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

use matrix_sdk::{
    self, async_trait,
    events::{
        room::message::{MessageEventContent, TextMessageEventContent},
        AnyMessageEventContent, SyncMessageEvent,
    },
    Client, ClientConfig, EventHandler, RoomState, SyncSettings,
};
use url::Url;

struct CommandBot {
    /// This clone of the `Client` will send requests to the server,
    /// while the other keeps us in sync with the server using `sync`.
    client: Client,
}

impl CommandBot {
    pub fn new(client: Client) -> Self {
        Self { client }
    }
}

#[async_trait]
impl EventHandler for CommandBot {
    async fn on_room_message(
        &self,
        room: RoomState,
        event: &SyncMessageEvent<MessageEventContent>,
    ) {
        if let RoomState::Joined(room) = room {
            let msg_body = if let SyncMessageEvent {
                content: MessageEventContent::Text(TextMessageEventContent { body: msg_body, .. }),
                ..
            } = event
            {
                msg_body.clone()
            } else {
                String::new()
            };

            if msg_body.contains("!party") {
                let content = AnyMessageEventContent::RoomMessage(MessageEventContent::text_plain(
                    "🎉🎊🥳 let's PARTY!! 🥳🎊🎉",
                ));

                println!("sending");

                self.client
                    // send our message to the room we found the "!party" command in
                    // the last parameter is an optional Uuid which we don't care about.
                    .room_send(room.room_id(), content, None)
                    .await
                    .unwrap();

                println!("message sent");
            }
        }
    }
}

async fn login_and_sync(
    homeserver_url: String,
    username: String,
    password: String,
) -> Result<(), matrix_sdk::Error> {
    // the location for `JsonStore` to save files to
    let mut home = dirs::home_dir().expect("no home directory found");
    home.push("party_bot");

    let client_config = ClientConfig::new().store_path(home);

    let homeserver_url = Url::parse(&homeserver_url).expect("Couldn't parse the homeserver URL");
    // create a new Client with the given homeserver url and config
    let client = Client::new_with_config(homeserver_url, client_config).unwrap();

    client
        .login(&username, &password, None, Some("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.
    // If the `StateStore` finds saved state in the location given the initial sync will
    // be skipped in favor of loading state from the store
    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
        .set_event_handler(Box::new(CommandBot::new(client.clone())))
        .await;

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

    Ok(())
}

#[tokio::main]
async fn main() -> Result<(), matrix_sdk::Error> {
    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(())
}