import { createContext, useContext, useState, useEffect, useCallback } from 'react';
import { useLocation } from 'react-router-dom';
import api, { setTokens, clearTokens, getAccessToken } from '../api/client';

const AuthContext = createContext(null);

export function AuthProvider({ children }) {
  const [user, setUser] = useState(() => {
    try {
      const stored = localStorage.getItem('user');
      return stored ? JSON.parse(stored) : null;
    } catch {
      return null;
    }
  });
  const [loading, setLoading] = useState(true);
  const location = useLocation();

  const refreshUser = useCallback(async () => {
    try {
      const { data } = await api.get('/auth/me');
      setUser(data.user);
      localStorage.setItem('user', JSON.stringify(data.user));
    } catch {
      /* If /me fails, we might be logged out or server is down */
    }
  }, []);

  /* On mount, verify the stored token is still valid */
  useEffect(() => {
    async function verify() {
      const token = getAccessToken();
      if (!token) {
        setLoading(false);
        return;
      }
      try {
        const { data } = await api.get('/auth/me');
        setUser(data.user);
        localStorage.setItem('user', JSON.stringify(data.user));
      } catch {
        clearTokens();
        setUser(null);
      } finally {
        setLoading(false);
      }
    }
    verify();
  }, []);

  /* Refresh user profile on navigation to ensure role is up to date */
  useEffect(() => {
    if (user) {
      refreshUser();
    }
  }, [location.pathname, user?.id]);

  const login = useCallback(async (email, password) => {
    const { data } = await api.post('/auth/login', { email, password });
    setTokens(data.accessToken, data.refreshToken);
    setUser(data.user);
    localStorage.setItem('user', JSON.stringify(data.user));
    return data.user;
  }, []);

  const logout = useCallback(async () => {
    try {
      await api.post('/auth/logout');
    } catch {
      /* ignore — we clear locally regardless */
    }
    clearTokens();
    setUser(null);
  }, []);

  const isAdmin = ['office', 'admin', 'super_admin'].includes(user?.role);

  const value = {
    user,
    loading,
    login,
    logout,
    isAdmin,
    isAuthenticated: !!user,
  };

  return <AuthContext.Provider value={value}>{children}</AuthContext.Provider>;
}

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

export default AuthContext;