import { decode } from "./protocol";
import { type Client, getOrCreateSession, getSession } from "./session";

const PORT = Number(process.env.PORT) || 4040;

const server = Bun.serve({
  port: PORT,
  fetch(req, server) {
    const url = new URL(req.url);
    if (url.pathname === "/ws") {
      const upgraded = server.upgrade(req, { data: { room: null } });
      if (!upgraded) {
        return new Response("websocket upgrade failed", { status: 400 });
      }
      return;
    }
    return new Response("collabd running");
  },
  websocket: {
    open(ws) {
      console.debug("client connected");
    },
    message(ws, raw) {
      const msg = decode(raw.toString());
      if (!msg) return;

      const client: Client = { ws };

      switch (msg.type) {
        case "join": {
          const session = getOrCreateSession(msg.room);
          ws.data.room = msg.room;
          session.join(client);
          console.debug(`client joined room: ${msg.room}`);
          break;
        }
        case "leave": {
          if (ws.data.room) {
            const session = getSession(ws.data.room);
            session?.leave(client);
            ws.data.room = null;
          }
          break;
        }
        case "update": {
          if (ws.data.room) {
            const session = getSession(ws.data.room);
            session?.applyUpdate(new Uint8Array(msg.data), client);
          }
          break;
        }
      }
    },
    close(ws) {
      if (ws.data.room) {
        const session = getSession(ws.data.room);
        session?.leave({ ws });
      }
      console.debug("client disconnected");
    },
  },
});

console.log(`collabd listening on :${PORT}`);