<template>
  <div class="welcome-screen">
    <!-- Logo 和标题 -->
    <div class="welcome-header">
      <div class="logo-wrapper">
        <div class="logo-icon">
          <Bot :size="40" />
        </div>
        <div class="logo-glow"></div>
      </div>
      <h1 class="title">AI 智能助手</h1>
      <p class="subtitle">我可以帮助你解答问题、生成内容、分析数据等</p>
    </div>

    <!-- 功能卡片 -->
    <div class="feature-cards">
      <div
          v-for="feature in features"
          :key="feature.title"
          class="feature-card"
      >
        <div class="feature-icon" :style="{ background: feature.gradient }">
          <component :is="feature.icon" :size="22" />
        </div>
        <h3>{{ feature.title }}</h3>
        <p>{{ feature.description }}</p>
      </div>
    </div>

    <!-- 快速开始建议 -->
    <div class="quick-start">
      <h4>试试这些问题</h4>
      <div class="suggestions-grid">
        <button
            v-for="suggestion in suggestions"
            :key="suggestion.text"
            class="suggestion-card"
            @click="$emit('select', suggestion.text)"
        >
          <component :is="suggestion.icon" :size="18" class="suggestion-icon" />
          <span>{{ suggestion.text }}</span>
          <ChevronRight :size="16" class="arrow-icon" />
        </button>
      </div>
    </div>

    <!-- 底部提示 -->
    <div class="welcome-footer">
      <div class="tip">
        <Keyboard :size="14" />
        <span>按 <kbd>Ctrl</kbd> + <kbd>/</kbd> 聚焦输入框</span>
      </div>
      <div class="tip">
        <Zap :size="14" />
        <span>支持 Markdown、代码高亮、LaTeX 公式</span>
      </div>
    </div>
  </div>
</template>

<script setup lang="ts">
import { computed } from 'vue'
import {
  Bot,
  MessageSquare,
  Code,
  Image,
  FileText,
  ChevronRight,
  Keyboard,
  Zap,
  Globe,
  Lightbulb,
  PenTool,
} from '@/components/icons'

defineEmits<{
  select: [text: string]
}>()

const features = computed(() => [
  {
    icon: MessageSquare,
    title: '智能对话',
    description: '自然流畅的对话体验，理解上下文',
    gradient: 'linear-gradient(135deg, #3b82f6 0%, #2563eb 100%)',
  },
  {
    icon: Code,
    title: '代码助手',
    description: '编写、解释、优化各种编程语言代码',
    gradient: 'linear-gradient(135deg, #8b5cf6 0%, #6366f1 100%)',
  },
  {
    icon: Image,
    title: '图像理解',
    description: '分析图片内容，提取关键信息',
    gradient: 'linear-gradient(135deg, #ec4899 0%, #d946ef 100%)',
  },
  {
    icon: FileText,
    title: '文档处理',
    description: '阅读、总结、翻译各类文档',
    gradient: 'linear-gradient(135deg, #f59e0b 0%, #f97316 100%)',
  },
])

const suggestions = computed(() => [
  {
    icon: Lightbulb,
    text: '帮我写一个 Vue 3 组件示例',
  },
  {
    icon: Globe,
    text: '解释一下什么是机器学习',
  },
  {
    icon: PenTool,
    text: '帮我写一封商务邮件',
  },
  {
    icon: Code,
    text: '如何优化 React 应用性能',
  },
])
</script>

<style lang="scss" scoped>
.welcome-screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100%;
  padding: 40px 24px;
  animation: fadeIn 0.5s ease;
}

.welcome-header {
  text-align: center;
  margin-bottom: 48px;
}

.logo-wrapper {
  position: relative;
  display: inline-flex;
  margin-bottom: 20px;
}

.logo-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 80px;
  height: 80px;
  background: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
  border-radius: 24px;
  color: white;
  box-shadow: 0 20px 40px -12px rgba(59, 130, 246, 0.35);
}

.logo-glow {
  position: absolute;
  inset: -20px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.2) 0%, transparent 70%);
  pointer-events: none;
}

.title {
  margin: 0 0 12px;
  font-size: 32px;
  font-weight: 700;
  color: #1f2937;

  .dark & {
    color: #f3f4f6;
  }
}

.subtitle {
  margin: 0;
  font-size: 16px;
  color: #6b7280;

  .dark & {
    color: #9ca3af;
  }
}

.feature-cards {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 900px;
  width: 100%;
  margin-bottom: 48px;

  @media (max-width: 900px) {
    grid-template-columns: repeat(2, 1fr);
  }

  @media (max-width: 500px) {
    grid-template-columns: 1fr;
  }
}

.feature-card {
  padding: 24px;
  background: white;
  border: 1px solid #e2e8f0;
  border-radius: 16px;
  text-align: center;
  transition: all 0.3s ease;

  .dark & {
    background: #1e1e2e;
    border-color: #2d2d3d;
  }

  &:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px -8px rgba(0, 0, 0, 0.1);

    .dark & {
      box-shadow: 0 12px 24px -8px rgba(0, 0, 0, 0.4);
    }
  }

  .feature-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 14px;
    color: white;
    margin-bottom: 16px;
  }

  h3 {
    margin: 0 0 8px;
    font-size: 16px;
    font-weight: 600;
    color: #1f2937;

    .dark & {
      color: #f3f4f6;
    }
  }

  p {
    margin: 0;
    font-size: 13px;
    color: #6b7280;
    line-height: 1.5;

    .dark & {
      color: #9ca3af;
    }
  }
}

.quick-start {
  max-width: 700px;
  width: 100%;
  margin-bottom: 40px;

  h4 {
    margin: 0 0 16px;
    font-size: 14px;
    font-weight: 600;
    color: #6b7280;
    text-align: center;

    .dark & {
      color: #9ca3af;
    }
  }
}

.suggestions-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;

  @media (max-width: 600px) {
    grid-template-columns: 1fr;
  }
}

.suggestion-card {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  background: white;
  border: 1px solid #e2e8f0;
  border-radius: 14px;
  color: #374151;
  font-size: 14px;
  text-align: left;
  cursor: pointer;
  transition: all 0.2s ease;

  .dark & {
    background: #1e1e2e;
    border-color: #2d2d3d;
    color: #e5e7eb;
  }

  &:hover {
    border-color: #3b82f6;
    background: rgba(59, 130, 246, 0.05);

    .arrow-icon {
      transform: translateX(4px);
      color: #3b82f6;
    }
  }

  .suggestion-icon {
    flex-shrink: 0;
    color: #3b82f6;
  }

  span {
    flex: 1;
  }

  .arrow-icon {
    flex-shrink: 0;
    color: #9ca3af;
    transition: all 0.2s ease;
  }
}

.welcome-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 24px;
}

.tip {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: #9ca3af;

  kbd {
    padding: 2px 8px;
    background: #f3f4f6;
    border-radius: 4px;
    font-size: 12px;

    .dark & {
      background: #374151;
    }
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
</style>