<?php
namespace JVBase\managers;

use JVBase\managers\Cache;
use WP_Error;
use WP_Post;

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

class TaxonomyRelationships
{
    private string $table_name;
    protected object $cache;


    public function __construct()
    {
        global $wpdb;
        $this->table_name = $wpdb->prefix . BASE.'taxonomy_relationships';
        $this->cache = Cache::for('term_relationship', WEEK_IN_SECONDS);

        // Ensure the table exists
//        $this->create_table_if_not_exists();


        add_action('init', [$this, 'init']);
    }

    /**
     * @return string
     */
    public function getTableName():string
    {
        return $this->table_name;
    }

    /**
     * Hook into term and post saves
     * @return void
     */
    public function init():void
    {
        add_action('save_post', [$this, 'updatePostRelationships'], 10, 2);
        add_action('before_delete_post', [$this, 'updatePostRelationships'], 10, 2);
        add_action('delete_term', [$this, 'deleteTermRelationships']);

        add_filter(BASE.'handle_bulk_operation', [$this, 'processOperation'], 10, 3);
    }


    // Update relationships for a post

    /**
     * @param int $post_id
     *
     * @return void
     */
    public function updatePostRelationships(int $post_id, WP_Post $post):void
    {
		$post_type = $post->post_type;
		if (in_array($post_type, jvbIgnoredPostTypes())) {
			return;
		}
        // Get all taxonomies for this post type
        $taxonomies = get_object_taxonomies($post_type);

        if (empty($taxonomies)) {
            return;
        }

        // Get terms for each taxonomy
        $taxonomy_terms = [];
        foreach ($taxonomies as $taxonomy) {
            $terms = wp_get_post_terms($post_id, $taxonomy, ['fields' => 'ids']);

            if (!is_wp_error($terms) && !empty($terms)) {
                $taxonomy_terms[$taxonomy] = $terms;

                // Add parent terms for hierarchical taxonomies
                if (is_taxonomy_hierarchical($taxonomy)) {
                    foreach ($terms as $term_id) {
                        $ancestors = get_ancestors($term_id, $taxonomy, 'taxonomy');
                        if (!empty($ancestors)) {
                            $taxonomy_terms[$taxonomy] = array_merge($taxonomy_terms[$taxonomy], $ancestors);
                        }
                    }
                    // Remove duplicates
                    $taxonomy_terms[$taxonomy] = array_unique($taxonomy_terms[$taxonomy]);
                }
            }
        }

        // Create relationships between all taxonomy terms
        foreach ($taxonomy_terms as $taxonomy => $terms) {
            foreach ($terms as $term_id) {
                foreach ($taxonomy_terms as $related_taxonomy => $related_terms) {
                    if ($taxonomy === $related_taxonomy) {
                        continue; // Skip same taxonomy relationships
                    }

                    foreach ($related_terms as $related_term_id) {
                        $this->updateRelationship((int)$term_id, (int)$related_term_id, $taxonomy, $related_taxonomy);
                    }
                }
            }
        }
    }


    /**
     * @param int $term_id
     * @param int $related_term_id
     * @param string $taxonomy
     * @param string $related_taxonomy
     *
     * @return bool
     */
    public function updateRelationship(int $term_id, int $related_term_id, string $taxonomy, string $related_taxonomy):bool
    {
        global $wpdb;

        // Make sure both terms exist
        $term = get_term($term_id, $taxonomy);
        $related_term = get_term($related_term_id, $related_taxonomy);

        if (is_wp_error($term) || is_wp_error($related_term) || empty($term) || empty($related_term)) {
            // One or both terms don't exist, so don't create a relationship
            return false;
        }

        // Ensure term_id and related_term_id are integers
        $term_id = (int)$term_id;
        $related_term_id = (int)$related_term_id;

        // Check if relationship exists
        $existing = $wpdb->get_row($wpdb->prepare(
            "SELECT id, post_count FROM {$this->table_name}
        WHERE term_id = %d AND related_term_id = %d
        AND taxonomy = %s AND related_taxonomy = %s",
            $term_id,
            $related_term_id,
            $taxonomy,
            $related_taxonomy
        ));

        // Calculate number of shared posts
        $shared_posts_count = $this->countSharedPosts($term_id, $related_term_id, $taxonomy, $related_taxonomy);

        // Check if term is parent of related term
        $is_hierarchical = 0;
        if ($taxonomy === $related_taxonomy) {
            $ancestors = get_ancestors($related_term_id, $taxonomy, 'taxonomy');
            if (in_array($term_id, $ancestors)) {
                $is_hierarchical = 1;
            }
        }

        if ($existing) {
            // Update existing relationship
            $wpdb->update(
                $this->table_name,
                [
                    'post_count' => $shared_posts_count,
                    'is_hierarchical' => $is_hierarchical
                ],
                [
                    'id' => $existing->id
                ]
            );
        } else {
            // Insert new relationship
            $wpdb->insert(
                $this->table_name,
                [
                    'term_id' => $term_id,
                    'related_term_id' => $related_term_id,
                    'taxonomy' => $taxonomy,
                    'related_taxonomy' => $related_taxonomy,
                    'post_count' => $shared_posts_count,
                    'is_hierarchical' => $is_hierarchical
                ]
            );
        }

        return true;
    }

    /**
     * @param int $term_id
     * @param int $related_term_id
     * @param string $taxonomy
     * @param string $related_taxonomy
     *
     * @return int
     */
    private function countSharedPosts(int $term_id, int $related_term_id, string $taxonomy, string $related_taxonomy):int
    {
        global $wpdb;

        $term_posts = $wpdb->get_col($wpdb->prepare(
            "SELECT object_id FROM {$wpdb->term_relationships} tr
            JOIN {$wpdb->term_taxonomy} tt ON tr.term_taxonomy_id = tt.term_taxonomy_id
            WHERE tt.term_id = %d AND tt.taxonomy = %s",
            $term_id,
            $taxonomy
        ));

        $related_term_posts = $wpdb->get_col($wpdb->prepare(
            "SELECT object_id FROM {$wpdb->term_relationships} tr
            JOIN {$wpdb->term_taxonomy} tt ON tr.term_taxonomy_id = tt.term_taxonomy_id
            WHERE tt.term_id = %d AND tt.taxonomy = %s",
            $related_term_id,
            $related_taxonomy
        ));

        return count(array_intersect($term_posts, $related_term_posts));
    }

    // Get related terms based on a term ID and desired taxonomy

    /**
     * @param int $term_id
     * @param string $desired_taxonomy
     * @param bool $include_hierarchical
     *
     * @return array
     */
    public function getRelatedTerms(int $term_id, string $desired_taxonomy, bool $include_hierarchical = true):array
    {

        $key = sprintf(
            '%d_to_%s',
            $term_id,
            $desired_taxonomy
        );
        if ($include_hierarchical) {
            $key.='_hierarchy';
        }
        $cache = $this->cache->get($key);
        if ($cache) {
            return $cache;
        }

        global $wpdb;

        $term = get_term($term_id);
        if (is_wp_error($term) || empty($term)) {
            return [];
        }

        $query = $wpdb->prepare(
            "SELECT related_term_id
            FROM {$this->table_name}
            WHERE term_id = %d
            AND related_taxonomy = %s",
            $term_id,
            $desired_taxonomy
        );

        // Optionally include hierarchical relationships
        if (!$include_hierarchical) {
            $query .= " AND is_hierarchical = 0";
        }

        // Order by post count for popularity
        $query .= " ORDER BY post_count DESC";

        $related_term_ids = $wpdb->get_col($query);

        $this->cache->set($key, $related_term_ids);

        return $related_term_ids;
    }

    // Get all related terms based on multiple source terms (for "any" match)

    /**
     * @param array $term_ids
     * @param string $taxonomy
     *
     * @return array
     */
    public function getAnyRelatedTerms(array $term_ids, string $taxonomy):array
    {
        if (empty($term_ids)) {
            return [];
        }

        $related_term_ids = [];
        foreach ($term_ids as $term_id) {
            $related = $this->getRelatedTerms($term_id, $taxonomy);
            $related_term_ids = array_merge($related_term_ids, $related);
        }

        return array_unique($related_term_ids);
    }

    // Get related terms that are common to all source terms (for "all" match)

    /**
     * @param array $term_ids
     * @param string $taxonomy
     *
     * @return array
     */
    public function getAllRelatedTerms(array $term_ids, string $taxonomy):array
    {
        if (empty($term_ids)) {
            return [];
        }

        $related_sets = [];
        foreach ($term_ids as $term_id) {
            $related = $this->getRelatedTerms($term_id, $taxonomy);
            if (!empty($related)) {
                $related_sets[] = $related;
            }
        }

        if (count($related_sets) === 1) {
            return $related_sets[0];
        } elseif (count($related_sets) > 1) {
            // Find intersection of all sets
            $result = array_intersect(...$related_sets);
            return array_values($result);
        }

        return [];
    }

    // Rebuild all relationships (useful for initial setup)

    /**
     * @return true
     */
    public function rebuildAllRelationships():bool
    {
        $this->cache->flush();
        global $wpdb;

        // Clear existing relationships
        $wpdb->query("TRUNCATE TABLE {$this->table_name}");
        $total_posts = $wpdb->get_var("SELECT COUNT(ID) FROM {$wpdb->posts} WHERE post_status = 'publish'");

        // Calculate number of batches needed (50 posts per batch)
        $batch_size = 50;
        $total_batches = ceil($total_posts / $batch_size);

        // Queue the operation
        $queue = JVB()->queue();
        $operation_id = 'taxonomy_rebuild_' . uniqid();

        $queue->queueOperation(
            'taxonomy_relationships',
            1,
            [
                'action' => 'rebuild_all',
                'offset' => 0,
                'limit' => $batch_size,
                'total_posts' => $total_posts,
                'total_batches' => $total_batches
            ],
            [
                'operation_id' => $operation_id,
                'count' => $total_batches,
                'priority' => 'normal',
            ]
        );

        $this->cache->flush();

        return true;
    }

    /**
     * @param WP_Error|array $result
     * @param object $operation
     * @param array $data
     *
     * @return WP_Error|array
     */
    public function processOperation(WP_Error|array $result, object $operation, array $data):WP_Error|array
    {
        if ($operation->type !== 'taxonomy_relationships') {
            return $result;
        }

        if (isset($data['action']) && $data['action'] === 'rebuild_all') {
            // Clear existing relationships
            global $wpdb;

            // Get batch of posts to process
            $offset = isset($data['offset']) ? $data['offset'] : 0;
            $limit = isset($data['limit']) ? $data['limit'] : 50; // Process in batches

            $posts = $wpdb->get_col($wpdb->prepare(
                "SELECT ID FROM {$wpdb->posts}
             WHERE post_status = 'publish'
             ORDER BY ID
             LIMIT %d OFFSET %d",
                $limit,
                $offset
            ));

            // Process each post
            foreach ($posts as $post_id) {
                $this->updatePostRelationships($post_id);
            }

            // Get total number of posts
            $total_posts = $wpdb->get_var("SELECT COUNT(ID) FROM {$wpdb->posts} WHERE post_status = 'publish'");

            // Return progress information
            return [
                'success' => true,
				'result'	=> [
					'processed' => count($posts),
					'offset' => $offset,
					'next_offset' => $offset + $limit,
					'total' => $total_posts,
					'completed' => ($offset + $limit >= $total_posts)
				]
            ];
        }
        return [
            'success'   => false,
            'message'   => __('Hmmm.', 'jvb')
        ];
    }

    // Hook this to term deletion

    /**
     * @param int $term_id
     *
     * @return void
     */
    public function deleteTermRelationships(int $term_id):void
    {
        global $wpdb;

        $wpdb->query($wpdb->prepare(
            "DELETE FROM {$this->table_name}
            WHERE term_id = %d OR related_term_id = %d",
            $term_id,
            $term_id
        ));
    }
}