improve aggregations

internal/report/snapshots.go

@@ -8,6 +8,7 @@ import (
 	"log/slog"
 	"os"
 	"path/filepath"
+	"sort"
 	"strconv"
 	"strings"
 	"time"
@@ -341,6 +342,7 @@ func ListSnapshotsByRange(ctx context.Context, database db.Database, snapshotTyp
 
 	startUnix := start.Unix()
 	endUnix := end.Unix()
+	loc := start.Location()
 
 	var rows *sqlx.Rows
 	var err error
@@ -386,7 +388,7 @@ ORDER BY snapshot_time ASC, table_name ASC
 		}
 		records = append(records, SnapshotRecord{
 			TableName:     tableName,
-			SnapshotTime:  time.Unix(snapshotTime, 0),
+			SnapshotTime:  time.Unix(snapshotTime, 0).In(loc),
 			SnapshotType:  recordType,
 			SnapshotCount: snapshotCnt,
 		})
@@ -394,6 +396,65 @@ ORDER BY snapshot_time ASC, table_name ASC
 	return records, rows.Err()
 }
 
+func SnapshotRecordsWithFallback(ctx context.Context, database db.Database, snapshotType, prefix, layout string, start, end time.Time) ([]SnapshotRecord, error) {
+	records, err := ListSnapshotsByRange(ctx, database, snapshotType, start, end)
+	if err == nil && len(records) > 0 {
+		return records, nil
+	}
+
+	fallback, err2 := recordsFromTableNames(ctx, database, snapshotType, prefix, layout, start, end)
+	if err2 != nil {
+		if err != nil {
+			return nil, err
+		}
+		return nil, err2
+	}
+	if len(fallback) > 0 {
+		return fallback, nil
+	}
+	return records, err
+}
+
+func recordsFromTableNames(ctx context.Context, database db.Database, snapshotType, prefix, layout string, start, end time.Time) ([]SnapshotRecord, error) {
+	tables, err := ListTablesByPrefix(ctx, database, prefix)
+	if err != nil {
+		return nil, err
+	}
+	records := make([]SnapshotRecord, 0, len(tables))
+	for _, table := range tables {
+		if !strings.HasPrefix(table, prefix) {
+			continue
+		}
+		suffix := strings.TrimPrefix(table, prefix)
+		var ts time.Time
+		switch layout {
+		case "epoch":
+			val, err := strconv.ParseInt(suffix, 10, 64)
+			if err != nil {
+				continue
+			}
+			ts = time.Unix(val, 0)
+		default:
+			parsed, err := time.ParseInLocation(layout, suffix, time.Local)
+			if err != nil {
+				continue
+			}
+			ts = parsed
+		}
+		if !ts.Before(start) && ts.Before(end) {
+			records = append(records, SnapshotRecord{
+				TableName:    table,
+				SnapshotTime: ts,
+				SnapshotType: snapshotType,
+			})
+		}
+	}
+	sort.Slice(records, func(i, j int) bool {
+		return records[i].SnapshotTime.Before(records[j].SnapshotTime)
+	})
+	return records, nil
+}
+
 func LatestSnapshotTime(ctx context.Context, database db.Database, snapshotType string) (time.Time, error) {
 	dbConn := database.DB()
 	driver := strings.ToLower(dbConn.DriverName())
@@ -665,7 +726,7 @@ func SaveTableReport(logger *slog.Logger, Database db.Database, ctx context.Cont
 func addTotalsChartSheet(logger *slog.Logger, database db.Database, ctx context.Context, xlsx *excelize.File, tableName string) {
 	if strings.HasPrefix(tableName, "inventory_daily_summary_") {
 		suffix := strings.TrimPrefix(tableName, "inventory_daily_summary_")
-		dayStart, err := time.Parse("20060102", suffix)
+		dayStart, err := time.ParseInLocation("20060102", suffix, time.Local)
 		if err != nil {
 			return
 		}
@@ -673,7 +734,7 @@ func addTotalsChartSheet(logger *slog.Logger, database db.Database, ctx context.
 		if err := EnsureSnapshotRegistry(ctx, database); err != nil {
 			return
 		}
-		records, err := ListSnapshotsByRange(ctx, database, "hourly", dayStart, dayEnd)
+		records, err := SnapshotRecordsWithFallback(ctx, database, "hourly", "inventory_hourly_", "epoch", dayStart, dayEnd)
 		if err != nil || len(records) == 0 {
 			return
 		}
@@ -687,7 +748,7 @@ func addTotalsChartSheet(logger *slog.Logger, database db.Database, ctx context.
 
 	if strings.HasPrefix(tableName, "inventory_monthly_summary_") {
 		suffix := strings.TrimPrefix(tableName, "inventory_monthly_summary_")
-		monthStart, err := time.Parse("200601", suffix)
+		monthStart, err := time.ParseInLocation("200601", suffix, time.Local)
 		if err != nil {
 			return
 		}
@@ -695,7 +756,7 @@ func addTotalsChartSheet(logger *slog.Logger, database db.Database, ctx context.
 		if err := EnsureSnapshotRegistry(ctx, database); err != nil {
 			return
 		}
-		records, err := ListSnapshotsByRange(ctx, database, "daily", monthStart, monthEnd)
+		records, err := SnapshotRecordsWithFallback(ctx, database, "daily", "inventory_daily_summary_", "20060102", monthStart, monthEnd)
 		if err != nil || len(records) == 0 {
 			return
 		}