example_image_bot/
main.rs

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

use matrix_sdk::{
    attachment::AttachmentConfig,
    config::SyncSettings,
    ruma::events::room::message::{MessageType, OriginalSyncRoomMessageEvent},
    Client, Room, RoomState,
};
use url::Url;

async fn on_room_message(event: OriginalSyncRoomMessageEvent, room: Room, image: Vec<u8>) {
    if room.state() != RoomState::Joined {
        return;
    }
    let MessageType::Text(text_content) = event.content.msgtype else { return };

    if text_content.body.contains("!image") {
        println!("sending image");
        room.send_attachment(
            "cat.jpg",
            &mime::IMAGE_JPEG,
            image,
            AttachmentConfig::new().caption(Some("my pretty cat".to_owned())),
        )
        .await
        .unwrap();

        println!("message sent");
    }
}

async fn login_and_sync(
    homeserver_url: String,
    username: String,
    password: String,
    image: Vec<u8>,
) -> matrix_sdk::Result<()> {
    let homeserver_url = Url::parse(&homeserver_url).expect("Couldn't parse the homeserver URL");
    let client = Client::new(homeserver_url).await.unwrap();

    client
        .matrix_auth()
        .login_username(&username, &password)
        .initial_device_display_name("command bot")
        .await?;

    let response = client.sync_once(SyncSettings::default()).await.unwrap();

    client.add_event_handler(move |ev, room| on_room_message(ev, room, image));

    let settings = SyncSettings::default().token(response.next_batch);
    client.sync(settings).await?;

    Ok(())
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    tracing_subscriber::fmt::init();
    let (homeserver_url, username, password, image_path) =
        match (env::args().nth(1), env::args().nth(2), env::args().nth(3), env::args().nth(4)) {
            (Some(a), Some(b), Some(c), Some(d)) => (a, b, c, d),
            _ => {
                eprintln!(
                    "Usage: {} <homeserver_url> <username> <password> <image>",
                    env::args().next().unwrap()
                );
                exit(1)
            }
        };

    println!("helloooo {homeserver_url} {username} {password} {image_path:#?}");
    let image = fs::read(&image_path).expect("Can't open image file.");

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

example_image_bot/
main.rs
