import { Router, type Router as RouterType } from 'express';
import { z } from 'zod';
import { prisma } from '@agent-fox/shared';
import { hashPassword, verifyPassword } from '../lib/password.js';
import { generateTokenPair, verifyRefreshToken } from '../lib/jwt.js';
import { requireAuth } from '../middleware/auth.js';
import { generateApiKey } from '../lib/api-key.js';
import { encryptApiKey, decryptApiKey } from '../lib/crypto.js';

const router: RouterType = Router();

const registerSchema = z.object({
  email: z.string().email(),
  password: z.string().min(8),
  name: z.string().min(1).max(100),
});

const loginSchema = z.object({
  email: z.string().email(),
  password: z.string(),
});

router.post('/register', async (req, res) => {
  const parsed = registerSchema.safeParse(req.body);
  if (!parsed.success) {
    res.status(400).json({ success: false, error: { code: 'VALIDATION', message: parsed.error.issues[0].message } });
    return;
  }

  const { email, password, name } = parsed.data;

  const existing = await prisma.user.findUnique({ where: { email } });
  if (existing) {
    res.status(409).json({ success: false, error: { code: 'CONFLICT', message: 'Email already registered' } });
    return;
  }

  const passwordHash = await hashPassword(password);
  const user = await prisma.user.create({
    data: { email, passwordHash, name },
  });

  const tokens = generateTokenPair({ userId: user.id, email: user.email });
  res.status(201).json({ success: true, data: { user: { id: user.id, email: user.email, name: user.name }, ...tokens } });
});

router.post('/login', async (req, res) => {
  const parsed = loginSchema.safeParse(req.body);
  if (!parsed.success) {
    res.status(400).json({ success: false, error: { code: 'VALIDATION', message: parsed.error.issues[0].message } });
    return;
  }

  const { email, password } = parsed.data;
  const user = await prisma.user.findUnique({ where: { email } });

  if (!user || !user.passwordHash) {
    res.status(401).json({ success: false, error: { code: 'UNAUTHORIZED', message: 'Invalid credentials' } });
    return;
  }

  const valid = await verifyPassword(password, user.passwordHash);
  if (!valid) {
    res.status(401).json({ success: false, error: { code: 'UNAUTHORIZED', message: 'Invalid credentials' } });
    return;
  }

  const tokens = generateTokenPair({ userId: user.id, email: user.email });
  res.json({ success: true, data: { user: { id: user.id, email: user.email, name: user.name }, ...tokens } });
});

router.post('/refresh', async (req, res) => {
  const { refreshToken } = req.body;
  if (!refreshToken) {
    res.status(400).json({ success: false, error: { code: 'VALIDATION', message: 'Refresh token required' } });
    return;
  }

  try {
    const payload = verifyRefreshToken(refreshToken);
    const user = await prisma.user.findUnique({ where: { id: payload.userId } });
    if (!user) {
      res.status(401).json({ success: false, error: { code: 'UNAUTHORIZED', message: 'User not found' } });
      return;
    }
    const tokens = generateTokenPair({ userId: user.id, email: user.email });
    res.json({ success: true, data: tokens });
  } catch {
    res.status(401).json({ success: false, error: { code: 'UNAUTHORIZED', message: 'Invalid refresh token' } });
  }
});

const setPasswordSchema = z.object({
  password: z.string().min(8),
});

router.post('/set-password', requireAuth, async (req, res) => {
  const parsed = setPasswordSchema.safeParse(req.body);
  if (!parsed.success) {
    res.status(400).json({ success: false, error: { code: 'VALIDATION', message: parsed.error.issues[0].message } });
    return;
  }

  const user = await prisma.user.findUnique({ where: { id: req.user!.userId } });
  if (!user) {
    res.status(404).json({ success: false, error: { code: 'NOT_FOUND', message: 'User not found' } });
    return;
  }

  if (user.passwordHash) {
    res.status(400).json({ success: false, error: { code: 'ALREADY_HAS_PASSWORD', message: 'Password already set. Use change-password instead.' } });
    return;
  }

  const passwordHash = await hashPassword(parsed.data.password);
  await prisma.user.update({ where: { id: user.id }, data: { passwordHash } });
  res.json({ success: true, data: { message: 'Password set successfully' } });
});

const changePasswordSchema = z.object({
  currentPassword: z.string(),
  newPassword: z.string().min(8),
});

router.post('/change-password', requireAuth, async (req, res) => {
  const parsed = changePasswordSchema.safeParse(req.body);
  if (!parsed.success) {
    res.status(400).json({ success: false, error: { code: 'VALIDATION', message: parsed.error.issues[0].message } });
    return;
  }

  const { currentPassword, newPassword } = parsed.data;
  const user = await prisma.user.findUnique({ where: { id: req.user!.userId } });

  if (!user || !user.passwordHash) {
    res.status(400).json({ success: false, error: { code: 'NO_PASSWORD', message: 'No password set for this account' } });
    return;
  }

  const valid = await verifyPassword(currentPassword, user.passwordHash);
  if (!valid) {
    res.status(401).json({ success: false, error: { code: 'UNAUTHORIZED', message: 'Current password is incorrect' } });
    return;
  }

  const newHash = await hashPassword(newPassword);
  await prisma.user.update({ where: { id: user.id }, data: { passwordHash: newHash } });
  res.json({ success: true, data: { message: 'Password changed' } });
});

const profileSchema = z.object({
  name: z.string().min(1).max(100),
});

router.put('/profile', requireAuth, async (req, res) => {
  const parsed = profileSchema.safeParse(req.body);
  if (!parsed.success) {
    res.status(400).json({ success: false, error: { code: 'VALIDATION', message: parsed.error.issues[0].message } });
    return;
  }

  const user = await prisma.user.update({
    where: { id: req.user!.userId },
    data: { name: parsed.data.name },
    select: { id: true, email: true, name: true },
  });
  res.json({ success: true, data: user });
});

router.get('/me', requireAuth, async (req, res) => {
  const user = await prisma.user.findUnique({
    where: { id: req.user!.userId },
    select: { id: true, email: true, name: true, avatarUrl: true, passwordHash: true },
  });
  if (!user) {
    res.status(404).json({ success: false, error: { code: 'NOT_FOUND', message: 'User not found' } });
    return;
  }
  const { passwordHash, ...rest } = user;
  res.json({ success: true, data: { ...rest, hasPassword: !!passwordHash } });
});

// --- API Key Management ---

router.get('/api-key/status', requireAuth, async (req, res) => {
  const user = await prisma.user.findUnique({
    where: { id: req.user!.userId },
    select: { apiKeyPrefix: true, apiKeyHash: true },
  });
  res.json({
    success: true,
    data: { hasKey: !!user?.apiKeyHash, prefix: user?.apiKeyPrefix || null },
  });
});

router.post('/api-key/generate', requireAuth, async (req, res) => {
  const user = await prisma.user.findUnique({
    where: { id: req.user!.userId },
    select: { apiKeyHash: true },
  });
  if (user?.apiKeyHash) {
    res.status(400).json({ success: false, error: { code: 'ALREADY_EXISTS', message: 'API key already exists. Use rotate to replace it.' } });
    return;
  }

  const { raw, hash } = generateApiKey();
  const encrypted = encryptApiKey(raw);
  const prefix = raw.slice(0, 12);

  await prisma.user.update({
    where: { id: req.user!.userId },
    data: { apiKeyHash: hash, apiKeyEncrypted: encrypted, apiKeyPrefix: prefix },
  });

  res.json({ success: true, data: { apiKey: raw } });
});

router.post('/api-key/rotate', requireAuth, async (req, res) => {
  const { raw, hash } = generateApiKey();
  const encrypted = encryptApiKey(raw);
  const prefix = raw.slice(0, 12);

  await prisma.user.update({
    where: { id: req.user!.userId },
    data: { apiKeyHash: hash, apiKeyEncrypted: encrypted, apiKeyPrefix: prefix },
  });

  res.json({ success: true, data: { apiKey: raw } });
});

const revealSchema = z.object({ password: z.string() });

router.post('/api-key/reveal', requireAuth, async (req, res) => {
  const parsed = revealSchema.safeParse(req.body);
  if (!parsed.success) {
    res.status(400).json({ success: false, error: { code: 'VALIDATION', message: 'Password is required' } });
    return;
  }

  const user = await prisma.user.findUnique({
    where: { id: req.user!.userId },
    select: { passwordHash: true, apiKeyEncrypted: true },
  });

  if (!user?.passwordHash) {
    res.status(400).json({ success: false, error: { code: 'NO_PASSWORD', message: 'No password set' } });
    return;
  }

  const valid = await verifyPassword(parsed.data.password, user.passwordHash);
  if (!valid) {
    res.status(401).json({ success: false, error: { code: 'UNAUTHORIZED', message: 'Incorrect password' } });
    return;
  }

  if (!user.apiKeyEncrypted) {
    res.status(404).json({ success: false, error: { code: 'NOT_FOUND', message: 'No API key generated' } });
    return;
  }

  const apiKey = decryptApiKey(user.apiKeyEncrypted);
  res.json({ success: true, data: { apiKey } });
});

export default router;