<?php

namespace AIEO\Claude\Abilities;

defined( 'ABSPATH' ) || exit;

class RecommendProductsForCustomerAbility {

	const ABILITY_NAME = 'aieo/recommend-products-for-customer';

	public static function register() {
		wp_register_ability(
			self::ABILITY_NAME,
			array(
				'label'               => __( 'Recommend products for customer', 'ai-eshop-optimizer' ),
				'description'         => __( "Return a ranked list of product recommendations for one customer. Leverages the customer's wishlisted/affinity brands and the cached bundle recommendations (`wp_aieo_product_recommendations`). PII-safe.", 'ai-eshop-optimizer' ),
				'category'            => \AIEO\Claude\Bootstrap::CATEGORY,
				'input_schema'        => self::input_schema(),
				'output_schema'       => array( 'type' => 'object' ),
				'execute_callback'    => array( __CLASS__, 'execute' ),
				'permission_callback' => array( __CLASS__, 'permission_check' ),
				'meta'                => array(
					'annotations'  => array(
						'readonly'   => true,
						'idempotent' => true,
					),
					'show_in_rest' => true,
				),
			)
		);
	}

	public static function permission_check( $input = null ) {
		unset( $input );
		return current_user_can( 'manage_woocommerce' );
	}

	private static function input_schema() {
		return array(
			'default'    => array(),
			'type'       => 'object',
			'required'   => array( 'customer_id' ),
			'properties' => array(
				'customer_id' => array(
					'type'    => 'integer',
					'minimum' => 1,
				),
				'limit'       => array(
					'type'    => 'integer',
					'minimum' => 1,
					'maximum' => 50,
					'default' => 12,
				),
			),
		);
	}

	public static function execute( $input ) {
		$input   = is_array( $input ) ? $input : array();
		$user_id = isset( $input['customer_id'] ) ? (int) $input['customer_id'] : 0;
		$limit   = isset( $input['limit'] ) ? max( 1, min( 50, (int) $input['limit'] ) ) : 12;
		if ( $user_id <= 0 ) {
			return new \WP_Error( 'aieo_invalid_input', __( 'customer_id is required.', 'ai-eshop-optimizer' ) );
		}

		$seed_brand_ids = array();
		if ( class_exists( 'AIEO_Customer_Intelligence_Query' ) ) {
			$seed_brand_ids = \AIEO_Customer_Intelligence_Query::get_brand_preferences( $user_id, 5 );
		}
		$seed_product_ids = self::recent_rated_products( $user_id, 5 );

		
		
		
		$accum = array();
		if ( ! empty( $seed_product_ids ) && class_exists( 'AIEO_Recommendations_Cache' ) ) {
			$rels = \AIEO_Recommendations_Cache::get_valid_relation_types();
			$rels = array_intersect( $rels, array( 'related', 'upsells', 'crosssells', 'product_needs' ) );
			foreach ( $seed_product_ids as $sid ) {
				foreach ( $rels as $rel ) {
					$cached = \AIEO_Recommendations_Cache::get( $sid, $rel );
					if ( ! is_array( $cached ) || empty( $cached ) ) { continue; }
					foreach ( $cached as $row ) {
						$pid = isset( $row['product_id'] ) ? (int) $row['product_id'] : ( isset( $row['id'] ) ? (int) $row['id'] : 0 );
						if ( $pid <= 0 || $pid === $sid ) { continue; }
						$accum[ $pid ] = ( $accum[ $pid ] ?? 0 ) + 1;
					}
				}
			}
		}

		
		
		if ( empty( $accum ) && ! empty( $seed_brand_ids ) ) {
			global $wpdb;
			$placeholders = implode( ',', array_fill( 0, count( $seed_brand_ids ), '%d' ) );
			
			$pids = $wpdb->get_col( $wpdb->prepare(
				"SELECT DISTINCT tr.object_id
				   FROM {$wpdb->term_relationships} tr
				   INNER JOIN {$wpdb->term_taxonomy} tt
				           ON tt.term_taxonomy_id = tr.term_taxonomy_id
				  WHERE tt.taxonomy = 'product_brand'
				    AND tt.term_id IN ({$placeholders})
				  LIMIT %d",
				array_merge( $seed_brand_ids, array( $limit * 3 ) )
			) );
			foreach ( (array) $pids as $pid ) {
				$accum[ (int) $pid ] = 1;
			}
		}

		arsort( $accum, SORT_NUMERIC );
		$recommended = array();
		$i = 0;
		foreach ( $accum as $pid => $score ) {
			$recommended[] = array(
				'product_id' => (int) $pid,
				'title'      => get_the_title( (int) $pid ),
				'permalink'  => get_permalink( (int) $pid ),
				'signal'     => (int) $score,
			);
			if ( ++$i >= $limit ) { break; }
		}

		return array(
			'customer_id'   => $user_id,
			'pseudonym'     => 'Customer #' . $user_id,
			'seed_brand_ids'   => $seed_brand_ids,
			'seed_product_ids' => $seed_product_ids,
			'recommendations'  => $recommended,
		);
	}

	private static function recent_rated_products( $user_id, $limit = 5 ) {
		global $wpdb;
		$table = $wpdb->prefix . 'aieo_ratings';
		$exists = (string) $wpdb->get_var( $wpdb->prepare(
			"SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = %s LIMIT 1",
			$table
		) );
		if ( $exists === '' ) { return array(); }
		
		$pids = $wpdb->get_col( $wpdb->prepare(
			"SELECT DISTINCT product_id FROM {$table}
			  WHERE user_id = %d
			    AND rating > 0
			    AND (object_type = 'product' OR object_type IS NULL)
			  ORDER BY created_at DESC
			  LIMIT %d",
			$user_id, max( 1, (int) $limit )
		) );
		return array_values( array_filter( array_map( 'intval', (array) $pids ), static function ( $v ) {
			return $v > 0;
		} ) );
	}
}