<template>
  <div class="error-page" :class="{ 'dark-mode': isDarkMode }">
    <!-- 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>

    <!-- Windows-style Error Window -->
    <div class="error-window">
      <!-- Title Bar -->
      <div class="title-bar">
        <div class="title-bar-content">
          <div class="title-bar-icon">⚠️</div>
          <div class="title-bar-text">{{ $t('error.title') }}</div>
        </div>
        <div class="title-bar-controls">
          <button class="control-btn close-btn" @click="goHome">
            <span class="control-btn-icon">×</span>
          </button>
        </div>
      </div>

      <!-- Window Content -->
      <div class="window-content">
        <div class="error-content">
          <!-- Error Icon -->
          <div class="error-icon">
            <div class="error-code">500</div>
            <div class="error-symbol">⚠️</div>
          </div>

          <!-- Error Message -->
          <div class="error-message">
            <h1 class="error-title">{{ $t('error.serverError') }}</h1>
            <p class="error-description">{{ $t('error.serverErrorDescription') }}</p>
          </div>

          <!-- Action Button -->
          <div class="error-actions">
            <button class="action-btn primary" @click="goHome">
              <span class="btn-icon">🏠</span>
              {{ $t('error.goHome') }}
            </button>
          </div>
        </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, computed, onMounted, onUnmounted, watch } from 'vue';
import { useRouter } from 'vue-router';
import { useI18n } from 'vue-i18n';
import { useSettingsStore } from '../../stores/settings';

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

// Reactive state
const currentTime = ref('');
const requestId = ref('');
const userAgent = ref('');

// --- 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';
});

// Theme state from settings store
const isDarkMode = computed(() => settingsStore.theme === 'dark');

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

const refreshPage = () => {
  window.location.reload();
};

const reportError = () => {
  // In a real application, this would open an error reporting dialog
  console.log('Error reported');
  alert(t('error.reportSent'));
};

// 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;
  }
};

// Initialize data
onMounted(() => {
  currentTime.value = new Date().toLocaleString();
  requestId.value = Math.random().toString(36).substr(2, 9);
  userAgent.value = navigator.userAgent.substring(0, 50) + '...';
});

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

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

// Set page title
useHead({
  title: t('error.title')
});
</script>

<style scoped>
.error-page {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  overflow: hidden;
}

.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%
  );
}

.error-window {
  position: relative;
  z-index: 2;
  width: 90%;
  max-width: 600px;
  background: var(--window-background);
  border: 1px solid var(--window-border-color);
  border-radius: var(--rounded-window);
  box-shadow: var(--shadow-window);
  overflow: hidden;
  animation: window-appear 0.5s ease-out;
}

@keyframes window-appear {
  from {
    opacity: 0;
    transform: scale(0.9) translateY(20px);
  }
  to {
    opacity: 1;
    transform: scale(1) translateY(0);
  }
}

.title-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--title-bar-background);
  color: var(--title-bar-text-color);
  padding: 8px 12px;
  border-bottom: 1px solid var(--window-border-color);
}

.title-bar-content {
  display: flex;
  align-items: center;
  gap: 8px;
}

.title-bar-icon {
  font-size: 16px;
}

.title-bar-text {
  font-weight: 600;
  font-size: 14px;
}

.title-bar-controls {
  display: flex;
  gap: 4px;
}

.control-btn {
  width: 20px;
  height: 20px;
  border: none;
  border-radius: var(--rounded-control-btn);
  background: var(--control-btn-close-bg);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 12px;
  font-weight: bold;
}

.control-btn:hover {
  transform: scale(1.1);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.window-content {
  padding: 32px;
  color: var(--content-text-color);
}

.error-content {
  text-align: center;
}

.error-icon {
  margin-bottom: 24px;
  position: relative;
}

.error-code {
  font-size: 72px;
  font-weight: 900;
  color: var(--control-btn-close-bg);
  text-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
  margin-bottom: 8px;
}

.error-symbol {
  font-size: 48px;
  position: absolute;
  top: -10px;
  right: 50%;
  transform: translateX(50%);
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateX(50%) translateY(0);
  }
  40% {
    transform: translateX(50%) translateY(-10px);
  }
  60% {
    transform: translateX(50%) translateY(-5px);
  }
}

.error-message {
  margin-bottom: 32px;
}

.error-title {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--content-text-color);
}

.error-description {
  font-size: 16px;
  line-height: 1.6;
  color: var(--content-text-color);
  opacity: 0.8;
  max-width: 400px;
  margin: 0 auto;
}

.error-actions {
  display: flex;
  justify-content: center;
  margin-bottom: 32px;
}

.action-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border: none;
  border-radius: var(--rounded-button);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  text-decoration: none;
  min-width: 120px;
  justify-content: center;
}

.action-btn.primary {
  background: var(--control-btn-maximize-bg);
  color: white;
  box-shadow: var(--shadow-button);
}

.action-btn.primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(76, 209, 55, 0.4);
}

.action-btn.secondary {
  background: var(--taskbar-item-background);
  color: var(--content-text-color);
  border: 1px solid var(--window-border-color);
}

.action-btn.secondary:hover {
  background: var(--taskbar-item-background-hover);
  transform: translateY(-1px);
}

.btn-icon {
  font-size: 16px;
}


.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) {
  .error-window {
    width: 95%;
    margin: 20px;
  }
  
  .window-content {
    padding: 24px;
  }
  
  .error-code {
    font-size: 56px;
  }
  
  .error-title {
    font-size: 24px;
  }
  
  .action-btn {
    width: 100%;
    max-width: 200px;
  }
  
  .status-bar {
    padding: 8px 16px;
    font-size: 0.8rem;
  }
}

/* Light mode (default) */
.background-image {
  background: linear-gradient(135deg, 
    #f8fafc 0%, 
    #e2e8f0 25%, 
    #cbd5e1 50%, 
    #94a3b8 75%, 
    #64748b 100%);
}

.glass-layer {
  background: rgba(255, 255, 255, 0.1);
}

.error-window {
  background: rgba(255, 255, 255, 0.95);
  border: 1px solid rgba(255, 255, 255, 0.2);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.title-bar {
  background: rgba(255, 255, 255, 0.9);
  color: #1f2937;
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.window-content {
  color: #1f2937;
}

.error-title {
  color: #1f2937;
}

.error-description {
  color: #4b5563;
}

.action-btn.primary {
  background: #10b981;
  color: white;
}

.action-btn.primary:hover {
  background: #059669;
  box-shadow: 0 6px 20px rgba(16, 185, 129, 0.4);
}

.action-btn.secondary {
  background: rgba(0, 0, 0, 0.05);
  color: #374151;
  border: 1px solid rgba(0, 0, 0, 0.1);
}

.action-btn.secondary:hover {
  background: rgba(0, 0, 0, 0.1);
}

.details-toggle {
  color: #374151;
}

.details-toggle:hover {
  background: rgba(0, 0, 0, 0.05);
}

.details-content {
  background: rgba(0, 0, 0, 0.05);
  border: 1px solid rgba(0, 0, 0, 0.1);
}

.details-item {
  color: #4b5563;
}

/* Dark mode adjustments */
.dark-mode .background-image {
  background: linear-gradient(135deg, 
    #0f172a 0%, 
    #1e293b 25%, 
    #334155 50%, 
    #475569 75%, 
    #64748b 100%);
}

.dark-mode .glass-layer {
  background: rgba(0, 0, 0, 0.1);
}

.dark-mode .error-window {
  background: rgba(15, 23, 42, 0.95);
  border: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.dark-mode .title-bar {
  background: rgba(15, 23, 42, 0.9);
  color: #f1f5f9;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.dark-mode .window-content {
  color: #f1f5f9;
}

.dark-mode .error-title {
  color: #f1f5f9;
}

.dark-mode .error-description {
  color: #cbd5e1;
}

.dark-mode .action-btn.primary {
  background: #10b981;
  color: white;
}

.dark-mode .action-btn.primary:hover {
  background: #059669;
  box-shadow: 0 6px 20px rgba(16, 185, 129, 0.4);
}

.dark-mode .action-btn.secondary {
  background: rgba(255, 255, 255, 0.1);
  color: #e2e8f0;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.dark-mode .action-btn.secondary:hover {
  background: rgba(255, 255, 255, 0.2);
}

.dark-mode .details-toggle {
  color: #e2e8f0;
}

.dark-mode .details-toggle:hover {
  background: rgba(255, 255, 255, 0.1);
}

.dark-mode .details-content {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.dark-mode .details-item {
  color: #cbd5e1;
}
</style>
