<?php
namespace Extendiment\Checkoutline;

defined( 'ABSPATH' ) || exit;

use WC_Order;

/**
 * Shows the answers WooCommerce doesn't. WooCommerce only lists additional checkout fields for
 * orders created through the Store API, and only fields registered right now. So Checkoutline lists
 * its own fields the same way on classic checkout (and manual) orders, and on Checkout block
 * orders lists those WooCommerce leaves out (a field switched off since, or one that can't show
 * on this site at the moment): on the order screen (editable, through the address boxes like
 * WooCommerce does), on the order confirmation and My Account's order page, and in order emails.
 *
 * A label is followed by a colon before its answer, unless it already ends in punctuation ("How did
 * you hear about us?"). WooCommerce's order screen adds the colon itself, so there such fields are
 * listed after its own, in the same markup.
 */
class Display {

	/** @var array<string, array<int, array>> Fields of the order screen's boxes listed after WooCommerce's: box => order ID => fields. */
	private static $moved = array(
		'billing'  => array(),
		'shipping' => array(),
	);

	public function register(): void {
		add_filter( 'woocommerce_admin_billing_fields', array( $this, 'billing' ), 20, 3 );
		add_filter( 'woocommerce_admin_shipping_fields', array( $this, 'shipping' ), 20, 3 );
		add_action( 'woocommerce_admin_order_data_after_billing_address', array( $this, 'after_billing' ) );
		add_action( 'woocommerce_admin_order_data_after_shipping_address', array( $this, 'after_shipping' ) );
		add_action( 'woocommerce_order_details_after_customer_details', array( $this, 'order_details' ) );
		add_action( 'woocommerce_email_order_meta', array( $this, 'email' ), 20, 3 );
	}

	/**
	 * The fields Checkoutline lists on an order: all of them on orders the Checkout block didn't place,
	 * those WooCommerce doesn't list on orders it did.
	 *
	 * @param WC_Order|mixed $order
	 * @return array<string, array>
	 */
	private static function fields_for( $order ): array {
		if ( ! $order instanceof WC_Order ) {
			return array();
		}
		$fields = Fields::all();
		if ( 'store-api' !== $order->get_created_via() ) {
			return $fields;
		}
		return array_filter( $fields, static fn( $field ) => ! Checkout::registered( $field['key'] ) );
	}

	private static function group_of( array $field, string $box ): string {
		return 'address' === $field['location'] ? $box : 'other';
	}

	/** Whether a label ends in punctuation of its own (?, :, ! or .), so it needs no colon before the answer. */
	public static function ends_in_punctuation( string $label ): bool {
		return (bool) preg_match( '/[?:!.？：！。]\s*$/u', $label );
	}

	/** A label as it's shown before an answer: "Gift message:", but "How did you hear about us?". */
	public static function with_colon( string $label ): string {
		return self::ends_in_punctuation( $label ) ? rtrim( $label ) : $label . ':';
	}

	/** A value as customers read it: an option's label, Yes/No for a checkbox. */
	public static function format( array $field, $value ): string {
		if ( 'checkbox' === Fields::block_type( $field['type'] ) ) {
			$text = wc_string_to_bool( $value ) ? __( 'Yes', 'checkoutline' ) : __( 'No', 'checkoutline' );
		} elseif ( $field['options'] ) {
			$text = (string) ( $field['options'][ (string) $value ] ?? $value );
		} else {
			$text = (string) $value;
		}
		/**
		 * An answer as it's shown on orders, in My Account and in emails.
		 *
		 * @param string $text  The answer as text.
		 * @param array  $field The field.
		 * @param mixed  $value The saved answer.
		 */
		return (string) apply_filters( 'checkoutline_display_value', $text, $field, $value );
	}

	/**
	 * Fields with a value on an order, as [ label, value ] (address fields from one address).
	 *
	 * @param array<string, array>|null $fields The fields to look at (default all).
	 * @return array<string, array{0: string, 1: string}>
	 */
	public static function rows( WC_Order $order, array $locations, string $address = 'billing', ?array $fields = null ): array {
		$rows = array();
		foreach ( null === $fields ? Fields::all() : $fields as $key => $field ) {
			if ( ! in_array( $field['location'], $locations, true ) ) {
				continue;
			}
			$value = Checkout::value( $order, $key, self::group_of( $field, $address ) );
			if ( '' === $value || null === $value || ( 'checkbox' === Fields::block_type( $field['type'] ) && ! wc_string_to_bool( $value ) ) ) {
				continue;
			}
			$rows[ $key ] = array( $field['label'], self::format( $field, $value ) );
		}
		return $rows;
	}

	/** The fields of a box, in the shape WooCommerce's order screen uses (as its own CheckoutFieldsAdmin does). */
	private static function box_fields( WC_Order $order, array $locations, string $box, string $context ): array {
		$out = array();
		foreach ( self::fields_for( $order ) as $key => $field ) {
			if ( ! in_array( $field['location'], $locations, true ) ) {
				continue;
			}
			$group = self::group_of( $field, $box );
			$value = Checkout::value( $order, $key, $group );
			if ( ( 'view' === $context || ! $field['enabled'] ) && ( '' === $value || null === $value ) ) {
				continue;
			}
			$checkbox = 'checkbox' === Fields::block_type( $field['type'] );
			$type     = 'text';
			if ( $field['options'] ) {
				$type = 'select';
			} elseif ( $checkbox ) {
				$type = 'checkbox';
			} elseif ( 'textarea' === Fields::classic_type( $field['type'] ) ) {
				$type = 'textarea';
			}
			$entry = array(
				'id'              => '_wc_' . $group . '/' . Fields::id( $key ),
				'label'           => $field['label'],
				'value'           => 'view' === $context ? self::format( $field, $value ) : $value,
				'type'            => $type,
				'update_callback' => array( __CLASS__, 'update' ),
				'show'            => true,
				'wrapper_class'   => 'form-field-wide',
			);
			if ( 'select' === $type ) {
				$entry['options'] = array( '' => __( 'Select an option', 'checkoutline' ) ) + $field['options'];
			}
			if ( $checkbox ) {
				$entry['checked_value']   = '1';
				$entry['unchecked_value'] = '0';
			}
			$out[ Fields::id( $key ) ] = $entry;
		}
		return $out;
	}

	/** Saving a field edited on the order screen. */
	public static function update( $key, $value, $order ): void {
		if ( ! $order instanceof WC_Order || ! preg_match( '#^_wc_(billing|shipping|other)/(.+)$#', (string) $key, $m ) ) {
			return;
		}
		$service = Checkout::service();
		if ( $service ) {
			$service->persist_field_for_order( $m[2], $value, $order, $m[1], false );
		}
	}

	/**
	 * Contact and billing address fields in the Billing box.
	 *
	 * @param array $fields
	 */
	public function billing( $fields, $order = null, $context = 'edit' ) {
		return $order instanceof WC_Order ? self::move( array_merge( (array) $fields, self::box_fields( $order, array( 'contact', 'address' ), 'billing', (string) $context ) ), $order, 'billing', (string) $context ) : $fields;
	}

	/**
	 * Shipping address and order fields in the Shipping box (where WooCommerce puts them too).
	 *
	 * @param array $fields
	 */
	public function shipping( $fields, $order = null, $context = 'edit' ) {
		return $order instanceof WC_Order ? self::move( array_merge( (array) $fields, self::box_fields( $order, array( 'address', 'order' ), 'shipping', (string) $context ) ), $order, 'shipping', (string) $context ) : $fields;
	}

	/**
	 * Where the order screen shows a box's answers (view context), fields whose label ends in
	 * punctuation (WooCommerce's own additional fields too) are taken out of WooCommerce's list, which
	 * would add a colon ("How did you hear about us?:"), and listed after it instead: see listed().
	 */
	private static function move( array $fields, WC_Order $order, string $box, string $context ): array {
		if ( 'view' !== $context ) {
			return $fields;
		}
		$moved = array();
		foreach ( $fields as $key => $field ) {
			if ( is_array( $field ) && isset( $field['value'] ) && ( $field['show'] ?? true ) && self::ends_in_punctuation( (string) ( $field['label'] ?? '' ) ) ) {
				$moved[ $key ]          = $field;
				$fields[ $key ]['show'] = false;
			}
		}
		self::$moved[ $box ][ $order->get_id() ] = $moved;
		return $fields;
	}

	/** The fields move() took out of a box, in WooCommerce's markup for them (hidden with the box's answers while it's edited). */
	private static function listed( $order, string $box ): void {
		$fields = $order instanceof WC_Order ? ( self::$moved[ $box ][ $order->get_id() ] ?? array() ) : array();
		$lines  = '';
		foreach ( $fields as $field ) {
			$value = make_clickable( esc_html( (string) $field['value'] ) );
			if ( '' !== $value ) {
				$lines .= '<p><strong>' . esc_html( self::with_colon( (string) $field['label'] ) ) . '</strong> ' . wp_kses_post( $value ) . '</p>';
			}
		}
		if ( '' !== $lines ) {
			echo '<div class="address checkoutline-address">' . $lines . '</div>'; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped above.
		}
	}

	/** @param WC_Order $order */
	public function after_billing( $order ): void {
		self::listed( $order, 'billing' );
	}

	/** @param WC_Order $order */
	public function after_shipping( $order ): void {
		self::listed( $order, 'shipping' );
	}

	/** Rows for the confirmation page and emails: contact and order fields, then address fields from the address it ships to. */
	private static function order_rows( WC_Order $order ): array {
		$fields = self::fields_for( $order );
		if ( ! $fields ) {
			return array();
		}
		return self::rows( $order, array( 'contact', 'order' ), 'billing', $fields ) + self::rows( $order, array( 'address' ), $order->has_shipping_address() ? 'shipping' : 'billing', $fields );
	}

	/** The order confirmation and My Account's order page, in the markup WooCommerce uses for these fields. */
	public function order_details( $order ): void {
		$rows = $order instanceof WC_Order ? self::order_rows( $order ) : array();
		if ( ! $rows ) {
			return;
		}
		echo '<section class="woocommerce-order-details checkoutline-order-details"><h2 class="woocommerce-column__title">' . esc_html__( 'Additional information', 'checkoutline' ) . '</h2>';
		echo '<dl class="wc-block-components-additional-fields-list">';
		$any = false;
		foreach ( $rows as $row ) {
			// WooCommerce's styles may add ": " after each label; not after one that ends in punctuation.
			$own = self::ends_in_punctuation( $row[0] );
			$any = $any || $own;
			echo '<dt' . ( $own ? ' class="checkoutline-punctuated"' : '' ) . '>' . esc_html( $row[0] ) . '</dt><dd>' . esc_html( $row[1] ) . '</dd>';
		}
		echo '</dl></section>';
		if ( $any ) {
			wp_enqueue_style( 'checkoutline-order', CHECKOUTLINE_URL . 'assets/css/order.css', array(), CHECKOUTLINE_VERSION ); // In the footer, this late.
		}
	}

	/**
	 * Order emails.
	 *
	 * @param WC_Order $order
	 * @param bool     $sent_to_admin
	 * @param bool     $plain_text
	 */
	public function email( $order, $sent_to_admin = false, $plain_text = false ): void {
		$rows = $order instanceof WC_Order ? self::order_rows( $order ) : array();
		if ( ! $rows ) {
			return;
		}
		if ( $plain_text ) {
			echo "\n" . esc_html( wc_strtoupper( __( 'Additional information', 'checkoutline' ) ) ) . "\n\n";
			foreach ( $rows as $row ) {
				echo esc_html( self::with_colon( $row[0] ) . ' ' . $row[1] ) . "\n";
			}
			return;
		}
		echo '<h2>' . esc_html__( 'Additional information', 'checkoutline' ) . '</h2><ul class="checkoutline-email-fields">';
		foreach ( $rows as $row ) {
			echo '<li><strong>' . esc_html( self::with_colon( $row[0] ) ) . '</strong> ' . esc_html( $row[1] ) . '</li>';
		}
		echo '</ul>';
	}
}