import { useState, useEffect, useCallback } from 'react';
import { User, AuthSession, LoginCredentials } from '../types/auth';

const ADMIN_EMAIL = 'tradewithoutstrategy@gmail.com';
const ADMIN_PASSWORD = 'admin123'; // In production, use proper password hashing

const initializeUsers = (): User[] => {
  const existingUsers = JSON.parse(localStorage.getItem('users') || '[]');
  
  // Add admin user if not exists
  if (!existingUsers.some((u: User) => u.email === ADMIN_EMAIL)) {
    const adminUser: User = {
      id: 'admin_1',
      email: ADMIN_EMAIL,
      password: ADMIN_PASSWORD,
      role: 'admin',
      name: 'Admin',
      createdAt: new Date().toISOString(),
    };
    existingUsers.push(adminUser);
    localStorage.setItem('users', JSON.stringify(existingUsers));
  }
  
  return existingUsers;
};

export const useAuth = () => {
  const [session, setSession] = useState<AuthSession | null>(null);
  const [isLoading, setIsLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);

  // Initialize users and check for existing session
  useEffect(() => {
    initializeUsers();
    
    const existingSession = localStorage.getItem('auth_session');
    if (existingSession) {
      try {
        setSession(JSON.parse(existingSession));
      } catch (err) {
        console.error('Error parsing session:', err);
        localStorage.removeItem('auth_session');
      }
    }
  }, []);

  const login = useCallback(async (credentials: LoginCredentials): Promise<boolean> => {
    setIsLoading(true);
    setError(null);

    try {
      const users = JSON.parse(localStorage.getItem('users') || '[]');
      const user = users.find((u: User) => 
        u.email === credentials.email && u.password === credentials.password
      );

      if (!user) {
        setError('Invalid email or password');
        return false;
      }

      const newSession: AuthSession = {
        user,
        isLoggedIn: true,
        loginTime: new Date().toISOString(),
      };

      setSession(newSession);
      localStorage.setItem('auth_session', JSON.stringify(newSession));
      return true;
    } catch (err) {
      setError('Login failed. Please try again.');
      console.error('Login error:', err);
      return false;
    } finally {
      setIsLoading(false);
    }
  }, []);

  const logout = useCallback(() => {
    setSession(null);
    localStorage.removeItem('auth_session');
  }, []);

  const isAdmin = session?.user.role === 'admin';
  const isInfluencer = session?.user.role === 'influencer';
  const isViewer = session?.user.role === 'viewer';
  const isLoggedIn = session?.isLoggedIn || false;

  // Check if current user is the owner of the influencer account
  const isInfluencerOwner = useCallback((influencerId: string): boolean => {
    return session?.user.influencerId === influencerId;
  }, [session]);

  return {
    session,
    user: session?.user,
    isLoggedIn,
    isAdmin,
    isInfluencer,
    isViewer,
    isLoading,
    error,
    login,
    logout,
    isInfluencerOwner,
  };
};