<?php
/**
 * Product texts from 7BE, for stores that already apply them into their descriptions: when the merchant clicks
 * Apply on a product text in the 7BE dashboard, 7BE sends the new description to this REST route, signed with
 * the store's key. The plugin keeps the description the product had before the first text, so Undo (from 7BE)
 * puts it back. Nothing changes without that click.
 *
 * New 7BE work for a product is not written here: it is rented content that blocks.php shows on the product page
 * while the store is connected. This route stays for the stores that already use it; 7BE decides what it sends.
 *
 * @package SevenBE_AI_Shelf
 */

defined( 'ABSPATH' ) || exit;

define( 'SEVENBE_TEXT_BACKUP', '_sevenbe_original_description' );
define( 'SEVENBE_TEXT_APPLIED', '_sevenbe_text_applied' );

add_action(
	'rest_api_init',
	function () {
		register_rest_route(
			'sevenbe/v1',
			'/texts',
			array(
				'methods'             => 'POST',
				'permission_callback' => 'sevenbe_texts_signed',
				'callback'            => 'sevenbe_texts_route',
			)
		);
	}
);

/**
 * Only 7BE may call the route: the body signed with the store's key, sent within the last hour.
 *
 * @param WP_REST_Request $request The request.
 * @return true|WP_Error
 */
function sevenbe_texts_signed( $request ) {
	$options   = sevenbe_options();
	$signature = (string) $request->get_header( 'x-7be-signature' );
	$raw       = (string) $request->get_body();
	if ( '' === $options['key'] || '' === $signature || ! hash_equals( hash_hmac( 'sha256', $raw, $options['key'] ), $signature ) ) {
		return new WP_Error( 'sevenbe_signature', 'Bad signature.', array( 'status' => 401 ) );
	}
	$body = json_decode( $raw, true );
	$sent = is_array( $body ) && isset( $body['sent'] ) ? (int) floor( (float) $body['sent'] / 1000 ) : 0;
	if ( abs( time() - $sent ) > HOUR_IN_SECONDS ) {
		return new WP_Error( 'sevenbe_clock', 'The request is too old.', array( 'status' => 401 ) );
	}
	return true;
}

/**
 * Apply a text to a product, or undo it.
 *
 * @param WP_REST_Request $request The request.
 * @return array|WP_Error
 */
function sevenbe_texts_route( $request ) {
	$body    = json_decode( (string) $request->get_body(), true );
	$action  = isset( $body['action'] ) ? sanitize_key( $body['action'] ) : '';
	$product = wc_get_product( isset( $body['product'] ) ? absint( $body['product'] ) : 0 );
	if ( ! $product || $product->get_parent_id() ) {
		return new WP_Error( 'sevenbe_product', 'No such product.', array( 'status' => 404 ) );
	}
	$id = $product->get_id();

	if ( 'apply' === $action ) {
		$html = isset( $body['html'] ) ? wp_kses_post( (string) $body['html'] ) : '';
		if ( '' === trim( wp_strip_all_tags( $html ) ) ) {
			return new WP_Error( 'sevenbe_empty', 'The text is empty.', array( 'status' => 400 ) );
		}
		// The description before the first text is kept; later texts replace each other.
		if ( ! metadata_exists( 'post', $id, SEVENBE_TEXT_BACKUP ) ) {
			update_post_meta( $id, SEVENBE_TEXT_BACKUP, $product->get_description() );
		}
		$product->set_description( $html );
		$product->save();
		update_post_meta( $id, SEVENBE_TEXT_APPLIED, gmdate( 'c' ) );
		return array(
			'ok'       => true,
			'original' => (string) get_post_meta( $id, SEVENBE_TEXT_BACKUP, true ),
		);
	}

	if ( 'undo' === $action ) {
		if ( ! metadata_exists( 'post', $id, SEVENBE_TEXT_BACKUP ) ) {
			return new WP_Error( 'sevenbe_nothing', 'No text to undo on this product.', array( 'status' => 409 ) );
		}
		$product->set_description( (string) get_post_meta( $id, SEVENBE_TEXT_BACKUP, true ) );
		$product->save();
		delete_post_meta( $id, SEVENBE_TEXT_BACKUP );
		delete_post_meta( $id, SEVENBE_TEXT_APPLIED );
		return array( 'ok' => true );
	}

	return new WP_Error( 'sevenbe_action', 'Unknown action.', array( 'status' => 400 ) );
}