import { createRouter } from '../../create-router';
import { FORBIDDEN, BAD_REQUEST } from '../../custom-errors';
import {
  getServerIntegration,
  upsertServerIntegration,
  getUserByEmail,
  getUserIntegration,
  upsertUserIntegration,
  deleteUserIntegration,
  getDockPaths,
  setDockPaths,
} from 'officerdb';
import { getValidGoogleAccessToken } from './google-auth';

const GOOGLE_SCOPES = [
  'https://mail.google.com/',
  'https://www.googleapis.com/auth/calendar.readonly',
  'https://www.googleapis.com/auth/userinfo.email',
];

type GoogleConfig = { clientId: string; clientSecret: string };

export const readGoogleConfig = async (): Promise<GoogleConfig | null> => {
  const integration = await getServerIntegration('google');
  if (!integration) return null;
  const config = integration.config as Record<string, unknown>;
  if (!config.clientId || !config.clientSecret) return null;
  return config as unknown as GoogleConfig;
};

export const integrationsRouter = createRouter();

integrationsRouter.get('/', async (ctx) => {
  return ctx.json([]);
});

// --- Apify config ---

type ApifyConfig = { apiToken: string };

export const readApifyConfig = async (): Promise<ApifyConfig | null> => {
  const integration = await getServerIntegration('apify');
  if (!integration) return null;
  const config = integration.config as Record<string, unknown>;
  if (!config.apiToken) return null;
  return config as unknown as ApifyConfig;
};

integrationsRouter.get('/apify/config', async (ctx) => {
  return ctx.json(await readApifyConfig());
});

integrationsRouter.put('/apify/config', async (ctx) => {
  const body = ctx.get('body') as { apiToken?: string };
  const config = { apiToken: body.apiToken ?? '' };

  await upsertServerIntegration('apify', config);
  return ctx.json(config);
});

integrationsRouter.get('/apify/status', async (ctx) => {
  const config = await readApifyConfig();
  return ctx.json({ configured: !!config?.apiToken });
});

// --- Google OAuth config ---

integrationsRouter.get('/google/config', async (ctx) => {
  return ctx.json(await readGoogleConfig());
});

integrationsRouter.put('/google/config', async (ctx) => {
  const body = ctx.get('body') as { clientId?: string; clientSecret?: string };
  const config = { clientId: body.clientId ?? '', clientSecret: body.clientSecret ?? '' };

  await upsertServerIntegration('google', config);
  return ctx.json(config);
});

integrationsRouter.get('/google/verify', async (ctx) => {
  const config = await readGoogleConfig();
  if (!config?.clientId || !config?.clientSecret) {
    return ctx.json({ valid: false, error: 'Missing credentials' });
  }

  const res = await fetch('https://oauth2.googleapis.com/token', {
    method: 'POST',
    headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
    body: new URLSearchParams({
      client_id: config.clientId,
      client_secret: config.clientSecret,
      code: 'invalid_code',
      redirect_uri: 'https://localhost',
      grant_type: 'authorization_code',
    }),
  });

  const body = await res.json();
  const valid = body.error === 'invalid_grant' || body.error === 'redirect_uri_mismatch';

  return ctx.json({ valid, error: valid ? null : (body.error_description ?? body.error) });
});

// --- Personal: Google account connection status ---

integrationsRouter.get('/google/status', async (ctx) => {
  const user = ctx.get('user');
  const config = await readGoogleConfig();
  const connection = await getUserIntegration(user.id, 'google');
  const connConfig = connection?.config as Record<string, unknown> | undefined;

  return ctx.json({
    configured: !!(config?.clientId && config?.clientSecret),
    connected: !!connConfig?.accessToken,
    email: connConfig?.email ?? null,
    picture: connConfig?.picture ?? null,
    hasAppPassword: !!connConfig?.imapAppPassword,
  });
});

integrationsRouter.put('/google/app-password', async (ctx) => {
  const user = ctx.get('user');
  const body = ctx.get('body') as { appPassword?: string; email?: string };
  if (!body.appPassword) throw BAD_REQUEST('Missing appPassword');

  const connection = await getUserIntegration(user.id, 'google');
  const connConfig = (connection?.config as Record<string, unknown>) ?? {};

  const updated: Record<string, unknown> = { ...connConfig, imapAppPassword: body.appPassword };
  if (body.email) updated.email = body.email;

  await upsertUserIntegration({
    userId: user.id,
    provider: 'google',
    serverIntegrationId: connection?.serverIntegrationId ?? undefined,
    config: updated,
  });

  return ctx.json({ ok: true });
});

integrationsRouter.delete('/google/connection', async (ctx) => {
  const user = ctx.get('user');
  const connection = await getUserIntegration(user.id, 'google');
  const connConfig = connection?.config as Record<string, unknown> | undefined;

  // Revoke token at Google so the old grant is fully removed
  const token = (connConfig?.refreshToken as string) || (connConfig?.accessToken as string);
  if (token) {
    fetch(`https://oauth2.googleapis.com/revoke?token=${token}`, { method: 'POST' }).catch(() => {});
  }

  await deleteUserIntegration(user.id, 'google');
  return ctx.json({ ok: true });
});

// --- Gmail proxy: forwards arbitrary Gmail REST calls with auto-refreshed OAuth ---

type GmailProxyBody = { method?: string; path?: string; body?: unknown };
const GMAIL_ALLOWED_METHODS = new Set(['GET', 'POST', 'PUT', 'PATCH', 'DELETE']);

integrationsRouter.post('/google/gmail-proxy', async (ctx) => {
  const user = ctx.get('user');
  const body = ctx.get('body') as GmailProxyBody;

  const method = (body.method ?? '').toUpperCase();
  const path = body.path ?? '';
  if (!GMAIL_ALLOWED_METHODS.has(method)) throw BAD_REQUEST('Invalid method');
  if (!path.startsWith('/')) throw BAD_REQUEST('path must start with /');

  const accessToken = await getValidGoogleAccessToken(user.id);
  if (!accessToken) throw BAD_REQUEST('No Google account connected — connect in Settings → Integrations');

  const url = `https://gmail.googleapis.com/gmail/v1${path}`;
  const init: RequestInit = {
    method,
    headers: { Authorization: `Bearer ${accessToken}` },
  };
  if (body.body !== undefined && method !== 'GET' && method !== 'DELETE') {
    (init.headers as Record<string, string>)['Content-Type'] = 'application/json';
    init.body = JSON.stringify(body.body);
  }

  const upstream = await fetch(url, init);
  const text = await upstream.text();
  let parsed: unknown;
  try {
    parsed = JSON.parse(text);
  } catch {
    parsed = text;
  }

  return ctx.json({ status: upstream.status, ok: upstream.ok, body: parsed });
});

// --- OAuth flow: authorize (protected — user must be logged in) ---

integrationsRouter.get('/google/authorize', async (ctx) => {
  const config = await readGoogleConfig();
  if (!config?.clientId || !config?.clientSecret) {
    throw BAD_REQUEST('Google OAuth not configured');
  }

  const email = ctx.get('user').email;
  const origin = ctx.req.query('origin');
  if (!origin) throw BAD_REQUEST('Missing origin parameter');
  const redirectUri = `${origin}/api/integrations/google/callback`;

  const state = Buffer.from(JSON.stringify({ email, redirectUri })).toString('base64url');

  const params = new URLSearchParams({
    client_id: config.clientId,
    redirect_uri: redirectUri,
    response_type: 'code',
    scope: GOOGLE_SCOPES.join(' '),
    access_type: 'offline',
    prompt: 'consent',
    include_granted_scopes: 'false',
    state,
  });

  return ctx.redirect(`https://accounts.google.com/o/oauth2/v2/auth?${params.toString()}`);
});

// --- OAuth callback (public — called by Google, exported for hono.ts) ---

export const googleCallbackHandler = async (ctx: any) => {
  const code = ctx.req.query('code');
  const stateParam = ctx.req.query('state');
  const error = ctx.req.query('error');

  if (error || !code || !stateParam) {
    return ctx.redirect('/settings/integrations?google=error');
  }

  let email: string;
  let redirectUri: string;
  try {
    const parsed = JSON.parse(Buffer.from(stateParam, 'base64url').toString());
    email = parsed.email;
    redirectUri = parsed.redirectUri;
  } catch {
    return ctx.redirect('/settings/integrations?google=error');
  }

  const config = await readGoogleConfig();
  if (!config?.clientId || !config?.clientSecret) {
    return ctx.redirect('/settings/integrations?google=error');
  }

  const tokenResponse = await fetch('https://oauth2.googleapis.com/token', {
    method: 'POST',
    headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
    body: new URLSearchParams({
      code,
      client_id: config.clientId,
      client_secret: config.clientSecret,
      redirect_uri: redirectUri,
      grant_type: 'authorization_code',
    }),
  });

  if (!tokenResponse.ok) {
    console.error('Google token exchange failed:', await tokenResponse.text());
    return ctx.redirect('/settings/integrations?google=error');
  }

  const tokens = await tokenResponse.json();

  const userinfoResponse = await fetch('https://www.googleapis.com/oauth2/v2/userinfo', {
    headers: { Authorization: `Bearer ${tokens.access_token}` },
  });

  let googleEmail = email;
  let picture: string | null = null;
  if (userinfoResponse.ok) {
    const userinfo = await userinfoResponse.json();
    googleEmail = userinfo.email ?? email;
    picture = userinfo.picture ?? null;
  }

  const dbUser = await getUserByEmail(email);
  if (!dbUser) {
    return ctx.redirect('/settings/integrations?google=error');
  }

  const serverIntegration = await getServerIntegration('google');

  // Merge with existing config to preserve fields like imapAppPassword
  const existingIntegration = await getUserIntegration(dbUser.id, 'google');
  const existingConfig = (existingIntegration?.config as Record<string, unknown>) ?? {};

  await upsertUserIntegration({
    userId: dbUser.id,
    provider: 'google',
    serverIntegrationId: serverIntegration?.id,
    config: {
      ...existingConfig,
      accessToken: tokens.access_token,
      refreshToken: tokens.refresh_token,
      expiresAt: Date.now() + tokens.expires_in * 1000,
      email: googleEmail,
      picture,
      scope: tokens.scope,
    },
  });

  // Auto-add /email to dock
  try {
    const existing = await getDockPaths(dbUser.id);
    const paths = existing ?? ['/', '/files', '/automation', '/dashboards', '/chat'];

    if (!paths.includes('/email')) {
      paths.push('/email');
      await setDockPaths(dbUser.id, paths);
    }
  } catch {
    // Non-critical — don't block the OAuth flow
  }

  return ctx.redirect('/settings/integrations?google=success');
};