import { useState, useEffect } from 'react'
import { Card, Upload, Table, Button, Space, Select, Popconfirm, message, Tag } from 'antd'
import { InboxOutlined, DeleteOutlined, ReloadOutlined } from '@ant-design/icons'
import useAuthStore from '../../stores/authStore'
import knowledgeService from '../../services/knowledgeService'
import KnowledgeTree from '../../components/KnowledgeTree/KnowledgeTree'

const { Dragger } = Upload

// source_type 枚举值（固定五类，不写死但供 Select 用）
const SOURCE_TYPE_OPTIONS = [
  { label: '全部类型', value: '' },
  { label: '杂志文章', value: 'military_report' },
  { label: '节目文稿', value: 'manuscript' },
  { label: '报题单', value: 'baoti' },
]

// source_type 中文标签
const SOURCE_TYPE_LABEL = {
  military_report: '杂志文章',
  manuscript: '节目文稿',
  baoti: '报题单',
  manual: '其他',
}

export default function KnowledgeBase() {
  const { user } = useAuthStore()
  const [items, setItems] = useState([])
  const [treeData, setTreeData] = useState([])
  const [loading, setLoading] = useState(false)
  const [uploading, setUploading] = useState(false)
  const [sources, setSources] = useState([]) // 出处下拉选项
  const [sourceTypeFilter, setSourceTypeFilter] = useState('')
  const [sourceDetailFilter, setSourceDetailFilter] = useState('')
  const [selectedTreeNode, setSelectedTreeNode] = useState(null) // { type, detail }

  const fetchItems = async () => {
    setLoading(true)
    try {
      const data = await knowledgeService.listItems(sourceTypeFilter || null)
      setItems(data)
    } catch {
      message.error('加载知识库失败')
    } finally {
      setLoading(false)
    }
  }

  const fetchTree = async () => {
    try {
      const data = await knowledgeService.getGroupedItems()
      setTreeData(data || [])
    } catch {
      // ignore
    }
  }

  const fetchSources = async () => {
    try {
      const data = await knowledgeService.listSources()
      // 接口返回 [{source: "航空知识 2026年第1期"}, ...]，提取 source 字段
      setSources(data.map(s => s.source).filter(Boolean))
    } catch {
      // ignore
    }
  }

  useEffect(() => {
    fetchItems()
    fetchTree()
    fetchSources()
  }, [sourceTypeFilter])

  // 上传
  const handleUpload = async (file) => {
    if (!file.name.endsWith('.md')) {
      message.warning('仅支持 .md 文件')
      return false
    }
    setUploading(true)
    try {
      const result = await knowledgeService.uploadFiles([file])
      const { uploaded, errors } = result
      if (uploaded.length > 0) {
        message.success(`成功入库 ${uploaded.length} 篇`)
        fetchItems()
        fetchTree()
      }
      if (errors.length > 0) {
        errors.forEach(e => message.error(`${e.file}: ${e.error}`))
      }
    } catch {
      message.error('上传失败')
    } finally {
      setUploading(false)
    }
    return false // 阻止默认上传行为
  }

  // 删除
  const handleDelete = async (id) => {
    try {
      await knowledgeService.deleteItem(id)
      message.success('删除成功')
      fetchItems()
      fetchTree()
    } catch {
      message.error('删除失败')
    }
  }

  // 树节点选中 → 联动过滤
  const handleNodeSelect = (node) => {
    setSelectedTreeNode(node)
  }

  // 根据树节点过滤列表
  const displayedItems = (() => {
    let result = items

    // 树节点过滤优先（覆盖原有 Select 筛选）
    if (selectedTreeNode) {
      const { type, detail } = selectedTreeNode
      result = result.filter(i => {
        if (i.source_type !== type) return false
        if (detail !== null && i.source_detail !== detail) return false
        return true
      })
    } else if (sourceDetailFilter) {
      // 保留原有的 source_detail 筛选逻辑
      result = result.filter(i => i.source_detail === sourceDetailFilter)
    }

    return result
  })()

  const columns = [
    {
      title: '标题',
      dataIndex: 'title',
      key: 'title',
      width: 240,
      render: (text) => (
        <span style={{ fontWeight: 500, color: '#3b4a3b', overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap', display: 'block' }}>{text}</span>
      ),
    },
    {
      title: '作者',
      dataIndex: 'author',
      key: 'author',
      width: 80,
      render: (val) => val || '-',
    },
    {
      title: '播出/发表时间',
      dataIndex: 'publish_date',
      key: 'publish_date',
      width: 156,
      render: (val) => val || '-',
    },
    {
      title: '出处',
      dataIndex: 'source_detail',
      key: 'source_detail',
      width: 170,
      render: (val) => val || '-',
    },
    {
      title: '类型',
      dataIndex: 'source_type',
      key: 'source_type',
      width: 88,
      render: (val) => (
        <Tag color="default" style={{ borderRadius: 8 }}>
          {SOURCE_TYPE_LABEL[val] || val}
        </Tag>
      ),
    },
    {
      title: '入库时间',
      dataIndex: 'created_at',
      key: 'created_at',
      width: 140,
      render: (val) => val ? new Date(val).toLocaleString('zh-CN', { hour12: false }).replace(' ', ' ') : '-',
    },
    {
      title: '操作',
      key: 'action',
      width: 86,
      render: (_, record) => (
        <Popconfirm
          title="确认删除"
          description="删除后不可恢复，该篇及其向量将一并清除"
          onConfirm={() => handleDelete(record.id)}
          okText="确认删除"
          cancelText="取消"
          placement="left"
        >
          <Button size="small" danger icon={<DeleteOutlined />}>
            删除
          </Button>
        </Popconfirm>
      ),
    },
  ]

  return (
    <div style={{ maxWidth: 1200, padding: '12px' }}>
      <div style={{ marginBottom: 12 }}>
        <h2 style={{ margin: 0, fontSize: 18, fontWeight: 600, color: '#3b4a3b' }}>知识库</h2>
        <p style={{ margin: '4px 0 0', fontSize: 12, color: '#888' }}>上传 md 笔记 · 语义检索 · 报题参考</p>
      </div>

      {/* 上传区 */}
      <Card style={{ borderRadius: 14, marginBottom: 12 }} bodyStyle={{ padding: 0 }}>
        <Dragger
          accept=".md"
          multiple
          showUploadList={false}
          beforeUpload={handleUpload}
          disabled={uploading}
          style={{ padding: '28px 20px', borderRadius: 14 }}
        >
          <p className="ant-upload-drag-icon" style={{ marginBottom: 8 }}>
            <InboxOutlined style={{ fontSize: 40, color: '#6b8e6b' }} />
          </p>
          <p className="ant-upload-text" style={{ fontSize: 15, fontWeight: 500, color: '#3b4a3b' }}>
            {uploading ? '正在上传并生成向量…' : '点击或拖拽 .md 文件上传'}
          </p>
          <p className="ant-upload-hint" style={{ fontSize: 12, color: '#888' }}>
            支持批量上传，系统自动解析 yaml frontmatter 并生成语义向量
          </p>
        </Dragger>
      </Card>

      {/* 主体：左侧树 + 右侧列表 */}
      <div style={{ display: 'flex', gap: 12, alignItems: 'flex-start' }}>
        {/* 左侧树 */}
        <Card
          style={{ borderRadius: 14, width: 280, flexShrink: 0 }}
          bodyStyle={{ padding: 0, height: '100%' }}
        >
          <KnowledgeTree
            treeData={treeData}
            onNodeSelect={handleNodeSelect}
            selectedKey={selectedTreeNode ? `${selectedTreeNode.type}${selectedTreeNode.detail ? '|' + selectedTreeNode.detail : ''}` : 'all'}
          />
        </Card>

        {/* 右侧列表 + 筛选栏 */}
        <div style={{ flex: 1, minWidth: 0 }}>
          {/* 筛选栏 */}
          <Card style={{ borderRadius: 14, marginBottom: 12 }}>
            <Space size="middle" wrap>
              <span style={{ fontSize: 13, color: '#666' }}>筛选：</span>
              <Select
                placeholder="按类型"
                options={SOURCE_TYPE_OPTIONS}
                value={sourceTypeFilter}
                onChange={val => { setSourceTypeFilter(val); setSourceDetailFilter(''); setSelectedTreeNode(null) }}
                style={{ width: 140 }}
                allowClear
              />
              <Select
                placeholder="按出处"
                options={[{ label: '全部出处', value: '' }, ...sources.map(s => ({ label: s, value: s }))]}
                value={sourceDetailFilter}
                onChange={val => { setSourceDetailFilter(val); setSelectedTreeNode(null) }}
                style={{ width: 200 }}
                allowClear
              />
              <Button
                icon={<ReloadOutlined />}
                onClick={() => { fetchItems(); fetchTree() }}
                size="small"
              >
                刷新
              </Button>
            </Space>
          </Card>

          {/* 列表 */}
          <Card style={{ borderRadius: 14 }}>
            <Table
              columns={columns}
              dataSource={displayedItems}
              rowKey="id"
              loading={loading}
              pagination={{ pageSize: 10, size: 'small' }}
              locale={{ emptyText: '暂无知识库条目，上传 md 文件开始入库' }}
            />
          </Card>
        </div>
      </div>
    </div>
  )
}