<template>
  <div class="setup-screen">
    <!-- macOS Style Background -->
    <div class="background-image">
      <div class="blur-overlay"></div>
      <div class="gradient-overlay"></div>
    </div>

    <!-- Glass Layer -->
    <div class="glass-layer"></div>

    <!-- Setup Content -->
    <div class="setup-content">
      <!-- Setup Header -->
      <div class="setup-header">
        <div class="setup-icon">👤</div>
        <h1 class="setup-title">{{ $t('auth.register.title') }}</h1>
        <p class="setup-subtitle">{{ $t('auth.register.subtitle') }}</p>
      </div>

      <!-- Setup Form -->
      <div class="setup-form">
        <form @submit.prevent="handleRegister" class="form">
          <!-- Full Name Field -->
          <div class="form-field">
            <input
              v-model="form.fullName"
              type="text"
              :placeholder="$t('auth.register.fullNamePlaceholder')"
              class="setup-input"
              :class="{ 'error': errors.fullName }"
              required
            />
          </div>

          <!-- Email Field -->
          <div class="form-field">
            <input
              v-model="form.email"
              type="email"
              :placeholder="$t('auth.register.emailPlaceholder')"
              class="setup-input"
              :class="{ 'error': errors.email }"
              required
            />
          </div>

          <!-- Password Field -->
          <div class="form-field">
            <input
              v-model="form.password"
              type="password"
              :placeholder="$t('auth.register.passwordPlaceholder')"
              class="setup-input"
              :class="{ 'error': errors.password }"
              required
            />
          </div>

          <!-- Confirm Password Field -->
          <div class="form-field">
            <input
              v-model="form.confirmPassword"
              type="password"
              :placeholder="$t('auth.register.confirmPasswordPlaceholder')"
              class="setup-input"
              :class="{ 'error': errors.confirmPassword }"
              required
            />
          </div>

          <!-- Terms and Conditions -->
          <div class="terms-section">
            <label class="terms-label">
              <input v-model="form.agreeTerms" type="checkbox" class="terms-checkbox" required />
              <span class="terms-text">
                {{ $t('auth.register.agreeTerms') }}
                <button type="button" class="terms-link" @click="showTerms">
                  {{ $t('auth.register.termsAndConditions') }}
                </button>
              </span>
            </label>
          </div>

          <!-- Unified Error Messages -->
          <div class="error-messages">
            <div v-if="errors.fullName" class="error-message">{{ errors.fullName }}</div>
            <div v-if="errors.email" class="error-message">{{ errors.email }}</div>
            <div v-if="errors.password" class="error-message">{{ errors.password }}</div>
            <div v-if="errors.confirmPassword" class="error-message">{{ errors.confirmPassword }}</div>
          </div>

          <!-- Submit Button -->
          <button type="submit" class="setup-button" :disabled="isLoading">
            <span v-if="isLoading" class="loading-spinner"></span>
            {{ isLoading ? $t('auth.common.loading') : $t('auth.register.registerButton') }}
          </button>
        </form>

        <!-- Sign In Link -->
        <div class="setup-footer">
          <p class="footer-text">
            {{ $t('auth.register.hasAccount') }}
            <button class="footer-link" @click="goToLogin">
              {{ $t('auth.register.signIn') }}
            </button>
          </p>
        </div>
      </div>
    </div>

    <!-- Status Bar -->
    <div class="status-bar">
      <div class="status-left">
        <!-- Empty for now -->
      </div>
      <div class="status-center">
        <!-- Empty for now -->
      </div>
      <div class="status-right">
        <!-- Language Toggle -->
        <div class="language-switcher-wrapper" ref="languageSwitcherWrapper">
          <button @click="toggleLanguageMenu" class="language-switcher">
            {{ currentLanguageDisplay }}
          </button>
          <div v-if="isLanguageMenuOpen" class="language-menu">
            <ul>
              <li v-for="lang in availableLanguages" :key="lang.key" @click="selectLanguage(lang.key as 'en' | 'zh')">
                <span class="checkmark" :style="{ visibility: locale === lang.key ? 'visible' : 'hidden' }">✓</span>
                <span>{{ lang.label }}</span>
              </li>
            </ul>
          </div>
        </div>
      </div>
    </div>
  </div>
</template>

<script setup lang="ts">
import { ref, reactive, computed, onMounted, onUnmounted, watch } from 'vue';
import { useRouter } from 'vue-router';
import { useI18n } from 'vue-i18n';

const router = useRouter();
const { t, locale, setLocale } = useI18n();

// Form data
const form = reactive({
  fullName: '',
  email: '',
  password: '',
  confirmPassword: '',
  agreeTerms: false
});

// Form validation
const errors = reactive({
  fullName: '',
  email: '',
  password: '',
  confirmPassword: ''
});

// Loading state
const isLoading = ref(false);

// --- Language Switcher Logic ---
const isLanguageMenuOpen = ref(false);
const languageSwitcherWrapper = ref<HTMLElement | null>(null);
const availableLanguages = computed(() => [
  { key: 'en', label: 'English', display: 'EN' },
  { key: 'zh', label: '繁體中文', display: '注' },
]);

const currentLanguageDisplay = computed(() => {
  const current = availableLanguages.value.find(lang => lang.key === locale.value);
  return current?.display || '注';
});

// Validation functions
const validateEmail = (email: string) => {
  const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
  return emailRegex.test(email);
};

const validateForm = () => {
  errors.fullName = '';
  errors.email = '';
  errors.password = '';
  errors.confirmPassword = '';

  if (!form.fullName) {
    errors.fullName = t('auth.common.required');
    return false;
  }
  if (!form.email) {
    errors.email = t('auth.common.required');
    return false;
  }
  if (!validateEmail(form.email)) {
    errors.email = t('auth.common.invalidEmail');
    return false;
  }
  if (!form.password) {
    errors.password = t('auth.common.required');
    return false;
  }
  if (form.password.length < 8) {
    errors.password = t('auth.common.passwordTooShort');
    return false;
  }
  if (!form.confirmPassword) {
    errors.confirmPassword = t('auth.common.required');
    return false;
  }
  if (form.password !== form.confirmPassword) {
    errors.confirmPassword = t('auth.common.passwordsDoNotMatch');
    return false;
  }
  if (!form.agreeTerms) {
    alert(t('auth.common.required'));
    return false;
  }

  return true;
};

// Event handlers
const handleRegister = async () => {
  if (!validateForm()) return;

  isLoading.value = true;
  
  try {
    // Simulate API call
    await new Promise(resolve => setTimeout(resolve, 2000));
    
    // Success - redirect to home
    router.push('/');
  } catch (error) {
    console.error('Registration error:', error);
  } finally {
    isLoading.value = false;
  }
};

const showTerms = () => {
  // TODO: Implement terms and conditions modal
  alert('Terms and Conditions coming soon!');
};

const goToLogin = () => {
  router.push('/login');
};

const goHome = () => {
  router.push('/');
};

// Language switcher functions
function toggleLanguageMenu() {
  isLanguageMenuOpen.value = !isLanguageMenuOpen.value;
}

function selectLanguage(lang: 'en' | 'zh') {
  setLocale(lang);
  isLanguageMenuOpen.value = false;
}

const handleClickOutside = (event: MouseEvent) => {
  if (languageSwitcherWrapper.value && !languageSwitcherWrapper.value.contains(event.target as Node)) {
    isLanguageMenuOpen.value = false;
  }
};

// Lifecycle
onMounted(() => {
  // Add any initialization logic here
});

onUnmounted(() => {
  document.removeEventListener('click', handleClickOutside);
});

// Watch for language menu state
watch(isLanguageMenuOpen, (isOpen) => {
  if (isOpen) {
    document.addEventListener('click', handleClickOutside);
  } else {
    document.removeEventListener('click', handleClickOutside);
  }
});
</script>

<style scoped>
.setup-screen {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.background-image {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, 
    #f8fafc 0%, 
    #e2e8f0 25%, 
    #cbd5e1 50%, 
    #94a3b8 75%, 
    #64748b 100%);
  background-size: 400% 400%;
  animation: gradient-shift 15s ease infinite;
  z-index: 0;
}

.glass-layer {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  z-index: 1;
}

@keyframes gradient-shift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.blur-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

.gradient-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    180deg,
    rgba(0, 0, 0, 0.1) 0%,
    rgba(0, 0, 0, 0.3) 50%,
    rgba(0, 0, 0, 0.6) 100%
  );
}

.setup-content {
  position: relative;
  z-index: 2;
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 60px 40px 40px;
  color: white;
  min-height: 100vh;
  box-sizing: border-box;
}

.setup-header {
  text-align: center;
  margin-bottom: 40px;
  position: relative;
  width: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

.setup-icon {
  font-size: 4rem;
  margin-bottom: 20px;
  filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.3));
}

.setup-title {
  font-size: 2.5rem;
  font-weight: 300;
  margin-bottom: 12px;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
  line-height: 1.2;
}

.setup-subtitle {
  font-size: 1.2rem;
  font-weight: 300;
  opacity: 0.9;
  text-shadow: 0 1px 10px rgba(0, 0, 0, 0.3);
  line-height: 1.4;
}

.setup-form {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  position: relative;
  width: 100%;
  max-width: 400px;
  justify-content: center;
}

.form {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  width: 100%;
}

.form-field {
  width: 100%;
  position: relative;
}

.setup-input {
  width: 100%;
  height: 50px;
  padding: 14px 24px;
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(20px);
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 50px;
  color: white;
  font-size: 1rem;
  font-weight: 300;
  text-align: center;
  outline: none;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
  transition: all 0.3s ease;
  box-sizing: border-box;
}

.setup-input::placeholder {
  color: rgba(255, 255, 255, 0.7);
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.setup-input:focus {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.5);
  outline: none;
}

.setup-input.error {
  border-color: #ff6b6b;
  background: rgba(255, 107, 107, 0.2);
  animation: shake 0.5s ease-in-out;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-10px); }
  75% { transform: translateX(10px); }
}

.terms-section {
  width: 100%;
  margin: 8px 0;
}

.terms-label {
  display: flex;
  align-items: flex-start;
  cursor: pointer;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.8);
  line-height: 1.4;
  text-align: center;
  justify-content: center;
}

.terms-checkbox {
  margin-right: 8px;
  margin-top: 2px;
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.terms-text {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
}

.terms-link {
  background: none;
  border: none;
  color: rgba(255, 255, 255, 0.9);
  font-size: 0.9rem;
  cursor: pointer;
  text-decoration: underline;
  margin-left: 4px;
}

.terms-link:hover {
  color: white;
}

.error-messages {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  margin-top: 12px;
  min-height: 20px;
}

.error-message {
  font-size: 0.9rem;
  color: #ff6b6b;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.5);
  text-align: center;
  white-space: nowrap;
}

.setup-button {
  width: 100%;
  height: 50px;
  padding: 14px 24px;
  background: rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(20px);
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 50px;
  color: white;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  outline: none;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.setup-button:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.3);
  border-color: rgba(255, 255, 255, 0.5);
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
}

.setup-button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.loading-spinner {
  width: 20px;
  height: 20px;
  border: 2px solid transparent;
  border-top: 2px solid currentColor;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.setup-footer {
  margin-top: 24px;
  text-align: center;
}

.footer-text {
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.8);
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.5);
}

.footer-link {
  background: none;
  border: none;
  color: rgba(255, 255, 255, 0.9);
  font-size: 0.9rem;
  cursor: pointer;
  text-decoration: underline;
  margin-left: 4px;
}

.footer-link:hover {
  color: white;
}

.status-bar {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 22px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 20px;
  background: var(--taskbar-background);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  color: var(--taskbar-item-text-color);
  font-size: 12px;
  font-weight: 500;
  z-index: 2;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.status-left,
.status-center,
.status-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.language-switcher-wrapper {
  position: relative;
}

.language-switcher {
  background: none;
  border: none;
  color: var(--taskbar-item-text-color);
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  padding: 0 4px;
  width: 24px;
  height: 22px;
  text-align: center;
  line-height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.language-menu {
  position: absolute;
  top: calc(100% + 4px);
  right: 0;
  width: 160px;
  background-color: var(--start-menu-background);
  border: 1px solid var(--start-menu-border-color);
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
  padding: 4px;
  z-index: 10001;
}

.language-menu ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.language-menu li {
  display: flex;
  align-items: center;
  padding: 4px 8px;
  border-radius: 4px;
  cursor: pointer;
  transition: background-color 0.15s ease-in-out;
}

.language-menu li:hover {
  background-color: var(--taskbar-item-background-hover);
}

.checkmark {
  width: 16px;
  text-align: center;
  margin-right: 4px;
}

/* Responsive Design */
@media (max-width: 768px) {
  .setup-content {
    padding: 60px 20px 20px;
  }
  
  .setup-title {
    font-size: 2rem;
  }
  
  .setup-subtitle {
    font-size: 1rem;
  }
  
  .setup-icon {
    font-size: 3rem;
  }
  
  .setup-input {
    height: 44px;
    padding: 12px 20px;
    font-size: 0.9rem;
  }
  
  .setup-button {
    height: 44px;
    font-size: 0.9rem;
  }
  
  .status-bar {
    padding: 8px 16px;
    font-size: 0.8rem;
  }
}

@media (max-width: 480px) {
  .setup-content {
    padding: 40px 16px 16px;
  }
  
  .setup-title {
    font-size: 1.8rem;
  }
  
  .setup-subtitle {
    font-size: 0.9rem;
  }
  
  .setup-icon {
    font-size: 2.5rem;
  }
  
  .setup-input {
    height: 40px;
    padding: 10px 16px;
    font-size: 0.85rem;
  }
  
  .setup-button {
    height: 40px;
    font-size: 0.85rem;
  }
  
  .terms-label {
    font-size: 0.8rem;
  }
  
  .footer-text {
    font-size: 0.8rem;
  }
}

/* Dark mode adjustments */
@media (prefers-color-scheme: dark) {
  .background-image {
    background: linear-gradient(135deg, 
      #1e293b 0%, 
      #334155 25%, 
      #475569 50%, 
      #64748b 75%, 
      #94a3b8 100%);
  }
  
  .glass-layer {
    background: rgba(0, 0, 0, 0.1);
  }
}
</style>
