<?php
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

if ( ! class_exists( 'MetaForge_TaxonomyOrderManager' ) ) {
	class MetaForge_TaxonomyOrderManager {

		const META_KEY     = 'metaforge_term_order';
		const SETTINGS_KEY = 'metaforge_taxonomy_order_settings';

		public function __construct() {
			add_action( 'admin_init', array( $this, 'save_settings' ) );
			add_action( 'admin_menu', array( $this, 'admin_menu' ), 30 );
			add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_scripts' ) );
			add_action( 'wp_ajax_metaforge_save_term_order', array( $this, 'ajax_save_term_order' ) );
			add_filter( 'get_terms_args', array( $this, 'filter_get_terms_args' ), 10, 2 );
			add_action( 'created_term', array( $this, 'set_default_term_order' ), 10, 3 );
		}

		// Admin Menu ------------------------------------------------------------

		public function admin_menu() {
			// Hidden from sidebar menu, accessible via top header nav
			add_submenu_page( null, 'Taxonomy Order', 'Taxonomy Order', 'manage_metaforge', 'metaforge_term_order', array( $this, 'settings_page' ) );

			$settings     = get_option( self::SETTINGS_KEY, array() );
			$enabled_taxs = $settings['enabled_taxonomies'] ?? array();

			foreach ( $enabled_taxs as $tax_slug ) {
				$tax_obj = get_taxonomy( $tax_slug );
				if ( ! $tax_obj ) {
					continue;
				}
				$label = $tax_obj->labels->name ?? $tax_slug;

				// Get associated post types to place it in the correct menu structure
				$object_types = $tax_obj->object_type ?? array();
				$parent_slug  = 'edit.php'; // Fallback to posts
				if ( ! empty( $object_types ) ) {
					$first_pt = $object_types[0];
					if ( $first_pt !== 'post' ) {
						$parent_slug = 'edit.php?post_type=' . $first_pt;
					}
				}

				add_submenu_page(
					$parent_slug,
					'Reorder ' . $label,
					'Reorder ' . $label,
					'manage_categories',
					'metaforge_term_reorder_' . $tax_slug,
					function () use ( $tax_slug, $tax_obj ) {
						$this->reorder_page( $tax_slug, $tax_obj ); }
				);
			}
		}

		// Enqueue Scripts -------------------------------------------------------

		public function enqueue_scripts( $hook ) {
			if ( strpos( $hook, 'metaforge_term_reorder_' ) === false ) {
				return;
			}

			wp_enqueue_script( 'metaforge-sortable-js' ); // registered by MetaForge_Loader
			$js_ver = METAFORGE_VERSION;
			wp_enqueue_script( 'metaforge-taxonomy-order-js', METAFORGE_URL . 'assets/js/taxonomy-order.js', array( 'jquery', 'metaforge-sortable-js' ), $js_ver, true );
			wp_localize_script(
				'metaforge-taxonomy-order-js',
				'metaforgeTaxOrderConfig',
				array(
					'ajaxUrl' => admin_url( 'admin-ajax.php' ),
					'nonce'   => wp_create_nonce( 'metaforge_term_order_nonce' ),
				)
			);
			// admin.css is already enqueued by MetaForge_Loader for $is_reorder pages
		}


		// Settings Page ---------------------------------------------------------

		public function save_settings() {
			if ( isset( $_POST['metaforge_save_term_order_settings'] ) ) {
				check_admin_referer( 'metaforge_term_order_settings_action', 'metaforge_term_order_settings_nonce' );
				if ( ! current_user_can( 'manage_metaforge' ) ) {
					wp_die( 'Insufficient permissions.' );
				}
				$enabled = array();
				if ( isset( $_POST['enabled_taxonomies'] ) && is_array( $_POST['enabled_taxonomies'] ) ) {
					$enabled = array_map( 'sanitize_key', $_POST['enabled_taxonomies'] );
				}
				update_option( self::SETTINGS_KEY, array( 'enabled_taxonomies' => $enabled ) );
				flush_rewrite_rules();

				wp_safe_redirect( admin_url( 'admin.php?page=metaforge_term_order&settings-updated=true' ) );
				exit;
			}
		}

		public function settings_page() {
			if ( ! current_user_can( 'manage_metaforge' ) ) {
				return;
			}
			// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Read-only notice query flag.
			$saved = isset( $_GET['settings-updated'] ) && sanitize_text_field( wp_unslash( $_GET['settings-updated'] ) ) === 'true';

			$settings     = get_option( self::SETTINGS_KEY, array( 'enabled_taxonomies' => array() ) );
			$enabled_taxs = $settings['enabled_taxonomies'] ?? array();

			$builtin        = get_taxonomies(
				array(
					'public'   => true,
					'_builtin' => true,
				),
				'objects'
			);
			$metaforge_taxs = get_option( 'metaforge_taxonomies', array() );
			$all_taxs       = $builtin;
			foreach ( $metaforge_taxs as $tax ) {
				$slug = $tax['slug'] ?? '';
				if ( $slug && ( $obj = get_taxonomy( $slug ) ) ) {
					$all_taxs[ $slug ] = $obj;
				}
			}
			?>
		<div class="wrap mfe-wrap">
			<?php MetaForge_AdminHeader::render_top_bar( 'taxonomy_order' ); ?>
			<form method="post">
				<?php wp_nonce_field( 'metaforge_term_order_settings_action', 'metaforge_term_order_settings_nonce' ); ?>
				<div class="mfe-top-bar">
					<div class="mfe-top-bar-left"><h1>Taxonomy Order Settings</h1></div>
					<div class="mfe-top-bar-right">
						<a href="?page=metaforge" class="mfe-btn-secondary">← Back</a>
						<button type="submit" name="metaforge_save_term_order_settings" class="mfe-btn-primary">
							<span class="dashicons dashicons-saved"></span> Save Settings
						</button>
					</div>
				</div>

				<?php if ( $saved ) : ?>
					<div class="mfe-notice-success">
						<span class="dashicons dashicons-yes mfe-notice-icon"></span>
						<p><?php esc_html_e( 'Settings saved. Reorder links appear under each enabled taxonomy in the left menu.', 'metaforge-engine' ); ?></p>
						<button type="button" class="mfe-notice-close" aria-label="<?php esc_attr_e( 'Dismiss notice', 'metaforge-engine' ); ?>">&times;</button>
					</div>
				<?php endif; ?>




				<div class="mfe-builder-wrap mfe-mt-20">
					<div class="mfe-card">
						<div class="mfe-card-header"><div class="mfe-card-header-left"><span class="dashicons dashicons-category"></span> Enable Taxonomy Ordering</div></div>
						<div class="mfe-card-body">
							<div class="mfe-setting-row">
								<div class="mfe-setting-label">Taxonomies<small>Select taxonomies to enable drag-and-drop taxonomy ordering.</small></div>
								<div class="mfe-setting-input">
									<div class="mfe-order-grid">
										<?php foreach ( $all_taxs as $slug => $tax_obj ) : ?>
										<label class="mfe-order-check-label">
											<input type="checkbox" name="enabled_taxonomies[]" value="<?php echo esc_attr( $slug ); ?>" class="mfe-order-check-input" <?php checked( in_array( $slug, $enabled_taxs ) ); ?>>
											<?php echo esc_html( $tax_obj->labels->name ?? $slug ); ?>
										</label>
										<?php endforeach; ?>
									</div>
								</div>
							</div>

							<?php if ( ! empty( $enabled_taxs ) ) : ?>
							<div class="mfe-setting-row mfe-border-none">
								<div class="mfe-setting-label">Quick Links</div>
								<div class="mfe-setting-input mfe-quick-links-wrap">
									<?php
									foreach ( $enabled_taxs as $slug ) :
										$tax_obj = get_taxonomy( $slug );
										if ( ! $tax_obj ) {
											continue;
										}
										?>
									<a href="<?php echo esc_url( admin_url( 'edit-tags.php?taxonomy=' . $slug . '&page=metaforge_term_reorder_' . $slug ) ); ?>" class="mfe-btn-secondary">
										<span class="dashicons dashicons-move"></span>
										Reorder <?php echo esc_html( $tax_obj->labels->name ?? $slug ); ?>
									</a>
									<?php endforeach; ?>
								</div>
							</div>
							<?php endif; ?>
						</div>
					</div>
				</div>
			</form>
				<?php MetaForge_AdminHeader::render_footer(); ?>
		</div>
			<?php
		}

		// Reorder Page ----------------------------------------------------------

		public function reorder_page( $tax_slug, $tax_obj ) {
			if ( ! current_user_can( 'manage_categories' ) ) {
				return;
			}
			$label = $tax_obj->labels->name ?? $tax_slug;

			// Ensure all existing terms have an order meta value before displaying
			$this->lazy_init_order( $tax_slug );

			// Fetch terms sorted by saved order - bypass apply_term_order by using explicit args
			// phpcs:disable WordPress.DB.SlowDBQuery.slow_db_query_meta_key -- Required for taxonomy term reordering interface.
			$terms = get_terms(
				array(
					'taxonomy'   => $tax_slug,
					'hide_empty' => false,
					'meta_key'   => self::META_KEY,
					'orderby'    => 'meta_value_num',
					'order'      => 'ASC',
				)
			);
			// phpcs:enable WordPress.DB.SlowDBQuery.slow_db_query_meta_key

			if ( is_wp_error( $terms ) ) {
				$terms = array();
			}

			?>
		<div class="wrap mfe-wrap">
			<?php MetaForge_AdminHeader::render_top_bar( 'taxonomy_order' ); ?>
			<div class="mfe-top-bar">
				<div class="mfe-top-bar-left"><h1>Reorder: <?php echo esc_html( $label ); ?></h1></div>
				<div class="mfe-top-bar-right">
					<a href="<?php echo esc_url( admin_url( 'edit-tags.php?taxonomy=' . $tax_slug ) ); ?>" class="mfe-btn-secondary">← Back</a>
					<button id="mfe-save-term-order-btn" class="mfe-btn-primary" data-taxonomy="<?php echo esc_attr( $tax_slug ); ?>">
						<span class="dashicons dashicons-saved"></span> Save Order
					</button>
				</div>
			</div>
			<div class="mfe-builder-wrap mfe-mt-20">
				<div class="mfe-card">
					<div class="mfe-card-body mfe-p-0">
						<ul id="mfe-term-reorder-list" class="mfe-sortable-list">
							<?php if ( empty( $terms ) || is_wp_error( $terms ) ) : ?>
								<li class="mfe-no-items">No terms found.</li>
							<?php else : ?>
								<?php foreach ( $terms as $term ) : ?>
								<li class="mfe-sortable-item" data-id="<?php echo (int) $term->term_id; ?>">
									<div class="mfe-sortable-handle">
										<span class="dashicons dashicons-move"></span>
									</div>
									<div class="mfe-sortable-title">
										<?php echo esc_html( $term->name ); ?>
										<span class="mfe-item-id">#<?php echo (int) $term->term_id; ?> &middot; <?php echo (int) $term->count; ?> posts</span>
									</div>
								</li>
								<?php endforeach; ?>
							<?php endif; ?>
						</ul>
					</div>
				</div>
			</div>
			<?php MetaForge_AdminHeader::render_footer(); ?>
		</div>
			<?php
		}

		// AJAX ------------------------------------------------------------------

		public function ajax_save_term_order() {
			check_ajax_referer( 'metaforge_term_order_nonce', 'nonce' );
			if ( ! current_user_can( 'manage_categories' ) ) {
				wp_send_json_error( array( 'message' => 'Permission denied.' ) );
			}

			$term_ids = isset( $_POST['order'] ) ? array_map( 'intval', (array) $_POST['order'] ) : array();
			$taxonomy = isset( $_POST['taxonomy'] ) ? sanitize_key( $_POST['taxonomy'] ) : '';

			if ( empty( $term_ids ) || empty( $taxonomy ) || ! taxonomy_exists( $taxonomy ) ) {
				wp_send_json_error( array( 'message' => 'Invalid data.' ) );
			}

			// Multiply by 10 to leave gaps for future insertions and
			// avoid collisions with lazy_init values (which start from max+10)
			foreach ( $term_ids as $position => $term_id ) {
				update_term_meta( $term_id, self::META_KEY, ( $position + 1 ) * 10 );
			}

			wp_send_json_success( array( 'message' => 'Taxonomy order saved.' ) );
		}

		// Hooks -----------------------------------------------------------------

		public function filter_get_terms_args( $args, $taxonomies ) {
			$settings     = get_option( self::SETTINGS_KEY, array() );
			$enabled_taxs = $settings['enabled_taxonomies'] ?? array();

			if ( empty( $enabled_taxs ) ) {
				return $args;
			}

			$has_enabled = false;
			$current_tax = '';
			foreach ( (array) $taxonomies as $tax ) {
				if ( in_array( $tax, $enabled_taxs, true ) ) {
					$has_enabled = true;
					$current_tax = $tax;
					break;
				}
			}

			if ( ! $has_enabled ) {
				return $args;
			}

			// Skip lightweight sub-queries — only sort full object result sets
			$fields = $args['fields'] ?? '';
			if ( in_array( $fields, array( 'count', 'ids', 'tt_ids', 'id=>name', 'id=>slug', 'id=>parent', 'names' ), true ) ) {
				return $args;
			}

			// Only intercept default / name / count ordering
			$current_orderby = $args['orderby'] ?? '';
			if ( ! empty( $current_orderby ) && ! in_array( $current_orderby, array( 'name', 'count', '' ), true ) ) {
				return $args;
			}

			// Guarantee every term in this taxonomy has a meta record so that the
			// INNER JOIN WordPress adds for meta_key does not drop any rows.
			// lazy_init_order() is a no-op (single fast SELECT) once all terms
			// already have the key, so the overhead is negligible.
			$this->lazy_init_order( $current_tax );

			// phpcs:disable WordPress.DB.SlowDBQuery.slow_db_query_meta_key -- Required for taxonomy term reordering filter.
			$args['meta_key'] = self::META_KEY;
			$args['orderby']  = 'meta_value_num';
			$args['order']    = 'ASC';
			// phpcs:enable WordPress.DB.SlowDBQuery.slow_db_query_meta_key

			return $args;
		}



		public function set_default_term_order( $term_id, $tt_id, $taxonomy ) {
			$settings     = get_option( self::SETTINGS_KEY, array() );
			$enabled_taxs = $settings['enabled_taxonomies'] ?? array();
			if ( ! in_array( $taxonomy, $enabled_taxs, true ) ) {
				return;
			}

			$taxonomy_obj = get_taxonomy( $taxonomy );
			if ( ! $taxonomy_obj || ! current_user_can( $taxonomy_obj->cap->edit_terms ) || ! current_user_can( 'edit_term', $term_id ) ) {
				return;
			}

			// phpcs:disable WordPress.DB.SlowDBQuery.slow_db_query_meta_key -- Querying max term order meta.
			$terms = get_terms(
				array(
					'taxonomy'   => $taxonomy,
					'hide_empty' => false,
					'fields'     => 'ids',
					'meta_key'   => self::META_KEY,
					'orderby'    => 'meta_value_num',
					'order'      => 'DESC',
					'number'     => 1,
				)
			);
			// phpcs:enable WordPress.DB.SlowDBQuery.slow_db_query_meta_key
			$max = ( ! is_wp_error( $terms ) && ! empty( $terms ) ) ? (int) get_term_meta( $terms[0], self::META_KEY, true ) : 0;
			update_term_meta( $term_id, self::META_KEY, $max + 10 );
		}

		private function lazy_init_order( $taxonomy ) {
			global $wpdb;
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Custom query needed to lazy-init missing term order metadata.
			$term_ids = $wpdb->get_col(
				$wpdb->prepare(
					"
                SELECT tt.term_id 
                FROM {$wpdb->term_taxonomy} tt 
                LEFT JOIN {$wpdb->termmeta} tm ON (tt.term_id = tm.term_id AND tm.meta_key = %s)
                WHERE tt.taxonomy = %s AND tm.meta_id IS NULL
            ",
					self::META_KEY,
					$taxonomy
				)
			);
			if ( empty( $term_ids ) ) {
				return;
			}

			// Find the current max order
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Custom query needed to get maximum term order.
			$max = (int) $wpdb->get_var(
				$wpdb->prepare(
					"
                SELECT MAX(CAST(meta_value AS SIGNED)) 
                FROM {$wpdb->termmeta} 
                WHERE meta_key = %s
            ",
					self::META_KEY
				)
			);

			// Update the missing terms starting from max + 10
			$position = $max + 10;
			foreach ( $term_ids as $term_id ) {
				update_term_meta( $term_id, self::META_KEY, $position );
				$position += 10;
			}
		}
	}
}