<?php
/**
 * AEO (AI Engine Optimization) Handler
 *
 * Handles organization and product schema storage and injection into the storefront.
 * Follows WooCommerce structured data patterns for compatibility.
 *
 * @see WC_Structured_Data for WooCommerce core implementation patterns.
 *
 * @package AgentShop\Aeo
 */

namespace AgentShop\Aeo;

defined( 'ABSPATH' ) || exit;

/**
 * AEO Handler class.
 */
class Handler {

	/**
	 * Option name for organization schema storage.
	 *
	 * @var string
	 */
	const OPTION_NAME = 'agentshop_organization_schema';

	/**
	 * Meta key for product schema storage.
	 *
	 * Must match the key used in woocommerce.adapter.js.
	 *
	 * @var string
	 */
	const PRODUCT_SCHEMA_META_KEY = '_agentshop_aeo_schema';

	/**
	 * Meta key for product schema update timestamp.
	 *
	 * @var string
	 */
	const PRODUCT_SCHEMA_UPDATED_META_KEY = '_agentshop_aeo_updated';

	/**
	 * Constructor.
	 */
	public function __construct() {
		$this->init_hooks();
	}

	/**
	 * Initialize hooks.
	 */
	private function init_hooks() {
		// REST API endpoints.
		add_action( 'rest_api_init', array( $this, 'register_rest_routes' ) );

		// Output schema in footer (same as WooCommerce core WC_Structured_Data).
		add_action( 'wp_footer', array( $this, 'output_organization_schema' ), 10 );
		add_action( 'wp_footer', array( $this, 'output_product_schema' ), 10 );
	}

	/**
	 * Register REST API routes.
	 */
	public function register_rest_routes() {
		register_rest_route(
			'agentshop/v1',
			'/aeo/organization-schema',
			array(
				array(
					'methods'             => \WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'store_schema' ),
					'permission_callback' => array( $this, 'check_permission' ),
					'args'                => $this->get_store_args(),
				),
				array(
					'methods'             => \WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_schema' ),
					'permission_callback' => array( $this, 'check_permission' ),
				),
				array(
					'methods'             => \WP_REST_Server::DELETABLE,
					'callback'            => array( $this, 'delete_schema' ),
					'permission_callback' => array( $this, 'check_permission' ),
				),
			)
		);
	}

	/**
	 * Get arguments for store endpoint.
	 *
	 * @return array
	 */
	private function get_store_args() {
		return array(
			'schema'     => array(
				'required'          => true,
				'type'              => array( 'object', 'string' ),
				'description'       => __( 'Organization schema JSON-LD object.', 'agentshop' ),
				'validate_callback' => array( $this, 'validate_schema' ),
				'sanitize_callback' => array( $this, 'sanitize_schema' ),
			),
			'updated_at' => array(
				'required'          => false,
				'type'              => 'string',
				'sanitize_callback' => 'sanitize_text_field',
			),
		);
	}

	/**
	 * Check if current user has permission.
	 *
	 * @return bool|\WP_Error
	 */
	public function check_permission() {
		if ( ! current_user_can( 'manage_woocommerce' ) ) {
			return new \WP_Error(
				'rest_forbidden',
				__( 'You do not have permission to manage organization schema.', 'agentshop' ),
				array( 'status' => 403 )
			);
		}
		return true;
	}

	/**
	 * Validate schema has required fields.
	 *
	 * @param mixed $schema Schema to validate.
	 * @return bool|\WP_Error
	 */
	public function validate_schema( $schema ) {
		// Parse if string.
		if ( is_string( $schema ) ) {
			$schema = json_decode( $schema, true );
			if ( json_last_error() !== JSON_ERROR_NONE ) {
				return new \WP_Error(
					'invalid_json',
					__( 'Schema must be valid JSON.', 'agentshop' )
				);
			}
		}

		if ( ! is_array( $schema ) || empty( $schema['@type'] ) ) {
			return new \WP_Error(
				'invalid_schema',
				__( 'Schema must have @type field.', 'agentshop' )
			);
		}

		return true;
	}

	/**
	 * Sanitize schema input.
	 *
	 * @param mixed $schema Schema input.
	 * @return array
	 */
	public function sanitize_schema( $schema ) {
		if ( is_string( $schema ) ) {
			$schema = json_decode( $schema, true );
		}

		if ( ! is_array( $schema ) ) {
			return array();
		}

		return $this->sanitize_schema_recursive( $schema );
	}

	/**
	 * Recursively sanitize schema values.
	 *
	 * @param array $data Data to sanitize.
	 * @return array
	 */
	private function sanitize_schema_recursive( $data ) {
		$sanitized = array();

		foreach ( $data as $key => $value ) {
			$key = sanitize_text_field( $key );

			if ( is_array( $value ) ) {
				$sanitized[ $key ] = $this->sanitize_schema_recursive( $value );
			} elseif ( is_string( $value ) ) {
				// Allow URLs and basic text.
				if ( filter_var( $value, FILTER_VALIDATE_URL ) ) {
					$sanitized[ $key ] = esc_url_raw( $value );
				} else {
					$sanitized[ $key ] = sanitize_text_field( $value );
				}
			} else {
				$sanitized[ $key ] = $value;
			}
		}

		return $sanitized;
	}

	/**
	 * Store organization schema.
	 *
	 * @param \WP_REST_Request $request Request object.
	 * @return \WP_REST_Response
	 */
	public function store_schema( $request ) {
		$schema     = $request->get_param( 'schema' );
		$updated_at = $request->get_param( 'updated_at' ) ?: current_time( 'c' );

		$data = array(
			'schema'     => $schema,
			'updated_at' => $updated_at,
		);

		// Store with autoload false - only loaded when needed.
		$result = update_option( self::OPTION_NAME, $data, false );

		// Log if AgentShop is available.
		if ( function_exists( 'AgentShop' ) ) {
			\agentshop()->log(
				'Organization schema stored via REST API',
				'info',
				array( 'schema_type' => $schema['@type'] ?? 'unknown' )
			);
		}

		return new \WP_REST_Response(
			array(
				'success'    => true,
				'message'    => __( 'Organization schema stored successfully.', 'agentshop' ),
				'updated_at' => $updated_at,
			),
			200
		);
	}

	/**
	 * Get stored organization schema.
	 *
	 * @param \WP_REST_Request $request Request object.
	 * @return \WP_REST_Response
	 */
	public function get_schema( $request ) {
		$data = get_option( self::OPTION_NAME, null );

		if ( empty( $data ) || empty( $data['schema'] ) ) {
			return new \WP_REST_Response(
				array(
					'success' => true,
					'schema'  => null,
					'message' => __( 'No organization schema configured.', 'agentshop' ),
				),
				200
			);
		}

		return new \WP_REST_Response(
			array(
				'success'    => true,
				'schema'     => $data['schema'],
				'updated_at' => $data['updated_at'] ?? null,
			),
			200
		);
	}

	/**
	 * Delete organization schema.
	 *
	 * @param \WP_REST_Request $request Request object.
	 * @return \WP_REST_Response
	 */
	public function delete_schema( $request ) {
		$deleted = delete_option( self::OPTION_NAME );

		if ( function_exists( 'AgentShop' ) ) {
			\agentshop()->log( 'Organization schema deleted via REST API', 'info' );
		}

		return new \WP_REST_Response(
			array(
				'success' => true,
				'deleted' => $deleted,
				'message' => __( 'Organization schema removed.', 'agentshop' ),
			),
			200
		);
	}

	/**
	 * Output organization schema as JSON-LD in footer.
	 *
	 * Follows WooCommerce pattern: wp_footer hook, wc_esc_json encoding.
	 */
	public function output_organization_schema() {
		$data = get_option( self::OPTION_NAME, null );

		if ( empty( $data['schema'] ) ) {
			return;
		}

		/**
		 * Filter organization schema before output.
		 *
		 * Follows WooCommerce pattern (e.g., woocommerce_structured_data_product).
		 *
		 * @param array $schema Organization schema array.
		 */
		$schema = apply_filters( 'agentshop_structured_data_organization', $data['schema'] );

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

		// Encode with same flags as WooCommerce core.
		$encoded = wp_json_encode( $schema, JSON_HEX_TAG | JSON_UNESCAPED_SLASHES );

		if ( ! $encoded ) {
			return;
		}

		// Use wp_print_inline_script_tag for WordPress-compliant script output.
		// See: https://developer.wordpress.org/reference/functions/wp_print_inline_script_tag/
		wp_print_inline_script_tag(
			$encoded,
			array(
				'type' => 'application/ld+json',
				'id'   => 'agentshop-organization-schema',
			)
		);
	}

	/**
	 * Output product schema as JSON-LD in footer on single product pages.
	 *
	 * Follows WooCommerce WC_Structured_Data pattern:
	 * - Only outputs on single product pages (is_product()).
	 * - Uses wc_esc_json() for secure JSON output.
	 * - Provides filter for customization.
	 *
	 * @since 1.0.0
	 */
	public function output_product_schema() {
		// Only output on single product pages.
		if ( ! is_product() ) {
			return;
		}

		global $product;

		// Use a local prefixed variable to avoid modifying the global.
		$agentshop_product = $product;

		// Ensure we have a valid product object.
		if ( ! $agentshop_product instanceof \WC_Product ) {
			$agentshop_product = wc_get_product( get_the_ID() );
		}

		if ( ! $agentshop_product ) {
			return;
		}

		// Get stored schema from product meta.
		$schema_data = get_post_meta( $agentshop_product->get_id(), self::PRODUCT_SCHEMA_META_KEY, true );

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

		// Handle both JSON string and array formats.
		if ( is_string( $schema_data ) ) {
			$schema_data = json_decode( $schema_data, true );
			if ( json_last_error() !== JSON_ERROR_NONE ) {
				return;
			}
		}

		if ( ! is_array( $schema_data ) ) {
			return;
		}

		// Schema data may be stored in different formats:
		// 1. Array of schemas: [{ "@type": "Product", ... }, { "@type": "BreadcrumbList", ... }]
		// 2. Keyed object: { product: {...}, faq: {...}, breadcrumbList: {...} }
		// 3. Single schema: { "@type": "Product", ... }
		$schemas_to_output = array();

		// Check if it's a sequential array (list of schemas).
		if ( isset( $schema_data[0] ) && is_array( $schema_data[0] ) ) {
			// Array format: [{ "@type": "Product" }, { "@type": "BreadcrumbList" }]
			foreach ( $schema_data as $schema ) {
				if ( ! empty( $schema['@type'] ) ) {
					$type = $schema['@type'];
					// Normalize type to lowercase key.
					$key = strtolower( str_replace( array( 'Page', 'List' ), '', $type ) );
					$schemas_to_output[ $key ] = $schema;
				}
			}
		} elseif ( isset( $schema_data['product'] ) || isset( $schema_data['faq'] ) || isset( $schema_data['breadcrumbList'] ) || isset( $schema_data['howTo'] ) ) {
			// Keyed object format: { product: {...}, faq: {...} }
			foreach ( array( 'product', 'faq', 'breadcrumbList', 'howTo' ) as $schema_type ) {
				if ( ! empty( $schema_data[ $schema_type ] ) ) {
					$schemas_to_output[ $schema_type ] = $schema_data[ $schema_type ];
				}
			}
		} elseif ( ! empty( $schema_data['@type'] ) ) {
			// Single schema object.
			$schemas_to_output['product'] = $schema_data;
		}

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

		// Output each schema separately for better debugging and control.
		foreach ( $schemas_to_output as $schema_type => $schema ) {
			$this->output_single_product_schema( $schema, $schema_type, $agentshop_product );
		}
	}

	/**
	 * Output a single product-related schema.
	 *
	 * @param array       $schema      Schema data array.
	 * @param string      $schema_type Schema type identifier (product, faq, breadcrumbList, howTo).
	 * @param \WC_Product $product     Product object.
	 */
	private function output_single_product_schema( $schema, $schema_type, $product ) {
		/**
		 * Filter product schema before output.
		 *
		 * Follows WooCommerce pattern (e.g., woocommerce_structured_data_product).
		 *
		 * @since 1.0.0
		 *
		 * @param array       $schema      Schema array.
		 * @param string      $schema_type Schema type (product, faq, breadcrumbList, howTo).
		 * @param \WC_Product $product     Product object.
		 */
		$schema = apply_filters( 'agentshop_structured_data_product', $schema, $schema_type, $product );

		/**
		 * Filter specific schema type before output.
		 *
		 * @since 1.0.0
		 *
		 * @param array       $schema  Schema array.
		 * @param \WC_Product $product Product object.
		 */
		$schema = apply_filters( "agentshop_structured_data_{$schema_type}", $schema, $product );

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

		// Encode with same flags as WooCommerce core.
		$encoded = wp_json_encode( $schema, JSON_HEX_TAG | JSON_UNESCAPED_SLASHES );

		if ( ! $encoded ) {
			return;
		}

		// Sanitize schema type for use in ID attribute.
		$safe_type = sanitize_html_class( $schema_type );

		// Use wp_print_inline_script_tag for WordPress-compliant script output.
		// See: https://developer.wordpress.org/reference/functions/wp_print_inline_script_tag/
		wp_print_inline_script_tag(
			$encoded,
			array(
				'type' => 'application/ld+json',
				'id'   => 'agentshop-' . $safe_type . '-schema',
			)
		);
	}

	/**
	 * Check if organization schema is configured.
	 *
	 * @return bool
	 */
	public static function has_schema() {
		$data = get_option( self::OPTION_NAME, null );
		return ! empty( $data['schema'] );
	}

	/**
	 * Get the stored schema data.
	 *
	 * @return array|null
	 */
	public static function get_stored_schema() {
		$data = get_option( self::OPTION_NAME, null );
		return $data['schema'] ?? null;
	}

	/**
	 * Check if a product has AEO schema configured.
	 *
	 * @param int $product_id Product ID.
	 * @return bool
	 */
	public static function product_has_schema( $product_id ) {
		$schema = get_post_meta( $product_id, self::PRODUCT_SCHEMA_META_KEY, true );
		return ! empty( $schema );
	}

	/**
	 * Get the stored product schema.
	 *
	 * @param int $product_id Product ID.
	 * @return array|null
	 */
	public static function get_product_schema( $product_id ) {
		$schema = get_post_meta( $product_id, self::PRODUCT_SCHEMA_META_KEY, true );

		if ( empty( $schema ) ) {
			return null;
		}

		if ( is_string( $schema ) ) {
			$schema = json_decode( $schema, true );
		}

		return is_array( $schema ) ? $schema : null;
	}

	/**
	 * Get the product schema update timestamp.
	 *
	 * @param int $product_id Product ID.
	 * @return string|null ISO 8601 timestamp or null.
	 */
	public static function get_product_schema_updated( $product_id ) {
		return get_post_meta( $product_id, self::PRODUCT_SCHEMA_UPDATED_META_KEY, true ) ?: null;
	}
}