<?php
/**
 * Category Manipulator class
 *
 * Handles manipulation operations for product categories
 *
 * @since      1.0.0
 * @package    Studiou_WC_Product_Cat_Manage
 * @subpackage Studiou_WC_Product_Cat_Manage/includes
 */

// If this file is called directly, abort.
if (!defined('WPINC')) {
    die;
}

class Studiou_WC_Product_Cat_Manage_Manipulator {
    
    /**
     * Database handler
     *
     * @var Studiou_WC_Product_Cat_Manage_DB
     */
    private $db;
    
    /**
     * Constructor
     *
     * @param Studiou_WC_Product_Cat_Manage_DB $db Database handler
     */
    public function __construct($db) {
        $this->db = $db;
        
        // Register AJAX handlers
        add_action('wp_ajax_studiou_wcpcm_move_products', array($this, 'handle_move_products_ajax'));
    }
    
    /**
     * Handle AJAX move products request
     */
    public function handle_move_products_ajax() {
        // Check nonce
        if (!isset($_POST['nonce']) || !wp_verify_nonce($_POST['nonce'], 'studiou-wcpcm-nonce')) {
            wp_send_json_error(array(
                'message' => __('Security check failed', 'studiou-wc-product-cat-manage')
            ));
        }
        
        // Check permissions
        if (!current_user_can('manage_woocommerce')) {
            wp_send_json_error(array(
                'message' => __('You do not have sufficient permissions', 'studiou-wc-product-cat-manage')
            ));
        }
        
        // Validate input
        if (!isset($_POST['source_category']) || !isset($_POST['target_category'])) {
            wp_send_json_error(array(
                'message' => __('Missing required parameters', 'studiou-wc-product-cat-manage')
            ));
        }
        
        $source_category_id = intval($_POST['source_category']);
        $target_category_id = intval($_POST['target_category']);
        
        // Validate categories
        if ($source_category_id === $target_category_id) {
            wp_send_json_error(array(
                'message' => __('Source and target categories must be different', 'studiou-wc-product-cat-manage')
            ));
        }
        
        if ($source_category_id <= 0 || $target_category_id <= 0) {
            wp_send_json_error(array(
                'message' => __('Invalid category selection', 'studiou-wc-product-cat-manage')
            ));
        }
        
        try {
            // Execute move operation
            $result = $this->move_products_between_categories($source_category_id, $target_category_id);
            
            // Return success response
            wp_send_json_success(array(
                'message' => $result['message'],
                'moved_count' => $result['moved_count'],
                'source_count' => $result['source_count'],
                'target_count' => $result['target_count']
            ));
        } catch (Exception $e) {
            wp_send_json_error(array(
                'message' => sprintf(
                    __('Error during move operation: %s', 'studiou-wc-product-cat-manage'),
                    $e->getMessage()
                )
            ));
        }
    }
    
    /**
     * Move all products from source category to target category
     *
     * @param int $source_category_id Source category ID
     * @param int $target_category_id Target category ID
     * @return array Result with counts and message
     * @throws Exception On error
     */
    public function move_products_between_categories($source_category_id, $target_category_id) {
        // Get source and target category terms
        $source_category = get_term($source_category_id, 'product_cat');
        $target_category = get_term($target_category_id, 'product_cat');
        
        if (is_wp_error($source_category) || is_wp_error($target_category)) {
            throw new Exception(__('Invalid category specified', 'studiou-wc-product-cat-manage'));
        }
        
        // Get all products in source category
        $product_args = array(
            'post_type' => 'product',
            'post_status' => array('publish', 'private', 'draft'),
            'posts_per_page' => -1,
            'fields' => 'ids',
            'tax_query' => array(
                array(
                    'taxonomy' => 'product_cat',
                    'field' => 'term_id',
                    'terms' => $source_category_id,
                )
            )
        );
        
        $products = get_posts($product_args);
        $moved_count = 0;
        
        // Move each product
        foreach ($products as $product_id) {
            // Get current categories for the product
            $current_categories = wp_get_post_terms($product_id, 'product_cat', array('fields' => 'ids'));
            
            if (is_wp_error($current_categories)) {
                continue;
            }
            
            // Remove source category and add target category
            $new_categories = array_diff($current_categories, array($source_category_id));
            $new_categories[] = $target_category_id;
            
            // Update product categories
            $result = wp_set_post_terms($product_id, $new_categories, 'product_cat');
            
            if (!is_wp_error($result)) {
                $moved_count++;
            }
        }
        
        // Get updated counts
        $source_count = $this->get_category_product_count($source_category_id);
        $target_count = $this->get_category_product_count($target_category_id);
        
        // Generate result message
        $message = sprintf(
            __('Moved %d products from "%s" to "%s". Source category now has %d products, target category now has %d products.', 'studiou-wc-product-cat-manage'),
            $moved_count,
            $source_category->name,
            $target_category->name,
            $source_count,
            $target_count
        );
        
        return array(
            'moved_count' => $moved_count,
            'source_count' => $source_count,
            'target_count' => $target_count,
            'message' => $message
        );
    }
    
    /**
     * Get product count for a category
     *
     * @param int $category_id Category ID
     * @return int Product count
     */
    private function get_category_product_count($category_id) {
        $args = array(
            'post_type' => 'product',
            'post_status' => array('publish', 'private', 'draft'),
            'posts_per_page' => -1,
            'fields' => 'ids',
            'tax_query' => array(
                array(
                    'taxonomy' => 'product_cat',
                    'field' => 'term_id',
                    'terms' => $category_id,
                )
            )
        );
        
        $products = get_posts($args);
        return count($products);
    }
    
    /**
     * Get all categories with product counts for select lists
     *
     * @return array Array of categories with ID, name, and product count
     */
    public function get_categories_with_counts() {
        $args = array(
            'taxonomy' => 'product_cat',
            'orderby' => 'name',
            'hide_empty' => false,
        );
        
        $categories = get_terms($args);
        $categories_with_counts = array();
        
        if (!is_wp_error($categories)) {
            foreach ($categories as $category) {
                $product_count = $this->get_category_product_count($category->term_id);
                
                $categories_with_counts[] = array(
                    'id' => $category->term_id,
                    'name' => $category->name,
                    'count' => $product_count,
                    'display_name' => sprintf('%s (%d products)', $category->name, $product_count)
                );
            }
        }
        
        return $categories_with_counts;
    }
}