import { defineStore } from 'pinia'
import { ref } from 'vue'
import { API_BASE_URL } from '@/config/api'

const API_URL = API_BASE_URL

export const useAuthStore = defineStore('auth', () => {
  const user = ref(null)
  const token = ref(null)
  const isAuthenticated = ref(false)
  const isLoading = ref(false)

  /**
   * Token in localStorage speichern
   */
  const saveToken = (newToken) => {
    token.value = newToken
    localStorage.setItem('timeclock_token', newToken)
  }

  /**
   * Token aus localStorage laden
   */
  const loadToken = () => {
    const savedToken = localStorage.getItem('timeclock_token')
    if (savedToken) {
      token.value = savedToken
      return savedToken
    }
    return null
  }

  /**
   * Token und Benutzerdaten löschen
   */
  const clearAuth = () => {
    token.value = null
    user.value = null
    isAuthenticated.value = false
    localStorage.removeItem('timeclock_token')
  }

  /**
   * Registrierung
   */
  const register = async (userData) => {
    try {
      isLoading.value = true
      
      const response = await fetch(`${API_URL}/auth/register`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json'
        },
        body: JSON.stringify(userData)
      })

      const data = await response.json()

      if (!response.ok) {
        throw new Error(data.error || 'Registrierung fehlgeschlagen')
      }

      return data
    } catch (error) {
      console.error('Registrierungsfehler:', error)
      throw error
    } finally {
      isLoading.value = false
    }
  }

  /**
   * Login
   */
  const login = async (credentials) => {
    try {
      isLoading.value = true
      
      const response = await fetch(`${API_URL}/auth/login`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json'
        },
        body: JSON.stringify(credentials)
      })

      const data = await response.json()

      if (!response.ok) {
        throw new Error(data.error || 'Login fehlgeschlagen')
      }

      // Token speichern
      saveToken(data.token)
      
      // Benutzerdaten setzen
      user.value = data.user
      isAuthenticated.value = true

      return data
    } catch (error) {
      console.error('Login-Fehler:', error)
      clearAuth()
      throw error
    } finally {
      isLoading.value = false
    }
  }

  /**
   * Logout
   */
  const logout = async () => {
    try {
      if (token.value) {
        await fetch(`${API_URL}/auth/logout`, {
          method: 'POST',
          headers: {
            'Authorization': `Bearer ${token.value}`
          }
        })
      }
    } catch (error) {
      console.error('Logout-Fehler:', error)
    } finally {
      clearAuth()
    }
  }

  /**
   * Aktuellen Benutzer laden (für Session-Wiederherstellung)
   */
  const fetchCurrentUser = async () => {
    try {
      const savedToken = loadToken()
      
      if (!savedToken) {
        return false
      }

      isLoading.value = true

      const response = await fetch(`${API_URL}/auth/me`, {
        headers: {
          'Authorization': `Bearer ${savedToken}`
        }
      })

      const data = await response.json()

      if (!response.ok) {
        // Token ungültig - ausloggen
        clearAuth()
        return false
      }

      // Session wiederherstellen
      user.value = data.user
      isAuthenticated.value = true

      return true
    } catch (error) {
      console.error('Fehler beim Laden des Benutzers:', error)
      clearAuth()
      return false
    } finally {
      isLoading.value = false
    }
  }

  /**
   * Token validieren
   */
  const validateToken = async () => {
    try {
      const savedToken = loadToken()
      
      if (!savedToken) {
        return false
      }

      const response = await fetch(`${API_URL}/auth/validate`, {
        headers: {
          'Authorization': `Bearer ${savedToken}`
        }
      })

      if (!response.ok) {
        clearAuth()
        return false
      }

      return true
    } catch (error) {
      console.error('Token-Validierungsfehler:', error)
      clearAuth()
      return false
    }
  }

  /**
   * Passwort-Reset anfordern
   */
  const requestPasswordReset = async (email) => {
    try {
      isLoading.value = true
      
      const response = await fetch(`${API_URL}/auth/request-reset`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json'
        },
        body: JSON.stringify({ email })
      })

      const data = await response.json()

      if (!response.ok) {
        throw new Error(data.error || 'Anfrage fehlgeschlagen')
      }

      return data
    } catch (error) {
      console.error('Passwort-Reset-Anfrage-Fehler:', error)
      throw error
    } finally {
      isLoading.value = false
    }
  }

  /**
   * Passwort zurücksetzen
   */
  const resetPassword = async (resetToken, password) => {
    try {
      isLoading.value = true
      
      const response = await fetch(`${API_URL}/auth/reset-password`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json'
        },
        body: JSON.stringify({
          token: resetToken,
          password
        })
      })

      const data = await response.json()

      if (!response.ok) {
        throw new Error(data.error || 'Passwort-Reset fehlgeschlagen')
      }

      return data
    } catch (error) {
      console.error('Passwort-Reset-Fehler:', error)
      throw error
    } finally {
      isLoading.value = false
    }
  }

  /**
   * Passwort ändern (eingeloggter Benutzer)
   */
  const changePassword = async (oldPassword, newPassword) => {
    try {
      isLoading.value = true
      
      const response = await fetch(`${API_URL}/auth/change-password`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${token.value}`
        },
        body: JSON.stringify({
          oldPassword,
          newPassword
        })
      })

      const data = await response.json()

      if (!response.ok) {
        throw new Error(data.error || 'Passwort-Änderung fehlgeschlagen')
      }

      return data
    } catch (error) {
      console.error('Passwort-Änderungs-Fehler:', error)
      throw error
    } finally {
      isLoading.value = false
    }
  }

  /**
   * HTTP-Header mit Authorization zurückgeben
   */
  const getAuthHeaders = () => {
    const savedToken = token.value || loadToken()
    
    if (savedToken) {
      return {
        'Authorization': `Bearer ${savedToken}`,
        'Content-Type': 'application/json'
      }
    }
    
    return {
      'Content-Type': 'application/json'
    }
  }

  return {
    // State
    user,
    token,
    isAuthenticated,
    isLoading,
    
    // Actions
    register,
    login,
    logout,
    fetchCurrentUser,
    validateToken,
    requestPasswordReset,
    resetPassword,
    changePassword,
    getAuthHeaders,
    loadToken,
    saveToken,
    clearAuth
  }
})