// app/api/sync/status/route.ts

import { syncService } from "@/lib/vendor-document-list/sync-service"
import { NextRequest, NextResponse } from "next/server"
import { getServerSession } from "next-auth"
import { authOptions } from "@/app/api/auth/[...nextauth]/route"

// JSON 직렬화 가능한 형태로 변환하는 헬퍼 함수
function serializeForJSON(obj: any): any {
  if (obj === null || obj === undefined) {
    return null
  }
  
  if (obj instanceof Date) {
    return obj.toISOString()
  }
  
  if (typeof obj === 'bigint') {
    return obj.toString()
  }
  
  if (Array.isArray(obj)) {
    return obj.map(serializeForJSON)
  }
  
  if (typeof obj === 'object') {
    const serialized: any = {}
    for (const [key, value] of Object.entries(obj)) {
      serialized[key] = serializeForJSON(value)
    }
    return serialized
  }
  
  return obj
}

export async function GET(request: NextRequest) {
  try {

    const session = await getServerSession(authOptions)
    if (!session?.user?.id) {
      return NextResponse.json({ error: "Unauthorized" }, { status: 401 })
    }

    const { searchParams } = new URL(request.url)
    const projectId = searchParams.get('projectId')
    const targetSystem = searchParams.get('targetSystem') || 'DOLCE' // 기본값 DOLCE로 변경
    const realtime = searchParams.get('realtime') === 'true'
    
    if (!projectId) {
      return NextResponse.json(
        { error: 'Project ID is required' },
        { status: 400 }
      )
    }
    
    let status
    
    try {
      // 실제 데이터베이스에서 조회
      status = await syncService.getSyncStatus(
        parseInt(projectId),
        targetSystem
      )
      
    } catch (error) {
      console.error('Database query failed:', error)
      
      // 개발 환경에서만 목업 데이터 반환
      if (process.env.NODE_ENV === 'development') {
        console.log('Using mock data for development')
        
        status = {
          projectId: parseInt(projectId),
          vendorId: 1, // 임시 vendorId
          targetSystem,
          totalChanges: 15,
          pendingChanges: 3,
          syncedChanges: 12,
          failedChanges: 0,
          // entityType별 상세 통계 추가
          entityTypeDetails: {
            document: {
              pending: 1,
              synced: 4,
              failed: 0,
              total: 5
            },
            revision: {
              pending: 2,
              synced: 6,
              failed: 0,
              total: 8
            },
            attachment: {
              pending: 0,
              synced: 2,
              failed: 0,
              total: 2
            }
          },
          lastSyncAt: new Date(Date.now() - 30 * 60 * 1000).toISOString(),
          nextSyncAt: new Date(Date.now() + 30 * 60 * 1000).toISOString(),
          syncEnabled: true,
          hasPendingChanges: true,
          hasFailedChanges: false,
          syncHealthy: true,
          requiresSync:false
        }
      } else {
        // 프로덕션에서는 에러 반환
        return NextResponse.json(
          { 
            error: 'Failed to get sync status',
            message: error instanceof Error ? error.message : 'Unknown error'
          },
          { status: 500 }
        )
      }
    }
    
    // JSON 직렬화 가능한 형태로 변환
    const serializedStatus = serializeForJSON(status)
    
    // 실시간 모드일 경우 캐시 비활성화
    if (realtime) {
      return NextResponse.json(serializedStatus, {
        headers: {
          'Cache-Control': 'no-cache, no-store, must-revalidate',
          'Pragma': 'no-cache',
          'Expires': '0'
        }
      })
    }
    
    // 일반 모드: 캐시 헤더 설정 (30초)
    return NextResponse.json(serializedStatus, {
      headers: {
        'Cache-Control': 'public, max-age=30, s-maxage=30, stale-while-revalidate=60'
      }
    })
    
  } catch (error) {
    console.error('Failed to get sync status:', error)
    return NextResponse.json(
      { 
        error: 'Failed to get sync status',
        message: error instanceof Error ? error.message : 'Unknown error'
      },
      { status: 500 }
    )
  }
}