Add random_sticker example

examples/random_sticker/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "random_sticker"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+rand = "0.8.5"
+telers = { path = "../../telers", features = ["default"] }
+tokio = { version = "1.36", features = ["macros"] }
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] } 

examples/random_sticker/src/main.rs

@@ -0,0 +1,128 @@
+//! This example shows how to use the `Stickers` and `StickerSet`
+//! types and how to use the Telegram bot API methods for processing stickers.
+//!
+//! You can run this example by setting `BOT_TOKEN` and optional `RUST_LOG` environment variable and running:
+//! ```bash
+//! RUST_LOG={log_level} BOT_TOKEN={your_bot_token} cargo run --package random_sticker
+//! ```
+
+use rand::Rng;
+
+use telers::{
+    enums::{ContentType as ContentTypeEnum, UpdateType},
+    event::{telegram::HandlerResult, EventReturn, ToServiceProvider as _},
+    filters::{Command, ContentType},
+    methods::{GetStickerSet, SendMessage, SendSticker},
+    types::{InputFile, Message, MessageSticker, MessageText},
+    Bot, Dispatcher, Filter, Router,
+};
+use tracing::{event, Level};
+use tracing_subscriber::{fmt, layer::SubscriberExt as _, util::SubscriberInitExt as _, EnvFilter};
+
+/// This handler send greeting message to chat.
+async fn start_handler(bot: Bot, message: MessageText) -> HandlerResult {
+    bot.send(SendMessage::new(
+        message.chat.id(),
+        "Hello! Send me a sticker, and I'll send you a random sticker from this sticker pack!",
+    ))
+    .await?;
+
+    Ok(EventReturn::Finish)
+}
+
+/// This handler get sticker set from sent sticker and send random sticker
+/// from this sticker set.
+async fn sticker_handler(bot: Bot, message: MessageSticker) -> HandlerResult {
+    // get the the sticker set name of the sent sticker
+    let sticker_set_name = match message.sticker.set_name {
+        Some(sticker_set_name) => sticker_set_name,
+
+        // if the sticker does not have the name of the sticker set to which it belongs,
+        // then the sticker does not have a sticker set and exit from handler
+        None => {
+            bot.send(SendMessage::new(
+                message.chat.id(),
+                "Sorry, but this sticker without sticker set. Try send another sticker.",
+            ))
+            .await?;
+
+            return Ok(EventReturn::Finish);
+        }
+    };
+
+    // get sticker set using sent sticker set name
+    let sticker_set = bot.send(GetStickerSet::new(sticker_set_name)).await?;
+
+    // generate a random number no longer than the number of stickers in the sticker set
+    let rand_index_of_sticker_set = rand::thread_rng().gen_range(0..sticker_set.stickers.len());
+
+    // get a sticker by random index in a sticker pack
+    let sticker_to_send = &sticker_set.stickers[rand_index_of_sticker_set];
+
+    // send sticker by file ID of specify sticker
+    bot.send(SendSticker::new(
+        message.chat.id(),
+        InputFile::id(sticker_to_send.file_id.as_ref()),
+    ))
+    .await?;
+
+    Ok(EventReturn::Finish)
+}
+
+/// This handler process all non-sticker messages
+async fn wrong_message_handler(bot: Bot, message: Message) -> HandlerResult {
+    bot.send(SendMessage::new(
+        message.chat().id(),
+        "Please, send me any sticker.",
+    ))
+    .await?;
+
+    Ok(EventReturn::Finish)
+}
+
+#[tokio::main(flavor = "current_thread")]
+async fn main() {
+    tracing_subscriber::registry()
+        .with(fmt::layer())
+        .with(EnvFilter::from_env("RUST_LOG"))
+        .init();
+
+    let bot = Bot::from_env_by_key("BOT_TOKEN");
+
+    let mut router = Router::new("main");
+
+    // register handler that sends a greeting message when you use commands `/start` and `/help`
+    router
+        .message
+        .register(start_handler)
+        .filter(ContentType::one(ContentTypeEnum::Text))
+        .filter(Command::many(["help", "start"]));
+
+    // register handler that process sent sticker and send random sticker from this sticker set
+    router
+        .message
+        .register(sticker_handler)
+        .filter(ContentType::one(ContentTypeEnum::Sticker));
+
+    // register handler that handles all non-sticker messages
+    router
+        .message
+        .register(wrong_message_handler)
+        .filter(ContentType::one(ContentTypeEnum::Sticker).invert());
+
+    let dispatcher = Dispatcher::builder()
+        .main_router(router)
+        .bot(bot)
+        .allowed_update(UpdateType::Message)
+        .build();
+
+    match dispatcher
+        .to_service_provider_default()
+        .unwrap()
+        .run_polling()
+        .await
+    {
+        Ok(()) => event!(Level::INFO, "Bot stopped"),
+        Err(err) => event!(Level::ERROR, error = %err, "Bot stopped"),
+    }
+}