import { computed, readonly, shallowRef } from "vue";

import { createApiClient } from "@geo/http-client";
import type {
  AuthTokens,
  DesktopClientInfo,
  DesktopClientRegisterRequest,
  DesktopClientRegisterResponse,
  DesktopRuntimeSessionSyncRequest,
  LoginRequest,
  LoginResponse,
  RefreshResponse,
  UserInfo,
} from "@geo/shared-types";

type SessionMode = "authenticated" | "preview";

interface DesktopSession {
  mode: SessionMode;
  accessToken: string | null;
  refreshToken: string | null;
  user: UserInfo | null;
  clientToken: string | null;
  clientTokenExpiresAt: number | null;
  desktopClient: DesktopClientInfo | null;
}

interface ResolvedDeviceInfo {
  device_name: string;
  os: string;
  cpu_arch: string;
}

const sessionStorageKey = "geo.desktop.session.v1";
const apiBaseURLStorageKey = "geo.desktop.api-base-url";

const session = shallowRef<DesktopSession | null>(readStoredSession());
const apiBaseURL = shallowRef(readStoredApiBaseURL());
const pending = shallowRef(false);
const error = shallowRef<string | null>(null);

function readStoredSession(): DesktopSession | null {
  if (typeof window === "undefined") {
    return null;
  }

  try {
    const raw = window.localStorage.getItem(sessionStorageKey);
    if (!raw) {
      return null;
    }
    return JSON.parse(raw) as DesktopSession;
  } catch {
    return null;
  }
}

function persistSession(next: DesktopSession | null): void {
  session.value = next;

  if (typeof window === "undefined") {
    return;
  }

  if (!next) {
    window.localStorage.removeItem(sessionStorageKey);
  } else {
    window.localStorage.setItem(sessionStorageKey, JSON.stringify(next));
  }

  void syncRuntimeSessionToMain(next);
}

function readStoredApiBaseURL(): string {
  if (typeof window === "undefined") {
    return "http://localhost:8080";
  }

  return window.localStorage.getItem(apiBaseURLStorageKey) ?? "http://localhost:8080";
}

function persistApiBaseURL(value: string): void {
  const trimmed = value.trim() || "http://localhost:8080";
  apiBaseURL.value = trimmed;

  if (typeof window !== "undefined") {
    window.localStorage.setItem(apiBaseURLStorageKey, trimmed);
  }

  void syncRuntimeSessionToMain();
}

function createPublicClient() {
  return createApiClient({
    baseURL: apiBaseURL.value,
    timeoutMs: 15000,
  });
}

function createAuthenticatedClient() {
  return createApiClient({
    baseURL: apiBaseURL.value,
    timeoutMs: 15000,
    auth: {
      getAccessToken: () => session.value?.accessToken ?? null,
      getRefreshToken: () => session.value?.refreshToken ?? null,
      setTokens: (tokens: AuthTokens) => {
        if (!session.value) {
          return;
        }

        persistSession({
          ...session.value,
          accessToken: tokens.accessToken,
          refreshToken: tokens.refreshToken,
        });
      },
      clearTokens: () => persistSession(null),
      async refresh(refreshToken: string): Promise<AuthTokens> {
        const next = await createPublicClient().post<RefreshResponse, { refresh_token: string }>(
          "/api/auth/refresh",
          { refresh_token: refreshToken },
        );

        return {
          accessToken: next.access_token,
          refreshToken: next.refresh_token,
        };
      },
    },
  });
}

function resolveFallbackPlatform(): string {
  const currentNavigator = globalThis.navigator as Navigator & {
    userAgentData?: { platform?: string };
  };
  return currentNavigator.userAgentData?.platform || currentNavigator.platform || "unknown";
}

function resolveFallbackOS(platform: string): string {
  const normalized = platform.toLowerCase();
  if (normalized.includes("mac")) {
    return "darwin";
  }
  if (normalized.includes("win")) {
    return "windows";
  }
  if (normalized.includes("linux")) {
    return "linux";
  }
  return normalized || "unknown";
}

function resolveFallbackDeviceName(platform: string): string {
  const normalized = platform.toLowerCase();
  if (normalized.includes("mac")) {
    return "Current Mac";
  }
  if (normalized.includes("win")) {
    return "Current Windows PC";
  }
  if (normalized.includes("linux")) {
    return "Current Linux Desktop";
  }
  return "Current Desktop";
}

async function resolveDeviceInfo(): Promise<ResolvedDeviceInfo> {
  try {
    const info = await window.desktopBridge?.app?.deviceInfo?.();
    if (info?.device_name && info.os && info.cpu_arch) {
      return info;
    }
  } catch (err) {
    console.warn("[desktop-session] deviceInfo bridge failed", err);
  }

  const platform = resolveFallbackPlatform();
  return {
    device_name: resolveFallbackDeviceName(platform),
    os: resolveFallbackOS(platform),
    cpu_arch: "unknown",
  };
}

async function resolveDesktopClientID(user: UserInfo): Promise<string> {
  const clientID = await window.desktopBridge?.app?.clientId?.({
    tenant_id: user.tenant_id,
    workspace_id: user.primary_workspace_id,
    user_id: user.id,
  });
  if (!clientID) {
    throw new Error("无法生成本机账号 client_id，请重启桌面客户端后重试");
  }
  return clientID;
}

async function syncStoredDesktopClientDeviceInfo(): Promise<void> {
  const current = session.value;
  if (typeof window === "undefined" || current?.mode !== "authenticated" || !current.desktopClient || !current.user) {
    return;
  }

  const [device, clientID] = await Promise.all([
    resolveDeviceInfo(),
    resolveDesktopClientID(current.user),
  ]);
  if (session.value !== current) {
    return;
  }

  const desktopClient = current.desktopClient;
  if (desktopClient.id !== clientID) {
    try {
      const registered = await registerDesktopClient(current.user, device);
      const latest = session.value;
      if (latest?.mode !== "authenticated" || latest.user?.id !== current.user?.id) {
        return;
      }
      persistSession({
        ...latest,
        clientToken: registered.client_token,
        clientTokenExpiresAt: registered.expires_at,
        desktopClient: registered.client,
      });
    } catch (err) {
      console.warn("[desktop-session] stable client migration failed", err);
    }
    return;
  }

  if (
    desktopClient.device_name === device.device_name
    && desktopClient.os === device.os
    && desktopClient.cpu_arch === device.cpu_arch
  ) {
    return;
  }

  persistSession({
    ...current,
    desktopClient: {
      ...desktopClient,
      device_name: device.device_name,
      os: device.os,
      cpu_arch: device.cpu_arch,
    },
  });
}

async function registerPayload(
  user: UserInfo,
  device?: ResolvedDeviceInfo,
): Promise<DesktopClientRegisterRequest> {
  const resolvedDevice = device ?? await resolveDeviceInfo();
  return {
    client_id: await resolveDesktopClientID(user),
    device_name: resolvedDevice.device_name,
    os: resolvedDevice.os,
    cpu_arch: resolvedDevice.cpu_arch,
    client_version: "0.1.0-dev",
    channel: "dev",
  };
}

async function registerDesktopClient(
  user: UserInfo,
  device?: ResolvedDeviceInfo,
): Promise<DesktopClientRegisterResponse> {
  const resolvedDevice = device ?? await resolveDeviceInfo();
  return createAuthenticatedClient().post<
    DesktopClientRegisterResponse,
    DesktopClientRegisterRequest
  >("/api/desktop/clients/register", await registerPayload(user, resolvedDevice));
}

function createPreviewUser(): UserInfo {
  return {
    id: 0,
    email: "preview@geo-rankly.local",
    name: "开发预览账号",
    avatar_url: null,
    tenant_id: 0,
    primary_workspace_id: 0,
    tenant_role: "owner",
    permissions: ["desktop.preview"],
    membership: null,
    kol_profile: null,
  };
}

async function createPreviewClient(): Promise<DesktopClientInfo> {
  const now = new Date().toISOString();
  const device = await resolveDeviceInfo();
  return {
    id: "preview-client",
    tenant_id: 0,
    workspace_id: 0,
    user_id: 0,
    device_name: `Preview ${device.device_name}`,
    os: device.os,
    cpu_arch: device.cpu_arch,
    client_version: "0.1.0-preview",
    channel: "dev",
    created_at: now,
    last_seen_at: now,
    last_rotated_at: now,
    revoked_at: null,
  };
}

function buildRuntimeSessionPayload(next: DesktopSession | null): DesktopRuntimeSessionSyncRequest | null {
  if (!next) {
    return null;
  }

  return {
    api_base_url: apiBaseURL.value,
    mode: next.mode,
    client_token: next.clientToken,
    desktop_client: next.desktopClient,
  };
}

async function syncRuntimeSessionToMain(next: DesktopSession | null = session.value): Promise<void> {
  if (typeof window === "undefined") {
    return;
  }

  if (!window.desktopBridge?.app?.syncRuntimeSession) {
    return;
  }

  await window.desktopBridge.app.syncRuntimeSession(buildRuntimeSessionPayload(next));
}

async function login(payload: LoginRequest): Promise<void> {
  pending.value = true;
  error.value = null;

  try {
    const authData = await createPublicClient().post<LoginResponse, LoginRequest>(
      "/api/auth/login",
      payload,
    );

    persistSession({
      mode: "authenticated",
      accessToken: authData.access_token,
      refreshToken: authData.refresh_token,
      user: authData.user,
      clientToken: null,
      clientTokenExpiresAt: null,
      desktopClient: null,
    });

    const registered = await registerDesktopClient(authData.user);

    persistSession({
      mode: "authenticated",
      accessToken: authData.access_token,
      refreshToken: authData.refresh_token,
      user: authData.user,
      clientToken: registered.client_token,
      clientTokenExpiresAt: registered.expires_at,
      desktopClient: registered.client,
    });
  } catch (err) {
    error.value = err instanceof Error ? err.message : "登录失败，请稍后重试";
    persistSession(null);
    throw err;
  } finally {
    pending.value = false;
  }
}

async function enterPreview(): Promise<void> {
  error.value = null;
  persistSession({
    mode: "preview",
    accessToken: null,
    refreshToken: null,
    user: createPreviewUser(),
    clientToken: "preview-client-token",
    clientTokenExpiresAt: Date.now() + 7 * 24 * 60 * 60 * 1000,
    desktopClient: await createPreviewClient(),
  });
}

async function logout(): Promise<void> {
  error.value = null;
  const current = session.value;

  if (current?.mode === "authenticated") {
    try {
      await window.desktopBridge?.app?.releaseRuntimeSession?.(true);
    } catch (err) {
      console.warn("[desktop-session] releaseRuntimeSession failed", err);
    }

    try {
      await createAuthenticatedClient().post<null, Record<string, never>>("/api/auth/logout", {});
    } catch (err) {
      console.warn("[desktop-session] auth logout failed", err);
    }
  }

  persistSession(null);
}

if (typeof window !== "undefined") {
  void syncStoredDesktopClientDeviceInfo();
}

export function useDesktopSession() {
  return {
    session: readonly(session),
    apiBaseURL: readonly(apiBaseURL),
    pending: readonly(pending),
    error: readonly(error),
    isAuthenticated: computed(() => Boolean(session.value?.clientToken)),
    isPreviewMode: computed(() => session.value?.mode === "preview"),
    setApiBaseURL: persistApiBaseURL,
    syncRuntimeSession: syncRuntimeSessionToMain,
    login,
    logout,
    enterPreview,
  };
}