<template>
  <AuthLayout>
    <div class="space-y-6">
      <!-- Title -->
      <div class="text-center">
        <h2 class="text-2xl font-bold text-gray-900 dark:text-white">
          {{ t('auth.createAccount') }}
        </h2>
        <p class="mt-2 text-sm text-gray-500 dark:text-dark-400">
          {{ t('auth.signUpToStart', { siteName }) }}
        </p>
      </div>

      <!-- LinuxDo Connect OAuth 登录 -->
      <LinuxDoOAuthSection v-if="linuxdoOAuthEnabled" :disabled="isLoading" />

      <!-- Registration Disabled Message -->
      <div
        v-if="!registrationEnabled && settingsLoaded"
        class="rounded-xl border border-amber-200 bg-amber-50 p-4 dark:border-amber-800/50 dark:bg-amber-900/20"
      >
        <div class="flex items-start gap-3">
          <div class="flex-shrink-0">
            <Icon name="exclamationCircle" size="md" class="text-amber-500" />
          </div>
          <p class="text-sm text-amber-700 dark:text-amber-400">
            {{ t('auth.registrationDisabled') }}
          </p>
        </div>
      </div>

      <!-- Registration Form -->
      <form v-else @submit.prevent="handleRegister" class="space-y-5">
        <!-- Email Input -->
        <div>
          <label for="email" class="input-label">
            {{ t('auth.emailLabel') }}
          </label>
          <div class="relative">
            <div class="pointer-events-none absolute inset-y-0 left-0 flex items-center pl-3.5">
              <Icon name="mail" size="md" class="text-gray-400 dark:text-dark-500" />
            </div>
            <input
              id="email"
              v-model="formData.email"
              type="email"
              required
              autofocus
              autocomplete="email"
              :disabled="isLoading"
              class="input pl-11"
              :class="{ 'input-error': errors.email }"
              :placeholder="t('auth.emailPlaceholder')"
            />
          </div>
          <p v-if="errors.email" class="input-error-text">
            {{ errors.email }}
          </p>
        </div>

        <!-- Password Input -->
        <div>
          <label for="password" class="input-label">
            {{ t('auth.passwordLabel') }}
          </label>
          <div class="relative">
            <div class="pointer-events-none absolute inset-y-0 left-0 flex items-center pl-3.5">
              <Icon name="lock" size="md" class="text-gray-400 dark:text-dark-500" />
            </div>
            <input
              id="password"
              v-model="formData.password"
              :type="showPassword ? 'text' : 'password'"
              required
              autocomplete="new-password"
              :disabled="isLoading"
              class="input pl-11 pr-11"
              :class="{ 'input-error': errors.password }"
              :placeholder="t('auth.createPasswordPlaceholder')"
            />
            <button
              type="button"
              @click="showPassword = !showPassword"
              class="absolute inset-y-0 right-0 flex items-center pr-3.5 text-gray-400 transition-colors hover:text-gray-600 dark:hover:text-dark-300"
            >
              <Icon v-if="showPassword" name="eyeOff" size="md" />
              <Icon v-else name="eye" size="md" />
            </button>
          </div>
          <p v-if="errors.password" class="input-error-text">
            {{ errors.password }}
          </p>
          <p v-else class="input-hint">
            {{ t('auth.passwordHint') }}
          </p>
        </div>

        <!-- Invitation Code Input (Required when enabled) -->
        <div v-if="invitationCodeEnabled">
          <label for="invitation_code" class="input-label">
            {{ t('auth.invitationCodeLabel') }}
          </label>
          <div class="relative">
            <div class="pointer-events-none absolute inset-y-0 left-0 flex items-center pl-3.5">
              <Icon name="key" size="md" :class="invitationValidation.valid ? 'text-green-500' : 'text-gray-400 dark:text-dark-500'" />
            </div>
            <input
              id="invitation_code"
              v-model="formData.invitation_code"
              type="text"
              :disabled="isLoading"
              class="input pl-11 pr-10"
              :class="{
                'border-green-500 focus:border-green-500 focus:ring-green-500': invitationValidation.valid,
                'border-red-500 focus:border-red-500 focus:ring-red-500': invitationValidation.invalid || errors.invitation_code
              }"
              :placeholder="t('auth.invitationCodePlaceholder')"
              @input="handleInvitationCodeInput"
            />
            <!-- Validation indicator -->
            <div v-if="invitationValidating" class="absolute inset-y-0 right-0 flex items-center pr-3.5">
              <svg class="h-4 w-4 animate-spin text-gray-400" fill="none" viewBox="0 0 24 24">
                <circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"></circle>
                <path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"></path>
              </svg>
            </div>
            <div v-else-if="invitationValidation.valid" class="absolute inset-y-0 right-0 flex items-center pr-3.5">
              <Icon name="checkCircle" size="md" class="text-green-500" />
            </div>
            <div v-else-if="invitationValidation.invalid || errors.invitation_code" class="absolute inset-y-0 right-0 flex items-center pr-3.5">
              <Icon name="exclamationCircle" size="md" class="text-red-500" />
            </div>
          </div>
          <!-- Invitation code validation result -->
          <transition name="fade">
            <div v-if="invitationValidation.valid" class="mt-2 flex items-center gap-2 rounded-lg bg-green-50 px-3 py-2 dark:bg-green-900/20">
              <Icon name="checkCircle" size="sm" class="text-green-600 dark:text-green-400" />
              <span class="text-sm text-green-700 dark:text-green-400">
                {{ t('auth.invitationCodeValid') }}
              </span>
            </div>
            <p v-else-if="invitationValidation.invalid" class="input-error-text">
              {{ invitationValidation.message }}
            </p>
            <p v-else-if="errors.invitation_code" class="input-error-text">
              {{ errors.invitation_code }}
            </p>
          </transition>
        </div>

        <!-- Promo Code Input (Optional) -->
        <div v-if="promoCodeEnabled">
          <label for="promo_code" class="input-label">
            {{ t('auth.promoCodeLabel') }}
            <span class="ml-1 text-xs font-normal text-gray-400 dark:text-dark-500">({{ t('common.optional') }})</span>
          </label>
          <div class="relative">
            <div class="pointer-events-none absolute inset-y-0 left-0 flex items-center pl-3.5">
              <Icon name="gift" size="md" :class="promoValidation.valid ? 'text-green-500' : 'text-gray-400 dark:text-dark-500'" />
            </div>
            <input
              id="promo_code"
              v-model="formData.promo_code"
              type="text"
              :disabled="isLoading"
              class="input pl-11 pr-10"
              :class="{
                'border-green-500 focus:border-green-500 focus:ring-green-500': promoValidation.valid,
                'border-red-500 focus:border-red-500 focus:ring-red-500': promoValidation.invalid
              }"
              :placeholder="t('auth.promoCodePlaceholder')"
              @input="handlePromoCodeInput"
            />
            <!-- Validation indicator -->
            <div v-if="promoValidating" class="absolute inset-y-0 right-0 flex items-center pr-3.5">
              <svg class="h-4 w-4 animate-spin text-gray-400" fill="none" viewBox="0 0 24 24">
                <circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"></circle>
                <path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"></path>
              </svg>
            </div>
            <div v-else-if="promoValidation.valid" class="absolute inset-y-0 right-0 flex items-center pr-3.5">
              <Icon name="checkCircle" size="md" class="text-green-500" />
            </div>
            <div v-else-if="promoValidation.invalid" class="absolute inset-y-0 right-0 flex items-center pr-3.5">
              <Icon name="exclamationCircle" size="md" class="text-red-500" />
            </div>
          </div>
          <!-- Promo code validation result -->
          <transition name="fade">
            <div v-if="promoValidation.valid" class="mt-2 flex items-center gap-2 rounded-lg bg-green-50 px-3 py-2 dark:bg-green-900/20">
              <Icon name="gift" size="sm" class="text-green-600 dark:text-green-400" />
              <span class="text-sm text-green-700 dark:text-green-400">
                {{ t('auth.promoCodeValid', { amount: promoValidation.bonusAmount?.toFixed(2) }) }}
              </span>
            </div>
            <p v-else-if="promoValidation.invalid" class="input-error-text">
              {{ promoValidation.message }}
            </p>
          </transition>
        </div>

        <!-- Turnstile Widget -->
        <div v-if="turnstileEnabled && turnstileSiteKey">
          <TurnstileWidget
            ref="turnstileRef"
            :site-key="turnstileSiteKey"
            @verify="onTurnstileVerify"
            @expire="onTurnstileExpire"
            @error="onTurnstileError"
          />
          <p v-if="errors.turnstile" class="input-error-text mt-2 text-center">
            {{ errors.turnstile }}
          </p>
        </div>

        <!-- Error Message -->
        <transition name="fade">
          <div
            v-if="errorMessage"
            class="rounded-xl border border-red-200 bg-red-50 p-4 dark:border-red-800/50 dark:bg-red-900/20"
          >
            <div class="flex items-start gap-3">
              <div class="flex-shrink-0">
                <Icon name="exclamationCircle" size="md" class="text-red-500" />
              </div>
              <p class="text-sm text-red-700 dark:text-red-400">
                {{ errorMessage }}
              </p>
            </div>
          </div>
        </transition>

        <!-- Submit Button -->
        <button
          type="submit"
          :disabled="isLoading || (turnstileEnabled && !turnstileToken)"
          class="btn btn-primary w-full"
        >
          <svg
            v-if="isLoading"
            class="-ml-1 mr-2 h-4 w-4 animate-spin text-white"
            fill="none"
            viewBox="0 0 24 24"
          >
            <circle
              class="opacity-25"
              cx="12"
              cy="12"
              r="10"
              stroke="currentColor"
              stroke-width="4"
            ></circle>
            <path
              class="opacity-75"
              fill="currentColor"
              d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"
            ></path>
          </svg>
          <Icon v-else name="userPlus" size="md" class="mr-2" />
          {{
            isLoading
              ? t('auth.processing')
              : emailVerifyEnabled
                ? t('auth.continue')
                : t('auth.createAccount')
          }}
        </button>
      </form>
    </div>

    <!-- Footer -->
    <template #footer>
      <p class="text-gray-500 dark:text-dark-400">
        {{ t('auth.alreadyHaveAccount') }}
        <router-link
          to="/login"
          class="font-medium text-primary-600 transition-colors hover:text-primary-500 dark:text-primary-400 dark:hover:text-primary-300"
        >
          {{ t('auth.signIn') }}
        </router-link>
      </p>
    </template>
  </AuthLayout>
</template>

<script setup lang="ts">
import { ref, reactive, onMounted, onUnmounted } from 'vue'
import { useRouter, useRoute } from 'vue-router'
import { useI18n } from 'vue-i18n'
import { AuthLayout } from '@/components/layout'
import LinuxDoOAuthSection from '@/components/auth/LinuxDoOAuthSection.vue'
import Icon from '@/components/icons/Icon.vue'
import TurnstileWidget from '@/components/TurnstileWidget.vue'
import { useAuthStore, useAppStore } from '@/stores'
import { getPublicSettings, validatePromoCode, validateInvitationCode } from '@/api/auth'
import { buildAuthErrorMessage } from '@/utils/authError'
import {
  isRegistrationEmailSuffixAllowed,
  normalizeRegistrationEmailSuffixWhitelist
} from '@/utils/registrationEmailPolicy'

const { t, locale } = useI18n()

// ==================== Router & Stores ====================

const router = useRouter()
const route = useRoute()
const authStore = useAuthStore()
const appStore = useAppStore()

// ==================== State ====================

const isLoading = ref<boolean>(false)
const settingsLoaded = ref<boolean>(false)
const errorMessage = ref<string>('')
const showPassword = ref<boolean>(false)

// Public settings
const registrationEnabled = ref<boolean>(true)
const emailVerifyEnabled = ref<boolean>(false)
const promoCodeEnabled = ref<boolean>(true)
const invitationCodeEnabled = ref<boolean>(false)
const turnstileEnabled = ref<boolean>(false)
const turnstileSiteKey = ref<string>('')
const siteName = ref<string>('Sub2API')
const linuxdoOAuthEnabled = ref<boolean>(false)
const registrationEmailSuffixWhitelist = ref<string[]>([])

// Turnstile
const turnstileRef = ref<InstanceType<typeof TurnstileWidget> | null>(null)
const turnstileToken = ref<string>('')

// Promo code validation
const promoValidating = ref<boolean>(false)
const promoValidation = reactive({
  valid: false,
  invalid: false,
  bonusAmount: null as number | null,
  message: ''
})
let promoValidateTimeout: ReturnType<typeof setTimeout> | null = null

// Invitation code validation
const invitationValidating = ref<boolean>(false)
const invitationValidation = reactive({
  valid: false,
  invalid: false,
  message: ''
})
let invitationValidateTimeout: ReturnType<typeof setTimeout> | null = null

const formData = reactive({
  email: '',
  password: '',
  promo_code: '',
  invitation_code: ''
})

const errors = reactive({
  email: '',
  password: '',
  turnstile: '',
  invitation_code: ''
})

// ==================== Lifecycle ====================

onMounted(async () => {
  try {
    const settings = await getPublicSettings()
    registrationEnabled.value = settings.registration_enabled
    emailVerifyEnabled.value = settings.email_verify_enabled
    promoCodeEnabled.value = settings.promo_code_enabled
    invitationCodeEnabled.value = settings.invitation_code_enabled
    turnstileEnabled.value = settings.turnstile_enabled
    turnstileSiteKey.value = settings.turnstile_site_key || ''
    siteName.value = settings.site_name || 'Sub2API'
    linuxdoOAuthEnabled.value = settings.linuxdo_oauth_enabled
    registrationEmailSuffixWhitelist.value = normalizeRegistrationEmailSuffixWhitelist(
      settings.registration_email_suffix_whitelist || []
    )

    // Read promo code from URL parameter only if promo code is enabled
    if (promoCodeEnabled.value) {
      const promoParam = route.query.promo as string
      if (promoParam) {
        formData.promo_code = promoParam
        // Validate the promo code from URL
        await validatePromoCodeDebounced(promoParam)
      }
    }
  } catch (error) {
    console.error('Failed to load public settings:', error)
  } finally {
    settingsLoaded.value = true
  }
})

onUnmounted(() => {
  if (promoValidateTimeout) {
    clearTimeout(promoValidateTimeout)
  }
  if (invitationValidateTimeout) {
    clearTimeout(invitationValidateTimeout)
  }
})

// ==================== Promo Code Validation ====================

function handlePromoCodeInput(): void {
  const code = formData.promo_code.trim()

  // Clear previous validation
  promoValidation.valid = false
  promoValidation.invalid = false
  promoValidation.bonusAmount = null
  promoValidation.message = ''

  if (!code) {
    promoValidating.value = false
    return
  }

  // Debounce validation
  if (promoValidateTimeout) {
    clearTimeout(promoValidateTimeout)
  }

  promoValidateTimeout = setTimeout(() => {
    validatePromoCodeDebounced(code)
  }, 500)
}

async function validatePromoCodeDebounced(code: string): Promise<void> {
  if (!code.trim()) return

  promoValidating.value = true

  try {
    const result = await validatePromoCode(code)

    if (result.valid) {
      promoValidation.valid = true
      promoValidation.invalid = false
      promoValidation.bonusAmount = result.bonus_amount || 0
      promoValidation.message = ''
    } else {
      promoValidation.valid = false
      promoValidation.invalid = true
      promoValidation.bonusAmount = null
      // 根据错误码显示对应的翻译
      promoValidation.message = getPromoErrorMessage(result.error_code)
    }
  } catch (error) {
    console.error('Failed to validate promo code:', error)
    promoValidation.valid = false
    promoValidation.invalid = true
    promoValidation.message = t('auth.promoCodeInvalid')
  } finally {
    promoValidating.value = false
  }
}

function getPromoErrorMessage(errorCode?: string): string {
  switch (errorCode) {
    case 'PROMO_CODE_NOT_FOUND':
      return t('auth.promoCodeNotFound')
    case 'PROMO_CODE_EXPIRED':
      return t('auth.promoCodeExpired')
    case 'PROMO_CODE_DISABLED':
      return t('auth.promoCodeDisabled')
    case 'PROMO_CODE_MAX_USED':
      return t('auth.promoCodeMaxUsed')
    case 'PROMO_CODE_ALREADY_USED':
      return t('auth.promoCodeAlreadyUsed')
    default:
      return t('auth.promoCodeInvalid')
  }
}

// ==================== Invitation Code Validation ====================

function handleInvitationCodeInput(): void {
  const code = formData.invitation_code.trim()

  // Clear previous validation
  invitationValidation.valid = false
  invitationValidation.invalid = false
  invitationValidation.message = ''
  errors.invitation_code = ''

  if (!code) {
    return
  }

  // Debounce validation
  if (invitationValidateTimeout) {
    clearTimeout(invitationValidateTimeout)
  }

  invitationValidateTimeout = setTimeout(() => {
    validateInvitationCodeDebounced(code)
  }, 500)
}

async function validateInvitationCodeDebounced(code: string): Promise<void> {
  invitationValidating.value = true

  try {
    const result = await validateInvitationCode(code)

    if (result.valid) {
      invitationValidation.valid = true
      invitationValidation.invalid = false
      invitationValidation.message = ''
    } else {
      invitationValidation.valid = false
      invitationValidation.invalid = true
      invitationValidation.message = getInvitationErrorMessage(result.error_code)
    }
  } catch {
    invitationValidation.valid = false
    invitationValidation.invalid = true
    invitationValidation.message = t('auth.invitationCodeInvalid')
  } finally {
    invitationValidating.value = false
  }
}

function getInvitationErrorMessage(errorCode?: string): string {
  switch (errorCode) {
    case 'INVITATION_CODE_NOT_FOUND':
      return t('auth.invitationCodeInvalid')
    case 'INVITATION_CODE_INVALID':
      return t('auth.invitationCodeInvalid')
    case 'INVITATION_CODE_USED':
      return t('auth.invitationCodeInvalid')
    case 'INVITATION_CODE_DISABLED':
      return t('auth.invitationCodeInvalid')
    default:
      return t('auth.invitationCodeInvalid')
  }
}

// ==================== Turnstile Handlers ====================

function onTurnstileVerify(token: string): void {
  turnstileToken.value = token
  errors.turnstile = ''
}

function onTurnstileExpire(): void {
  turnstileToken.value = ''
  errors.turnstile = t('auth.turnstileExpired')
}

function onTurnstileError(): void {
  turnstileToken.value = ''
  errors.turnstile = t('auth.turnstileFailed')
}

// ==================== Validation ====================

function validateEmail(email: string): boolean {
  const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/
  return emailRegex.test(email)
}

function buildEmailSuffixNotAllowedMessage(): string {
  const normalizedWhitelist = normalizeRegistrationEmailSuffixWhitelist(
    registrationEmailSuffixWhitelist.value
  )
  if (normalizedWhitelist.length === 0) {
    return t('auth.emailSuffixNotAllowed')
  }
  const separator = String(locale.value || '').toLowerCase().startsWith('zh') ? '、' : ', '
  return t('auth.emailSuffixNotAllowedWithAllowed', {
    suffixes: normalizedWhitelist.join(separator)
  })
}

function validateForm(): boolean {
  // Reset errors
  errors.email = ''
  errors.password = ''
  errors.turnstile = ''
  errors.invitation_code = ''

  let isValid = true

  // Email validation
  if (!formData.email.trim()) {
    errors.email = t('auth.emailRequired')
    isValid = false
  } else if (!validateEmail(formData.email)) {
    errors.email = t('auth.invalidEmail')
    isValid = false
  } else if (
    !isRegistrationEmailSuffixAllowed(formData.email, registrationEmailSuffixWhitelist.value)
  ) {
    errors.email = buildEmailSuffixNotAllowedMessage()
    isValid = false
  }

  // Password validation
  if (!formData.password) {
    errors.password = t('auth.passwordRequired')
    isValid = false
  } else if (formData.password.length < 6) {
    errors.password = t('auth.passwordMinLength')
    isValid = false
  }

  // Invitation code validation (required when enabled)
  if (invitationCodeEnabled.value) {
    if (!formData.invitation_code.trim()) {
      errors.invitation_code = t('auth.invitationCodeRequired')
      isValid = false
    }
  }

  // Turnstile validation
  if (turnstileEnabled.value && !turnstileToken.value) {
    errors.turnstile = t('auth.completeVerification')
    isValid = false
  }

  return isValid
}

// ==================== Form Handlers ====================

async function handleRegister(): Promise<void> {
  // Clear previous error
  errorMessage.value = ''

  // Validate form
  if (!validateForm()) {
    return
  }

  // Check promo code validation status
  if (formData.promo_code.trim()) {
    // If promo code is being validated, wait
    if (promoValidating.value) {
      errorMessage.value = t('auth.promoCodeValidating')
      return
    }
    // If promo code is invalid, block submission
    if (promoValidation.invalid) {
      errorMessage.value = t('auth.promoCodeInvalidCannotRegister')
      return
    }
  }

  // Check invitation code validation status (if enabled and code provided)
  if (invitationCodeEnabled.value) {
    // If still validating, wait
    if (invitationValidating.value) {
      errorMessage.value = t('auth.invitationCodeValidating')
      return
    }
    // If invitation code is invalid, block submission
    if (invitationValidation.invalid) {
      errorMessage.value = t('auth.invitationCodeInvalidCannotRegister')
      return
    }
    // If invitation code is required but not validated yet
    if (formData.invitation_code.trim() && !invitationValidation.valid) {
      errorMessage.value = t('auth.invitationCodeValidating')
      // Trigger validation
      await validateInvitationCodeDebounced(formData.invitation_code.trim())
      if (!invitationValidation.valid) {
        errorMessage.value = t('auth.invitationCodeInvalidCannotRegister')
        return
      }
    }
  }

  isLoading.value = true

  try {
    // If email verification is enabled, redirect to verification page
    if (emailVerifyEnabled.value) {
      // Store registration data in sessionStorage
      sessionStorage.setItem(
        'register_data',
        JSON.stringify({
          email: formData.email,
          password: formData.password,
          turnstile_token: turnstileToken.value,
          promo_code: formData.promo_code || undefined,
          invitation_code: formData.invitation_code || undefined
        })
      )

      // Navigate to email verification page
      await router.push('/email-verify')
      return
    }

    // Otherwise, directly register
    await authStore.register({
      email: formData.email,
      password: formData.password,
      turnstile_token: turnstileEnabled.value ? turnstileToken.value : undefined,
      promo_code: formData.promo_code || undefined,
      invitation_code: formData.invitation_code || undefined
    })

    // Show success toast
    appStore.showSuccess(t('auth.accountCreatedSuccess', { siteName: siteName.value }))

    // Redirect to dashboard
    await router.push('/dashboard')
  } catch (error: unknown) {
    // Reset Turnstile on error
    if (turnstileRef.value) {
      turnstileRef.value.reset()
      turnstileToken.value = ''
    }

    // Handle registration error
    errorMessage.value = buildAuthErrorMessage(error, {
      fallback: t('auth.registrationFailed')
    })

    // Also show error toast
    appStore.showError(errorMessage.value)
  } finally {
    isLoading.value = false
  }
}
</script>

<style scoped>
.fade-enter-active,
.fade-leave-active {
  transition: all 0.3s ease;
}

.fade-enter-from,
.fade-leave-to {
  opacity: 0;
  transform: translateY(-8px);
}
</style>
