<?php
/**
 * Connecting the bot: check the token with getMe, then choose how updates reach the site.
 * Telegram only calls HTTPS webhooks, so a site without HTTPS (or one the owner switches to
 * polling) asks Telegram for updates once a minute instead.
 *
 * @package Orderchirp
 */

namespace Orderchirp;

defined( 'ABSPATH' ) || exit;

final class Connection {

	/**
	 * Connect a bot token. Nothing is saved unless Telegram accepts the token.
	 *
	 * @param string $token         Token.
	 * @param bool   $force_polling Use polling even on HTTPS.
	 * @return true|\WP_Error
	 */
	public static function connect( $token, $force_polling = false ) {
		$token = trim( (string) $token );
		if ( ! Settings::valid_bot_token( $token ) ) {
			return new \WP_Error( 'orderchirp_token', __( 'That does not look like a bot token. It has the form 123456789:AA… and comes from @BotFather.', 'orderchirp' ) );
		}
		$api = new Telegram_Api( $token );
		$me  = $api->call( 'getMe' );
		if ( ! $me['ok'] || empty( $me['result']['username'] ) || empty( $me['result']['is_bot'] ) ) {
			/* translators: %s: Telegram's error */
			return new \WP_Error( 'orderchirp_token', sprintf( __( 'Telegram did not accept this token: %s', 'orderchirp' ), Telegram_Api::redact( $me['description'], $token ) ) );
		}
		Settings::update(
			array(
				'bot_token'    => $token,
				'bot_username' => (string) $me['result']['username'],
			)
		);
		return self::configure_delivery( $force_polling );
	}

	/**
	 * Point Telegram at the webhook, or fall back to polling.
	 *
	 * @param bool $force_polling Use polling even on HTTPS.
	 * @return true|\WP_Error
	 */
	public static function configure_delivery( $force_polling = false ) {
		$api = Telegram_Api::from_settings();
		$url = Webhook::url();
		if ( ! $force_polling && 0 === strpos( $url, 'https://' ) ) {
			$set = $api->call(
				'setWebhook',
				array(
					'url'             => $url,
					'secret_token'    => Settings::webhook_token( Settings::secret() ),
					'allowed_updates' => array( 'message' ),
					'max_connections' => 10,
				)
			);
			if ( $set['ok'] ) {
				Settings::update( array( 'delivery' => 'webhook' ) );
				Poller::unschedule();
				return true;
			}
			/* translators: %s: Telegram's error */
			$error = new \WP_Error( 'orderchirp_webhook', sprintf( __( 'Telegram could not use this site as a webhook (%s). Orderchirp will check for messages once a minute instead.', 'orderchirp' ), Telegram_Api::redact( $set['description'], (string) Settings::get( 'bot_token' ) ) ) );
		}
		$api->call( 'deleteWebhook' );
		Settings::update( array( 'delivery' => 'polling' ) );
		Poller::schedule();
		return isset( $error ) ? $error : true;
	}

	/**
	 * Disconnect: Telegram stops calling, the token is forgotten. Linked customers stay linked,
	 * so connecting the same bot again resumes their updates.
	 */
	public static function disconnect() {
		if ( Settings::connected() ) {
			Telegram_Api::from_settings()->call( 'deleteWebhook', array(), 5 );
		}
		Poller::unschedule();
		Settings::update(
			array(
				'bot_token'    => '',
				'bot_username' => '',
			)
		);
	}

	/**
	 * What Telegram reports about delivery, for the settings page.
	 *
	 * @return array{ok:bool,delivery:string,pending:int,last_error:string,last_error_at:int}
	 */
	public static function status() {
		$delivery = (string) Settings::get( 'delivery' );
		$info     = Telegram_Api::from_settings()->call( 'getWebhookInfo', array(), 10 );
		$result   = is_array( $info['result'] ) ? $info['result'] : array();
		return array(
			'ok'            => $info['ok'],
			'delivery'      => $delivery,
			'pending'       => isset( $result['pending_update_count'] ) ? (int) $result['pending_update_count'] : 0,
			'last_error'    => isset( $result['last_error_message'] ) ? (string) $result['last_error_message'] : ( $info['ok'] ? '' : $info['description'] ),
			'last_error_at' => isset( $result['last_error_date'] ) ? (int) $result['last_error_date'] : 0,
		);
	}

	/**
	 * A t.me deep link for a payload.
	 *
	 * @param string $payload Payload.
	 * @return string
	 */
	public static function deep_link( $payload ) {
		return 'https://t.me/' . rawurlencode( (string) Settings::get( 'bot_username' ) ) . '?start=' . rawurlencode( (string) $payload );
	}
}