import { NextRequest } from 'next/server'
import { join } from 'path'
import pino from 'pino'

/* 실행 모드 */
const isProduction = process.env.NODE_ENV === 'production'

/* 로그 데이터 인터페이스 */
interface ApiLogData {
  responseStatus: number
  method: string
  url: string
  // headers: { [k: string]: string }
  query: { [k: string]: string }
  body: string | undefined
}

/* 현재 날짜 반환 함수 (YYYY-MM-DD 형식) */
const getCurrentDate = (): string => {
  return new Date().toISOString().split('T')[0]
}

/* 날짜별 로그 파일 경로 생성 함수 */
const getLogFilePath = (): string => {
  const today: string = getCurrentDate()
  return join(process.cwd(), 'logs', `onsite-survey-${today}.log`)
}

/* 날짜별 로거 생성 클래스 */
class DailyLogger {
  private currentDate: string
  private logger: pino.Logger
  private destination?: ReturnType<typeof pino.destination>

  constructor() {
    this.currentDate = getCurrentDate()
    this.logger = this.createLogger()

    /* kill signal 핸들러 등록 */
    process.on('SIGTERM', this.handleShutdown.bind(this))
    process.on('SIGINT', this.handleShutdown.bind(this))
  }

  private async handleShutdown(): Promise<void> {
    if (isProduction && this.destination) {
      this.destination.flushSync()
      this.destination.end()
    }
    this.logger.flush()
  }

  private createLogger(): pino.Logger {
    if (!isProduction) return pino({ level: 'silent' })

    /* 기존 destination 종료 */
    if (this.destination) {
      this.destination.flushSync()
      this.destination.end()
    }
    /* 새로운 destination 생성 */
    this.destination = pino.destination({
      dest: getLogFilePath(),
      mkdir: true,
      sync: false,
    })

    return pino(
      {
        level: 'info',
        timestamp: pino.stdTimeFunctions.isoTime,
      },
      this.destination,
    )
  }

  public info(obj: any, msg?: string): void {
    try {
      const today: string = getCurrentDate()
      if (today !== this.currentDate) {
        this.currentDate = today
        this.logger = this.createLogger()
      }
      this.logger.info(obj, msg)
    } catch (error) {
      console.error(`[DailyLogger] Failed to write log: ${error}`)
    }
  }
}

/* 로거 인스턴스 */
const dailyLogger = new DailyLogger()

/* API 로그 기록 함수 */
export const writeApiLog = async (request: NextRequest, responseStatus: number): Promise<void> => {
  if (!isProduction) return

  let bodyString: string | undefined
  if (
    request.method === 'POST' &&
    (request.headers.get('content-type') === 'multipart/form-data' || request.headers.get('content-type') === 'application/x-www-form-urlencoded')
  ) {
    const formData = await request.formData()
    bodyString = JSON.stringify(Object.fromEntries(formData))
  } else {
    bodyString = await request.text()
  }

  const logData: ApiLogData = {
    responseStatus: responseStatus,
    method: request.method,
    url: request.url,
    // headers: Object.fromEntries(request.headers),
    query: Object.fromEntries(new URL(request.url).searchParams),
    body: bodyString,
  }
  dailyLogger.info(logData, 'API Request')
}