<?php

class WC_Connect_TaxJar_Integration {

	/**
	 * @var WC_Connect_API_Client
	 */
	public $api_client;

	/**
	 * @var WC_Connect_Logger
	 */
	public $logger;

	public $wc_connect_base_url;

	private $expected_options = array(
		// Users can set either billing or shipping address for tax rates but not shop
		'woocommerce_tax_based_on'          => 'shipping',
		// Rate calculations assume tax not included
		'woocommerce_prices_include_tax'    => 'no',
		// Use no special handling on shipping taxes, our API handles that
		'woocommerce_shipping_tax_class'    => '',
		// API handles rounding precision
		'woocommerce_tax_round_at_subtotal' => 'no',
		// Rates are calculated in the cart assuming tax not included
		'woocommerce_tax_display_shop'      => 'excl',
		// TaxJar returns one total amount, not line item amounts
		'woocommerce_tax_display_cart'      => 'excl',
		// TaxJar returns one total amount, not line item amounts
		'woocommerce_tax_total_display'     => 'single',
	);

	const PROXY_PATH               = 'taxjar/v2';
	const OPTION_NAME              = 'wc_connect_taxes_enabled';
	const SETUP_WIZARD_OPTION_NAME = 'woocommerce_setup_automated_taxes';

	public function __construct(
		WC_Connect_API_Client $api_client,
		WC_Connect_Logger $logger,
		$wc_connect_base_url
	) {
		$this->api_client          = $api_client;
		$this->logger              = $logger;
		$this->wc_connect_base_url = $wc_connect_base_url;

		// Cache rates for 1 hour.
		$this->cache_time = HOUR_IN_SECONDS;

		// Cache error response for 5 minutes.
		$this->error_cache_time = MINUTE_IN_SECONDS * 5;
	}

	/**
	 * @param mixed  $taxjar_response
	 * @param string $to_country
	 * @param string $to_state
	 *
	 * @return string
	 */
	private static function generate_tax_rate_name( $taxjar_response, $to_country, $to_state ) {
		if ( 'US' !== $to_country ) {
			return $to_state;
		}

		// for a list of possible attributes in the `jurisdictions` attribute, see:
		// https://developers.taxjar.com/api/reference/#post-calculate-sales-tax-for-an-order
		$jurisdiction_pieces = array_merge(
			[
				'city'    => '',
				'county'  => '',
				'state'   => $to_state,
				'country' => $to_country,
			],
			(array) $taxjar_response->jurisdictions
		);

		// sometimes TaxJar returns a string with the value 'FALSE' for `state`.
		if ( rest_is_boolean( $to_state ) ) {
			$jurisdiction_pieces['state'] = '';
		}

		return join(
			'-',
			array_filter(
				[
					// the `$jurisdiction_pieces` is not really sorted
					// so let's sort it with COUNTRY-STATE-COUNTY-CITY
					// `array_filter` will take care of filtering out the "falsy" entries
					$jurisdiction_pieces['country'],
					$jurisdiction_pieces['state'],
					$jurisdiction_pieces['county'],
					$jurisdiction_pieces['city'],
				]
			)
		);
	}

	public function init() {
		// Only enable WCS TaxJar integration if the official TaxJar plugin isn't active.
		if ( class_exists( 'WC_Taxjar' ) ) {
			return;
		}

		$store_settings = $this->get_store_settings();
		$store_country  = $store_settings['country'];

		// TaxJar supports USA, Canada, Australia, and the European Union
		if ( ! $this->is_supported_country( $store_country ) ) {
			return;
		}

		// Add toggle for automated taxes to the core settings page
		add_filter( 'woocommerce_tax_settings', array( $this, 'add_tax_settings' ) );

		// Fix tooltip with link on older WC.
		if ( version_compare( WOOCOMMERCE_VERSION, '4.4.0', '<' ) ) {
			add_action( 'admin_enqueue_scripts', array( $this, 'fix_tooltip_keepalive' ), 11 );
		}

		// Settings values filter to handle the hardcoded settings
		add_filter( 'woocommerce_admin_settings_sanitize_option', array( $this, 'sanitize_tax_option' ), 10, 2 );

		// Bow out if we're not wanted
		if ( ! $this->is_enabled() ) {
			return;
		}

		// Scripts / Stylesheets
		add_action( 'admin_enqueue_scripts', array( $this, 'load_taxjar_admin_new_order_assets' ) );

		$this->configure_tax_settings();

		// Calculate Taxes at Cart / Checkout
		if ( class_exists( 'WC_Cart_Totals' ) ) { // Woo 3.2+
			add_action( 'woocommerce_after_calculate_totals', array( $this, 'maybe_calculate_totals' ), 20 );
		} else {
			add_action( 'woocommerce_calculate_totals', array( $this, 'maybe_calculate_totals' ), 20 );
		}

		// Calculate Taxes for Backend Orders (Woo 2.6+)
		add_action( 'woocommerce_before_save_order_items', array( $this, 'calculate_backend_totals' ), 20 );

		// Set customer taxable location for local pickup
		add_filter( 'woocommerce_customer_taxable_address', array( $this, 'append_base_address_to_customer_taxable_address' ), 10, 1 );

		add_filter( 'woocommerce_calc_tax', array( $this, 'override_woocommerce_tax_rates' ), 10, 3 );
		add_filter( 'woocommerce_matched_rates', array( $this, 'allow_street_address_for_matched_rates' ), 10, 2 );
	}

	/**
	 * Are automated taxes enabled?
	 *
	 * @return bool
	 */
	public function is_enabled() {
		// Migrate automated taxes selection from the setup wizard
		if ( get_option( self::SETUP_WIZARD_OPTION_NAME ) ) {
			update_option( self::OPTION_NAME, 'yes' );
			delete_option( self::SETUP_WIZARD_OPTION_NAME );

			return true;
		}

		return ( wc_tax_enabled() && 'yes' === get_option( self::OPTION_NAME ) );
	}

	/**
	 * Add our "automated taxes" setting to the core group.
	 *
	 * @param array $tax_settings WooCommerce Tax Settings
	 *
	 * @return array
	 */
	public function add_tax_settings( $tax_settings ) {
		$enabled                = $this->is_enabled();
		$backedup_tax_rates_url = admin_url( '/admin.php?page=wc-status&tab=connect#tax-rate-backups' );

		$powered_by_wct_notice = '<p>' . __( 'Powered by WooCommerce Tax. If automated taxes are enabled, you\'ll need to enter prices exclusive of tax.', 'woocommerce-services' ) . '</p>';

		if ( ! empty( WC_Connect_Functions::get_backed_up_tax_rate_files() ) ) {
			$powered_by_wct_notice .= '<p>' . sprintf( __( 'Your previous tax rates were backed up and can be downloaded %1$shere%2$s.', 'woocommerce-services' ), '<a href="' . esc_url( $backedup_tax_rates_url ) . '">', '</a>' ) . '</p>';
		}

		$desctructive_action_notice  = '<p>' . __( 'Enabling this option overrides any tax rates you have manually added.', 'woocommerce-services' ) . '</p>';
		$desctructive_action_notice .= '<p>' . sprintf( __( 'Your existing tax rates will be backed-up to a CSV that you can download %1$shere%2$s.', 'woocommerce-services' ), '<a href="' . esc_url( $backedup_tax_rates_url ) . '">', '</a>' ) . '</p>';

		$tax_nexus_notice = '<p>' . $this->get_tax_tooltip() . '</p>';

		$automated_taxes_description = join(
			'',
			$enabled ? [
				$powered_by_wct_notice,
				$tax_nexus_notice,
			] : [ $desctructive_action_notice, $tax_nexus_notice ]
		);
		$automated_taxes             = array(
			'title'    => __( 'Automated taxes', 'woocommerce-services' ),
			'id'       => self::OPTION_NAME, // TODO: save in `wc_connect_options`?
			'desc_tip' => $this->get_tax_tooltip(),
			'desc'     => $automated_taxes_description,
			'default'  => 'no',
			'type'     => 'select',
			'class'    => 'wc-enhanced-select',
			'options'  => array(
				'no'  => __( 'Disable automated taxes', 'woocommerce-services' ),
				'yes' => __( 'Enable automated taxes', 'woocommerce-services' ),
			),
		);

		// Insert the "automated taxes" setting at the top (under the section title)
		array_splice( $tax_settings, 1, 0, array( $automated_taxes ) );

		if ( $enabled ) {
			// If the automated taxes are enabled, disable the settings that would be reverted in the original plugin
			foreach ( $tax_settings as $index => $tax_setting ) {
				if ( ! array_key_exists( $tax_setting['id'], $this->expected_options ) ) {
					continue;
				}
				$tax_settings[ $index ]['custom_attributes'] = array( 'disabled' => true );
			}
		}

		return $tax_settings;
	}

	/**
	 * Get the text to show in the tooltip next to automatted tax settings.
	 */
	private function get_tax_tooltip() {
		$store_settings = $this->get_store_settings();
		$all_states     = WC()->countries->get_states( $store_settings['country'] );
		$all_countries  = WC()->countries->get_countries();
		$full_country   = $all_countries[ $store_settings['country'] ];
		$full_state     = isset( $all_states[ $store_settings['state'] ] ) ? $all_states[ $store_settings['state'] ] : '';
		if ( $full_state ) {
			/* translators: 1: Full state name 2: full country name */
			return sprintf( __( 'Your tax rates and settings will be automatically configured for %1$s, %2$s. <a href="https://docs.woocommerce.com/document/setting-up-taxes-in-woocommerce/#section-12">Learn more about setting up tax rates for additional nexuses</a>', 'woocommerce-services' ), $full_state, $full_country );
		}
		/* translators: 1: full country name */
		return sprintf( __( 'Your tax rates and settings will be automatically configured for %1$s. <a href="https://docs.woocommerce.com/document/setting-up-taxes-in-woocommerce/#section-12">Learn more about setting up tax rates for additional nexuses</a>', 'woocommerce-services' ), $full_country );
	}

	/**
	 * Hack to force keepAlive: true on tax setting tooltip.
	 */
	public function fix_tooltip_keepalive() {
		global $pagenow;
		if ( 'admin.php' !== $pagenow || ! isset( $_GET['page'] ) || 'wc-settings' !== $_GET['page'] || ! isset( $_GET['tab'] ) || 'tax' !== $_GET['tab'] || ! empty( $_GET['section'] ) ) {
			return;
		}

		$tooltip = $this->get_tax_tooltip();
		// Links in tooltips will not work unless keepAlive is true.
		wp_add_inline_script(
			'woocommerce_admin',
			"jQuery( function () {
					jQuery( 'label[for=wc_connect_taxes_enabled] .woocommerce-help-tip')
						.off( 'mouseenter mouseleave' )
						.tipTip( {
							'fadeIn': 50,
							'fadeOut': 50,
							'delay': 200,
							keepAlive: true,
							content: '" . $tooltip . "'
						} );
				} );"
		);
	}

	/**
	 * When automated taxes are enabled, overwrite core tax settings that might break the API integration
	 * This is similar to the original plugin functionality where these options were reverted on page load
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/82bf7c58/includes/class-wc-taxjar-integration.php#L66-L91
	 *
	 * @param mixed $value - option value
	 * @param array $option - option metadata
	 * @return string new option value, based on the automated taxes state or $value
	 */
	public function sanitize_tax_option( $value, $option ) {
		if (
			// skip unrecognized option format
			! is_array( $option )
			// skip if unexpected option format
			|| ! isset( $option['id'] )
			// skip if not enabled or not being enabled in the current request
			|| ! $this->is_enabled() && ( ! isset( $_POST[ self::OPTION_NAME ] ) || 'yes' != $_POST[ self::OPTION_NAME ] ) ) {
			return $value;
		}

		// the option is currently being enabled - backup the rates and flush the rates table
		if ( ! $this->is_enabled() && self::OPTION_NAME === $option['id'] && 'yes' === $value ) {
			$this->backup_existing_tax_rates();
			return $value;
		}

		// skip if unexpected option
		if ( ! array_key_exists( $option['id'], $this->expected_options ) ) {
			return $value;
		}

		return $this->expected_options[ $option['id'] ];
	}

	/**
	 * Overwrite WooCommerce core tax settings if they are different than expected
	 *
	 * Ported from TaxJar's plugin and modified to support $this->expected_options
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/82bf7c58/includes/class-wc-taxjar-integration.php#L66-L91
	 */
	public function configure_tax_settings() {
		foreach ( $this->expected_options as $option => $value ) {
			// first check the option value - with default memory caching this should help to avoid unnecessary DB operations
			if ( get_option( $option ) !== $value ) {
				update_option( $option, $value );
			}
		}
	}

	/**
	 * TaxJar supports USA, Canada, Australia, and the European Union + Great Britain
	 * See: https://developers.taxjar.com/api/reference/#countries
	 *
	 * @return array Countries supported by TaxJar.
	 */
	public function get_supported_countries() {
		// Hard code list instead of using `WC()->countries->get_european_union_countries()` just in case anyone else decides to leave the EU.
		return array( 'US', 'CA', 'AU', 'AT', 'BE', 'BG', 'CY', 'CZ', 'DE', 'DK', 'EE', 'ES', 'FI', 'FR', 'GB', 'GR', 'HU', 'HR', 'IE', 'IT', 'LT', 'LU', 'LV', 'MT', 'NL', 'PL', 'PT', 'RO', 'SE', 'SI', 'SK' );
	}

	/**
	 * Check if a given country is supported by TaxJar.
	 *
	 * @param string $country Two character country code.
	 *
	 * @return bool Whether or not the country is supported by TaxJar.
	 */
	public function is_supported_country( $country ) {
		return in_array( $country, $this->get_supported_countries() );
	}

	/**
	 * Gets the store's location settings.
	 *
	 * Modified version of TaxJar's plugin.
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/4b481f5/includes/class-wc-taxjar-integration.php#L910
	 *
	 * @return array
	 */
	public function get_store_settings() {
		$store_settings = array(
			'street'   => WC()->countries->get_base_address(),
			'city'     => WC()->countries->get_base_city(),
			'state'    => WC()->countries->get_base_state(),
			'country'  => WC()->countries->get_base_country(),
			'postcode' => WC()->countries->get_base_postcode(),
		);

		return apply_filters( 'taxjar_store_settings', $store_settings, array() );
	}

	/**
	 * @param $message
	 */
	public function _log( $message ) {
		$formatted_message = is_scalar( $message ) ? $message : json_encode( $message );

		$this->logger->log( $formatted_message, 'WCS Tax' );
	}

	/**
	 * @param $message
	 */
	public function _error( $message ) {
		$formatted_message = is_scalar( $message ) ? $message : json_encode( $message );

		// ignore error messages caused by customer input
		$state_zip_mismatch = false !== strpos( $formatted_message, 'to_zip' ) && false !== strpos( $formatted_message, 'is not used within to_state' );
		$invalid_postcode   = false !== strpos( $formatted_message, 'isn\'t a valid postal code for' );
		$malformed_postcode = false !== strpos( $formatted_message, 'zip code has incorrect format' );
		if ( ! is_admin() && ( $state_zip_mismatch || $invalid_postcode || $malformed_postcode ) ) {
			$fields              = WC()->countries->get_address_fields();
			$postcode_field_name = __( 'ZIP/Postal code', 'woocommerce-services' );
			if ( isset( $fields['billing_postcode'] ) && isset( $fields['billing_postcode']['label'] ) ) {
				$postcode_field_name = $fields['billing_postcode']['label'];
			}

			if ( $state_zip_mismatch ) {
				$message = sprintf( _x( '%s does not match the selected state.', '%s - ZIP/Postal code checkout field label', 'woocommerce-services' ), $postcode_field_name );
			} elseif ( $malformed_postcode ) {
				$message = sprintf( _x( '%s is not formatted correctly.', '%s - ZIP/Postal code checkout field label', 'woocommerce-services' ), $postcode_field_name );
			} else {
				$message = sprintf( _x( 'Invalid %s entered.', '%s - ZIP/Postal code checkout field label', 'woocommerce-services' ), $postcode_field_name );
			}

			// if on checkout page load (not ajax), don't set an error as it prevents checkout page from displaying
			if ( (
					( is_cart() || ( is_checkout() && is_ajax() ) ) ||
					( WC_Connect_Functions::has_cart_or_checkout_block() || WC_Connect_functions::is_store_api_call() )
				)
				&& ! wc_has_notice( $message, 'error' )
			) {
				wc_add_notice( $message, 'error' );
			}

			return;
		}

		$this->logger->error( $formatted_message, 'WCS Tax' );
	}

	/**
	 * Wrapper to avoid calling calculate_totals() for admin carts.
	 *
	 * @param $wc_cart_object
	 */
	public function maybe_calculate_totals( $wc_cart_object ) {
		if ( ! WC_Connect_Functions::should_send_cart_api_request() ) {
			return;
		}

		$this->calculate_totals( $wc_cart_object );
	}
	/**
	 * Calculate tax / totals using TaxJar at checkout
	 *
	 * Unchanged from the TaxJar plugin.
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/4b481f5/includes/class-wc-taxjar-integration.php#L471
	 *
	 * @param WC_Cart $wc_cart_object
	 * @return void
	 */
	public function calculate_totals( $wc_cart_object ) {
		/*
		 * Don't calculate if we are outside cart and checkout page, or pages with WooCommerce Cart and Checkout blocks.
		 * Don't calculate if we are inside mini-cart.
		 * If this is an API call don't calculate unless this is store/cart request.
		 */
		if (
			! WC_Connect_Functions::has_cart_or_checkout_block() &&
			! WC_Connect_Functions::is_store_api_call() &&
			(
				( ! is_cart() && ! is_checkout() ) ||
				( is_cart() && is_ajax() )
			)
		) {
			return;
		}

		$cart_taxes     = array();
		$cart_tax_total = 0;

		/**
		 * WC Coupon object.
		 *
		 * @var WC_Coupon $coupon
		*/
		foreach ( $wc_cart_object->coupons as $coupon ) {
			if ( method_exists( $coupon, 'get_limit_usage_to_x_items' ) ) { // Woo 3.0+.
				$limit_usage_qty = $coupon->get_limit_usage_to_x_items();

				if ( $limit_usage_qty ) {
					$coupon->set_limit_usage_to_x_items( $limit_usage_qty );
				}
			}
		}

		$address    = $this->get_address( $wc_cart_object );
		$line_items = $this->get_line_items( $wc_cart_object );

		$taxes = $this->calculate_tax(
			array(
				'to_country'      => $address['to_country'],
				'to_zip'          => $address['to_zip'],
				'to_state'        => $address['to_state'],
				'to_city'         => $address['to_city'],
				'to_street'       => $address['to_street'],
				'shipping_amount' => method_exists( $wc_cart_object, 'get_shipping_total' ) ?
					$wc_cart_object->get_shipping_total() : WC()->shipping->shipping_total,
				'line_items'      => $line_items,
			)
		);

		// Return if taxes could not be calculated.
		if ( false === $taxes ) {
			return;
		}

		$this->response_rate_ids   = $taxes['rate_ids'];
		$this->response_line_items = $taxes['line_items'];

		if ( isset( $this->response_line_items ) ) {
			foreach ( $this->response_line_items as $response_line_item_key => $response_line_item ) {
				$line_item = $this->get_line_item( $response_line_item_key, $line_items );
				if ( isset( $line_item ) ) {
					$this->response_line_items[ $response_line_item_key ]->line_total = ( $line_item['unit_price'] * $line_item['quantity'] ) - $line_item['discount'];
				}
			}
		}

		foreach ( $wc_cart_object->get_cart() as $cart_item_key => $cart_item ) {
			$product       = $cart_item['data'];
			$line_item_key = $product->get_id() . '-' . $cart_item_key;
			if ( isset( $taxes['line_items'][ $line_item_key ] ) && ! $taxes['line_items'][ $line_item_key ]->combined_tax_rate ) {
				if ( method_exists( $product, 'set_tax_status' ) ) {
					$product->set_tax_status( 'none' ); // Woo 3.0+
				} else {
					$product->tax_status = 'none'; // Woo 2.6
				}
			}
		}

		// Recalculate shipping package rates
		foreach ( $wc_cart_object->get_shipping_packages() as $package_key => $package ) {
			WC()->session->set( 'shipping_for_package_' . $package_key, null );
		}

		if ( class_exists( 'WC_Cart_Totals' ) ) { // Woo 3.2+
			do_action( 'woocommerce_cart_reset', $wc_cart_object, false );
			do_action( 'woocommerce_before_calculate_totals', $wc_cart_object );
			new WC_Cart_Totals( $wc_cart_object );
			remove_action( 'woocommerce_after_calculate_totals', array( $this, 'maybe_calculate_totals' ), 20 );
			do_action( 'woocommerce_after_calculate_totals', $wc_cart_object );
			add_action( 'woocommerce_after_calculate_totals', array( $this, 'maybe_calculate_totals' ), 20 );
		} else {
			remove_action( 'woocommerce_calculate_totals', array( $this, 'maybe_calculate_totals' ), 20 );
			$wc_cart_object->calculate_totals();
			add_action( 'woocommerce_calculate_totals', array( $this, 'maybe_calculate_totals' ), 20 );
		}
	}

	/**
	 * Calculate tax / totals using TaxJar for backend orders
	 *
	 * Unchanged from the TaxJar plugin.
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/96b5d57/includes/class-wc-taxjar-integration.php#L557
	 *
	 * @return void
	 */
	public function calculate_backend_totals( $order_id ) {
		$order      = wc_get_order( $order_id );
		$address    = $this->get_backend_address();
		$line_items = $this->get_backend_line_items( $order );
		if ( method_exists( $order, 'get_shipping_total' ) ) {
			$shipping = $order->get_shipping_total(); // Woo 3.0+
		} else {
			$shipping = $order->get_total_shipping(); // Woo 2.6
		}
		$taxes = $this->calculate_tax(
			array(
				'to_country'      => $address['to_country'],
				'to_state'        => $address['to_state'],
				'to_zip'          => $address['to_zip'],
				'to_city'         => $address['to_city'],
				'to_street'       => $address['to_street'],
				'shipping_amount' => $shipping,
				'line_items'      => $line_items,
			)
		);
		if ( class_exists( 'WC_Order_Item_Tax' ) ) { // Add tax rates manually for Woo 3.0+
			foreach ( $order->get_items() as $item_key => $item ) {
				$product_id    = $item->get_product_id();
				$line_item_key = $product_id . '-' . $item_key;
				if ( isset( $taxes['rate_ids'][ $line_item_key ] ) ) {
					$rate_id  = $taxes['rate_ids'][ $line_item_key ];
					$item_tax = new WC_Order_Item_Tax();
					$item_tax->set_rate( $rate_id );
					$item_tax->set_order_id( $order_id );
					$item_tax->save();
				}
			}
		} else { // Recalculate tax for Woo 2.6 to apply new tax rates
			if ( class_exists( 'WC_AJAX' ) ) {
				remove_action( 'woocommerce_before_save_order_items', array( $this, 'calculate_backend_totals' ), 20 );
				if ( check_ajax_referer( 'calc-totals', 'security', false ) ) {
					WC_AJAX::calc_line_taxes();
				}
				add_action( 'woocommerce_before_save_order_items', array( $this, 'calculate_backend_totals' ), 20 );
			}
		}
	}

	/**
	 * Get address details of customer at checkout
	 *
	 * Unchanged from the TaxJar plugin.
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/4b481f5/includes/class-wc-taxjar-integration.php#L585
	 *
	 * @return array
	 */
	protected function get_address() {
		$taxable_address = $this->get_taxable_address();
		$taxable_address = is_array( $taxable_address ) ? $taxable_address : array();

		$to_country = isset( $taxable_address[0] ) && ! empty( $taxable_address[0] ) ? $taxable_address[0] : false;
		$to_state   = isset( $taxable_address[1] ) && ! empty( $taxable_address[1] ) ? $taxable_address[1] : false;
		$to_zip     = isset( $taxable_address[2] ) && ! empty( $taxable_address[2] ) ? $taxable_address[2] : false;
		$to_city    = isset( $taxable_address[3] ) && ! empty( $taxable_address[3] ) ? $taxable_address[3] : false;
		$to_street  = isset( $taxable_address[4] ) && ! empty( $taxable_address[4] ) ? $taxable_address[4] : false;

		return array(
			'to_country' => $to_country,
			'to_state'   => $to_state,
			'to_zip'     => $to_zip,
			'to_city'    => $to_city,
			'to_street'  => $to_street,
		);
	}

	/**
	 * Allow street address to be passed when finding rates
	 *
	 * @param array  $matched_tax_rates
	 * @param string $tax_class
	 * @return array
	 */
	public function allow_street_address_for_matched_rates( $matched_tax_rates, $tax_class = '' ) {
		$tax_class         = sanitize_title( $tax_class );
		$location          = WC_Tax::get_tax_location( $tax_class );
		$matched_tax_rates = array();
		if ( sizeof( $location ) >= 4 ) {
			list( $country, $state, $postcode, $city, $street ) = array_pad( $location, 5, '' );
			$matched_tax_rates                                  = WC_Tax::find_rates(
				array(
					'country'   => $country,
					'state'     => $state,
					'postcode'  => $postcode,
					'city'      => $city,
					'tax_class' => $tax_class,
				)
			);
		}
		return $matched_tax_rates;
	}

	/**
	 * Get taxable address.
	 *
	 * @return array
	 */
	public function get_taxable_address() {
		$tax_based_on = get_option( 'woocommerce_tax_based_on' );
		// Check shipping method at this point to see if we need special handling
		// See WC_Customer get_taxable_address()
		// wc_get_chosen_shipping_method_ids() available since Woo 2.6.2+
		if ( function_exists( 'wc_get_chosen_shipping_method_ids' ) ) {
			if ( true === apply_filters( 'woocommerce_apply_base_tax_for_local_pickup', true ) && sizeof( array_intersect( wc_get_chosen_shipping_method_ids(), apply_filters( 'woocommerce_local_pickup_methods', array( 'legacy_local_pickup', 'local_pickup' ) ) ) ) > 0 ) {
				$tax_based_on = 'base';
			}
		} else {
			if ( true === apply_filters( 'woocommerce_apply_base_tax_for_local_pickup', true ) && sizeof( array_intersect( WC()->session->get( 'chosen_shipping_methods', array() ), apply_filters( 'woocommerce_local_pickup_methods', array( 'legacy_local_pickup', 'local_pickup' ) ) ) ) > 0 ) {
				$tax_based_on = 'base';
			}
		}

		if ( 'base' === $tax_based_on ) {
			$store_settings = $this->get_store_settings();
			$country        = $store_settings['country'];
			$state          = $store_settings['state'];
			$postcode       = $store_settings['postcode'];
			$city           = $store_settings['city'];
			$street         = $store_settings['street'];
		} elseif ( 'billing' === $tax_based_on ) {
			$country  = WC()->customer->get_billing_country();
			$state    = WC()->customer->get_billing_state();
			$postcode = WC()->customer->get_billing_postcode();
			$city     = WC()->customer->get_billing_city();
			$street   = WC()->customer->get_billing_address();
		} else {
			$country  = WC()->customer->get_shipping_country();
			$state    = WC()->customer->get_shipping_state();
			$postcode = WC()->customer->get_shipping_postcode();
			$city     = WC()->customer->get_shipping_city();
			$street   = WC()->customer->get_shipping_address();
		}

		return apply_filters( 'woocommerce_customer_taxable_address', array( $country, $state, $postcode, $city, $street ) );
	}

	/**
	 * Get address details of customer for backend orders
	 *
	 * Unchanged from the TaxJar plugin.
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/4b481f5/includes/class-wc-taxjar-integration.php#L607
	 *
	 * @return array
	 */
	protected function get_backend_address() {
		$to_country = isset( $_POST['country'] ) ? strtoupper( wc_clean( $_POST['country'] ) ) : false;
		$to_state   = isset( $_POST['state'] ) ? strtoupper( wc_clean( $_POST['state'] ) ) : false;
		$to_zip     = isset( $_POST['postcode'] ) ? strtoupper( wc_clean( $_POST['postcode'] ) ) : false;
		$to_city    = isset( $_POST['city'] ) ? strtoupper( wc_clean( $_POST['city'] ) ) : false;
		$to_street  = isset( $_POST['street'] ) ? strtoupper( wc_clean( $_POST['street'] ) ) : false;

		return array(
			'to_country' => $to_country,
			'to_state'   => $to_state,
			'to_zip'     => $to_zip,
			'to_city'    => $to_city,
			'to_street'  => $to_street,
		);
	}

	/**
	 * Get line items at checkout
	 *
	 * Unchanged from the TaxJar plugin.
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/96b5d57/includes/class-wc-taxjar-integration.php#L645
	 *
	 * @return array
	 */
	protected function get_line_items( $wc_cart_object ) {
		$line_items = array();

		foreach ( $wc_cart_object->get_cart() as $cart_item_key => $cart_item ) {
			$product       = $cart_item['data'];
			$id            = $product->get_id();
			$quantity      = $cart_item['quantity'];
			$unit_price    = wc_format_decimal( $product->get_price() );
			$line_subtotal = wc_format_decimal( $cart_item['line_subtotal'] );
			$discount      = wc_format_decimal( $cart_item['line_subtotal'] - $cart_item['line_total'] );
			$tax_class     = explode( '-', $product->get_tax_class() );
			$tax_code      = '';

			if ( isset( $tax_class ) && is_numeric( end( $tax_class ) ) ) {
				$tax_code = end( $tax_class );
			}

			if ( 'shipping' !== $product->get_tax_status() && ( ! $product->is_taxable() || 'zero-rate' == sanitize_title( $product->get_tax_class() ) ) ) {
				$tax_code = '99999';
			}

			// Get WC Subscription sign-up fees for calculations
			if ( class_exists( 'WC_Subscriptions_Cart' ) ) {
				if ( 'none' == WC_Subscriptions_Cart::get_calculation_type() ) {
					if ( class_exists( 'WC_Subscriptions_Synchroniser' ) ) {
						WC_Subscriptions_Synchroniser::maybe_set_free_trial();
					}
					$unit_price = WC_Subscriptions_Cart::set_subscription_prices_for_calculation( $unit_price, $product );
					if ( class_exists( 'WC_Subscriptions_Synchroniser' ) ) {
						WC_Subscriptions_Synchroniser::maybe_unset_free_trial();
					}
				}
			}

			array_push(
				$line_items,
				array(
					'id'               => $id . '-' . $cart_item_key,
					'quantity'         => $quantity,
					'product_tax_code' => $tax_code,
					'unit_price'       => $unit_price,
					'discount'         => $discount,
				)
			);
		}

		return $line_items;
	}

	/**
	 * Get line items for backend orders
	 *
	 * Unchanged from the TaxJar plugin.
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/96b5d57/includes/class-wc-taxjar-integration.php#L695
	 *
	 * @return array
	 */
	protected function get_backend_line_items( $order ) {
		$line_items                = array();
		$this->backend_tax_classes = array();
		foreach ( $order->get_items() as $item_key => $item ) {
			if ( is_object( $item ) ) { // Woo 3.0+
				$id             = $item->get_product_id();
				$quantity       = $item->get_quantity();
				$unit_price     = empty( $quantity ) ? $item->get_subtotal() : wc_format_decimal( $item->get_subtotal() / $quantity );
				$discount       = wc_format_decimal( $item->get_subtotal() - $item->get_total() );
				$tax_class_name = $item->get_tax_class();
				$tax_status     = $item->get_tax_status();
			} else { // Woo 2.6
				$id             = $item['product_id'];
				$quantity       = $item['qty'];
				$unit_price     = empty( $quantity ) ? $item['line_subtotal'] : wc_format_decimal( $item['line_subtotal'] / $quantity );
				$discount       = wc_format_decimal( $item['line_subtotal'] - $item['line_total'] );
				$tax_class_name = $item['tax_class'];
				$product        = $order->get_product_from_item( $item );
				$tax_status     = $product ? $product->get_tax_status() : 'taxable';
			}
			$this->backend_tax_classes[ $id ] = $tax_class_name;
			$tax_class                        = explode( '-', $tax_class_name );
			$tax_code                         = '';
			if ( isset( $tax_class[1] ) && is_numeric( $tax_class[1] ) ) {
				$tax_code = $tax_class[1];
			}
			if ( 'taxable' !== $tax_status ) {
				$tax_code = '99999';
			}
			if ( $unit_price ) {
				array_push(
					$line_items,
					array(
						'id'               => $id . '-' . $item_key,
						'quantity'         => $quantity,
						'product_tax_code' => $tax_code,
						'unit_price'       => $unit_price,
						'discount'         => $discount,
					)
				);
			}
		}
		return $line_items;
	}

	protected function get_line_item( $id, $line_items ) {
		foreach ( $line_items as $line_item ) {
			if ( $line_item['id'] === $id ) {
				return $line_item;
			}
		}
		return null;
	}

	/**
	 * Override Woo's native tax rates to handle multiple line items with the same tax rate
	 * within the same tax class with different rates due to exemption thresholds
	 *
	 * Unchanged from the TaxJar plugin.
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/4b481f5/includes/class-wc-taxjar-integration.php#L729
	 *
	 * @return array
	 */
	public function override_woocommerce_tax_rates( $taxes, $price, $rates ) {
		if ( isset( $this->response_line_items ) && array_values( $rates ) ) {
			// Get tax rate ID for current item
			$keys        = array_keys( $taxes );
			$tax_rate_id = $keys[0];
			$line_items  = array();

			// Map line items using rate ID
			foreach ( $this->response_rate_ids as $line_item_key => $rate_id ) {
				if ( $rate_id == $tax_rate_id ) {
					$line_items[] = $line_item_key;
				}
			}

			// Remove number precision if Woo 3.2+
			if ( function_exists( 'wc_remove_number_precision' ) ) {
				$price = wc_remove_number_precision( $price );
			}

			foreach ( $this->response_line_items as $line_item_key => $line_item ) {
				// If line item belongs to rate and matches the price, manually set the tax
				if ( in_array( $line_item_key, $line_items ) && $price == $line_item->line_total ) {
					if ( function_exists( 'wc_add_number_precision' ) ) {
						$taxes[ $tax_rate_id ] = wc_add_number_precision( $line_item->tax_collectable );
					} else {
						$taxes[ $tax_rate_id ] = $line_item->tax_collectable;
					}
				}
			}
		}

		return $taxes;
	}

	/**
	 * Set customer zip code and state to store if local shipping option set
	 *
	 * Unchanged from the TaxJar plugin.
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/82bf7c587/includes/class-wc-taxjar-integration.php#L653
	 *
	 * @return array
	 */
	public function append_base_address_to_customer_taxable_address( $address ) {
		$tax_based_on = '';

		list( $country, $state, $postcode, $city, $street ) = array_pad( $address, 5, '' );

		// See WC_Customer get_taxable_address()
		// wc_get_chosen_shipping_method_ids() available since Woo 2.6.2+
		if ( function_exists( 'wc_get_chosen_shipping_method_ids' ) ) {
			if ( true === apply_filters( 'woocommerce_apply_base_tax_for_local_pickup', true ) && sizeof( array_intersect( wc_get_chosen_shipping_method_ids(), apply_filters( 'woocommerce_local_pickup_methods', array( 'legacy_local_pickup', 'local_pickup' ) ) ) ) > 0 ) {
				$tax_based_on = 'base';
			}
		} else {
			if ( true === apply_filters( 'woocommerce_apply_base_tax_for_local_pickup', true ) && sizeof( array_intersect( WC()->session->get( 'chosen_shipping_methods', array() ), apply_filters( 'woocommerce_local_pickup_methods', array( 'legacy_local_pickup', 'local_pickup' ) ) ) ) > 0 ) {
				$tax_based_on = 'base';
			}
		}

		if ( 'base' == $tax_based_on ) {
			$store_settings = $this->get_store_settings();
			$postcode       = $store_settings['postcode'];
			$city           = strtoupper( $store_settings['city'] );
			$street         = $store_settings['street'];
		}

		if ( '' != $street ) {
			return array( $country, $state, $postcode, $city, $street );
		} else {
			return array( $country, $state, $postcode, $city );
		}

		return array( $country, $state, $postcode, $city );
	}

	/**
	 * This method is used to override the TaxJar result.
	 *
	 * @param object $taxjar_resp_tax TaxJar response object.
	 * @param array  $body            Body of TaxJar request.
	 *
	 * @return object
	 */
	public function maybe_override_taxjar_tax( $taxjar_resp_tax, $body ) {
		if ( ! isset( $taxjar_resp_tax ) ) {
			return;
		}
		
		$new_tax_rate = floatval( apply_filters( 'woocommerce_services_override_tax_rate', $taxjar_resp_tax->rate, $taxjar_resp_tax, $body ) );

		if ( $new_tax_rate === floatval( $taxjar_resp_tax->rate ) ) {
			return $taxjar_resp_tax;
		}

		if ( ! empty( $taxjar_resp_tax->breakdown->line_items ) ) {
			$taxjar_resp_tax->breakdown->line_items = array_map(
				function( $line_item ) use ( $new_tax_rate ) {
					$line_item->combined_tax_rate       = $new_tax_rate;
					$line_item->country_tax_rate        = $new_tax_rate;
					$line_item->country_tax_collectable = $line_item->country_taxable_amount * $new_tax_rate;
					$line_item->tax_collectable         = $line_item->taxable_amount * $new_tax_rate;

					return $line_item;
				},
				$taxjar_resp_tax->breakdown->line_items
			);
		}

		$taxjar_resp_tax->breakdown->combined_tax_rate           = $new_tax_rate;
		$taxjar_resp_tax->breakdown->country_tax_rate            = $new_tax_rate;
		$taxjar_resp_tax->breakdown->shipping->combined_tax_rate = $new_tax_rate;
		$taxjar_resp_tax->breakdown->shipping->country_tax_rate  = $new_tax_rate;

		$taxjar_resp_tax->rate = $new_tax_rate;

		return $taxjar_resp_tax;
	}

	/**
	 * Calculate sales tax using SmartCalcs
	 *
	 * Direct from the TaxJar plugin, without Nexus check.
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/96b5d57/includes/class-wc-taxjar-integration.php#L247
	 *
	 * @return array|boolean
	 */
	public function calculate_tax( $options = array() ) {
		$this->_log( ':::: TaxJar Plugin requested ::::' );

		// Process $options array and turn them into variables
		$options = is_array( $options ) ? $options : array();

		extract(
			array_replace_recursive(
				array(
					'to_country'      => null,
					'to_state'        => null,
					'to_zip'          => null,
					'to_city'         => null,
					'to_street'       => null,
					'shipping_amount' => null,
					'line_items'      => null,
				),
				$options
			)
		);

		$taxes = array(
			'freight_taxable' => 1,
			'has_nexus'       => 0,
			'line_items'      => array(),
			'rate_ids'        => array(),
			'tax_rate'        => 0,
		);

		// Strict conditions to be met before API call can be conducted
		if (
			empty( $to_country ) ||
			empty( $to_zip ) ||
			( empty( $line_items ) && ( 0 == $shipping_amount ) ) ||
			WC()->customer->is_vat_exempt()
		) {
			return false;
		}

		$to_zip = explode( ',', $to_zip );
		$to_zip = array_shift( $to_zip );

		$store_settings  = $this->get_store_settings();
		$from_country    = $store_settings['country'];
		$from_state      = $store_settings['state'];
		$from_zip        = $store_settings['postcode'];
		$from_city       = $store_settings['city'];
		$from_street     = $store_settings['street'];
		$shipping_amount = is_null( $shipping_amount ) ? 0.0 : $shipping_amount;

		$this->_log( ':::: TaxJar API called ::::' );

		$body = array(
			'from_country' => $from_country,
			'from_state'   => $from_state,
			'from_zip'     => $from_zip,
			'from_city'    => $from_city,
			'from_street'  => $from_street,
			'to_country'   => $to_country,
			'to_state'     => $to_state,
			'to_zip'       => $to_zip,
			'to_city'      => $to_city,
			'to_street'    => $to_street,
			'shipping'     => $shipping_amount,
			'plugin'       => 'woo',
		);

		/**
		 * Change the API request body so that provincial sales tax (PST) is added
		 * in cases where TaxJar does not combine it with general sales tax (GST)
		 * based on from/to address alone. This is a limitation of their API.
		 * They said they would be working on adding specific cases like
		 * this in the future.
		 *
		 * As a temporary workaround, TaxJar suggested we remove the from address
		 * parameters and use the nexus_addresses[] parameter instead in cases that
		 * require it. This ensures that the PST is added in cases where it needs to be.
		 *
		 * In this case, when shipping from an address Canada to Quebec,
		 * PST should be charged in addition to GST. The combined tax is
		 * referred to as Québec sales tax (QST).
		 */
		if ( true === apply_filters( 'woocommerce_apply_taxjar_nexus_addresses_workaround', true ) && 'CA' === $body['to_country'] && 'QC' === $body['to_state'] && 'CA' === $body['from_country'] ) {
			$params_to_unset = array(
				'from_country',
				'from_state',
				'from_zip',
				'from_city',
				'from_street',
			);

			foreach ( $params_to_unset as $param ) {
				unset( $body[ $param ] );
			}

			$body['nexus_addresses'] = array(
				array(
					'street'  => $body['to_street'],
					'city'    => $body['to_city'],
					'state'   => $body['to_state'],
					'country' => $body['to_country'],
					'zip'     => $body['to_zip'],
				),
			);
		}

		// Either `amount` or `line_items` parameters are required to perform tax calculations.
		if ( empty( $line_items ) ) {
			$body['amount'] = 0.0;
		} else {
			$body['line_items'] = $line_items;
		}

		$response = $this->smartcalcs_cache_request( wp_json_encode( $body ) );

		// if no response, no need to keep going - bail early
		if ( ! isset( $response ) || ! $response ) {
			$this->_log( 'Received: none.' );

			return $taxes;
		}

		// Log the response
		$this->_log( 'Received: ' . $response['body'] );

		// Decode Response
		$taxjar_response = json_decode( $response['body'] );
		if ( empty( $taxjar_response->tax ) ) {
			return false;
		}

		$taxjar_response = $this->maybe_override_taxjar_tax( $taxjar_response->tax, $body );

		// Update Properties based on Response
		$taxes['freight_taxable'] = (int) $taxjar_response->freight_taxable;
		$taxes['has_nexus']       = (int) $taxjar_response->has_nexus;
		$taxes['tax_rate']        = $taxjar_response->rate;

		if ( ! empty( $taxjar_response->breakdown ) ) {
			if ( ! empty( $taxjar_response->breakdown->line_items ) ) {
				$line_items = array();
				foreach ( $taxjar_response->breakdown->line_items as $line_item ) {
					$line_items[ $line_item->id ] = $line_item;
				}
				$taxes['line_items'] = $line_items;
			}
		}

		if ( $taxes['has_nexus'] ) {
			// Use Woo core to find matching rates for taxable address
			$location = array(
				'from_country' => $from_country,
				'from_state'   => $from_state,
				'to_country'   => $to_country,
				'to_state'     => $to_state,
				'to_zip'       => $to_zip,
				'to_city'      => $to_city,
			);

			// Add line item tax rates
			foreach ( $taxes['line_items'] as $line_item_key => $line_item ) {
				$line_item_key_chunks = explode( '-', $line_item_key );
				$product_id           = $line_item_key_chunks[0];
				$product              = wc_get_product( $product_id );

				if ( $product ) {
					$tax_class = $product->get_tax_class();
				} else {
					if ( isset( $this->backend_tax_classes[ $product_id ] ) ) {
						$tax_class = $this->backend_tax_classes[ $product_id ];
					}
				}

				if ( $line_item->combined_tax_rate ) {
					$taxes['rate_ids'][ $line_item_key ] = $this->create_or_update_tax_rate(
						$taxjar_response,
						$location,
						$line_item->combined_tax_rate * 100,
						$tax_class,
						$taxes['freight_taxable']
					);
				}
			}

			// Add shipping tax rate
			$taxes['rate_ids']['shipping'] = $this->create_or_update_tax_rate(
				$taxjar_response,
				$location,
				$taxes['tax_rate'] * 100,
				'',
				$taxes['freight_taxable']
			);
		} // End if().

		return $taxes;
	} // End calculate_tax().

	/**
	 * Add or update a native WooCommerce tax rate
	 *
	 * Unchanged from the TaxJar plugin.
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/9d8e725/includes/class-wc-taxjar-integration.php#L396
	 *
	 * @return int
	 */
	public function create_or_update_tax_rate( $taxjar_response, $location, $rate, $tax_class = '', $freight_taxable = 1 ) {
		// all the states in GB have the same tax rate
		// prevents from saving a "state" column value for GB
		$to_state = 'GB' === $location['to_country'] ? '' : $location['to_state'];

		/**
		 * @see https://github.com/Automattic/woocommerce-services/issues/2531
		 * @see https://floridarevenue.com/faq/Pages/FAQDetails.aspx?FAQID=1277&IsDlg=1
		 *
		 * According to the Florida Department of Revenue, sales tax must be charged on
		 * shipping costs if the customer does not have an option to avoid paying the
		 * merchant for shipping costs by either picking up the merchandise themselves
		 * or arranging for a third party to pick up the merchandise and deliver it to
		 * them.
		 *
		 * Normally TaxJar enables taxes on shipping by default for Florida to
		 * Florida shipping, but because WooCommerce uses a single account, a nexus
		 * cannot be added for Florida (or any state) which means the shipping tax
		 * is not enabled. So, we will enable it here by default and give merchants
		 * the option to disable it if needed via filter.
		 *
		 * @since 1.26.0
		 */
		if ( true === apply_filters( 'woocommerce_taxjar_enable_florida_shipping_tax', true ) && 'US' === $location['to_country'] && 'FL' === $location['from_state'] && 'FL' === $location['to_state'] ) {
			$freight_taxable = 1;
		}

		$tax_rate = array(
			'tax_rate_country'  => $location['to_country'],
			'tax_rate_state'    => $to_state,
			// For the US, we're going to modify the name of the tax rate to simplify the reporting and distinguish between the tax rates at the counties level.
			// I would love to do this for other locations, but it looks like that would create issues.
			// For example, for the UK it would continuously rename the rate name with an updated `state` "piece", each time a request is made
			'tax_rate_name'     => sprintf( '%s Tax', self::generate_tax_rate_name( $taxjar_response, $location['to_country'], $to_state ) ),
			'tax_rate_priority' => 1,
			'tax_rate_compound' => false,
			'tax_rate_shipping' => $freight_taxable,
			'tax_rate'          => $rate,
			'tax_rate_class'    => $tax_class,
		);

		$wc_rate = WC_Tax::find_rates(
			array(
				'country'   => $location['to_country'],
				'state'     => $to_state,
				'postcode'  => $location['to_zip'],
				'city'      => $location['to_city'],
				'tax_class' => $tax_class,
			)
		);

		if ( ! empty( $wc_rate ) ) {
			$this->_log( ':: Tax Rate Found ::' );
			$this->_log( $wc_rate );

			// Get the existing ID
			$rate_id = key( $wc_rate );

			// Update Tax Rates with TaxJar rates ( rates might be coming from a cached taxjar rate )
			$this->_log( ':: Updating Tax Rate To ::' );
			$this->_log( $tax_rate );

			WC_Tax::_update_tax_rate( $rate_id, $tax_rate );
		} else {
			// Insert a rate if we did not find one
			$this->_log( ':: Adding New Tax Rate ::' );
			$this->_log( $tax_rate );
			$rate_id = WC_Tax::_insert_tax_rate( $tax_rate );
			WC_Tax::_update_tax_rate_postcodes( $rate_id, wc_normalize_postcode( wc_clean( $location['to_zip'] ) ) );
			WC_Tax::_update_tax_rate_cities( $rate_id, wc_clean( $location['to_city'] ) );
		}

		$this->_log( 'Tax Rate ID Set for ' . $rate_id );
		return $rate_id;
	}

	/**
	 * Validate TaxJar API request json value and add the error to log.
	 *
	 * @param $json
	 *
	 * @return bool
	 */
	public function validate_taxjar_request( $json ) {
		$this->_log( ':::: TaxJar API request validation ::::' );

		$json = json_decode( $json, true );

		if ( empty( $json['to_country'] ) ) {
			$this->_error( 'API request is stopped. Empty country destination.' );

			return false;
		}

		if ( ( 'US' === $json['to_country'] || 'CA' === $json['to_country'] ) && empty( $json['to_state'] ) ) {
			$this->_error( 'API request is stopped. Country destination is set to US or CA but the state is empty.' );

			return false;
		}

		if ( 'US' === $json['to_country'] && empty( $json['to_zip'] ) ) {
			$this->_error( 'API request is stopped. Country destination is set to US but the zip code is empty.' );

			return false;
		}

		// Apply this validation only if the destination country is the US and the zip code is 5 or 10 digits long.
		if ( 'US' === $json['to_country'] && ! empty( $json['to_zip'] ) && in_array( strlen( $json['to_zip'] ), array( 5, 10 ) ) && ! WC_Validation::is_postcode( $json['to_zip'], $json['to_country'] ) ) {
			$this->_error( 'API request is stopped. Country destination is set to US but the zip code has incorrect format.' );

			return false;
		}

		if ( ! empty( $json['from_country'] ) && ! empty( $json['from_zip'] ) && 'US' === $json['from_country'] && ! WC_Validation::is_postcode( $json['from_zip'], $json['from_country'] ) ) {
			$this->_error( 'API request is stopped. Country store is set to US but the zip code has incorrect format.' );

			return false;
		}

		$this->_log( 'API request is in good format.' );

		return true;
	}

	/**
	 * Wrap SmartCalcs API requests in a transient-based caching layer.
	 *
	 * Unchanged from the TaxJar plugin.
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/4b481f5/includes/class-wc-taxjar-integration.php#L451
	 *
	 * @param $json
	 *
	 * @return mixed|WP_Error
	 */
	public function smartcalcs_cache_request( $json ) {
		$cache_key        = 'tj_tax_' . hash( 'md5', $json );
		$response         = get_transient( $cache_key );
		$response_code    = wp_remote_retrieve_response_code( $response );
		$save_error_codes = array( 404, 400 );

		if ( false === $response ) {
			$response      = $this->smartcalcs_request( $json );
			$response_code = wp_remote_retrieve_response_code( $response );

			if ( 200 == $response_code ) {
				set_transient( $cache_key, $response, $this->cache_time );
			} elseif ( in_array( $response_code, $save_error_codes ) ) {
				set_transient( $cache_key, $response, $this->error_cache_time );
			}
		}

		if ( in_array( $response_code, $save_error_codes ) ) {
			$this->_log( 'Retrieved the error from the cache.' );
			$this->_error( 'Error retrieving the tax rates. Received (' . $response['response']['code'] . '): ' . $response['body'] );
			return false;
		}

		return $response;
	}

	/**
	 * Make a TaxJar SmartCalcs API request through the WCS proxy.
	 *
	 * Modified from TaxJar's plugin.
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/82bf7c58/includes/class-wc-taxjar-integration.php#L440
	 *
	 * @param $json
	 *
	 * @return array|WP_Error
	 */
	public function smartcalcs_request( $json ) {
		$path = trailingslashit( self::PROXY_PATH ) . 'taxes';

		// Validate the request before sending a request.
		if ( ! $this->validate_taxjar_request( $json ) ) {
			return false;
		}

		$this->_log( 'Requesting: ' . $path . ' - ' . $json );

		$response = $this->api_client->proxy_request(
			$path,
			array(
				'method'  => 'POST',
				'headers' => array(
					'Content-Type' => 'application/json',
				),
				'body'    => $json,
			)
		);

		if ( is_wp_error( $response ) ) {
			$this->_error( 'Error retrieving the tax rates. Received (' . $response->get_error_code() . '): ' . $response->get_error_message() );
		} elseif ( 200 == $response['response']['code'] ) {
			return $response;
		} elseif ( 404 == $response['response']['code'] || 400 == $response['response']['code'] ) {
			$this->_error( 'Error retrieving the tax rates. Received (' . $response['response']['code'] . '): ' . $response['body'] );

			return $response;
		} else {
			$this->_error( 'Error retrieving the tax rates. Received (' . $response['response']['code'] . '): ' . $response['body'] );
		}
	}

	/**
	 * Exports existing tax rates to a CSV and clears the table.
	 *
	 * Ported from TaxJar's plugin.
	 * See: https://github.com/taxjar/taxjar-woocommerce-plugin/blob/42cd4cd0/taxjar-woocommerce.php#L75
	 */
	public function backup_existing_tax_rates() {

		// Back up all tax rates to a csv file
		$backed_up = WC_Connect_Functions::backup_existing_tax_rates();

		if ( ! $backed_up ) {
			return;
		}

		global $wpdb;

		// Delete all tax rates
		$wpdb->query( 'TRUNCATE ' . $wpdb->prefix . 'woocommerce_tax_rates' );
		$wpdb->query( 'TRUNCATE ' . $wpdb->prefix . 'woocommerce_tax_rate_locations' );
	}

	/**
	 * Checks if currently on the WooCommerce new order page
	 *
	 * @return boolean
	 */
	public function on_order_page() {
		global $pagenow;
		return ( in_array( $pagenow, array( 'post-new.php' ) ) && isset( $_GET['post_type'] ) && 'shop_order' == $_GET['post_type'] );
	}

	/**
	 * Admin New Order Assets
	 */
	public function load_taxjar_admin_new_order_assets() {
		if ( ! $this->on_order_page() ) {
			return;
		}
		// Load Javascript for WooCommerce new order page
		wp_enqueue_script( 'wc-taxjar-order', $this->wc_connect_base_url . 'woocommerce-services-new-order-taxjar-' . WC_Connect_Loader::get_wcs_version() . '.js', array( 'jquery' ), null, true );
	}
}