transition time ranged queries to timeframe (#117)

internal/db/period.go

@@ -6,23 +6,6 @@ import (
 
 // should this be in db package ???
 
-type Timeframe struct {
-	Period Period
-	T1u    int64
-	T2u    int64
-}
-
-func TimeframeToTimeRange(timeframe Timeframe) (t1, t2 time.Time) {
-	if timeframe.T1u == 0 && timeframe.T2u == 0 {
-		t2 = time.Now()
-		t1 = StartTimeFromPeriod(timeframe.Period)
-	} else {
-		t1 = time.Unix(timeframe.T1u, 0)
-		t2 = time.Unix(timeframe.T2u, 0)
-	}
-	return
-}
-
 type Period string
 
 const (
@@ -31,9 +14,12 @@ const (
 	PeriodMonth   Period = "month"
 	PeriodYear    Period = "year"
 	PeriodAllTime Period = "all_time"
-	PeriodDefault Period = "day"
 )
 
+func (p Period) IsZero() bool {
+	return p == ""
+}
+
 func StartTimeFromPeriod(p Period) time.Time {
 	now := time.Now()
 	switch p {