/**
 * Auth Context
 *
 * Provides authentication state and methods to the application
 */

'use client';

import React, { createContext, useContext, useState, useEffect } from 'react';
import { useRouter } from 'next/navigation';
import {
  login as apiLogin,
  register as apiRegister,
  logout as apiLogout,
  getCurrentUser,
} from '../api/auth';
import { getAuthToken } from '../api/client';
import type { UserPayload } from '@/types/api';

interface AuthContextType {
  user: UserPayload | null;
  loading: boolean;
  login: (email: string, password: string) => Promise<void>;
  register: (data: {
    email: string;
    password: string;
    firstName: string;
    lastName: string;
    organizationId: string;
  }) => Promise<void>;
  logout: () => Promise<void>;
  refreshUser: () => Promise<void>;
  isAuthenticated: boolean;
}

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

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

  // Helper function to check if user is authenticated
  const isAuthenticated = () => {
    return !!getAuthToken();
  };

  // Helper function to get stored user
  const getStoredUser = (): UserPayload | null => {
    if (typeof window === 'undefined') return null;
    const storedUser = localStorage.getItem('user');
    return storedUser ? JSON.parse(storedUser) : null;
  };

  useEffect(() => {
    // Check if user is already logged in
    const checkAuth = async () => {
      try {
        if (isAuthenticated()) {
          // Try to fetch current user from API (will auto-refresh token if expired)
          try {
            const currentUser = await getCurrentUser();
            setUser(currentUser);
            // Update stored user
            localStorage.setItem('user', JSON.stringify(currentUser));
          } catch (apiError) {
            console.error('Failed to fetch user from API:', apiError);
            // If API fails after token refresh attempt, clear everything
            if (typeof window !== 'undefined') {
              localStorage.removeItem('access_token');
              localStorage.removeItem('refresh_token');
              localStorage.removeItem('user');
            }
            setUser(null);
          }
        }
      } catch (error) {
        console.error('Auth check failed, clearing tokens:', error);
        // Token invalid or no user data, clear storage
        if (typeof window !== 'undefined') {
          localStorage.removeItem('access_token');
          localStorage.removeItem('refresh_token');
          localStorage.removeItem('user');
        }
        setUser(null);
      } finally {
        setLoading(false);
      }
    };

    checkAuth();

    // Check token validity every 5 minutes and refresh if needed
    const tokenCheckInterval = setInterval(async () => {
      if (isAuthenticated()) {
        try {
          // This will automatically refresh the token if it's expired (via API client)
          await getCurrentUser();
        } catch (error) {
          console.error('Token validation failed:', error);
          // If token refresh fails, user will be redirected to login by the API client
        }
      }
    }, 5 * 60 * 1000); // 5 minutes

    return () => clearInterval(tokenCheckInterval);
  }, []);

  const login = async (email: string, password: string) => {
    try {
      const response = await apiLogin({ email, password });
      // Fetch complete user profile after login
      const currentUser = await getCurrentUser();
      setUser(currentUser);
      // Store user in localStorage
      if (typeof window !== 'undefined') {
        localStorage.setItem('user', JSON.stringify(currentUser));
      }
      router.push('/dashboard');
    } catch (error) {
      throw error;
    }
  };

  const register = async (data: {
    email: string;
    password: string;
    firstName: string;
    lastName: string;
    organizationId: string;
  }) => {
    try {
      const response = await apiRegister(data);
      // Fetch complete user profile after registration
      const currentUser = await getCurrentUser();
      setUser(currentUser);
      // Store user in localStorage
      if (typeof window !== 'undefined') {
        localStorage.setItem('user', JSON.stringify(currentUser));
      }
      router.push('/dashboard');
    } catch (error) {
      throw error;
    }
  };

  const logout = async () => {
    try {
      await apiLogout();
    } finally {
      setUser(null);
      // Clear user from localStorage
      if (typeof window !== 'undefined') {
        localStorage.removeItem('user');
      }
      router.push('/login');
    }
  };

  const refreshUser = async () => {
    try {
      const currentUser = await getCurrentUser();
      setUser(currentUser);
      if (typeof window !== 'undefined') {
        localStorage.setItem('user', JSON.stringify(currentUser));
      }
    } catch (error) {
      console.error('Failed to refresh user:', error);
    }
  };

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

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

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