<?php
/**
 * WooCommerce integration for PressNative: products, categories, cart nonce, session bridge.
 *
 * @package PressNative
 */

defined( 'ABSPATH' ) || exit;

/**
 * Class PressNative_WooCommerce
 *
 * Provides WooCommerce data and Store API nonce for native cart operations.
 * All methods guard with class_exists( 'WooCommerce' ).
 */
class PressNative_WooCommerce {

	/**
	 * Initialize WooCommerce integration hooks.
	 */
	public static function init() {
		add_action( 'rest_api_init', array( __CLASS__, 'register_rest_routes' ) );
		add_action( 'template_redirect', array( __CLASS__, 'handle_app_checkout' ), 1 );
	}

	/**
	 * Permission callback for cart mutation endpoints.
	 * Requires the WooCommerce Store API nonce from shop_config (Nonce / X-WC-Store-API-Nonce header).
	 *
	 * @param WP_REST_Request $request Request.
	 * @return true|WP_Error
	 */
	public static function permission_check_cart_mutate( $request ) {
		$nonce = $request->get_header( 'Nonce' );
		if ( empty( $nonce ) ) {
			$nonce = $request->get_header( 'X-WC-Store-API-Nonce' );
		}
		if ( empty( $nonce ) ) {
			$nonce = $request->get_param( 'store_api_nonce' );
		}
		$nonce = is_string( $nonce ) ? sanitize_text_field( $nonce ) : '';
		if ( '' === $nonce || ! wp_verify_nonce( $nonce, 'wc_store_api' ) ) {
			return new WP_Error(
				'pressnative_cart_forbidden',
				__( 'Valid cart nonce required.', 'pressnative-apps' ),
				array( 'status' => 403 )
			);
		}
		return true;
	}

	/**
	 * Create a short-lived checkout transfer token for the given cart items.
	 *
	 * @param array $items List of array{ product_id: int, quantity: int }.
	 * @return string Token string.
	 */
	public static function create_checkout_token( array $items ) {
		$token = wp_generate_password( 32, false, false );
		$clean = array();
		foreach ( $items as $item ) {
			$product_id = isset( $item['product_id'] ) ? absint( $item['product_id'] ) : 0;
			$quantity   = isset( $item['quantity'] ) ? absint( $item['quantity'] ) : 0;
			if ( $product_id > 0 && $quantity > 0 ) {
				$clean[] = array(
					'product_id' => $product_id,
					'quantity'   => $quantity,
				);
			}
		}
		set_transient( 'pressnative_co_' . $token, $clean, 10 * MINUTE_IN_SECONDS );
		return $token;
	}

	/**
	 * Handle checkout from the native app via a short-lived signed token.
	 *
	 * The app requests POST /cart/checkout-token (with Store API nonce), then opens:
	 * https://site.com/?pressnative_checkout_token=TOKEN
	 */
	public static function handle_app_checkout() {
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- one-time transfer token looked up server-side
		if ( empty( $_GET['pressnative_checkout_token'] ) ) {
			return;
		}
		if ( ! self::is_active() ) {
			return;
		}

		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- validated via transient lookup
		$token = sanitize_text_field( wp_unslash( $_GET['pressnative_checkout_token'] ) );
		// Marker value used after redirect (legacy); real tokens are 32+ chars from wp_generate_password.
		if ( '' === $token || strlen( $token ) < 16 || strlen( $token ) > 64 ) {
			return;
		}

		$key   = 'pressnative_co_' . $token;
		$items = get_transient( $key );
		delete_transient( $key );

		if ( ! is_array( $items ) ) {
			wp_die(
				esc_html__( 'This checkout link has expired. Please return to the app and try again.', 'pressnative-apps' ),
				esc_html__( 'Checkout expired', 'pressnative-apps' ),
				array( 'response' => 403 )
			);
		}

		wc_load_cart();
		WC()->cart->empty_cart();

		foreach ( $items as $item ) {
			$product_id = isset( $item['product_id'] ) ? absint( $item['product_id'] ) : 0;
			$quantity   = isset( $item['quantity'] ) ? absint( $item['quantity'] ) : 0;
			if ( $product_id > 0 && $quantity > 0 ) {
				WC()->cart->add_to_cart( $product_id, $quantity );
			}
		}

		$checkout_url = add_query_arg( 'pressnative_app_checkout', '1', wc_get_checkout_url() );
		wp_safe_redirect( $checkout_url );
		exit;
	}

	/**
	 * REST: create a checkout transfer URL from cart items (requires Store API nonce).
	 *
	 * @param WP_REST_Request $request Request with optional items[]; otherwise uses WC cart.
	 * @return WP_REST_Response|WP_Error
	 */
	public static function handle_create_checkout_token( $request ) {
		if ( ! self::is_active() || ! function_exists( 'WC' ) ) {
			return new WP_Error( 'woocommerce_unavailable', __( 'WooCommerce not available', 'pressnative-apps' ), array( 'status' => 503 ) );
		}

		$items = $request->get_param( 'items' );
		if ( ! is_array( $items ) || empty( $items ) ) {
			if ( ! WC()->cart ) {
				wc_load_cart();
				if ( method_exists( WC()->cart, 'get_cart_from_session' ) ) {
					WC()->cart->get_cart_from_session();
				}
			}
			$items = array();
			if ( WC()->cart ) {
				foreach ( WC()->cart->get_cart() as $cart_item ) {
					$items[] = array(
						'product_id' => (int) $cart_item['product_id'],
						'quantity'   => (int) $cart_item['quantity'],
					);
				}
			}
		}

		if ( empty( $items ) ) {
			return new WP_Error( 'empty_cart', __( 'No cart items to check out.', 'pressnative-apps' ), array( 'status' => 400 ) );
		}

		$token = self::create_checkout_token( $items );
		$url   = add_query_arg( 'pressnative_checkout_token', $token, home_url( '/' ) );

		return rest_ensure_response(
			array(
				'ok'           => true,
				'checkout_url' => $url,
				'expires_in'   => 600,
			)
		);
	}

	/**
	 * Register WooCommerce REST API routes.
	 */
	public static function register_rest_routes() {
		if ( ! class_exists( 'WooCommerce' ) ) {
			return;
		}

		register_rest_route(
			'pressnative/v1',
			'/cart/checkout-token',
			array(
				'methods'             => WP_REST_Server::CREATABLE,
				'callback'            => array( __CLASS__, 'handle_create_checkout_token' ),
				'permission_callback' => array( __CLASS__, 'permission_check_cart_mutate' ),
				'args'                => array(
					'items' => array(
						'required' => false,
						'type'     => 'array',
					),
				),
			)
		);

		register_rest_route(
			'pressnative/v1',
			'/shop/nonce',
			array(
				'methods'             => WP_REST_Server::READABLE,
				'callback'            => array( __CLASS__, 'handle_shop_nonce' ),
				// Public: issues a WooCommerce Store API nonce for the caller's own session.
				'permission_callback' => '__return_true',
			)
		);
	}

	/**
	 * Fresh Store API nonce so clients can retry cart mutations after 403.
	 *
	 * @return WP_REST_Response
	 */
	public static function handle_shop_nonce() {
		return rest_ensure_response(
			array(
				'store_api_nonce' => self::generate_cart_session_nonce(),
				'session_token'   => self::get_session_token(),
			)
		);
	}

	/**
	 * Whether WooCommerce is active.
	 *
	 * @return bool
	 */
	public static function is_active() {
		return class_exists( 'WooCommerce' );
	}

	/**
	 * Generate nonce for WooCommerce Store API (cart add, checkout).
	 * Native app sends this as Nonce header when calling Store API or PressNative cart proxy.
	 *
	 * @return string Nonce string, or empty if WooCommerce inactive.
	 */
	public static function generate_cart_session_nonce() {
		if ( ! self::is_active() ) {
			return '';
		}
		return wp_create_nonce( 'wc_store_api' );
	}

	/**
	 * Get a session/cart token for cookie bridge (checkout WebView).
	 * Uses current customer session so checkout can pre-fill user data.
	 *
	 * @return string Token or empty.
	 */
	public static function get_session_token() {
		if ( ! self::is_active() ) {
			return '';
		}
		if ( function_exists( 'WC' ) && isset( WC()->session ) && is_object( WC()->session ) ) {
			$session = WC()->session;
			if ( method_exists( $session, 'get_customer_id' ) ) {
				return (string) $session->get_customer_id();
			}
			if ( isset( $session->_customer_id ) ) {
				return (string) $session->_customer_id;
			}
		}
		return '';
	}

	/**
	 * Get cart URL for the site.
	 *
	 * @return string
	 */
	public static function get_cart_url() {
		if ( ! self::is_active() ) {
			return '';
		}
		$page_id = wc_get_page_id( 'cart' );
		return $page_id > 0 ? (string) get_permalink( $page_id ) : trailingslashit( home_url( 'cart' ) );
	}

	/**
	 * Get checkout URL for the site.
	 * Apps should obtain a transfer URL via POST /cart/checkout-token (requires Store API nonce).
	 *
	 * @return string
	 */
	public static function get_checkout_url() {
		if ( ! self::is_active() ) {
			return '';
		}
		$page_id = wc_get_page_id( 'checkout' );
		return $page_id > 0 ? (string) get_permalink( $page_id ) : trailingslashit( home_url( 'checkout' ) );
	}

	/**
	 * Get shop_config for layout responses (cart_url, checkout_url, nonce, session, currency).
	 *
	 * @return array
	 */
	public static function get_shop_config() {
		if ( ! self::is_active() ) {
			return array();
		}
		$currency = get_woocommerce_currency();
		$symbol  = get_woocommerce_currency_symbol();
		return array(
			'cart_url'                => self::get_cart_url(),
			'checkout_url'            => self::get_checkout_url(),
			'store_api_nonce'         => self::generate_cart_session_nonce(),
			'session_token'           => self::get_session_token(),
			'currency'                => $currency,
			'currency_symbol'         => $symbol,
			'supports_variations'     => true,
			'cart_recovery_enabled'   => class_exists( 'PressNative_Cart_Recovery' ) && PressNative_Cart_Recovery::is_enabled(),
			'product_display_preferences' => self::get_product_display_preferences(),
		);
	}

	/**
	 * Get product display preferences for different contexts.
	 *
	 * @return array
	 */
	public static function get_product_display_preferences() {
		$in_post_style = get_option( 'pressnative_product_in_post_style', 'compact_row' );
		$grid_style = get_option( 'pressnative_product_grid_style', 'card' );
		
		return array(
			'in_post_style' => $in_post_style,
			'grid_style'    => $grid_style,
			'available_styles' => array(
				'compact_row' => array(
					'name'        => __( 'Compact Row', 'pressnative-apps' ),
					'description' => __( 'Image on left, details on right - perfect for in-post products', 'pressnative-apps' ),
				),
				'card' => array(
					'name'        => __( 'Card', 'pressnative-apps' ),
					'description' => __( 'Full-width card with large image - great for product grids', 'pressnative-apps' ),
				),
				'mini_card' => array(
					'name'        => __( 'Mini Card', 'pressnative-apps' ),
					'description' => __( 'Smaller card with centered image - subtle in-post display', 'pressnative-apps' ),
				),
			),
		);
	}

	/**
	 * Get products for layout (grid, carousel).
	 *
	 * @param array $args Same as wc_get_products (limit, category, featured, etc.).
	 * @return array List of product data for contract (id, title, price, image_url, etc.).
	 */
	public static function get_products( $args = array() ) {
		if ( ! self::is_active() || ! function_exists( 'wc_get_products' ) ) {
			return array();
		}
		$defaults = array(
			'status'  => 'publish',
			'limit'   => 12,
			'orderby' => 'date',
			'order'   => 'DESC',
			'return'  => 'ids',
		);
		$ids = wc_get_products( array_merge( $defaults, $args ) );
		if ( ! is_array( $ids ) ) {
			return array();
		}
		$out = array();
		foreach ( $ids as $id ) {
			$product = wc_get_product( $id );
			if ( ! $product || ! $product->is_visible() ) {
				continue;
			}
			$out[] = self::product_to_contract_item( $product );
		}
		return $out;
	}

	/**
	 * Convert WC_Product to contract-style product item.
	 *
	 * @param WC_Product $product Product object.
	 * @return array
	 */
	public static function product_to_contract_item( $product ) {
		$id    = $product->get_id();
		$title = $product->get_name();
		$price = self::strip_price_html( $product->get_price_html() );
		$image = '';
		if ( $product->get_image_id() ) {
			$image = wp_get_attachment_image_url( $product->get_image_id(), 'medium' );
		}
		if ( empty( $image ) ) {
			$image = wc_placeholder_img_src( 'medium' );
		}
		$image = $image ? (string) $image : '';
		return array(
			'product_id'         => (string) $id,
			'title'              => $title,
			'price'              => $price,
			'price_raw'          => $product->get_price(),
			'image_url'          => $image,
			'action'             => array(
				'type'    => 'open_product',
				'payload' => array( 'product_id' => (string) $id ),
			),
			'add_to_cart_action' => array(
				'type'    => 'add_to_cart',
				'payload' => array( 'product_id' => (string) $id ),
			),
		);
	}

	/**
	 * Get product categories for ProductCategoryList.
	 *
	 * @param array $args get_terms args (hide_empty, parent, include, etc.).
	 * @return array List of category items for contract.
	 */
	public static function get_product_categories( $args = array() ) {
		if ( ! self::is_active() ) {
			return array();
		}
		$defaults = array(
			'taxonomy'   => 'product_cat',
			'hide_empty' => false,
			'parent'     => 0,
		);
		$terms = get_terms( array_merge( $defaults, $args ) );
		if ( is_wp_error( $terms ) || empty( $terms ) ) {
			return array();
		}
		$out = array();
		foreach ( $terms as $term ) {
			$icon = '';
			$meta = get_term_meta( $term->term_id, 'thumbnail_id', true );
			if ( $meta ) {
				$url = wp_get_attachment_image_url( (int) $meta, 'medium' );
				if ( $url ) {
					$icon = $url;
				}
			}
			if ( empty( $icon ) ) {
				$icon = get_site_icon_url( 512 ) ?: '';
			}
			$out[] = array(
				'product_category_id' => (string) $term->term_id,
				'name'                => $term->name,
				'icon_url'            => $icon,
				'action'              => array(
					'type'    => 'open_product_category',
					'payload' => array( 'product_category_id' => (string) $term->term_id ),
				),
			);
		}
		return $out;
	}

	/**
	 * Get single product for ProductDetail layout.
	 *
	 * @param int $product_id Product ID.
	 * @return array|null Contract product detail or null if not found.
	 */
	public static function get_product( $product_id ) {
		if ( ! self::is_active() ) {
			return null;
		}
		$product = wc_get_product( $product_id );
		if ( ! $product || ! $product->is_visible() ) {
			return null;
		}
		$id    = $product->get_id();
		$image = '';
		if ( $product->get_image_id() ) {
			$image = wp_get_attachment_image_url( $product->get_image_id(), 'large' );
		}
		if ( empty( $image ) ) {
			$image = wc_placeholder_img_src( 'large' );
		}
		$image = $image ? (string) $image : '';

		// Gallery: featured first, then gallery IDs, deduplicated URLs.
		$image_ids = array();
		$feat_id   = $product->get_image_id();
		if ( $feat_id ) {
			$image_ids[] = $feat_id;
		}
		if ( method_exists( $product, 'get_gallery_image_ids' ) ) {
			$gallery_ids = $product->get_gallery_image_ids();
			if ( is_array( $gallery_ids ) ) {
				foreach ( $gallery_ids as $aid ) {
					if ( $aid && ! in_array( $aid, $image_ids, true ) ) {
						$image_ids[] = $aid;
					}
				}
			}
		}
		$images = array();
		$seen   = array();
		foreach ( $image_ids as $aid ) {
			$url = wp_get_attachment_image_url( (int) $aid, 'large' );
			if ( $url && ! in_array( $url, $seen, true ) ) {
				$images[] = (string) $url;
				$seen[]   = $url;
			}
		}
		if ( empty( $images ) && $image ) {
			$images[] = $image;
		}
		if ( empty( $images ) && function_exists( 'wc_placeholder_img_src' ) ) {
			$images[] = (string) wc_placeholder_img_src( 'large' );
		}

		$desc = $product->get_short_description();
		if ( empty( $desc ) ) {
			$desc = $product->get_description();
		}
		$variations = self::variations_to_contract( $product );
		// Collect category names.
		$category_names = array();
		$terms = get_the_terms( $id, 'product_cat' );
		if ( ! empty( $terms ) && ! is_wp_error( $terms ) ) {
			foreach ( $terms as $term ) {
				$category_names[] = $term->name;
			}
		}

		return array(
			'product_id'         => (string) $id,
			'title'               => $product->get_name(),
			'price'               => self::strip_price_html( $product->get_price_html() ),
			'price_raw'           => $product->get_price(),
			'description'        => $desc,
			'image_url'           => $image,
			'images'              => $images,
			'categories'          => $category_names,
			'add_to_cart_action'   => array(
				'type'    => 'add_to_cart',
				'payload' => array( 'product_id' => (string) $id ),
			),
			'variations'          => $variations,
		);
	}

	/**
	 * Normalize WooCommerce variations into a client-friendly contract shape.
	 *
	 * @param WC_Product $product Product object.
	 * @return array
	 */
	private static function variations_to_contract( $product ) {
		if ( ! $product->is_type( 'variable' ) || ! method_exists( $product, 'get_available_variations' ) ) {
			return array();
		}
		$raw = $product->get_available_variations();
		if ( ! is_array( $raw ) ) {
			return array();
		}
		$out = array();
		foreach ( $raw as $variation ) {
			if ( ! is_array( $variation ) ) {
				continue;
			}
			$attributes = array();
			if ( ! empty( $variation['attributes'] ) && is_array( $variation['attributes'] ) ) {
				foreach ( $variation['attributes'] as $key => $value ) {
					$attr_name = str_replace( 'attribute_', '', (string) $key );
					$label     = function_exists( 'wc_attribute_label' ) ? wc_attribute_label( $attr_name ) : $attr_name;
					$attributes[ $label ] = (string) $value;
				}
			}
			$image_url = '';
			if ( ! empty( $variation['image']['src'] ) ) {
				$image_url = (string) $variation['image']['src'];
			} elseif ( ! empty( $variation['image']['url'] ) ) {
				$image_url = (string) $variation['image']['url'];
			}
			$display_price = isset( $variation['display_price'] ) ? $variation['display_price'] : ( isset( $variation['display_regular_price'] ) ? $variation['display_regular_price'] : 0 );
			$price_html    = isset( $variation['price_html'] ) ? $variation['price_html'] : '';
			$price         = $price_html ? self::strip_price_html( $price_html ) : ( function_exists( 'wc_price' ) ? self::strip_price_html( wc_price( $display_price ) ) : (string) $display_price );
			$out[]         = array(
				'variation_id' => isset( $variation['variation_id'] ) ? (int) $variation['variation_id'] : 0,
				'attributes'   => $attributes,
				'price'        => $price,
				'price_raw'    => is_numeric( $display_price ) ? (float) $display_price : 0,
				'in_stock'     => ! empty( $variation['is_in_stock'] ),
				'image_url'    => $image_url,
			);
		}
		return $out;
	}

	/**
	 * Convert WooCommerce price HTML to plain text (e.g. "$44.00").
	 *
	 * @param string $html Price HTML from get_price_html().
	 * @return string Plain text price.
	 */
	private static function strip_price_html( $html ) {
		$text = wp_strip_all_tags( $html );
		$text = html_entity_decode( $text, ENT_QUOTES, 'UTF-8' );
		return trim( $text );
	}
}