import { NextRequest, NextResponse } from 'next/server'
import { getMongoClient } from '@/lib/mongodb'

// 获取所有数据库结构
async function getDatabaseStructure() {
  const client = await getMongoClient()
  const admin = client.db().admin()
  
  // 获取数据库列表
  const dbList = await admin.listDatabases()
  const krDatabases = dbList.databases.filter(db => db.name.startsWith('KR'))
  
  const structure = []
  
  for (const dbInfo of krDatabases.slice(0, 10)) { // 限制前10个
    try {
      const db = client.db(dbInfo.name)
      const collections = await db.listCollections().toArray()
      
      // 获取每个集合的字段示例
      const collectionDetails = []
      for (const col of collections.slice(0, 5)) { // 每个库最多5个集合
        try {
          const sample = await db.collection(col.name).findOne()
          const fields = sample ? Object.keys(sample).filter(k => k !== '_id').slice(0, 10) : []
          const count = await db.collection(col.name).estimatedDocumentCount()
          
          collectionDetails.push({
            name: col.name,
            fields,
            count
          })
        } catch {
          // 忽略错误
        }
      }
      
      structure.push({
        database: dbInfo.name,
        sizeGB: (dbInfo.sizeOnDisk / 1024 / 1024 / 1024).toFixed(2),
        collections: collectionDetails
      })
    } catch {
      // 忽略错误
    }
  }
  
  return structure
}

// 生成血缘节点
function generateLineageNodes(structure: any[]) {
  const nodes: any[] = []
  const connections: any[] = []
  let yOffset = 50
  
  // 数据源节点 (左侧)
  const colors = [
    'from-blue-400 to-blue-600',
    'from-orange-400 to-orange-600',
    'from-green-400 to-green-600',
    'from-red-400 to-red-600',
    'from-purple-400 to-purple-600',
  ]
  
  structure.forEach((db, i) => {
    const mainCol = db.collections[0]
    if (!mainCol) return
    
    nodes.push({
      id: `source_${db.database}`,
      type: 'source',
      name: db.database.replace('KR_', ''),
      database: db.database,
      collection: mainCol.name,
      fields: mainCol.fields.slice(0, 5),
      x: 50,
      y: yOffset,
      color: colors[i % colors.length],
      count: mainCol.count,
      sizeGB: db.sizeGB
    })
    yOffset += 140
  })
  
  // AI引擎节点 (中间)
  nodes.push({
    id: 'transform_ai',
    type: 'transform',
    name: 'AI标签引擎',
    fields: ['phone_norm', 'qq_norm', 'rfm_score', 'user_level', 'tags'],
    x: 400,
    y: 150,
    color: 'from-violet-400 to-violet-600'
  })
  
  nodes.push({
    id: 'transform_clean',
    type: 'transform',
    name: '数据清洗',
    fields: ['unique_id', 'merged_data', 'quality'],
    x: 400,
    y: 350,
    color: 'from-yellow-400 to-yellow-600'
  })
  
  // 目标节点 (右侧)
  nodes.push({
    id: 'target_valuation',
    type: 'target',
    name: '用户估值',
    database: 'KR',
    collection: '用户估值',
    fields: ['phone', 'qq', 'rfm_score', 'user_level', 'tags'],
    x: 750,
    y: 200,
    color: 'from-emerald-400 to-emerald-600'
  })
  
  nodes.push({
    id: 'target_portrait',
    type: 'target',
    name: '用户画像',
    database: 'KR',
    collection: '用户画像',
    fields: ['user_id', 'portrait', 'behavior'],
    x: 750,
    y: 400,
    color: 'from-cyan-400 to-cyan-600'
  })
  
  // 自动生成连接
  structure.forEach(db => {
    const sourceId = `source_${db.database}`
    const mainCol = db.collections[0]
    if (!mainCol) return
    
    // 连接到AI引擎
    if (mainCol.fields.includes('phone') || mainCol.fields.includes('手机')) {
      connections.push({
        id: `conn_${sourceId}_phone`,
        sourceNode: sourceId,
        sourceField: mainCol.fields.includes('phone') ? 'phone' : '手机',
        targetNode: 'transform_ai',
        targetField: 'phone_norm'
      })
    }
    if (mainCol.fields.includes('qq') || mainCol.fields.includes('QQ')) {
      connections.push({
        id: `conn_${sourceId}_qq`,
        sourceNode: sourceId,
        sourceField: mainCol.fields.includes('qq') ? 'qq' : 'QQ',
        targetNode: 'transform_ai',
        targetField: 'qq_norm'
      })
    }
  })
  
  // AI引擎到目标
  connections.push({
    id: 'conn_ai_valuation',
    sourceNode: 'transform_ai',
    sourceField: 'rfm_score',
    targetNode: 'target_valuation',
    targetField: 'rfm_score'
  })
  connections.push({
    id: 'conn_clean_portrait',
    sourceNode: 'transform_clean',
    sourceField: 'merged_data',
    targetNode: 'target_portrait',
    targetField: 'portrait'
  })
  
  return { nodes, connections }
}

export async function GET(request: NextRequest) {
  const { searchParams } = new URL(request.url)
  const action = searchParams.get('action') || 'structure'
  
  try {
    const structure = await getDatabaseStructure()
    
    if (action === 'lineage') {
      const lineage = generateLineageNodes(structure)
      return NextResponse.json({ success: true, ...lineage })
    }
    
    return NextResponse.json({ success: true, databases: structure })
  } catch (error) {
    console.error('数据库结构查询失败:', error)
    return NextResponse.json({ error: '查询失败' }, { status: 500 })
  }
}