import { ref, computed } from 'vue'
import { lnbitsAPI, type User, type LoginCredentials, type RegisterData } from '@/lib/api/lnbits'
import { useMultiAsyncOperation } from '@/core/composables/useAsyncOperation'

const currentUser = ref<User | null>(null)

// Shared async operations for auth actions
const authOperations = useMultiAsyncOperation<{
  initialize: User | null
  login: User
  register: User
  logout: void
}>()

export function useAuth() {
  const isAuthenticated = computed(() => !!currentUser.value)
  
  // Get operation instances
  const initializeOp = authOperations.createOperation('initialize')
  const loginOp = authOperations.createOperation('login')
  const registerOp = authOperations.createOperation('register')
  const logoutOp = authOperations.createOperation('logout')

  /**
   * Initialize authentication on app start
   */
  async function initialize(): Promise<void> {
    try {
      await initializeOp.execute(async () => {
        if (lnbitsAPI.isAuthenticated()) {
          const user = await lnbitsAPI.getCurrentUser()
          currentUser.value = user
          return user
        }
        return null
      }, {
        errorMessage: 'Failed to initialize authentication',
        showToast: false // Don't show toast for initialization errors
      })
    } catch {
      // Clear invalid token on error
      await logout()
    }
  }

  /**
   * Login with username and password
   */
  async function login(credentials: LoginCredentials): Promise<void> {
    await loginOp.execute(async () => {
      await lnbitsAPI.login(credentials)
      
      // Get user details
      const user = await lnbitsAPI.getCurrentUser()
      currentUser.value = user
      return user
    }, {
      errorMessage: 'Login failed'
    })
  }

  /**
   * Register new user
   */
  async function register(data: RegisterData): Promise<void> {
    await registerOp.execute(async () => {
      await lnbitsAPI.register(data)
      
      // Get user details
      const user = await lnbitsAPI.getCurrentUser()
      currentUser.value = user
      return user
    }, {
      errorMessage: 'Registration failed'
    })
  }

  /**
   * Logout and clear user data
   */
  async function logout(): Promise<void> {
    await logoutOp.execute(async () => {
      // Clear local state
      lnbitsAPI.logout()
      currentUser.value = null
      // Clear all auth operation states
      authOperations.clearAll()
    }, {
      showToast: false // Don't show toast for logout
    })
  }

  /**
   * Update user password
   */
  async function updatePassword(currentPassword: string, newPassword: string): Promise<void> {
    const updatePasswordOp = authOperations.createOperation('updatePassword' as any)
    
    return await updatePasswordOp.execute(async () => {
      const updatedUser = await lnbitsAPI.updatePassword(currentPassword, newPassword)
      currentUser.value = updatedUser
      return updatedUser
    }, {
      errorMessage: 'Failed to update password'
    })
  }

  /**
   * Update user profile
   */
  async function updateProfile(data: Partial<User>): Promise<void> {
    const updateProfileOp = authOperations.createOperation('updateProfile' as any)
    
    return await updateProfileOp.execute(async () => {
      const updatedUser = await lnbitsAPI.updateProfile(data)
      currentUser.value = updatedUser
      return updatedUser
    }, {
      errorMessage: 'Failed to update profile'
    })
  }

  /**
   * Check if user is authenticated
   */
  function checkAuth(): boolean {
    return lnbitsAPI.isAuthenticated()
  }

  /**
   * Get user display info
   */
  const userDisplay = computed(() => {
    if (!currentUser.value) return null
    
    return {
      name: currentUser.value.username || currentUser.value.email || 'Anonymous',
      username: currentUser.value.username,
      email: currentUser.value.email,
      id: currentUser.value.id,
      shortId: currentUser.value.id.slice(0, 8) + '...' + currentUser.value.id.slice(-8)
    }
  })



  return {
    // State
    currentUser: computed(() => currentUser.value),
    isAuthenticated,
    isLoading: computed(() => authOperations.isAnyLoading()),
    error: computed(() => authOperations.hasAnyError() ? 
      (initializeOp.error.value || loginOp.error.value || registerOp.error.value || logoutOp.error.value) : null),
    userDisplay,

    // Actions
    initialize,
    login,
    register,
    logout,
    updatePassword,
    updateProfile,
    checkAuth
  }
}

// Export singleton instance for global state
export const auth = useAuth()