feat(dashboard): #82 add chart for sum of account and savings

internal/service/dashboard.go

@@ -109,3 +109,60 @@ func (s Dashboard) Summary(ctx context.Context, user *types.User, month time.Tim
 
 	return &summary, nil
 }
+
+func (s Dashboard) MainChart(
+	ctx context.Context,
+	user *types.User,
+) ([]types.DashboardMainChartEntry, error) {
+	if user == nil {
+		return nil, ErrUnauthorized
+	}
+
+	transactions := make([]types.Transaction, 0)
+	err := s.db.SelectContext(ctx, &transactions, `
+		SELECT *
+		FROM "transaction" 
+		WHERE user_id = ?
+		ORDER BY timestamp`, user.Id)
+	err = db.TransformAndLogDbError(ctx, "dashboard Chart", nil, err)
+	if err != nil {
+		return nil, err
+	}
+
+	timeEntries := make([]types.DashboardMainChartEntry, 0)
+	var lastEntry *types.DashboardMainChartEntry
+	for _, t := range transactions {
+		if t.Error != nil {
+			continue
+		}
+
+		newDay := t.Timestamp.Truncate(24 * time.Hour)
+		if lastEntry == nil {
+			lastEntry = &types.DashboardMainChartEntry{
+				Day:     newDay,
+				Value:   0,
+				Savings: 0,
+			}
+		} else if lastEntry.Day != newDay {
+			timeEntries = append(timeEntries, *lastEntry)
+			lastEntry = &types.DashboardMainChartEntry{
+				Day:     newDay,
+				Value:   lastEntry.Value,
+				Savings: lastEntry.Savings,
+			}
+		}
+
+		if t.AccountId != nil {
+			lastEntry.Value += t.Value
+		}
+		if t.TreasureChestId != nil {
+			lastEntry.Savings += t.Value
+		}
+	}
+
+	if lastEntry != nil {
+		timeEntries = append(timeEntries, *lastEntry)
+	}
+
+	return timeEntries, nil
+}