node-telegram-bot-api
Version:
203 lines (192 loc) • 6.6 kB
JavaScript
const errors = require('./errors');
const debug = require('debug')('node-telegram-bot-api');
const deprecate = require('./utils').deprecate;
const ANOTHER_WEB_HOOK_USED = 409;
class TelegramBotPolling {
/**
* Handles polling against the Telegram servers.
* @param {TelegramBot} bot
* @see https://core.telegram.org/bots/api#getting-updates
*/
constructor(bot) {
this.bot = bot;
this.options = (typeof bot.options.polling === 'boolean') ? {} : bot.options.polling;
this.options.interval = (typeof this.options.interval === 'number') ? this.options.interval : 300;
this.options.params = (typeof this.options.params === 'object') ? this.options.params : {};
this.options.params.offset = (typeof this.options.params.offset === 'number') ? this.options.params.offset : 0;
this.options.params.timeout = (typeof this.options.params.timeout === 'number') ? this.options.params.timeout : 10;
if (typeof this.options.timeout === 'number') {
deprecate('`options.polling.timeout` is deprecated. Use `options.polling.params` instead.');
this.options.params.timeout = this.options.timeout;
}
this._lastUpdate = 0;
this._lastRequest = null;
this._abort = false;
this._pollingTimeout = null;
}
/**
* Start polling
* @param {Object} [options]
* @param {Object} [options.restart]
* @return {Promise}
*/
start(options = {}) {
if (this._lastRequest) {
if (!options.restart) {
return Promise.resolve();
}
return this.stop({
cancel: true,
reason: 'Polling restart',
}).then(() => {
return this._polling();
});
}
return this._polling();
}
/**
* Stop polling
* @param {Object} [options] Options
* @param {Boolean} [options.cancel] Cancel current request
* @param {String} [options.reason] Reason for stopping polling
* @return {Promise}
*/
stop(options = {}) {
if (!this._lastRequest) {
return Promise.resolve();
}
const lastRequest = this._lastRequest;
this._lastRequest = null;
clearTimeout(this._pollingTimeout);
if (options.cancel) {
const reason = options.reason || 'Polling stop';
lastRequest.cancel(reason);
return Promise.resolve();
}
this._abort = true;
return lastRequest.finally(() => {
this._abort = false;
});
}
/**
* Return `true` if is polling. Otherwise, `false`.
*/
isPolling() {
return !!this._lastRequest;
}
/**
* Handle error thrown during polling.
* @private
* @param {Error} error
*/
_error(error) {
if (!this.bot.listeners('polling_error').length) {
return console.error('error: [polling_error] %j', error); // eslint-disable-line no-console
}
return this.bot.emit('polling_error', error);
}
/**
* Invokes polling (with recursion!)
* @return {Promise} promise of the current request
* @private
*/
_polling() {
this._lastRequest = this
._getUpdates()
.then(updates => {
this._lastUpdate = Date.now();
debug('polling data %j', updates);
updates.forEach(update => {
this.options.params.offset = update.update_id + 1;
debug('updated offset: %s', this.options.params.offset);
try {
this.bot.processUpdate(update);
} catch (err) {
err._processing = true;
throw err;
}
});
return null;
})
.catch(err => {
debug('polling error: %s', err.message);
if (!err._processing) {
return this._error(err);
}
delete err._processing;
/*
* An error occured while processing the items,
* i.e. in `this.bot.processUpdate()` above.
* We need to mark the already-processed items
* to avoid fetching them again once the application
* is restarted, or moves to next polling interval
* (in cases where unhandled rejections do not terminate
* the process).
* See https://github.com/yagop/node-telegram-bot-api/issues/36#issuecomment-268532067
*/
if (!this.bot.options.badRejection) {
return this._error(err);
}
const opts = {
offset: this.options.params.offset,
limit: 1,
timeout: 0,
};
return this.bot.getUpdates(opts).then(() => {
return this._error(err);
}).catch(requestErr => {
/*
* We have been unable to handle this error.
* We have to log this to stderr to ensure devops
* understands that they may receive already-processed items
* on app restart.
* We simply can not rescue this situation, emit "error"
* event, with the hope that the application exits.
*/
/* eslint-disable no-console */
const bugUrl = 'https://github.com/yagop/node-telegram-bot-api/issues/36#issuecomment-268532067';
console.error('error: Internal handling of The Offset Infinite Loop failed');
console.error(`error: Due to error '${requestErr}'`);
console.error('error: You may receive already-processed updates on app restart');
console.error(`error: Please see ${bugUrl} for more information`);
/* eslint-enable no-console */
return this.bot.emit('error', new errors.FatalError(err));
});
})
.finally(() => {
if (this._abort) {
debug('Polling is aborted!');
} else {
debug('setTimeout for %s miliseconds', this.options.interval);
this._pollingTimeout = setTimeout(() => this._polling(), this.options.interval);
}
});
return this._lastRequest;
}
/**
* Unset current webhook. Used when we detect that a webhook has been set
* and we are trying to poll. Polling and WebHook are mutually exclusive.
* @see https://core.telegram.org/bots/api#getting-updates
* @private
*/
_unsetWebHook() {
debug('unsetting webhook');
return this.bot._request('setWebHook');
}
/**
* Retrieve updates
*/
_getUpdates() {
debug('polling with options: %j', this.options.params);
return this.bot.getUpdates(this.options.params)
.catch(err => {
if (err.response && err.response.statusCode === ANOTHER_WEB_HOOK_USED) {
return this._unsetWebHook().then(() => {
return this.bot.getUpdates(this.options.params);
});
}
throw err;
});
}
}
module.exports = TelegramBotPolling;