<?php
/**
 * Quote list operations on top of the session.
 * Item key = md5( product_id . variation_id ) - same scheme as the market standard.
 *
 * @package BoringQuote
 */

namespace BoringQuote;

defined( 'ABSPATH' ) || exit;

/**
 * Class QuoteList
 */
class QuoteList {

	const SESSION_KEY = 'bbquote_items';

	const COUNT_COOKIE = 'bbquote_count';

	/**
	 * Session handler.
	 *
	 * @var Session
	 */
	protected $session;

	/**
	 * Constructor.
	 *
	 * @param Session $session Session handler.
	 */
	public function __construct( Session $session ) {
		$this->session = $session;

		// No-JS fallback: ?add-to-quote={product_id}&quantity=N, or the variations form submitted with
		// add-to-quote. Priority 19 runs before WooCommerce's add-to-cart handler on the same form.
		add_action( 'wp_loaded', array( $this, 'handle_query_string_add' ), 19 );
		// Logging out destroys the session; drop the counter with it.
		add_action( 'clear_auth_cookie', array( $this, 'clear_count_cookie' ) );
	}

	/**
	 * Remove the count cookie.
	 */
	public function clear_count_cookie() {
		if ( ! headers_sent() ) {
			wc_setcookie( self::COUNT_COOKIE, '', time() - YEAR_IN_SECONDS, false, false );
		}
	}

	/**
	 * All items in the list.
	 *
	 * @return array
	 */
	public function get_items() {
		return (array) $this->session->get( self::SESSION_KEY, array() );
	}

	/**
	 * Number of items.
	 *
	 * @return int
	 */
	public function count() {
		return count( $this->get_items() );
	}

	/**
	 * Whether the list is empty.
	 *
	 * @return bool
	 */
	public function is_empty() {
		return 0 === $this->count();
	}

	/**
	 * Item key for a product/variation pair.
	 *
	 * @param int $product_id   Product id.
	 * @param int $variation_id Variation id (0 for simple products).
	 * @return string
	 */
	public function item_key( $product_id, $variation_id = 0 ) {
		return md5( $product_id . ( $variation_id ? '-' . $variation_id : '' ) );
	}

	/**
	 * Whether the product is already in the list.
	 *
	 * @param int $product_id   Product id.
	 * @param int $variation_id Variation id.
	 * @return bool
	 */
	public function exists( $product_id, $variation_id = 0 ) {
		return array_key_exists( $this->item_key( $product_id, $variation_id ), $this->get_items() );
	}

	/**
	 * Product (or variation) object for a stored list item.
	 *
	 * @param array $item Item with product_id and variation_id.
	 * @return \WC_Product|false|null
	 */
	public static function item_product( array $item ) {
		return wc_get_product( ! empty( $item['variation_id'] ) ? $item['variation_id'] : $item['product_id'] );
	}

	/**
	 * Customer-facing message for an add_item() result.
	 *
	 * @param string $result added|exists|invalid.
	 * @return string
	 */
	public static function result_message( $result ) {
		switch ( $result ) {
			case 'added':
				return __( 'Product added to your quote list.', 'boring-quote' );
			case 'exists':
				return __( 'Product is already in your quote list.', 'boring-quote' );
			default:
				return __( 'This product cannot be added to the quote list. If it has options, choose them first.', 'boring-quote' );
		}
	}

	/**
	 * Add an item.
	 *
	 * @param int   $product_id   Product id.
	 * @param int   $quantity     Quantity.
	 * @param int   $variation_id Variation id.
	 * @param array $attributes   Chosen variation attributes (attribute_* => value).
	 * @return string 'added'|'exists'|'invalid'
	 */
	public function add_item( $product_id, $quantity = 1, $variation_id = 0, $attributes = array() ) {
		$product_id   = absint( $product_id );
		$variation_id = absint( $variation_id );
		$quantity     = max( 1, absint( $quantity ) );

		$product = wc_get_product( $variation_id ? $variation_id : $product_id );

		/**
		 * Filter whether the item may be added (visibility, roles in Pro, etc.).
		 *
		 * @param bool       $valid   Valid flag.
		 * @param int        $product_id Product id.
		 * @param \WC_Product|false $product Product object.
		 */
		$valid = apply_filters( 'bbquote_item_is_valid', self::is_quotable( $product ) && self::matches_parent( $product, $product_id ), $product_id, $product );

		if ( ! $valid ) {
			return 'invalid';
		}

		if ( $this->exists( $product_id, $variation_id ) ) {
			return 'exists';
		}

		$items = $this->get_items();

		$items[ $this->item_key( $product_id, $variation_id ) ] = array(
			'product_id'   => $product_id,
			'variation_id' => $variation_id,
			'quantity'     => $quantity,
			'attributes'   => array_filter( (array) $attributes, 'is_string' ),
		);

		$this->save( $items );

		do_action( 'bbquote_item_added', $product_id, $variation_id, $quantity );

		return 'added';
	}

	/**
	 * Whether a product may be quoted: published (and, for variations, enabled with a published parent).
	 * Deliberately NOT is_visible(): that hides out-of-stock products when the store hides them from
	 * the catalog, which is exactly when customers ask for a quote.
	 *
	 * @param \WC_Product|false|null $product Product.
	 * @return bool
	 */
	public static function is_quotable( $product ) {
		if ( ! $product instanceof \WC_Product || 'publish' !== $product->get_status() ) {
			return false;
		}
		if ( $product->is_type( 'variation' ) ) {
			$parent = wc_get_product( $product->get_parent_id() );
			return $parent instanceof \WC_Product && 'publish' === $parent->get_status();
		}
		return true;
	}

	/**
	 * Whether the resolved product fits the requested parent id: a variation must belong to it,
	 * and a variable product cannot be added without a chosen variation.
	 *
	 * @param \WC_Product|false|null $product    Product resolved from variation_id or product_id.
	 * @param int                    $product_id Requested product id.
	 * @return bool
	 */
	public static function matches_parent( $product, $product_id ) {
		if ( ! $product instanceof \WC_Product ) {
			return false;
		}
		if ( $product->is_type( 'variation' ) ) {
			return (int) $product->get_parent_id() === (int) $product_id;
		}
		return ! $product->is_type( 'variable' ) && (int) $product->get_id() === (int) $product_id;
	}

	/**
	 * Update item quantity.
	 *
	 * @param string $key      Item key.
	 * @param int    $quantity New quantity; 0 removes the item.
	 * @return bool
	 */
	public function update_quantity( $key, $quantity ) {
		$items = $this->get_items();
		if ( ! isset( $items[ $key ] ) ) {
			return false;
		}
		$quantity = absint( $quantity );
		if ( 0 === $quantity ) {
			return $this->remove_item( $key );
		}
		$items[ $key ]['quantity'] = $quantity;
		$this->save( $items );
		return true;
	}

	/**
	 * Remove an item.
	 *
	 * @param string $key Item key.
	 * @return bool
	 */
	public function remove_item( $key ) {
		$items = $this->get_items();
		if ( ! isset( $items[ $key ] ) ) {
			return false;
		}
		unset( $items[ $key ] );
		$this->save( $items );
		return true;
	}

	/**
	 * Empty the list.
	 */
	public function clear() {
		$this->save( array() );
	}

	/**
	 * Store items and refresh the count cookie.
	 * `bbquote_count` holds only a number, so cached pages can show the counter without
	 * varying HTML per visitor (read by frontend.js).
	 *
	 * @param array $items Items.
	 */
	protected function save( array $items ) {
		$this->session->set( self::SESSION_KEY, $items );
		if ( ! headers_sent() ) {
			$count = count( $items );
			wc_setcookie( self::COUNT_COOKIE, (string) $count, $count ? $this->session->get_expiration() : time() - YEAR_IN_SECONDS, is_ssl(), false );
		}
	}

	/**
	 * No-JS fallback for adding by query string.
	 */
	public function handle_query_string_add() {
		if ( empty( $_REQUEST['add-to-quote'] ) ) {
			return;
		}

		$nonce = isset( $_REQUEST['bbquote_add_nonce'] ) ? sanitize_text_field( wp_unslash( $_REQUEST['bbquote_add_nonce'] ) ) : '';
		if ( ! wp_verify_nonce( $nonce, 'bbquote_add_to_quote' ) ) {
			if ( function_exists( 'wc_add_notice' ) ) {
				wc_add_notice( __( 'Your session has expired. Please try again.', 'boring-quote' ), 'error' );
			}
			if ( ! wp_doing_ajax() && ! headers_sent() ) {
				wp_safe_redirect( remove_query_arg( array( 'add-to-quote', 'variation_id', 'quantity', 'bbquote_add_nonce' ) ) );
				exit;
			}
			return;
		}

		if ( ! is_numeric( $_REQUEST['add-to-quote'] ) ) {
			return;
		}
		$product_id   = absint( $_REQUEST['add-to-quote'] );
		$variation_id = isset( $_REQUEST['variation_id'] ) ? absint( $_REQUEST['variation_id'] ) : 0;
		$quantity     = isset( $_REQUEST['quantity'] ) ? absint( $_REQUEST['quantity'] ) : 1;

		// Without JS the variations form sends only the chosen attributes, not the variation id.
		$attributes = array();
		foreach ( wp_unslash( $_REQUEST ) as $name => $value ) { // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- sanitized below.
			if ( is_string( $name ) && 0 === strpos( $name, 'attribute_' ) && is_scalar( $value ) ) {
				$attributes[ sanitize_title( $name ) ] = sanitize_text_field( (string) $value );
			}
		}
		$product = wc_get_product( $product_id );
		if ( ! $variation_id && $attributes && $product && $product->is_type( 'variable' ) ) {
			$variation_id = (int) \WC_Data_Store::load( 'product' )->find_matching_product_variation( $product, $attributes );
		}

		$result = $this->add_item( $product_id, $quantity, $variation_id, $attributes );

		if ( function_exists( 'wc_add_notice' ) ) {
			$types = array(
				'added'  => 'success',
				'exists' => 'notice',
			);
			wc_add_notice( self::result_message( $result ), isset( $types[ $result ] ) ? $types[ $result ] : 'error' );
		}

		// Drop the query args so a reload does not add the product again.
		if ( ! wp_doing_ajax() && ! headers_sent() ) {
			wp_safe_redirect( remove_query_arg( array( 'add-to-quote', 'variation_id', 'quantity', 'bbquote_add_nonce' ) ) );
			exit;
		}
	}
}