import React from 'react';
import { Card, Button, Empty, Tag, Popconfirm, Space, Typography } from 'antd';
import { 
  PlusOutlined, 
  FolderOutlined, 
  FileTextOutlined, 
  EditOutlined, 
  DeleteOutlined 
} from '@ant-design/icons';
import type { KnowledgeBase } from '../../api/knowledgeBaseApi';

const { Title, Text, Paragraph } = Typography;

interface KnowledgeBaseListProps {
  knowledgeBases: KnowledgeBase[];
  loading: boolean;
  onCreateClick: () => void;
  onEditClick: (kb: KnowledgeBase) => void;
  onDeleteClick: (kb: KnowledgeBase) => void;
  onSelectClick: (kb: KnowledgeBase) => void;
}

const KnowledgeBaseList: React.FC<KnowledgeBaseListProps> = ({
  knowledgeBases,
  loading,
  onCreateClick,
  onEditClick,
  onDeleteClick,
  onSelectClick,
}) => {
  const formatFileSize = (bytes: number): string => {
    if (bytes === 0) return '0 B';
    const k = 1024;
    const sizes = ['B', 'KB', 'MB', 'GB'];
    const i = Math.floor(Math.log(bytes) / Math.log(k));
    return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
  };

  const canCreateMore = knowledgeBases.length < 3;

  return (
    <div>
      {/* 标题和创建按钮 */}
      <div style={{ 
        display: 'flex', 
        justifyContent: 'space-between', 
        alignItems: 'center',
        marginBottom: 24 
      }}>
        <div>
          <Title level={4} style={{ margin: 0 }}>我的知识库</Title>
          <Text type="secondary">
            已使用 {knowledgeBases.length}/3 个知识库
          </Text>
        </div>
        <Button
          type="primary"
          icon={<PlusOutlined />}
          onClick={onCreateClick}
          disabled={!canCreateMore || loading}
        >
          创建知识库
        </Button>
      </div>

      {/* 配额提示 */}
      {!canCreateMore && (
        <div style={{ marginBottom: 16 }}>
          <Tag color="warning">
            已达到知识库数量上限（3个）
          </Tag>
        </div>
      )}

      {/* 知识库列表 */}
      {knowledgeBases.length === 0 ? (
        <Card>
          <Empty
            image={Empty.PRESENTED_IMAGE_SIMPLE}
            description="还没有知识库，创建第一个吧！"
          >
            <Button 
              type="primary" 
              icon={<PlusOutlined />}
              onClick={onCreateClick}
            >
              创建知识库
            </Button>
          </Empty>
        </Card>
      ) : (
        <div style={{ 
          display: 'grid', 
          gridTemplateColumns: 'repeat(auto-fill, minmax(320px, 1fr))',
          gap: 16 
        }}>
          {knowledgeBases.map((kb) => (
            <Card
              key={kb.id}
              hoverable
              onClick={() => onSelectClick(kb)}
              style={{ cursor: 'pointer' }}
              actions={[
                <Button
                  key="edit"
                  type="text"
                  icon={<EditOutlined />}
                  onClick={(e) => {
                    e.stopPropagation();
                    onEditClick(kb);
                  }}
                >
                  编辑
                </Button>,
                <Popconfirm
                  key="delete"
                  title="确认删除？"
                  description={`删除知识库 "${kb.name}" 将同时删除其中的所有文档，此操作不可恢复。`}
                  onConfirm={(e) => {
                    e?.stopPropagation();
                    onDeleteClick(kb);
                  }}
                  okText="确认"
                  cancelText="取消"
                  okButtonProps={{ danger: true }}
                >
                  <Button
                    type="text"
                    danger
                    icon={<DeleteOutlined />}
                    onClick={(e) => e.stopPropagation()}
                  >
                    删除
                  </Button>
                </Popconfirm>,
              ]}
            >
              <Card.Meta
                avatar={
                  <div style={{ 
                    width: 48, 
                    height: 48, 
                    background: '#1890ff20',
                    borderRadius: 8,
                    display: 'flex',
                    alignItems: 'center',
                    justifyContent: 'center'
                  }}>
                    <FolderOutlined style={{ fontSize: 24, color: '#1890ff' }} />
                  </div>
                }
                title={
                  <div style={{ 
                    display: 'flex', 
                    alignItems: 'center', 
                    justifyContent: 'space-between' 
                  }}>
                    <Text strong ellipsis style={{ flex: 1 }}>
                      {kb.name}
                    </Text>
                  </div>
                }
                description={
                  <div>
                    <Paragraph 
                      ellipsis={{ rows: 2 }} 
                      type="secondary"
                      style={{ marginBottom: 12, minHeight: 44 }}
                    >
                      {kb.description || '暂无描述'}
                    </Paragraph>
                    
                    <Space direction="vertical" size={4} style={{ width: '100%' }}>
                      <div style={{ display: 'flex', alignItems: 'center' }}>
                        <FileTextOutlined style={{ marginRight: 8, color: '#8c8c8c' }} />
                        <Text type="secondary" style={{ fontSize: 13 }}>
                          {kb._count?.documents || kb.fileCount || 0} 个文档
                        </Text>
                      </div>
                      <div style={{ display: 'flex', alignItems: 'center' }}>
                        <Text type="secondary" style={{ fontSize: 13 }}>
                          总大小: {formatFileSize(kb.totalSizeBytes)}
                        </Text>
                      </div>
                      <div style={{ marginTop: 4 }}>
                        <Text type="secondary" style={{ fontSize: 12 }}>
                          创建于 {new Date(kb.createdAt).toLocaleDateString()}
                        </Text>
                      </div>
                    </Space>
                  </div>
                }
              />
            </Card>
          ))}
        </div>
      )}
    </div>
  );
};

export default KnowledgeBaseList;