import { computed, ref, watch } from 'vue'
import { storeToRefs } from 'pinia'
import { useAuthStore, type AuthUser } from '~/stores/auth'
import type { AuthClient, AuthMode } from '~/types/auth'

function normalizeAuthMode(value: string | undefined): AuthMode {
  if (value === 'mock' || value === 'userinfo') {
    return value
  }

  return 'disabled'
}

function createMockUser(): AuthUser {
  return {
    id: 'mock-user',
    email: 'mock@example.com',
    firstName: 'Mock',
    lastName: 'User',
    roles: ['USER']
  }
}

function canUseWindow() {
  return typeof window !== 'undefined'
}

export default defineNuxtPlugin(() => {
  const runtimeConfig = useRuntimeConfig()
  const authStore = useAuthStore()
  const { isAuthenticated, isInitialized, user } = storeToRefs(authStore)

  const mode = normalizeAuthMode(runtimeConfig.public.authMode)
  const ready = ref(false)

  const initialize = async () => {
    if (ready.value) {
      return
    }

    if (mode === 'disabled') {
      authStore.initialize(null)
      ready.value = true
      return
    }

    if (mode === 'mock') {
      authStore.initialize(createMockUser())
      ready.value = true
      return
    }

    try {
      const authUser = await $fetch<AuthUser | null>(runtimeConfig.public.authUserinfoUrl, {
        credentials: 'include'
      })

      authStore.initialize(authUser)
    } catch {
      authStore.initialize(null)
    }

    ready.value = true
  }

  watch(
    isInitialized,
    (value) => {
      if (value) {
        ready.value = true
      }
    },
    { immediate: true }
  )

  const login = () => {
    if (mode === 'disabled') {
      return
    }

    if (mode === 'mock') {
      authStore.setUser(createMockUser())
      return
    }

    if (canUseWindow()) {
      window.location.href = runtimeConfig.public.authLoginUrl
    }
  }

  const logout = () => {
    authStore.clearSession()

    if (mode === 'disabled') {
      return
    }

    if (mode === 'mock') {
      return
    }

    if (canUseWindow()) {
      window.location.href = runtimeConfig.public.authLogoutUrl
    }
  }

  const auth: AuthClient = {
    mode,
    isEnabled: mode !== 'disabled',
    isReady: ready,
    isAuthenticated: computed(() => isAuthenticated.value),
    user,
    ensureInitialized: initialize,
    login,
    logout
  }

  return {
    provide: {
      auth
    }
  }
})