From 24a1a8b96f133ff84ede87e13f4ffd7c7b316606 Mon Sep 17 00:00:00 2001
From: Kevin Chabowski <kevin@kch42.de>
Date: Wed, 28 Aug 2013 00:49:03 +0200
Subject: Chronos infos can now be stringified and parsed.

---
 chronos/chronos.go      | 64 +++++++++++++++++++++++++++++++++++++++++++++++++
 chronos/chronos_test.go | 40 ++++++++++++++++++-------------
 2 files changed, 88 insertions(+), 16 deletions(-)

diff --git a/chronos/chronos.go b/chronos/chronos.go
index e66fc76..1d2c943 100644
--- a/chronos/chronos.go
+++ b/chronos/chronos.go
@@ -1,12 +1,18 @@
 package chronos
 
 import (
+	"errors"
+	"fmt"
 	"math"
+	"strconv"
+	"strings"
 	"time"
 )
 
 type TimeUnit int
 
+const timefmt = "2006-01-02 15:04:05"
+
 const (
 	Minute TimeUnit = iota
 	Hour
@@ -18,6 +24,15 @@ const (
 
 var nilTime time.Time
 
+var tuLookup = map[string]TimeUnit{
+	"Minute": Minute,
+	"Hour":   Hour,
+	"Day":    Day,
+	"Week":   Week,
+	"Month":  Month,
+	"Year":   Year,
+}
+
 func (tu TimeUnit) String() string {
 	switch tu {
 	case Minute:
@@ -98,6 +113,10 @@ type Frequency struct {
 	Count uint
 }
 
+func (f Frequency) String() string {
+	return fmt.Sprintf("%d %s", f.Count, f.Unit)
+}
+
 func (f Frequency) addTo(t time.Time, mul uint) time.Time {
 	sec := t.Second()
 	min := t.Minute()
@@ -163,3 +182,48 @@ func (c Chronos) NextAfter(t time.Time) time.Time {
 
 	return nilTime // Should actually never happen...
 }
+
+func (c Chronos) String() string {
+	s := c.Start.UTC().Format(timefmt)
+	if c.Freq.Count > 0 {
+		s += " +" + c.Freq.String()
+		if !c.End.IsZero() {
+			s += " !" + c.End.UTC().Format(timefmt)
+		}
+	}
+	return s
+}
+
+func ParseChronos(s string) (c Chronos, err error) {
+	elems := strings.Split(s, " ")
+
+	switch len(elems) {
+	case 6: // Everything specified
+		_end := elems[4] + " " + elems[5]
+		if c.End, err = time.ParseInLocation(timefmt, _end[1:], time.UTC); err != nil {
+			return
+		}
+		fallthrough
+	case 4: // start time and frequency
+		var count uint64
+		if count, err = strconv.ParseUint(elems[2][1:], 10, 32); err != nil {
+			return
+		}
+		c.Freq.Count = uint(count)
+		
+		var ok bool
+		if c.Freq.Unit, ok = tuLookup[elems[3]]; !ok {
+			err = fmt.Errorf("Unknown timeunit %s", elems[3])
+			return
+		}
+		fallthrough
+	case 2: // Only start time
+		if c.Start, err = time.ParseInLocation(timefmt, elems[0]+" "+elems[1], time.UTC); err != nil {
+			return
+		}
+	default:
+		err = errors.New("Unknown chronos format")
+	}
+
+	return
+}
diff --git a/chronos/chronos_test.go b/chronos/chronos_test.go
index 692af14..1798b4c 100644
--- a/chronos/chronos_test.go
+++ b/chronos/chronos_test.go
@@ -6,32 +6,40 @@ import (
 )
 
 func mktime(y int, month time.Month, d, h, min int) time.Time {
-	return time.Date(y, month, d, h, min, 0, 0, time.Local)
+	return time.Date(y, month, d, h, min, 0, 0, time.UTC)
 }
 
 func TestChronos(t *testing.T) {
 	tbl := []struct {
-		start time.Time
-		end   time.Time
-		unit  TimeUnit
-		count uint
-		now   time.Time
-		want  time.Time
+		chronos string
+		now     time.Time
+		want    time.Time
 	}{
-		{mktime(1991, 4, 30, 0, 0), nilTime, Year, 1, mktime(2013, 8, 26, 13, 37), mktime(2014, 4, 30, 0, 0)},
-		{mktime(2013, 1, 1, 0, 0), nilTime, Year, 0, mktime(2013, 8, 26, 13, 37), nilTime},
-		{mktime(2013, 1, 1, 0, 0), nilTime, Year, 0, mktime(2012, 1, 1, 0, 0), mktime(2013, 1, 1, 0, 0)},
-		{mktime(1900, 12, 24, 12, 34), nilTime, Year, 5, mktime(2013, 8, 26, 13, 37), mktime(2015, 12, 24, 12, 34)},
-		{mktime(1900, 12, 24, 12, 34), mktime(2010, 1, 1, 1, 1), Year, 5, mktime(2013, 8, 26, 13, 37), nilTime},
-		{mktime(2013, 8, 1, 4, 2), nilTime, Week, 3, mktime(2013, 8, 26, 13, 37), mktime(2013, 9, 12, 4, 2)},
-		{mktime(2013, 8, 26, 13, 37), nilTime, Year, 0, mktime(2013, 8, 26, 13, 37), mktime(2013, 8, 26, 13, 37)},
-		{mktime(2013, 8, 25, 13, 37), nilTime, Day, 1, mktime(2013, 8, 26, 13, 37), mktime(2013, 8, 26, 13, 37)},
+		{"1991-04-30 00:00:00 +1 Year", mktime(2013, 8, 26, 13, 37), mktime(2014, 4, 30, 0, 0)},
+		{"2013-01-01 00:00:00", mktime(2013, 8, 26, 13, 37), nilTime},
+		{"2013-01-01 00:00:00", mktime(2012, 1, 1, 0, 0), mktime(2013, 1, 1, 0, 0)},
+		{"1900-12-24 12:34:00 +5 Year", mktime(2013, 8, 26, 13, 37), mktime(2015, 12, 24, 12, 34)},
+		{"1900-12-24 12:34:00 +5 Year !2010-01-01 01:01:00", mktime(2013, 8, 26, 13, 37), nilTime},
+		{"2013-08-01 04:02:00 +3 Week", mktime(2013, 8, 26, 13, 37), mktime(2013, 9, 12, 4, 2)},
+		{"2013-08-26 13:37:00", mktime(2013, 8, 26, 13, 37), mktime(2013, 8, 26, 13, 37)},
+		{"2013-08-25 13:37:00 +1 Day", mktime(2013, 8, 26, 13, 37), mktime(2013, 8, 26, 13, 37)},
+		{"2012-12-31 23:59:00 +100 Minute", mktime(2013, 1, 1, 0, 0), mktime(2013, 1, 1, 1, 39)},
 	}
 
 	for i, e := range tbl {
-		have := Chronos{e.start, e.end, Frequency{e.unit, e.count}}.NextAfter(e.now)
+		c, err := ParseChronos(e.chronos)
+		if err != nil {
+			t.Errorf("#%d: Failed parsing \"%s\": %s", i, e.chronos, err)
+			continue
+		}
+		have := c.NextAfter(e.now)
 		if !have.Equal(e.want) {
 			t.Errorf("#%d: Want: %s, Have: %s", i, e.want, have)
 		}
+
+		if s := c.String(); s != e.chronos {
+			t.Errorf("#%d: String() failed: \"%s\" != \"%s\"", i, e.chronos, s)
+		}
+
 	}
 }
-- 
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