Telebot - Telegram Bot Library for Rust
======================================

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This library allows you to write a Telegram Bot in the Rust language. It's an almost complete wrapper for the Telegram Bot API and uses hyper to send requests to the Telegram server. Each Telegram function call returns a future which carries the actual bot and the answer. 

## Usage
Add this to your `Cargo.toml`
``` toml
[dependencies]
telebot = "0.3.0"
```
You need a __nightly__ version of the Rust compiler, because procedural macros are not yet supported in the stable channel.

## How it works
This example shows the basic usage of the telebot library. It creates a new handler for a simple "/reply" command and replies the received text. The tokio eventloop polls every 200ms for new updates and matches them with the registered events. If the command matches with "/reply" it will call the function and execute the returned future.

``` rust
use telebot::Bot;
use futures::stream::Stream;
use std::env;

// import all available functions
use telebot::functions::*;

fn main() {
    // Create the bot
    let mut bot = Bot::new(&env::var("TELEGRAM_BOT_KEY").unwrap()).update_interval(200);

    // Register a reply command which answers a message
    let handle = bot.new_cmd("/reply")
        .and_then(|(bot, msg)| {
            let mut text = msg.text.unwrap().clone();
            if text.is_empty() {
                text = "<empty>".into();
            }

            bot.message(msg.chat.id, text).send()
        })
        .for_each(|_| Ok(()));

    bot.run_with(handle);
}
```

## Additional example
The former example was very simple with just one handler and no error handling. If you want to see a further explained and illustrated one, please see [here](example.md).

## Find a Telegram function in the source code
This crate uses custom derive to generate functions of the Telegram API. Therefore each complete function is described with a struct in [functions.rs](src/functions.rs) and the supplemental crate telebot-derive generates the complete signature. In order to find a function, the struct signature can be used. For example consider sendLocation:
``` rust
/// Use this method to send point on the map. On success, the sent Message is returned.
#[derive(TelegramFunction, Serialize)]
#[call = "sendLocation"]
#[answer = "Message"]
#[function = "location"]
pub struct SendLocation {
    chat_id: u32,
    latitude: f32,
    longitude: f32,
#[serde(skip_serializing_if="Option::is_none")]
    disable_notification: Option<bool>,
#[serde(skip_serializing_if="Option::is_none")]
    reply_to_message_id: Option<u32>,
#[serde(skip_serializing_if="Option::is_none")]
    reply_markup: Option<NotImplemented>
}
```

The field "function" defines the name of the function in the local API. Each optional field in the struct can be changed by calling an additional function with the name of the field.
So for example to send the location of Paris to chat 432432 without notification: `bot.location(432432, 48.8566, 2.3522).disable_notification(true).send() `

## License

Licensed under either of

- Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or <http://www.apache.org/licenses/LICENSE-2.0>)
- MIT license ([LICENSE-MIT](LICENSE-MIT) or <http://opensource.org/licenses/MIT>)

at your option.

### Contribution

Unless you explicitly state otherwise, any contribution intentionally
submitted for inclusion in the work by you, as defined in the Apache-2.0
license, shall be dual licensed as above, without any additional terms or
conditions.