<?php

namespace Awas\AdvancedSearch\Search;

use Awas\AdvancedSearch\Core\Container;

class Engine
{
    /**
     * @var Container
     */
    private $container;

    public function __construct(Container $container)
    {
        $this->container = $container;
    }

    /**
     * Executes a search and formats the output.
     *
     * @param string $keyword
     * @return array
     */
    public function search($keyword, $category = '')
    {
        if (empty(trim($keyword))) {
            return [];
        }

        $settings = get_option('awas_settings', []);
        
        $cache_enabled = !empty($settings['performance']['cache']);
        $cache_key = 'awas_search_' . md5($keyword . '_' . $category . '_' . wp_json_encode($settings['layouts'] ?? []));

        if ($cache_enabled) {
            $cached_results = get_transient($cache_key);
            if ($cached_results !== false) {
                return $cached_results;
            }
        }

        $queryBuilder = $this->container->get(QueryBuilder::class);
        $sql = $queryBuilder->build_query($keyword, $settings, $category);

        if (empty($sql)) {
            return [];
        }

        global $wpdb;
        $results = $wpdb->get_results($sql);

        $final_results = [];

        if (empty($results) && !empty($settings['suggestions']['did_you_mean'])) {
            // Did you mean logic using SOUNDEX
            $did_you_mean = $wpdb->get_var($wpdb->prepare("
                SELECT title FROM {$wpdb->prefix}awas_search_index 
                WHERE SOUNDEX(title) = SOUNDEX(%s) 
                AND status = 'publish'
                LIMIT 1
            ", $keyword));

            if ($did_you_mean && strtolower(trim($did_you_mean)) !== strtolower(trim($keyword))) {
                $final_results = ['did_you_mean' => $did_you_mean];
            }
        } else {
            $final_results = $this->format_results($results, $settings);
        }

        if ($cache_enabled && !empty($final_results)) {
            // Cache for 12 hours
            set_transient($cache_key, $final_results, 12 * HOUR_IN_SECONDS);
        }

        return $final_results;
    }

    /**
     * Formats DB results into a structured array for the frontend UI.
     *
     * @param array $db_results
     * @param array $settings
     * @return array
     */
    private function format_results($db_results, $settings)
    {
        $formatted = [];
        
        $desc_length = isset($settings['logic']['desc_length']) ? absint($settings['logic']['desc_length']) : 20;

        foreach ($db_results as $row) {
            $product_id = ($row->variation_id > 0) ? $row->variation_id : $row->object_id;
            $product = wc_get_product($product_id);

            if (!$product) continue;

            $image = wp_get_attachment_image_src($product->get_image_id(), 'thumbnail');
            $description = wp_trim_words($product->get_short_description() ?: $product->get_description(), $desc_length);
            
            // Get Categories with URLs
            $categories_data = [];
            $terms = get_the_terms($product->get_parent_id() ?: $product->get_id(), 'product_cat');
            if ($terms && !is_wp_error($terms)) {
                foreach ($terms as $term) {
                    $categories_data[] = [
                        'name' => $term->name,
                        'url' => get_term_link($term, 'product_cat')
                    ];
                }
            }

            // Stock status text
            $stock_text = '';
            if ($product->is_in_stock()) {
                $stock_text = __('In stock', 'awas-woo');
            } else {
                $stock_text = __('Out of stock', 'awas-woo');
            }

            // Product Type and Add to Cart
            $type = $product->get_type();
            $add_to_cart_url = $product->add_to_cart_url();
            $add_to_cart_text = $product->add_to_cart_text();
            
            // For variable products, we might want to return variations
            $attributes_string = '';
            if ($type === 'variation') {
                $attributes = $product->get_attributes();
                $attr_names = [];
                foreach ($attributes as $key => $value) {
                    $taxonomy = str_replace('attribute_', '', $key);
                    if (taxonomy_exists($taxonomy)) {
                        $term = get_term_by('slug', $value, $taxonomy);
                        $attr_names[] = wc_attribute_label($taxonomy) . ': ' . ($term ? $term->name : $value);
                    } else {
                        $attr_names[] = wc_attribute_label($taxonomy) . ': ' . $value;
                    }
                }
                $attributes_string = implode(', ', $attr_names);
            }

            $formatted[] = [
                'id' => $product_id,
                'title' => $product->get_name(),
                'price_html' => $product->get_price_html(),
                'image' => $image ? $image[0] : wc_placeholder_img_src(),
                'url' => $product->get_permalink(),
                'sku' => $product->get_sku(),
                'description' => $description,
                'is_in_stock' => $product->is_in_stock(),
                'stock_text' => $stock_text,
                'is_on_sale' => $product->is_on_sale(),
                'categories' => $categories_data,
                'type' => $type,
                'add_to_cart_url' => $add_to_cart_url,
                'add_to_cart_text' => $add_to_cart_text,
                'attributes_string' => $attributes_string
            ];
        }

        return $formatted;
    }
}