// frontend/src/api/hooks/useAuth.ts
/**
 * Authentication Hooks
 * React hooks for authentication operations
 */

import { useState, useEffect, useCallback } from 'react';
import { authService } from '../services';
import type {
  LoginRequest,
  LoginResponse,
  RegisterRequest,
  UserResponse,
  PasswordResetRequest,
} from '../types';

// Token management
const TOKEN_KEY = 'auth_token';
const REFRESH_TOKEN_KEY = 'refresh_token';
const USER_KEY = 'user_data';

export const useAuth = () => {
  const [user, setUser] = useState<UserResponse | null>(null);
  const [isAuthenticated, setIsAuthenticated] = useState(false);
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  // Initialize auth state from localStorage
  useEffect(() => {
    const initializeAuth = async () => {
      try {
        const token = localStorage.getItem(TOKEN_KEY);
        const userData = localStorage.getItem(USER_KEY);

        if (token && userData) {
          setUser(JSON.parse(userData));
          setIsAuthenticated(true);
          
          // Verify token is still valid
          try {
            const currentUser = await authService.getCurrentUser();
            setUser(currentUser);
          } catch (error) {
            // Token expired or invalid, clear auth state
            logout();
          }
        }
      } catch (error) {
        console.error('Auth initialization error:', error);
        logout();
      } finally {
        setIsLoading(false);
      }
    };

    initializeAuth();
  }, []);

  const login = useCallback(async (credentials: LoginRequest): Promise<void> => {
    try {
      setIsLoading(true);
      setError(null);

      const response = await authService.login(credentials);
      
      // Store tokens and user data
      localStorage.setItem(TOKEN_KEY, response.access_token);
      if (response.refresh_token) {
        localStorage.setItem(REFRESH_TOKEN_KEY, response.refresh_token);
      }
      if (response.user) {
        localStorage.setItem(USER_KEY, JSON.stringify(response.user));
        setUser(response.user);
      }

      setIsAuthenticated(true);
    } catch (error) {
      const message = error instanceof Error ? error.message : 'Login failed';
      setError(message);
      throw error;
    } finally {
      setIsLoading(false);
    }
  }, []);

  const register = useCallback(async (data: RegisterRequest): Promise<void> => {
    try {
      setIsLoading(true);
      setError(null);

      const response = await authService.register(data);
      
      // Auto-login after successful registration
      if (response.user) {
        await login({ email: data.email, password: data.password });
      }
    } catch (error) {
      const message = error instanceof Error ? error.message : 'Registration failed';
      setError(message);
      throw error;
    } finally {
      setIsLoading(false);
    }
  }, [login]);

  const logout = useCallback(async (): Promise<void> => {
    try {
      // Call logout endpoint if authenticated
      if (isAuthenticated) {
        await authService.logout();
      }
    } catch (error) {
      console.error('Logout error:', error);
    } finally {
      // Clear local state regardless of API call success
      localStorage.removeItem(TOKEN_KEY);
      localStorage.removeItem(REFRESH_TOKEN_KEY);
      localStorage.removeItem(USER_KEY);
      setUser(null);
      setIsAuthenticated(false);
      setError(null);
    }
  }, [isAuthenticated]);

  const updateProfile = useCallback(async (data: Partial<UserResponse>): Promise<void> => {
    try {
      setIsLoading(true);
      setError(null);

      const updatedUser = await authService.updateProfile(data);
      setUser(updatedUser);
      localStorage.setItem(USER_KEY, JSON.stringify(updatedUser));
    } catch (error) {
      const message = error instanceof Error ? error.message : 'Profile update failed';
      setError(message);
      throw error;
    } finally {
      setIsLoading(false);
    }
  }, []);

  const requestPasswordReset = useCallback(async (data: PasswordResetRequest): Promise<void> => {
    try {
      setIsLoading(true);
      setError(null);
      await authService.requestPasswordReset(data);
    } catch (error) {
      const message = error instanceof Error ? error.message : 'Password reset request failed';
      setError(message);
      throw error;
    } finally {
      setIsLoading(false);
    }
  }, []);

  const changePassword = useCallback(async (currentPassword: string, newPassword: string): Promise<void> => {
    try {
      setIsLoading(true);
      setError(null);
      await authService.changePassword(currentPassword, newPassword);
    } catch (error) {
      const message = error instanceof Error ? error.message : 'Password change failed';
      setError(message);
      throw error;
    } finally {
      setIsLoading(false);
    }
  }, []);

  return {
    user,
    isAuthenticated,
    isLoading,
    error,
    login,
    register,
    logout,
    updateProfile,
    requestPasswordReset,
    changePassword,
    clearError: () => setError(null),
  };
};

// Hook for getting authentication headers
export const useAuthHeaders = () => {
  const getAuthHeaders = useCallback(() => {
    const token = localStorage.getItem(TOKEN_KEY);
    return token ? { Authorization: `Bearer ${token}` } : {};
  }, []);

  return { getAuthHeaders };
};