<?php
/**
 * Settings: one option array with defaults filled in on read, so a setting added in a later
 * version is never missing on an older install.
 *
 * @package Orderchirp
 */

namespace Orderchirp;

defined( 'ABSPATH' ) || exit;

final class Settings {

	const OPTION        = 'orderchirp_settings';
	const SECRET_OPTION = 'orderchirp_secret';

	/**
	 * The default message for each order status. A line whose placeholder has no value is
	 * dropped (see Template), so the tracking line only appears when there is tracking.
	 *
	 * @return array<string,array{enabled:bool,text:string}>
	 */
	public static function default_status_messages() {
		return array(
			'processing' => array(
				'enabled' => true,
				/* translators: Keep the {placeholders} in English. */
				'text'    => __( "Hi {first_name}, thanks for your order #{order_number} at {shop_name}! We've received it and we're getting it ready.\nTotal: {order_total}", 'orderchirp' ),
			),
			'on-hold'    => array(
				'enabled' => false,
				/* translators: Keep the {placeholders} in English. */
				'text'    => __( 'Hi {first_name}, your order #{order_number} at {shop_name} is on hold until we confirm your payment.', 'orderchirp' ),
			),
			'completed'  => array(
				'enabled' => true,
				/* translators: Keep the {placeholders} in English. */
				'text'    => __( "Good news, {first_name}! Your order #{order_number} from {shop_name} is on its way.\nTracking: {tracking_number} {tracking_provider}\n{tracking_url}", 'orderchirp' ),
			),
			'cancelled'  => array(
				'enabled' => true,
				/* translators: Keep the {placeholders} in English. */
				'text'    => __( 'Hi {first_name}, your order #{order_number} at {shop_name} has been cancelled. If you have a question, just reply to this message.', 'orderchirp' ),
			),
			'refunded'   => array(
				'enabled' => true,
				/* translators: Keep the {placeholders} in English. */
				'text'    => __( 'Hi {first_name}, your order #{order_number} at {shop_name} has been refunded.', 'orderchirp' ),
			),
			'failed'     => array(
				'enabled' => false,
				/* translators: Keep the {placeholders} in English. */
				'text'    => __( 'Hi {first_name}, the payment for your order #{order_number} at {shop_name} did not go through. You can try again here: {order_url}', 'orderchirp' ),
			),
		);
	}

	/**
	 * Defaults.
	 *
	 * @return array<string,mixed>
	 */
	public static function defaults() {
		return array(
			'bot_token'         => '',
			'bot_username'      => '',
			'delivery'          => 'webhook',
			'owner_new_order'   => true,
			'owner_low_stock'   => true,
			'owner_replies'     => true,
			'optin_thankyou'    => true,
			'optin_email'       => true,
			'optin_account'     => true,
			'status_messages'   => self::default_status_messages(),
			'owner_chats'       => array(),
		);
	}

	/**
	 * All settings with defaults merged in.
	 *
	 * @return array<string,mixed>
	 */
	public static function all() {
		$stored = get_option( self::OPTION, array() );
		return self::merge( is_array( $stored ) ? $stored : array() );
	}

	/**
	 * Merge stored values over the defaults, one level deep for the status messages so a
	 * status the owner never touched keeps its default text.
	 *
	 * @param array<string,mixed> $stored Stored values.
	 * @return array<string,mixed>
	 */
	public static function merge( array $stored ) {
		$defaults = self::defaults();
		$merged   = array_merge( $defaults, array_intersect_key( $stored, $defaults ) );
		$messages = $defaults['status_messages'];
		if ( isset( $stored['status_messages'] ) && is_array( $stored['status_messages'] ) ) {
			foreach ( $stored['status_messages'] as $status => $message ) {
				if ( ! is_array( $message ) ) {
					continue;
				}
				$base                = isset( $messages[ $status ] ) ? $messages[ $status ] : array( 'enabled' => false, 'text' => '' );
				$messages[ $status ] = array(
					'enabled' => isset( $message['enabled'] ) ? (bool) $message['enabled'] : $base['enabled'],
					'text'    => isset( $message['text'] ) ? (string) $message['text'] : $base['text'],
				);
			}
		}
		$merged['status_messages'] = $messages;
		if ( ! is_array( $merged['owner_chats'] ) ) {
			$merged['owner_chats'] = array();
		}
		return $merged;
	}

	/**
	 * One setting.
	 *
	 * @param string $key Key.
	 * @return mixed
	 */
	public static function get( $key ) {
		$all = self::all();
		return isset( $all[ $key ] ) ? $all[ $key ] : null;
	}

	/**
	 * Save a partial update.
	 *
	 * @param array<string,mixed> $values Values to change.
	 */
	public static function update( array $values ) {
		$all = self::all();
		foreach ( $values as $key => $value ) {
			$all[ $key ] = $value;
		}
		update_option( self::OPTION, $all, false );
	}

	/**
	 * Whether a bot is connected.
	 *
	 * @return bool
	 */
	public static function connected() {
		return '' !== (string) self::get( 'bot_token' ) && '' !== (string) self::get( 'bot_username' );
	}

	/**
	 * The site secret: signs the Telegram links and is the webhook secret. Created once.
	 *
	 * @return string
	 */
	public static function secret() {
		$secret = (string) get_option( self::SECRET_OPTION, '' );
		if ( strlen( $secret ) < 32 ) {
			$secret = wp_generate_password( 48, false, false );
			update_option( self::SECRET_OPTION, $secret, false );
		}
		return $secret;
	}

	/**
	 * The value Telegram sends back in X-Telegram-Bot-Api-Secret-Token. Derived from the site
	 * secret so the secret itself never leaves the site. Telegram allows 1-256 of A-Z a-z 0-9 _ -.
	 *
	 * @param string $secret Site secret.
	 * @return string
	 */
	public static function webhook_token( $secret ) {
		return substr( hash_hmac( 'sha256', 'telegram-webhook', $secret ), 0, 48 );
	}

	/**
	 * A bot token as Telegram issues it: digits, a colon, then 30+ of A-Z a-z 0-9 _ -.
	 *
	 * @param string $token Candidate.
	 * @return bool
	 */
	public static function valid_bot_token( $token ) {
		return 1 === preg_match( '/^\d{5,16}:[A-Za-z0-9_-]{30,64}$/D', (string) $token );
	}
}