import { createContext, useContext, useState, useEffect, type ReactNode } from 'react';
import { getAccessToken, clearTokens, setTokens, apiFetch } from './api';

type User = { id: string; email: string; name: string; hasPassword?: boolean };

type AuthContextType = {
  user: User | null;
  loading: boolean;
  login: (email: string, password: string) => Promise<void>;
  register: (email: string, password: string, name: string) => Promise<void>;
  logout: () => void;
  updateUser: (updates: Partial<User>) => void;
  loginWithTokens: (accessToken: string, refreshToken: string) => Promise<void>;
};

const AuthContext = createContext<AuthContextType | null>(null);

export function AuthProvider({ children }: { children: ReactNode }) {
  const [user, setUser] = useState<User | null>(null);
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    if (getAccessToken()) {
      apiFetch<User>('/auth/me')
        .then(setUser)
        .catch(() => clearTokens())
        .finally(() => setLoading(false));
    } else {
      setLoading(false);
    }
  }, []);

  const login = async (email: string, password: string) => {
    const data = await apiFetch<{ user: User; accessToken: string; refreshToken: string }>(
      '/auth/login',
      { method: 'POST', body: JSON.stringify({ email, password }) },
    );
    setTokens(data.accessToken, data.refreshToken);
    setUser(data.user);
  };

  const register = async (email: string, password: string, name: string) => {
    const data = await apiFetch<{ user: User; accessToken: string; refreshToken: string }>(
      '/auth/register',
      { method: 'POST', body: JSON.stringify({ email, password, name }) },
    );
    setTokens(data.accessToken, data.refreshToken);
    setUser(data.user);
  };

  const logout = () => { clearTokens(); setUser(null); };

  const updateUser = (updates: Partial<User>) => {
    setUser(prev => prev ? { ...prev, ...updates } : null);
  };

  const loginWithTokens = async (access: string, refresh: string) => {
    setTokens(access, refresh);
    const user = await apiFetch<User>('/auth/me');
    setUser(user);
  };

  return (
    <AuthContext.Provider value={{ user, loading, login, register, logout, updateUser, loginWithTokens }}>
      {children}
    </AuthContext.Provider>
  );
}

export function useAuth() {
  const ctx = useContext(AuthContext);
  if (!ctx) throw new Error('useAuth must be used within AuthProvider');
  return ctx;
}