example_command_bot/
main.rs

use std::{env, process::exit};

use matrix_sdk::{
    config::SyncSettings,
    ruma::events::room::message::{
        MessageType, OriginalSyncRoomMessageEvent, RoomMessageEventContent,
    },
    Client, Room, RoomState,
};

async fn on_room_message(event: OriginalSyncRoomMessageEvent, room: Room) {
    if room.state() != RoomState::Joined {
        return;
    }
    let MessageType::Text(text_content) = event.content.msgtype else {
        return;
    };

    if text_content.body.contains("!party") {
        let content = RoomMessageEventContent::text_plain("🎉🎊🥳 let's PARTY!! 🥳🎊🎉");

        println!("sending");

        // send our message to the room we found the "!party" command in
        room.send(content).await.unwrap();

        println!("message sent");
    }
}

async fn login_and_sync(
    homeserver_url: String,
    username: String,
    password: String,
) -> anyhow::Result<()> {
    // Note that when encryption is enabled, you should use a persistent store to be
    // able to restore the session with a working encryption setup.
    // See the `persist_session` example.
    let client = Client::builder().homeserver_url(homeserver_url).build().await.unwrap();
    client
        .matrix_auth()
        .login_username(&username, &password)
        .initial_device_display_name("command bot")
        .await?;

    println!("logged in as {username}");

    // An initial sync to set up state and so our bot doesn't respond to old
    // messages.
    let response = client.sync_once(SyncSettings::default()).await.unwrap();
    // add our CommandBot to be notified of incoming messages, we do this after the
    // initial sync to avoid responding to messages before the bot was running.
    client.add_event_handler(on_room_message);

    // since we called `sync_once` before we entered our sync loop we must pass
    // that sync token to `sync`
    let settings = SyncSettings::default().token(response.next_batch);
    // this keeps state from the server streaming in to CommandBot via the
    // EventHandler trait
    client.sync(settings).await?;

    Ok(())
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    tracing_subscriber::fmt::init();

    let (homeserver_url, username, password) =
        match (env::args().nth(1), env::args().nth(2), env::args().nth(3)) {
            (Some(a), Some(b), Some(c)) => (a, b, c),
            _ => {
                eprintln!(
                    "Usage: {} <homeserver_url> <username> <password>",
                    env::args().next().unwrap()
                );
                exit(1)
            }
        };

    login_and_sync(homeserver_url, username, password).await?;
    Ok(())
}
example_command_bot/main.rs

example_command_bot/
main.rs
