import { NextRequest, NextResponse } from 'next/server'
import db from '@/db/db'
import { revisions, issueStages, documents, projects } from '@/db/schema'
import { eq, sql } from 'drizzle-orm'
import { alias } from 'drizzle-orm/pg-core'
import { debugLog, debugError, debugSuccess } from '@/lib/debug-utils'

// DOLCE Detail Document 타입 정의
interface DOLCEDetailDocument {
  RegisterSerialNoMax?: string | number
  // 다른 필드들도 필요시 추가
}

export async function GET(request: NextRequest) {
  try {
    const { searchParams } = new URL(request.url)
    const documentId = searchParams.get('documentId')

    debugLog('1. Input documentId:', documentId)

    if (!documentId) {
      debugLog('2. documentId is missing, returning 400')
      return NextResponse.json(
        { error: 'documentId is required' },
        { status: 400 }
      )
    }

    const parsedDocumentId = parseInt(documentId)
    debugLog('3. Parsed documentId:', parsedDocumentId)

    // 1. 내부 DB에서 최대 serialNo 조회
    const r = alias(revisions, 'r')
    const is = alias(issueStages, 'is')

    debugLog('4. Created aliases - r:', r, 'is:', is)

    const maxSerialResult = await db
      .select({
        maxSerial: sql<number>`
          COALESCE(MAX(CAST(${r.serialNo} AS INTEGER)), 0)
        `,
        maxRegisterSerial: sql<number>`
          COALESCE(MAX(CAST(${r.registerSerialNoMax} AS INTEGER)), 0)
        `
      })
      .from(r)
      .innerJoin(
        is,
        eq(r.issueStageId, is.id)
      )
      .where(eq(is.documentId, parsedDocumentId))

    debugLog('5. Internal DB query result:', maxSerialResult)

    const internalMaxSerial = maxSerialResult[0]?.maxSerial || 0
    const internalMaxRegisterSerial = maxSerialResult[0]?.maxRegisterSerial || 0
    const internalMaxSerialNo = Math.max(internalMaxSerial, internalMaxRegisterSerial)

    debugLog('6. Internal maxSerialNo:', internalMaxSerialNo)

    // 2. Document 정보 조회 (DOLCE API 호출을 위해)
    const documentInfo = await db
      .select({
        docNumber: documents.docNumber,
        drawingKind: documents.drawingKind,
        discipline: documents.discipline,
        projectId: documents.projectId,
        projectCode: projects.code
      })
      .from(documents)
      .leftJoin(projects, eq(documents.projectId, projects.id))
      .where(eq(documents.id, parsedDocumentId))
      .limit(1)

    debugLog('7. Document info:', documentInfo[0])

    if (!documentInfo[0]) {
      debugError('Document not found for id:', parsedDocumentId)
      return NextResponse.json(
        { error: 'Document not found' },
        { status: 404 }
      )
    }

    const { docNumber, drawingKind, discipline, projectCode } = documentInfo[0]

    // 필수 필드 검증
    if (!projectCode || !docNumber || !discipline || !drawingKind) {
      debugLog('8. Missing required fields for DOLCE API')
      debugLog('   - projectCode:', projectCode)
      debugLog('   - docNumber:', docNumber)
      debugLog('   - discipline:', discipline)
      debugLog('   - drawingKind:', drawingKind)
      
      // DOLCE API 호출 불가능한 경우, 내부 DB 값만 사용
      return NextResponse.json({
        maxSerialNo: internalMaxSerialNo,
        nextSerialNo: internalMaxSerialNo + 1,
        documentId: documentId,
        source: 'internal_only',
        debug: {
          parsedDocumentId,
          internalMaxSerialNo,
          missingFields: {
            projectCode: !projectCode,
            docNumber: !docNumber,
            discipline: !discipline,
            drawingKind: !drawingKind
          }
        }
      })
    }

    // 3. DOLCE API 호출
    let dolceMaxSerialNo = 0
    try {
      debugLog('9. Calling DOLCE API...')
      const dolceDocuments = await fetchDetailFromDOLCE(
        projectCode,
        docNumber,
        discipline,
        drawingKind
      )

      debugLog('10. DOLCE API response:', dolceDocuments)

      if (dolceDocuments && dolceDocuments.length > 0) {
        // 첫 번째 문서의 RegisterSerialNoMax 값 사용
        const firstDoc = dolceDocuments[0]
        if (firstDoc.RegisterSerialNoMax) {
          dolceMaxSerialNo = parseInt(String(firstDoc.RegisterSerialNoMax)) || 0
          debugLog('11. DOLCE maxSerialNo:', dolceMaxSerialNo)
        }
      }
    } catch (error) {
      debugError('DOLCE API call failed:', error)
      // DOLCE API 실패 시에도 내부 DB 값은 사용
    }

    // 4. 내부 DB와 DOLCE 값 중 최대값 선택
    const finalMaxSerialNo = Math.max(internalMaxSerialNo, dolceMaxSerialNo)

    debugSuccess('12. Final maxSerialNo:', finalMaxSerialNo)
    debugSuccess('13. Next serialNo:', finalMaxSerialNo + 1)

    return NextResponse.json({
      maxSerialNo: finalMaxSerialNo,
      nextSerialNo: finalMaxSerialNo + 1,
      documentId: documentId,
      source: dolceMaxSerialNo > internalMaxSerialNo ? 'dolce' : 'internal',
      debug: {
        parsedDocumentId,
        internalMaxSerialNo,
        dolceMaxSerialNo,
        documentInfo: {
          projectCode,
          docNumber,
          discipline,
          drawingKind
        }
      }
    })
  } catch (error) {
    debugError('Error fetching max serial no:', error)
    debugError('Error stack:', error?.stack)
    return NextResponse.json(
      { error: 'Failed to fetch max serial number', details: error?.message },
      { status: 500 }
    )
  }
}

// DOLCE Detail API 호출 함수
async function fetchDetailFromDOLCE(
  projectCode: string,
  drawingNo: string,
  discipline: string,
  drawingKind: string
): Promise<DOLCEDetailDocument[]> {
  const endpoint = process.env.DOLCE_DOC_DETAIL_API_URL || 'http://60.100.99.217:1111/Services/VDCSWebService.svc/DetailDwgReceiptMgmt'

  const requestBody = {
    project: projectCode,
    drawingNo: drawingNo,
    discipline: discipline,
    drawingKind: drawingKind
  }

  console.log(`Fetching detail from DOLCE: ${projectCode} - ${drawingNo}`)
  console.log('Request body:', requestBody)

  try {
    const response = await fetch(endpoint, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
      },
      body: JSON.stringify(requestBody)
    })

    if (!response.ok) {
      const errorText = await response.text()
      throw new Error(`DOLCE Detail API failed: HTTP ${response.status} - ${errorText}`)
    }

    const data = await response.json()

    // DOLCE Detail API 응답 구조에 맞게 처리
    if (data.DetailDwgReceiptMgmtResult) {
      const documents = data.DetailDwgReceiptMgmtResult as DOLCEDetailDocument[]
      console.log(`Found ${documents.length} detail records for ${drawingNo}`)
      return documents
    } else {
      console.warn(`Unexpected DOLCE Detail response structure:`, data)
      return []
    }

  } catch (error) {
    console.error(`DOLCE Detail API call failed for ${drawingNo}:`, error)
    throw error
  }
}