1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
use chrono::Utc;
use driftdb::{Database, MessageFromDatabase, MessageToDatabase};
use rand::{distributions::Alphanumeric, thread_rng, Rng};
use std::collections::HashMap;
use tokio_stream::StreamExt;
use worker::*;

mod utils;

pub fn cors() -> Cors {
    Cors::new()
        .with_methods(vec![Method::Post, Method::Get, Method::Options])
        .with_origins(vec!["*"])
}

fn room_result(req: Request, room_id: &str) -> Result<Response> {
    let host = req
        .headers()
        .get("Host")?
        .ok_or_else(|| worker::Error::JsError("No Host header provided.".to_string()))?;
    let response_body = serde_json::to_string(&serde_json::json!({
        "room": room_id,
        "url": format!("wss://{}/room/{}/connect", host, room_id),
    }))?;

    Response::ok(response_body)
}

pub fn handle_room(req: Request, ctx: RouteContext<()>) -> Result<Response> {
    if let Some(id) = ctx.param("room_id") {
        room_result(req, id)
    } else {
        Response::error("Bad Request", 400)
    }
}

/// Generate a random alphanumeric room ID.
fn random_room_id(length: usize) -> String {
    thread_rng()
        .sample_iter(&Alphanumeric)
        .take(length)
        .map(char::from)
        .collect()
}

pub fn handle_new_room(req: Request, _: RouteContext<()>) -> Result<Response> {
    let room_id = random_room_id(24);
    room_result(req, &room_id)
}

pub async fn handle_connect(req: Request, ctx: RouteContext<()>) -> Result<Response> {
    if let Some(id) = ctx.param("room_id") {
        let namespace = ctx.durable_object("DATABASE")?;
        let stub = namespace.id_from_name(id)?.get_stub()?;
        stub.fetch_with_request(req).await
    } else {
        Response::error("Bad Request", 400)
    }
}

#[cfg(feature = "fetch-event")]
#[event(fetch)]
pub async fn main(req: Request, env: Env, _ctx: worker::Context) -> Result<Response> {
    utils::set_panic_hook();
    let router = Router::new();

    let response = router
        .get("/", |_, _| Response::ok("DriftDB Worker service."))
        .post("/new", handle_new_room)
        .get("/room/:room_id", handle_room)
        .get_async("/room/:room_id/connect", handle_connect)
        .run(req, env)
        .await?;

    response.with_cors(&cors())
}

#[durable_object]
pub struct DbRoom {
    #[allow(unused)]
    state: State,
    db: Database,
}

/// A raw WebSocket is not Send or Sync, but that doesn't matter because we are compiling
/// to WebAssembly, which is single-threaded.
struct WrappedWebSocket(WebSocket);
unsafe impl Send for WrappedWebSocket {}
unsafe impl Sync for WrappedWebSocket {}

#[durable_object]
impl DurableObject for DbRoom {
    fn new(state: State, _: Env) -> Self {
        Self {
            state,
            db: Database::new(),
        }
    }

    async fn fetch(&mut self, req: Request) -> Result<Response> {
        let WebSocketPair { client, server } = WebSocketPair::new()?;
        server.accept()?;

        let db = self.db.clone();

        let url = req.url()?;

        let query: HashMap<String, String> = url
            .query_pairs()
            .map(|(k, v)| (k.into_owned(), v.into_owned()))
            .collect();

        let debug = query.get("debug").map(|s| s == "true").unwrap_or(false);

        wasm_bindgen_futures::spawn_local(async move {
            let mut event_stream = server.events().expect("could not open stream");

            let conn = {
                let server = WrappedWebSocket(server.clone());
                let callback = move |message: &MessageFromDatabase| {
                    server
                        .0
                        .send_with_str(
                            serde_json::to_string(&message).expect("Could not encode message."),
                        )
                        .expect("could not send message");
                };

                if debug {
                    db.connect_debug(callback)
                } else {
                    db.connect(callback)
                }
            };

            while let Some(event) = event_stream.next().await {
                match event.expect("received error in websocket") {
                    WebsocketEvent::Message(msg) => {
                        if let Some(text) = msg.text() {
                            if let Ok(message) = serde_json::from_str::<MessageToDatabase>(&text) {
                                conn.send_message(&message, Utc::now()).unwrap();
                            } else {
                                server
                                    .send_with_str(
                                        &serde_json::to_string(&MessageFromDatabase::Error {
                                            message: format!("Could not decode message: {}", text),
                                        })
                                        .unwrap(),
                                    )
                                    .unwrap();
                            }
                        }
                    }
                    WebsocketEvent::Close(_) => {
                        break;
                    }
                }
            }
        });

        Response::from_websocket(client)?.with_cors(&cors())
    }
}