transition time ranged queries to timeframe (#117)

internal/db/timeframe.go

@@ -0,0 +1,118 @@
+package db
+
+import (
+	"time"
+)
+
+type Timeframe struct {
+	Period   Period
+	Year     int
+	Month    int
+	Week     int
+	FromUnix int64
+	ToUnix   int64
+	From     time.Time
+	To       time.Time
+}
+
+func TimeframeToTimeRange(tf Timeframe) (t1, t2 time.Time) {
+	now := time.Now()
+	loc := now.Location()
+
+	// ---------------------------------------------------------------------
+	// 1. Explicit From / To (time.Time) — highest precedence
+	// ---------------------------------------------------------------------
+	if !tf.From.IsZero() {
+		if tf.To.IsZero() {
+			return tf.From, now
+		}
+		return tf.From, tf.To
+	}
+
+	// ---------------------------------------------------------------------
+	// 2. Unix timestamps
+	// ---------------------------------------------------------------------
+	if tf.FromUnix != 0 {
+		t1 = time.Unix(tf.FromUnix, 0).In(loc)
+		if tf.ToUnix == 0 {
+			return t1, now
+		}
+		t2 = time.Unix(tf.ToUnix, 0).In(loc)
+		return t1, t2
+	}
+
+	// ---------------------------------------------------------------------
+	// 3. Derived ranges (Year / Month / Week)
+	// ---------------------------------------------------------------------
+
+	// YEAR only
+	if tf.Year != 0 && tf.Month == 0 && tf.Week == 0 {
+		start := time.Date(tf.Year, 1, 1, 0, 0, 0, 0, loc)
+		end := time.Date(tf.Year+1, 1, 1, 0, 0, 0, 0, loc).Add(-time.Second)
+		return start, end
+	}
+
+	// MONTH (+ optional year)
+	if tf.Month != 0 {
+		year := tf.Year
+		if year == 0 {
+			year = now.Year()
+			if int(now.Month()) < tf.Month {
+				year--
+			}
+		}
+
+		start := time.Date(year, time.Month(tf.Month), 1, 0, 0, 0, 0, loc)
+		end := endOfMonth(year, time.Month(tf.Month), loc)
+		return start, end
+	}
+
+	// WEEK (+ optional year)
+	if tf.Week != 0 {
+		year := tf.Year
+		if year == 0 {
+			year = now.Year()
+			_, currentWeek := now.ISOWeek()
+			if currentWeek < tf.Week {
+				year--
+			}
+		}
+
+		// ISO week 1 contains Jan 4
+		jan4 := time.Date(year, 1, 4, 0, 0, 0, 0, loc)
+		week1Start := startOfWeek(jan4)
+
+		start := week1Start.AddDate(0, 0, (tf.Week-1)*7)
+		end := endOfWeek(start)
+		return start, end
+	}
+
+	// ---------------------------------------------------------------------
+	// 4. Period
+	// ---------------------------------------------------------------------
+
+	if !tf.Period.IsZero() {
+		return StartTimeFromPeriod(tf.Period), now
+	}
+
+	// ---------------------------------------------------------------------
+	// 5. Fallback: empty timeframe → zero values
+	// ---------------------------------------------------------------------
+	return time.Time{}, time.Time{}
+}
+
+func startOfWeek(t time.Time) time.Time {
+	// ISO week: Monday = 1
+	weekday := int(t.Weekday())
+	if weekday == 0 { // Sunday
+		weekday = 7
+	}
+	return time.Date(t.Year(), t.Month(), t.Day()-weekday+1, 0, 0, 0, 0, t.Location())
+}
+func endOfWeek(t time.Time) time.Time {
+	return startOfWeek(t).AddDate(0, 0, 7).Add(-time.Second)
+}
+func endOfMonth(year int, month time.Month, loc *time.Location) time.Time {
+	startNextMonth := time.Date(year, month+1, 1, 0, 0, 0, 0, loc)
+	return startNextMonth.Add(-time.Second)
+}