Implement adjusting absence scheduler

moit-api/src/main/kotlin/com/mashup/moit/config/AsyncConfig.kt

@@ -30,4 +30,15 @@ class AsyncConfig {
             setWaitForTasksToCompleteOnShutdown(true)
         }
     }
+
+    @Bean(name = ["absenceSchedulerExecutor"])
+    fun absenceSchedulerExecutor(): Executor {
+        return ThreadPoolTaskExecutor().apply {
+            corePoolSize = 5
+            maxPoolSize = 5
+            queueCapacity = 20
+            setThreadNamePrefix("AbsenceSchedulerThread-")
+            setWaitForTasksToCompleteOnShutdown(true)
+        }
+    }
 }

moit-api/src/main/kotlin/com/mashup/moit/scheduler/StudyAdjustAbsenceScheduler.kt

@@ -0,0 +1,39 @@
+package com.mashup.moit.scheduler
+
+import com.mashup.moit.domain.attendance.AttendanceService
+import com.mashup.moit.domain.fine.FineService
+import com.mashup.moit.domain.study.StudyService
+import org.springframework.scheduling.annotation.Async
+import org.springframework.scheduling.annotation.Scheduled
+import org.springframework.stereotype.Component
+import org.springframework.transaction.annotation.Transactional
+import java.time.LocalDateTime
+
+@Component
+class StudyAdjustAbsenceScheduler(
+    private val studyService: StudyService,
+    private val attendanceService: AttendanceService,
+    private val fineService: FineService
+) {
+
+    @Scheduled(cron = "0 */5 * * * *")
+    @Async("asyncSchedulerExecutor")
+    @Transactional
+    fun adjustAbsenceStatusFromNow() {
+        // 결석 확정을 지을 때 endAt을 현재 시간보다 15초 정도 유예기간을 줌. 5분마다 배치가 돌기 때문에 95% 시간 내에 끝난 스터디를 반환함
+        val undecided = studyService.findUnfinalizedStudiesByEndAt(LocalDateTime.now().minusSeconds(DECIDE_ABSENCE_RANGE))
+            .map { it.id }
+        studyService.findByStudyIds(undecided)
+            .groupBy { study -> study.moitId }
+            .forEach { (moitId, studies) ->
+                studies.forEach { study ->
+                    attendanceService.adjustUndecidedAttendancesByStudyId(study.id)
+                        .forEach { attendanceId -> fineService.create(attendanceId, moitId) }
+                }
+            }
+    }
+
+    companion object {
+        private const val DECIDE_ABSENCE_RANGE = 15L
+    }
+}