const STORAGE_KEY = "taiyi1224";
const MACHINE_KEY = "xhsp_machine_code";

export function getStoredAuth() {
  try {
    const raw = localStorage.getItem(STORAGE_KEY);
    return raw ? JSON.parse(raw) : null;
  } catch {
    return null;
  }
}

export function saveStoredAuth(data) {
  localStorage.setItem(STORAGE_KEY, JSON.stringify(data));
  window.dispatchEvent(new CustomEvent("license-auth-changed", { detail: data }));
}

export function clearStoredAuth() {
  localStorage.removeItem(STORAGE_KEY);
  window.dispatchEvent(new CustomEvent("license-auth-changed", { detail: null }));
}

export function getAccessToken() {
  return getStoredAuth()?.token || "";
}

async function sha256Hex(input) {
  const bytes = new TextEncoder().encode(input);
  const buffer = await crypto.subtle.digest("SHA-256", bytes);
  return Array.from(new Uint8Array(buffer)).map((item) => item.toString(16).padStart(2, "0")).join("");
}

export async function getMachineCode() {
  const cached = localStorage.getItem(MACHINE_KEY);
  if (cached) return cached;

  const fingerprint = [
    navigator.userAgent,
    navigator.language,
    navigator.platform,
    screen.width,
    screen.height,
    new Date().getTimezoneOffset(),
  ].join("|");

  const code = (await sha256Hex(fingerprint)).slice(0, 32).toUpperCase();
  localStorage.setItem(MACHINE_KEY, code);
  return code;
}

export async function verifyLicenseKey(licenseKey) {
  const machineCode = await getMachineCode();
  const response = await fetch("/api/license/verify", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ licenseKey, machineCode }),
  });

  const data = await response.json().catch(() => ({ success: false, message: "授权服务返回异常" }));
  if (!response.ok || data.success === false) {
    throw new Error(data.message || "卡密验证失败");
  }

  const auth = {
    token: data.token,
    auth: data.auth,
    recheckIntervalMs: data.recheckIntervalMs,
  };
  saveStoredAuth(auth);
  return auth;
}

export async function refreshLicenseStatus() {
  const token = getAccessToken();
  if (!token) return null;

  const response = await fetch("/api/license/status", {
    headers: { Authorization: `Bearer ${token}` },
  });

  const data = await response.json().catch(() => ({ success: false, message: "授权状态检查失败" }));
  if (!response.ok || data.success === false) {
    clearStoredAuth();
    throw new Error(data.message || "授权已失效");
  }

  const auth = {
    token: data.token || token,
    auth: data.auth,
    recheckIntervalMs: data.recheckIntervalMs,
  };
  saveStoredAuth(auth);
  return auth;
}

export async function unbindCurrentLicense() {
  const token = getAccessToken();
  if (!token) {
    throw new Error("当前没有有效授权");
  }

  const response = await fetch("/api/license/unbind", {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      Authorization: `Bearer ${token}`,
    },
  });

  const data = await response.json().catch(() => ({ success: false, message: "解绑服务返回异常" }));
  if (!response.ok || data.success === false) {
    throw new Error(data.message || "解绑失败");
  }

  clearStoredAuth();
  return data;
}