// Admin only: users, studies, sign-up rules and invites, server health and snapshots.
import { adminDeleteProject, adminDeleteUser, adminGetAllProjects, adminGetAllUsers, adminGetProject, createInvite, dataDir, deleteInvite, destroyAllSessionsForUser, getSetting, getUserById, listInvites, setSetting, setUserPassword } from '../db.js';
import { generateTemporaryPassword, hashPassword, requireAdmin, requireAuth } from '../auth.js';
import { SIGNUP_MODES, generateInviteCode, isSignupMode, normalizeInviteCode } from '../signup.js';
import { restoreSnapshot, runBackup, snapshotPath } from '../backups.js';
import { backupStatus, diskUse, logEvent, recentEvents, uptimeSeconds } from '../health.js';

export function registerAdminRoutes(app) {
  // ---------------------------------------------------------------------------
  // Admin — restricted to the single designated admin account (see ADMIN_EMAIL
  // in server/auth.js). Full visibility/control over every user and project.
  // ---------------------------------------------------------------------------

  app.get('/api/admin/users', requireAuth, requireAdmin, (req, res) => {
    try {
      res.json(adminGetAllUsers());
    } catch (err) {
      console.error('GET /api/admin/users error:', err);
      res.status(500).json({ error: 'Failed to list users.' });
    }
  });

  app.delete('/api/admin/users/:id', requireAuth, requireAdmin, (req, res) => {
    try {
      if (req.params.id === req.session.userId) {
        return res.status(400).json({ error: "Can't delete your own admin account." });
      }
      adminDeleteUser(req.params.id);
      destroyAllSessionsForUser(req.params.id);
      res.json({ ok: true });
    } catch (err) {
      console.error('DELETE /api/admin/users/:id error:', err);
      res.status(500).json({ error: 'Failed to delete user.' });
    }
  });

  // POST /api/admin/users/:id/reset-password — sets a random temporary password and
  // signs the user out everywhere, since there's no self-service "forgot password" flow yet.
  app.post('/api/admin/users/:id/reset-password', requireAuth, requireAdmin, async (req, res) => {
    try {
      const temporaryPassword = generateTemporaryPassword();
      const passwordHash = await hashPassword(temporaryPassword);
      setUserPassword(req.params.id, passwordHash);
      destroyAllSessionsForUser(req.params.id);
      res.json({ temporaryPassword });
    } catch (err) {
      console.error('POST /api/admin/users/:id/reset-password error:', err);
      res.status(500).json({ error: 'Failed to reset password.' });
    }
  });

  // Who may sign up, and the invite codes for it
  // Server health: disk use, snapshots, and a short log of failures (in memory; resets on restart).
  app.get('/api/admin/health', requireAuth, requireAdmin, (_req, res) => {
    try {
      const emailOf = (id) => (id ? getUserById(id)?.email ?? null : null);
      const withUser = (e) => ({ ...e, email: emailOf(e.userId) });
      res.json({
        uptimeSeconds: uptimeSeconds(), node: process.version, dataDir: dataDir(),
        disk: diskUse(), backups: backupStatus(),
        iqConfigured: !!process.env.IQBIBLE_API_KEY,
        signinFailures: recentEvents('signin', 30).map(withUser),
        notifyFailures: recentEvents('notify', 30).map(withUser),
        backupFailures: recentEvents('backup', 10),
      });
    } catch (err) {
      console.error('GET /api/admin/health error:', err);
      res.status(500).json({ error: 'Failed to read server health.' });
    }
  });

  app.post('/api/admin/backups', requireAuth, requireAdmin, async (_req, res) => {
    try {
      await runBackup();
      res.json(backupStatus());
    } catch (err) {
      console.error('POST /api/admin/backups error:', err);
      logEvent('backup', err.message);
      res.status(500).json({ error: 'The snapshot could not be made.' });
    }
  });

  app.get('/api/admin/backups/:name', requireAuth, requireAdmin, (req, res) => {
    const file = snapshotPath(req.params.name);
    if (!file) return res.status(404).json({ error: 'No such snapshot.' });
    res.download(file, req.params.name);
  });

  // Restoring replaces every account's data, so the snapshot's name has to be typed back as confirmation.
  app.post('/api/admin/backups/:name/restore', requireAuth, requireAdmin, async (req, res) => {
    if (!snapshotPath(req.params.name)) return res.status(404).json({ error: 'No such snapshot.' });
    if (req.body?.confirm !== req.params.name) return res.status(400).json({ error: 'Type the snapshot’s name to confirm.' });
    try {
      const result = await restoreSnapshot(req.params.name);
      res.json({ restored: result.restored, safetyCopy: result.safetyCopy.split('/').pop() });
    } catch (err) {
      console.error('POST /api/admin/backups/:name/restore error:', err);
      res.status(500).json({ error: 'The snapshot could not be restored.' });
    }
  });

  app.get('/api/admin/signup', requireAuth, requireAdmin, (_req, res) => {
    res.json({ mode: getSetting('signup', 'open'), invites: listInvites() });
  });

  app.put('/api/admin/signup', requireAuth, requireAdmin, (req, res) => {
    if (!isSignupMode(req.body?.mode)) return res.status(400).json({ error: `Mode must be one of: ${SIGNUP_MODES.join(', ')}.` });
    setSetting('signup', req.body.mode);
    res.json({ mode: req.body.mode });
  });

  app.post('/api/admin/invites', requireAuth, requireAdmin, (req, res) => {
    const days = Math.min(90, Math.max(1, Number(req.body?.days) || 7));
    const code = generateInviteCode();
    createInvite(code, String(req.body?.note ?? '').trim().slice(0, 80), Date.now() + days * 86_400_000);
    res.json({ code, expiresInDays: days });
  });

  app.delete('/api/admin/invites/:code', requireAuth, requireAdmin, (req, res) => {
    deleteInvite(normalizeInviteCode(req.params.code));
    res.json({ ok: true });
  });

  app.get('/api/admin/projects', requireAuth, requireAdmin, (req, res) => {
    try {
      res.json(adminGetAllProjects());
    } catch (err) {
      console.error('GET /api/admin/projects error:', err);
      res.status(500).json({ error: 'Failed to list projects.' });
    }
  });

  app.get('/api/admin/projects/:id', requireAuth, requireAdmin, (req, res) => {
    try {
      const project = adminGetProject(req.params.id);
      if (!project) return res.status(404).json({ error: 'Project not found.' });
      res.json(project);
    } catch (err) {
      console.error('GET /api/admin/projects/:id error:', err);
      res.status(500).json({ error: 'Failed to load project.' });
    }
  });

  app.delete('/api/admin/projects/:id', requireAuth, requireAdmin, (req, res) => {
    try {
      adminDeleteProject(req.params.id);
      res.json({ ok: true });
    } catch (err) {
      console.error('DELETE /api/admin/projects/:id error:', err);
      res.status(500).json({ error: 'Failed to delete project.' });
    }
  });
}