Geumpumta · kon28289 · Jan 16, 2026 · Jan 16, 2026 · Jan 16, 2026 · Jan 16, 2026
diff --git a/src/main/java/com/gpt/geumpumtabackend/statistics/dto/DayMaxFocusAndFullTimeStatistics.java b/src/main/java/com/gpt/geumpumtabackend/statistics/dto/DayMaxFocusAndFullTimeStatistics.java
@@ -1,6 +1,6 @@
 package com.gpt.geumpumtabackend.statistics.dto;
 
 public interface DayMaxFocusAndFullTimeStatistics {
-    Integer getTotalStudySeconds();
-    Integer getMaxFocusSeconds();
-}
+    Integer getTotalStudyMillis();
+    Integer getMaxFocusMillis();
+}
diff --git a/src/main/java/com/gpt/geumpumtabackend/statistics/dto/MonthlyStatistics.java b/src/main/java/com/gpt/geumpumtabackend/statistics/dto/MonthlyStatistics.java
@@ -1,8 +1,8 @@
 package com.gpt.geumpumtabackend.statistics.dto;
 
 public interface MonthlyStatistics {
-    Long getTotalMonthSeconds();        // 총 공부시간(초)
-    Integer getAverageDailySeconds();      // 월 일수로 나눈 일일 평균(초)
+    Long getTotalMonthMillis();        // 총 공부시간(ms)
+    Integer getAverageDailyMillis();      // 월 일수로 나눈 일일 평균(ms)
     Integer getMaxConsecutiveStudyDays();  // 해당 월 내 최장 연속 공부 일수
-    Integer getStudiedDays();              // 이번 달 공부 일수(>0초인 날의 수)
+    Integer getStudiedDays();              // 이번 달 공부 일수(>0ms인 날의 수)
 }
diff --git a/src/main/java/com/gpt/geumpumtabackend/statistics/dto/TwoHourSlotStatistics.java b/src/main/java/com/gpt/geumpumtabackend/statistics/dto/TwoHourSlotStatistics.java
@@ -3,5 +3,5 @@
 public interface TwoHourSlotStatistics {
     String getSlotStart();
     String getSlotEnd();
-    Integer getSecondsStudied();
+    Integer getMillisecondsStudied();
 }
diff --git a/src/main/java/com/gpt/geumpumtabackend/statistics/dto/WeeklyStatistics.java b/src/main/java/com/gpt/geumpumtabackend/statistics/dto/WeeklyStatistics.java
@@ -1,7 +1,7 @@
 package com.gpt.geumpumtabackend.statistics.dto;
 
 public interface WeeklyStatistics {
-    Long getTotalWeekSeconds();
+    Long getTotalWeekMillis();
     Integer getMaxConsecutiveStudyDays();
-    Integer getAverageDailySeconds(); // 7일 평균(초), 소수점 버림
+    Integer getAverageDailyMillis(); // 7일 평균(ms), 소수점 버림
 }
diff --git a/src/main/java/com/gpt/geumpumtabackend/statistics/repository/StatisticsRepository.java b/src/main/java/com/gpt/geumpumtabackend/statistics/repository/StatisticsRepository.java
@@ -0,0 +1,320 @@
+package com.gpt.geumpumtabackend.statistics.repository;
+
+import com.gpt.geumpumtabackend.statistics.dto.*;
+import com.gpt.geumpumtabackend.study.domain.StudySession;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.util.List;
+
+public interface StatisticsRepository extends JpaRepository<StudySession, Long> {
+    // 2시간 단위로 일일 통계를 불러옴
+    @Query(
+            value = """
+        WITH RECURSIVE buckets AS (
+            SELECT
+                0 AS idx,
+                :dayStart AS bucket_start,
+                :dayStart + INTERVAL 2 HOUR AS bucket_end
+            UNION ALL
+            SELECT
+                idx + 1,
+                bucket_end,
+                bucket_end + INTERVAL 2 HOUR
+            FROM buckets
+            WHERE idx < 11
+        )
+        SELECT
+            DATE_FORMAT(b.bucket_start, '%H:%i') AS slotStart,
+            DATE_FORMAT(b.bucket_end,   '%H:%i') AS slotEnd,
+            COALESCE(SUM(
+                GREATEST(
+                  0,
+                  TIMESTAMPDIFF(
+                    MICROSECOND,
+                    GREATEST(s.start_time, b.bucket_start),
+                    LEAST(s.end_time,   b.bucket_end)
+                  ) / 1000
+                )
+              ), 0) AS millisecondsStudied
+        FROM buckets b
+        LEFT JOIN study_session s
+          ON s.user_id    = :userId
+         AND s.start_time <  b.bucket_end
+         AND s.end_time   >  b.bucket_start
+        GROUP BY b.idx, b.bucket_start, b.bucket_end
+        ORDER BY b.idx
+        """,
+            nativeQuery = true
+    )
+    List<TwoHourSlotStatistics> getTwoHourSlotStats(
+            @Param("dayStart") LocalDateTime dayStart,
+            @Param("dayEnd")   LocalDateTime dayEnd,
+            @Param("userId") Long userId
+    );
+
+
+    @Query(value = """
+    WITH clipped AS (
+      SELECT GREATEST(
+               0,
+               TIMESTAMPDIFF(
+                 MICROSECOND,
+                 GREATEST(s.start_time, :dayStart),
+                 LEAST(s.end_time, :dayEnd)
+               ) / 1000
+             ) AS overlap_ms
+      FROM study_session s
+      WHERE s.user_id    = :userId
+        AND s.start_time < :dayEnd
+        AND s.end_time   > :dayStart
+    )
+    SELECT
+      CAST(COALESCE(SUM(c.overlap_ms), 0) AS SIGNED) AS totalStudyMillis,
+      CAST(COALESCE(MAX(c.overlap_ms), 0) AS SIGNED) AS maxFocusMillis
+    FROM clipped c
+    """, nativeQuery = true)
+    DayMaxFocusAndFullTimeStatistics getDayMaxFocusAndFullTime(
+            @Param("dayStart") LocalDateTime dayStart,
+            @Param("dayEnd")   LocalDateTime dayEnd,
+            @Param("userId")   Long userId
+    );
+
+    @Query(value = """
+        WITH RECURSIVE days AS (
+          SELECT 0 AS day_idx,
+                 :weekStart AS day_start,
+                 DATE_ADD(:weekStart, INTERVAL 1 DAY) AS day_end
+          UNION ALL
+          SELECT day_idx + 1,
+                 DATE_ADD(:weekStart, INTERVAL day_idx + 1 DAY),
+                 DATE_ADD(:weekStart, INTERVAL day_idx + 2 DAY)
+          FROM days
+          WHERE day_idx < 6
+        ),
+        per_day AS (
+          SELECT
+            d.day_idx,
+            CAST(
+              COALESCE(
+                SUM(
+                  GREATEST(
+                    0,
+                    TIMESTAMPDIFF(
+                      MICROSECOND,
+                      GREATEST(s.start_time, d.day_start),
+                      LEAST(COALESCE(s.end_time, d.day_end), d.day_end)
+                    ) / 1000
+                  )
+                ),
+                0
+              ) AS SIGNED
+            ) AS day_millis
+          FROM days d
+          LEFT JOIN study_session s
+            ON s.user_id    = :userId
+           AND s.start_time < d.day_end
+           AND s.end_time   > d.day_start
+          GROUP BY d.day_idx
+        ),
+        flags AS (
+          SELECT
+            day_idx,
+            day_millis,
+            CASE WHEN day_millis > 0 THEN 1 ELSE 0 END AS has_study
+          FROM per_day
+        ),
+        breaks AS (
+          SELECT
+            day_idx,
+            day_millis,
+            has_study,
+            SUM(CASE WHEN has_study = 0 THEN 1 ELSE 0 END)
+              OVER (ORDER BY day_idx) AS zero_grp
+          FROM flags
+        ),
+        streaks AS (
+          SELECT zero_grp, COUNT(*) AS streak_len
+          FROM breaks
+          WHERE has_study = 1
+          GROUP BY zero_grp
+        )
+        SELECT
+          /* 주간 총 공부시간(ms) */
+          (SELECT CAST(COALESCE(SUM(day_millis), 0) AS SIGNED) FROM per_day) AS totalWeekMillis,
+          /* 주간 최장 연속 공부일수 */
+          COALESCE((SELECT MAX(streak_len) FROM streaks), 0)                  AS maxConsecutiveStudyDays,
+          /* 7일 평균(ms) — 소수점 버림 */
+          CAST(((SELECT COALESCE(SUM(day_millis), 0) FROM per_day) / 7) AS SIGNED) AS averageDailyMillis
+        """, nativeQuery = true)
+    WeeklyStatistics getWeeklyStatistics(
+            @Param("weekStart") LocalDateTime weekStart,
+            @Param("userId") Long userId
+    );
+
+    @Query(value = """
+        WITH RECURSIVE
+        bounds AS (
+          SELECT
+            :monthStart AS start_at,
+            DATE_ADD(LAST_DAY(:monthStart), INTERVAL 1 DAY) AS end_at,
+            TIMESTAMPDIFF(
+              DAY, :monthStart,
+              DATE_ADD(LAST_DAY(:monthStart), INTERVAL 1 DAY)
+            ) AS days_cnt
+        ),
+        /* 월 전체 일자를 day_idx=0..(days_cnt-1)로 생성 */
+        days AS (
+          SELECT
+            0 AS day_idx,
+            b.start_at AS day_start,
+            LEAST(DATE_ADD(b.start_at, INTERVAL 1 DAY), b.end_at) AS day_end
+          FROM bounds b
+          UNION ALL
+          SELECT
+            d.day_idx + 1,
+            DATE_ADD(d.day_start, INTERVAL 1 DAY),
+            LEAST(DATE_ADD(d.day_start, INTERVAL 2 DAY), b.end_at)
+          FROM days d
+          JOIN bounds b
+            ON d.day_end < b.end_at
+        ),
+        /* 일자별 공부 총합(ms) */
+        per_day AS (
+          SELECT
+            d.day_idx,
+            CAST(
+              COALESCE(
+                SUM(
+                  GREATEST(
+                    0,
+                    TIMESTAMPDIFF(
+                      MICROSECOND,
+                      GREATEST(s.start_time, d.day_start),
+                      LEAST(COALESCE(s.end_time, d.day_end), d.day_end)
+                    ) / 1000
+                  )
+                ), 0
+              ) AS SIGNED
+            ) AS day_millis
+          FROM days d
+          LEFT JOIN study_session s
+            ON s.user_id    = :userId
+           AND s.start_time < d.day_end
+           AND s.end_time   > d.day_start
+          GROUP BY d.day_idx
+        ),
+        flags AS (
+          SELECT
+            day_idx,
+            day_millis,
+            CASE WHEN day_millis > 0 THEN 1 ELSE 0 END AS has_study
+          FROM per_day
+        ),
+        breaks AS (
+          /* 0(공부 안 한 날)을 경계로 그룹을 나눠 연속 구간 식별 */
+          SELECT
+            day_idx,
+            day_millis,
+            has_study,
+            SUM(CASE WHEN has_study = 0 THEN 1 ELSE 0 END)
+              OVER (ORDER BY day_idx) AS zero_grp
+          FROM flags
+        ),
+        streaks AS (
+          SELECT zero_grp, COUNT(*) AS streak_len
+          FROM breaks
+          WHERE has_study = 1
+          GROUP BY zero_grp
+        )
+        SELECT
+          /* 총 공부시간(ms) */
+          CAST(COALESCE((SELECT SUM(day_millis) FROM per_day), 0) AS SIGNED) AS totalMonthMillis,
+          /* 월 일수로 나눈 일일 평균(ms; 소수 버림) */
+          CAST( (COALESCE((SELECT SUM(day_millis) FROM per_day), 0)
+                / NULLIF((SELECT days_cnt FROM bounds), 0)) AS SIGNED)        AS averageDailyMillis,
+          /* 최장 연속 공부 일수 */
+          COALESCE((SELECT MAX(streak_len) FROM streaks), 0)                  AS maxConsecutiveStudyDays,
+          /* 이번 달 공부 일수(>0ms) */
+          (SELECT COUNT(*) FROM per_day WHERE day_millis > 0)                 AS studiedDays
+        """, nativeQuery = true)
+    MonthlyStatistics getMonthlyStatistics(
+            @Param("monthStart") LocalDateTime monthStart, // 해당 월 1일 00:00
+            @Param("userId") Long userId
+    );
+
+
+    @Query(value = """
+    WITH RECURSIVE
+    bounds AS (
+      SELECT DATE(:monthStart) AS start_at,
+             DATE(:monthEnd)   AS end_at_exclusive
+    ),
+    days AS (
+      SELECT b.start_at AS day_date,
+             CAST(b.start_at AS DATETIME) AS day_start,
+             CAST(DATE_ADD(b.start_at, INTERVAL 1 DAY) AS DATETIME) AS day_end
+      FROM bounds b
+      UNION ALL
+      SELECT DATE_ADD(d.day_date, INTERVAL 1 DAY),
+             DATE_ADD(d.day_start, INTERVAL 1 DAY),
+             DATE_ADD(d.day_end,   INTERVAL 1 DAY)
+      FROM days d
+      JOIN bounds b ON d.day_date < b.end_at_exclusive
+    ),
+    sessions_in_window AS (
+      SELECT s.user_id, s.start_time, s.end_time
+      FROM study_session s
+      JOIN bounds b
+        ON s.user_id = :userId
+       AND s.end_time   > b.start_at
+       AND s.start_time < b.end_at_exclusive
+       AND s.end_time IS NOT NULL
+    ),
+    day_overlap AS (
+      SELECT d.day_date,
+             GREATEST(s.start_time, d.day_start) AS seg_start,
+             LEAST(s.end_time,   d.day_end)      AS seg_end
+      FROM days d
+      JOIN sessions_in_window s
+        ON s.end_time   > d.day_start
+       AND s.start_time < d.day_end
+    ),
+    daily_ms AS (
+      SELECT day_date AS date,
+             GREATEST(SUM(GREATEST(TIMESTAMPDIFF(MICROSECOND, seg_start, seg_end), 0)) / 1000, 0) AS total_millis
+      FROM day_overlap
+      GROUP BY day_date
+    ),
+    daily_full AS (
+      SELECT d.day_date AS date,
+             COALESCE(ds.total_millis, 0) AS total_millis
+      FROM days d
+      LEFT JOIN daily_ms ds ON ds.date = d.day_date
+    ),
+    leveled AS (
+      SELECT date,
+             CASE
+               WHEN total_millis = 0 THEN 0
+               ELSE NTILE(4) OVER (
+                      PARTITION BY YEAR(date), MONTH(date)
+                      ORDER BY total_millis
+                    )
+             END AS level
+      FROM daily_full
+    )
+    SELECT
+      DATE_FORMAT(date, '%Y-%m-%d')              AS date,
+      CAST(level AS UNSIGNED)                    AS level
+    FROM leveled
+    ORDER BY date
+    """, nativeQuery = true)
+    List<GrassStatistics> getGrassStatistics(
+            @Param("monthStart") LocalDate monthStart,
+            @Param("monthEnd") LocalDate monthEnd,
+            @Param("userId") Long userId
+    );
+}