const { app, BrowserWindow, ipcMain, session } = require("electron");
const crypto = require("node:crypto");
const fs = require("node:fs");
const path = require("node:path");

app.commandLine.appendSwitch("autoplay-policy", "no-user-gesture-required");

let deviceConfig = null;
let desiredConfigRevision = 1;

function createWindow() {
  const window = new BrowserWindow({
    width: 1220,
    height: 820,
    minWidth: 980,
    minHeight: 700,
    backgroundColor: "#eef3f0",
    autoHideMenuBar: true,
    title: "语音终端模拟器",
    webPreferences: {
      preload: path.join(__dirname, "preload.cjs"),
      contextIsolation: true,
      nodeIntegration: false,
      sandbox: true,
    },
  });

  const devArgument = process.argv.find((argument) => argument.startsWith("--dev-server-url="));
  const devServerURL = devArgument ? devArgument.slice("--dev-server-url=".length) : "";
  if (devServerURL) {
    window.loadURL(devServerURL);
  } else {
    window.loadFile(path.join(__dirname, "..", "dist", "index.html"));
  }

  const screenshotPath = process.env.SIMULATOR_SCREENSHOT_PATH;
  if (screenshotPath) {
    window.webContents.once("did-finish-load", () => {
      setTimeout(async () => {
        const image = await window.webContents.capturePage();
        fs.writeFileSync(screenshotPath, image.toPNG());
        app.quit();
      }, 1200);
    });
  }
}

function ensureLoopbackURL(value) {
  const parsed = new URL(String(value || ""));
  const loopback = parsed.hostname === "127.0.0.1" || parsed.hostname === "localhost" || parsed.hostname === "[::1]";
  if (!loopback || (parsed.protocol !== "http:" && parsed.protocol !== "https:")) {
    throw new Error("本地测试只允许连接 localhost 或 127.0.0.1");
  }
  return parsed.origin;
}

function configure(input) {
  const apiURL = ensureLoopbackURL(input?.apiURL);
  const deviceID = String(input?.deviceID || "").trim();
  const deviceSecret = String(input?.deviceSecret || "");
  if (!/^[0-9a-f-]{36}$/i.test(deviceID)) {
    throw new Error("设备 ID 必须是 UUID");
  }
  if (deviceSecret.length < 32) {
    throw new Error("设备密钥至少需要 32 个字符");
  }
  deviceConfig = { apiURL, deviceID, deviceSecret };
  return { apiURL, deviceID };
}

function nonce() {
  return crypto.randomBytes(16).toString("hex");
}

function signedHeaders(method, requestURI, body) {
  if (!deviceConfig) throw new Error("请先连接本地平台");
  const timestamp = new Date().toISOString();
  const requestNonce = nonce();
  const digest = crypto.createHash("sha256").update(body).digest("hex");
  const canonical = [method.toUpperCase(), requestURI, timestamp, requestNonce, digest].join("\n");
  const signature = crypto.createHmac("sha256", deviceConfig.deviceSecret).update(canonical).digest("base64url");
  return {
    "X-Device-Id": deviceConfig.deviceID,
    "X-Device-Timestamp": timestamp,
    "X-Device-Nonce": requestNonce,
    "X-Device-Content-SHA256": digest,
    "X-Device-Signature": signature,
  };
}

async function deviceRequest(method, requestPath, payload, idempotencyKey) {
  if (!deviceConfig) throw new Error("请先连接本地平台");
  const target = new URL(requestPath, `${deviceConfig.apiURL}/`);
  const body = payload === undefined ? "" : JSON.stringify(payload);
  const headers = signedHeaders(method, `${target.pathname}${target.search}`, body);
  headers.Accept = "application/json";
  if (body) headers["Content-Type"] = "application/json";
  if (idempotencyKey) headers["Idempotency-Key"] = idempotencyKey;
  const response = await fetch(target, { method, headers, body: body || undefined });
  const text = await response.text();
  let parsed;
  try {
    parsed = text ? JSON.parse(text) : {};
  } catch {
    parsed = { message: text };
  }
  if (!response.ok) {
    const code = parsed?.error?.code || parsed?.code || `HTTP_${response.status}`;
    const message = parsed?.error?.message || parsed?.message || "本地平台请求失败";
    throw new Error(`${code}: ${message}`);
  }
  return parsed?.data ?? parsed;
}

ipcMain.handle("sim:configure", (_event, input) => configure(input));

ipcMain.handle("sim:probe", async () => {
  const query = new URLSearchParams({
    firmware_version: "0.3.0-windows-rtc",
    board_rev: "windows-x64",
    rtc_sdk_version: "web-4.69.0-electron",
    codec: "opus",
    sample_rate: "48000",
    network: "windows-local",
    device_time: new Date().toISOString(),
  });
  const bootstrap = await deviceRequest("GET", `/device/v2/bootstrap?${query.toString()}`);
  const configuration = await deviceRequest("GET", "/device/v2/config");
  desiredConfigRevision = Number(configuration.revision || bootstrap?.device?.config_revision || 1);
  return { bootstrap, configuration, desiredConfigRevision };
});

ipcMain.handle("sim:create-conversation", async () => deviceRequest("POST", "/device/v2/conversations", {
  device_time: new Date().toISOString(),
  monotonic_ms: Math.max(0, Math.round(performance.now())),
  capabilities: {
    rtc: true,
    audio_tracks: ["near", "far"],
    upload_resume: true,
    rtc_credential_renewal: true,
  },
  network: { type: "windows-local" },
  requested_goal: "open_conversation",
}, `windows-create-${nonce()}`));

ipcMain.handle("sim:activate-conversation", async (_event, input) => deviceRequest(
  "POST",
  `/device/v2/conversations/${encodeURIComponent(input.conversationID)}/activate`,
  {
    joined_at: new Date().toISOString(),
    room_id: input.roomID,
    rtc_user_id: input.userID,
    rtc_join_result: "success",
    config_revision: desiredConfigRevision,
    connection_reference: "windows-electron-web-rtc",
  },
  `windows-activate-${nonce()}`,
));

ipcMain.handle("sim:get-conversation", async (_event, conversationID) => deviceRequest(
  "GET",
  `/device/v2/conversations/${encodeURIComponent(conversationID)}`,
));

ipcMain.handle("sim:heartbeat", async (_event, input) => deviceRequest(
  "POST",
  `/device/v2/conversations/${encodeURIComponent(input.conversationID)}/heartbeat`,
  {
    sequence_no: input.sequenceNo,
    device_time: new Date().toISOString(),
    monotonic_ms: Math.max(0, Math.round(performance.now())),
    conversation_status: "ACTIVE",
    rtc: { joined: true, uplink: true, downlink: true },
    network: { type: "windows-local" },
    firmware_version: "0.3.0-windows-rtc",
    reported_config_revision: desiredConfigRevision,
    rtc_credential_expires_at: input.credentialExpiresAt,
    recording_queue: { pending_segments: 0, failed_segments: 0 },
    command_results: [],
  },
));

ipcMain.handle("sim:stop-conversation", async (_event, input) => deviceRequest(
  "POST",
  `/device/v2/conversations/${encodeURIComponent(input.conversationID)}/stop`,
  {
    reason: input.reason || "windows_user_hangup",
    device_time: new Date().toISOString(),
    last_heartbeat_sequence: input.lastHeartbeatSequence || 0,
    rtc_left: true,
    recording: { near_segments: 0, far_segments: 0 },
  },
  `windows-stop-${nonce()}`,
));

app.whenReady().then(() => {
  session.defaultSession.setPermissionCheckHandler((_webContents, permission) => permission === "media");
  session.defaultSession.setPermissionRequestHandler((_webContents, permission, callback) => callback(permission === "media"));
  createWindow();
});

app.on("window-all-closed", () => {
  if (process.platform !== "darwin") app.quit();
});

app.on("activate", () => {
  if (BrowserWindow.getAllWindows().length === 0) createWindow();
});