protected function prepare_item_for_database( $request ) {
		global $wpdb;

		$id        = isset( $request['id'] ) ? absint( $request['id'] ) : 0;
		$coupon    = new WC_Coupon( $id );
		$schema    = $this->get_item_schema();
		$data_keys = array_keys( array_filter( $schema['properties'], array( $this, 'filter_writable_props' ) ) );

		// Validate required POST fields.
		if ( 'POST' === $request->get_method() && 0 === $coupon->get_id() ) {
			if ( empty( $request['code'] ) ) {
				return new WP_Error( 'woocommerce_rest_empty_coupon_code', sprintf( __( 'The coupon code cannot be empty.', 'woocommerce' ), 'code' ), array( 'status' => 400 ) );
			}
		}

		// Handle all writable props.
		foreach ( $data_keys as $key ) {
			$value = $request[ $key ];

			if ( ! is_null( $value ) ) {
				switch ( $key ) {
					case 'code' :
						$coupon_code = wc_format_coupon_code( $value );
						$id          = $coupon->get_id() ? $coupon->get_id() : 0;
						$id_from_code = wc_get_coupon_id_by_code( $coupon_code, $id );

						if ( $id_from_code ) {
							return new WP_Error( 'woocommerce_rest_coupon_code_already_exists', __( 'The coupon code already exists', 'woocommerce' ), array( 'status' => 400 ) );
						}

						$coupon->set_code( $coupon_code );
						break;
					case 'meta_data' :
						if ( is_array( $value ) ) {
							foreach ( $value as $meta ) {
								$coupon->update_meta_data( $meta['key'], $meta['value'], isset( $meta['id'] ) ? $meta['id'] : '' );
							}
						}
						break;
					case 'description' :
						$coupon->set_description( wp_filter_post_kses( $value ) );
						break;
					default :
						if ( is_callable( array( $coupon, "set_{$key}" ) ) ) {
							$coupon->{"set_{$key}"}( $value );
						}
						break;
				}
			}
		}

		/**
		 * Filter the query_vars used in `get_items` for the constructed query.
		 *
		 * The dynamic portion of the hook name, $this->post_type, refers to post_type of the post being
		 * prepared for insertion.
		 *
		 * @param WC_Coupon       $coupon        The coupon object.
		 * @param WP_REST_Request $request       Request object.
		 */
		return apply_filters( "woocommerce_rest_pre_insert_{$this->post_type}", $coupon, $request );
	}