import { getErrorMessage } from "../utils/error-message.js";
import { WebSocketServer, WebSocket, type RawData } from "ws";
import { SerialPort } from "serialport";
import { AuthManager } from "../utils/auth-manager.js";
import { DataCrypto } from "../utils/data-crypto.js";
import { sshLogger } from "../utils/logger.js";
import { parseWsMessage } from "../utils/ws-message.js";
import { extractWebSocketToken } from "../utils/ws-auth.js";

interface SerialConnectData {
  path: string;
  baudRate: number;
  dataBits?: 5 | 6 | 7 | 8;
  stopBits?: 1 | 2;
  parity?: "none" | "even" | "odd";
}

const authManager = AuthManager.getInstance();

const wss = new WebSocketServer({ host: "127.0.0.1", port: 30011 });

wss.on("error", (error) => {
  sshLogger.error("Serial WebSocket server error", error, {
    operation: "wss_error",
  });
});

wss.on("connection", async (ws: WebSocket, req) => {
  let userId: string | undefined;

  try {
    const token = extractWebSocketToken(req);

    if (!token) {
      ws.close(1008, "Authentication required");
      return;
    }

    const payload = await authManager.verifyJWTToken(token);
    if (!payload?.userId || payload.pendingTOTP) {
      ws.close(1008, "Authentication required");
      return;
    }

    userId = payload.userId;
  } catch {
    ws.close(1008, "Authentication required");
    return;
  }

  const dataKey = DataCrypto.getUserDataKey(userId);
  if (!dataKey) {
    ws.send(JSON.stringify({ type: "error", data: "Data locked" }));
    ws.close(1008, "Data access required");
    return;
  }

  let port: SerialPort | null = null;

  const send = (msg: object) => {
    if (ws.readyState === WebSocket.OPEN) {
      ws.send(JSON.stringify(msg));
    }
  };

  const cleanup = () => {
    if (port?.isOpen) {
      port.close();
    }
    port = null;
  };

  ws.on("message", async (raw: RawData) => {
    let type: string;
    let data: unknown;
    try {
      ({ type, data } = parseWsMessage(raw));
    } catch {
      return;
    }

    try {
      switch (type) {
        case "list_ports": {
          try {
            const ports = await SerialPort.list();
            send({ type: "ports_list", data: ports });
          } catch (err) {
            send({
              type: "error",
              data: getErrorMessage(err, "Failed to list ports"),
            });
          }
          break;
        }

        case "connect": {
          if (port?.isOpen) {
            port.close();
            port = null;
          }

          const cfg = data as SerialConnectData;
          if (!cfg?.path || !cfg?.baudRate) {
            send({ type: "error", data: "Missing port path or baud rate" });
            break;
          }

          try {
            port = new SerialPort({
              path: cfg.path,
              baudRate: cfg.baudRate,
              dataBits: cfg.dataBits ?? 8,
              stopBits: cfg.stopBits ?? 1,
              parity: cfg.parity ?? "none",
              autoOpen: false,
            });

            port.open((err) => {
              if (err) {
                sshLogger.error("Serial port open failed", err, {
                  operation: "serial_open",
                  path: cfg.path,
                  userId,
                });
                send({ type: "error", data: err.message });
                port = null;
                return;
              }
              sshLogger.info("Serial port opened", {
                operation: "serial_open",
                path: cfg.path,
                baudRate: cfg.baudRate,
                userId,
              });
              send({ type: "connected" });
            });

            port.on("data", (chunk: Buffer) => {
              send({ type: "data", data: chunk.toString("binary") });
            });

            port.on("error", (err) => {
              send({ type: "error", data: err.message });
            });

            port.on("close", () => {
              send({ type: "disconnected" });
              port = null;
            });
          } catch (err) {
            send({
              type: "error",
              data: getErrorMessage(err, "Failed to open serial port"),
            });
          }
          break;
        }

        case "input": {
          if (!port?.isOpen) break;
          const input = typeof data === "string" ? data : "";
          if (!input) break;
          port.write(Buffer.from(input, "binary"), (err) => {
            if (err) {
              send({ type: "error", data: err.message });
            }
          });
          break;
        }

        case "disconnect": {
          cleanup();
          send({ type: "disconnected" });
          break;
        }
      }
    } catch (err) {
      sshLogger.error("Error handling serial WebSocket message", err, {
        operation: "serial_message_handler_error",
        userId,
        messageType: type,
      });
      send({ type: "error", data: "Failed to process message" });
    }
  });

  ws.on("close", () => {
    cleanup();
  });

  ws.on("error", () => {
    cleanup();
  });
});