post->ID );
				$category_name = ! empty( $categories ) ? $categories[0]->name : 'Uncategorized';

				// Standardize the ternary to pass PHPCS.
				$thumbnail_url = get_the_post_thumbnail_url( $post->ID, 'large' );

				$records[] = array(
					'_index'    => $index,
					'id'        => (string) $post->ID,
					'title'     => get_the_title( $post ),
					'excerpt'   => get_the_excerpt( $post ),
					'permalink' => get_permalink( $post ),
					'date'      => get_the_date( '', $post ),
					'thumbnail' => $thumbnail_url ? $thumbnail_url : '',
					'category'  => $category_name,
				);
			}

			// Hydrate the JSON node for React.
			$node['records'] = $records;

			// Save to our array for the HTML DOMDocument parser.
			$queries_data[ $node['id'] ] = $records;
		}

		// Recurse down the tree.
		foreach ( $node as $key => &$value ) {
			if ( is_array( $value ) ) {
				self::hydrate_tree_recursive( $value, $queries_data );
			}
		}
	}

/**
	 * Uses DOMDocument to find the React templates, process attribute bindings,
	 * replace text tokens, and inject the WordPress data directly into the HTML string.
	 *
	 * @param string $html         The raw HTML template string.
	 * @param array  $queries_data The array of fetched WordPress data mapped by query IDs.
	 * @return string The final, hydrated HTML string.
	 */
	private static function render_html_templates( $html, $queries_data ) {
		libxml_use_internal_errors( true );
		$dom = new DOMDocument();
		$dom->loadHTML( '<?xml encoding="utf-8" ?>' . $html, LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD );
		$xpath = new DOMXPath( $dom );

		// Find all elements marked with data-ssr-query.
		$wrappers = $xpath->query( '//*[@data-ssr-query]' );

		foreach ( $wrappers as $wrapper ) {
			$query_id = $wrapper->getAttribute( 'data-ssr-query' );

			if ( isset( $queries_data[ $query_id ] ) ) {

				// 1. Extract the raw React HTML template
				$template_html = '';
				// phpcs:ignore WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase
				foreach ( $wrapper->childNodes as $child ) {
					$template_html .= $dom->saveHTML( $child );
				}

				$rendered_html = '';

				// 2. Loop through the actual WP Posts
				foreach ( $queries_data[ $query_id ] as $item_data ) {
					
					// Create a temporary DOM for this specific iteration to safely manipulate attributes
					$temp_dom = new DOMDocument();
					$temp_dom->loadHTML( '<?xml encoding="utf-8" ?><div>' . $template_html . '</div>', LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD );
					$temp_xpath = new DOMXPath( $temp_dom );

					// --- NEW LOGIC: Process Attribute Bindings ---
					$bound_elements = $temp_xpath->query( '//*[@data-bind-attr]' );

					foreach ( $bound_elements as $el ) {
						// Support multiple bound attributes (e.g., "src,alt,href")
						$attrs_to_bind = explode( ',', $el->getAttribute( 'data-bind-attr' ) );

						foreach ( $attrs_to_bind as $attr ) {
							$attr = trim( $attr );
							if ( empty( $attr ) ) continue;

							// Grab the binding path (e.g., "item.thumbnail")
							$bind_path = $el->getAttribute( $attr );

							if ( strpos( $bind_path, 'item.' ) === 0 ) {
								$data_key = str_replace( 'item.', '', $bind_path );

								// Apply the actual WP data securely using setAttribute
								if ( isset( $item_data[ $data_key ] ) ) {
									$el->setAttribute( $attr, esc_attr( $item_data[ $data_key ] ) );
								} else {
									$el->setAttribute( $attr, '' ); // Clear it if no data exists
								}
							}
						}
						// Clean up the helper attribute so it doesn't render on the live site
						$el->removeAttribute( 'data-bind-attr' );
					}

					// --- Extract the processed HTML to run text replacements ---
					$current_item_html = '';
					// phpcs:ignore WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase
					foreach ( $temp_dom->documentElement->childNodes as $child ) {
						$current_item_html .= $temp_dom->saveHTML( $child );
					}

					// --- Standard Text Token Replacement (e.g., {{item.title}}) ---
					foreach ( $item_data as $key => $value ) {
						if ( is_scalar( $value ) ) {
							$current_item_html = str_replace(
								'{{item.' . $key . '}}',
								esc_html( $value ),
								$current_item_html
							);
						}
					}

					$rendered_html .= $current_item_html;
				}

				// 3. Clear out the original template node
				// phpcs:ignore WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase
				while ( $wrapper->firstChild ) {
					// phpcs:ignore WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase
					$wrapper->removeChild( $wrapper->firstChild );
				}

				// 4. Inject the compiled HTML back into the DOM safely
				if ( ! empty( $rendered_html ) ) {
					$final_temp_dom = new DOMDocument();
					$final_temp_dom->loadHTML( '<?xml encoding="utf-8" ?><div>' . $rendered_html . '</div>', LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD );
					$final_temp_wrapper = $final_temp_dom->documentElement;

					if ( $final_temp_wrapper ) {
						// phpcs:ignore WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase
						foreach ( $final_temp_wrapper->childNodes as $node ) {
							$imported_node = $dom->importNode( $node, true );
							$wrapper->appendChild( $imported_node );
						}
					}
				}

				$wrapper->removeAttribute( 'data-ssr-query' );
			}
		}

		$final_html = $dom->saveHTML();
		return str_replace( '<?xml encoding="utf-8" ?>', '', $final_html );
	}
}