Merge pull request #44 from shaohme/time-parsing

Extended time parsing

calendar.go

@@ -353,7 +353,7 @@ func (calendar *Calendar) SetDescription(s string, props ...PropertyParameter) {
 }
 
 func (calendar *Calendar) SetLastModified(t time.Time, props ...PropertyParameter) {
-	calendar.setProperty(PropertyLastModified, t.UTC().Format(icalTimeFormat), props...)
+	calendar.setProperty(PropertyLastModified, t.UTC().Format(icalTimestampFormatUtc), props...)
 }
 
 func (calendar *Calendar) SetRefreshInterval(s string, props ...PropertyParameter) {

calendar_test.go

@@ -9,10 +9,98 @@ import (
 	"strings"
 	"testing"
 	"unicode/utf8"
-
+	"time"
 	"github.com/stretchr/testify/assert"
 )
 
+func TestTimeParsing(t *testing.T) {
+	calFile, err := os.OpenFile("./testdata/timeparsing.ics", os.O_RDONLY, 0400)
+	if err != nil {
+		t.Errorf("read file: %v", err)
+	}
+	cal, err := ParseCalendar(calFile)
+	if err != nil {
+		t.Errorf("parse calendar: %v", err)
+	}
+
+	cphLoc, locErr := time.LoadLocation("Europe/Copenhagen")
+	if locErr != nil {
+		t.Errorf("could not load location")
+	}
+
+	var tests = []struct {
+		uid         string
+		start       time.Time
+		end         time.Time
+		allDayStart time.Time
+		allDayEnd   time.Time
+	}{
+		// FORM 1
+		{"be7c9690-d42a-40ef-b82f-1634dc5033b4",
+			time.Date(1998, 1, 18, 23, 0, 0, 0, time.Local),
+			time.Date(1998, 1, 19, 23, 0, 0, 0, time.Local),
+			time.Date(1998, 1, 18, 0, 0, 0, 0, time.Local),
+			time.Date(1998, 1, 19, 0, 0, 0, 0, time.Local)},
+		// FORM 2
+		{"53634aed-1b7d-4d85-aa38-ede76a2e4fe3",
+			time.Date(2022, 1, 22, 17, 0, 0, 0, time.UTC),
+			time.Date(2022, 1, 22, 20, 0, 0, 0, time.UTC),
+			time.Date(2022, 1, 22, 0, 0, 0, 0, time.UTC),
+			time.Date(2022, 1, 22, 0, 0, 0, 0, time.UTC)},
+		// FORM 3
+		{"269cf715-4e14-4a10-8753-f2feeb9d060e",
+			time.Date(2021, 12, 7, 14, 0, 0, 0, cphLoc),
+			time.Date(2021, 12, 7, 15, 0, 0, 0, cphLoc),
+			time.Date(2021, 12, 7, 0, 0, 0, 0, cphLoc),
+			time.Date(2021, 12, 7, 0, 0, 0, 0, cphLoc)},
+		// Unknown local date, with 'VALUE'
+		{"fb54680e-7f69-46d3-9632-00aed2469f7b",
+			time.Date(2021, 6, 27, 0, 0, 0, 0, time.Local),
+			time.Date(2021, 6, 28, 0, 0, 0, 0, time.Local),
+			time.Date(2021, 6, 27, 0, 0, 0, 0, time.Local),
+			time.Date(2021, 6, 28, 0, 0, 0, 0, time.Local)},
+		// Unknown UTC date
+		{"62475ad0-a76c-4fab-8e68-f99209afcca6",
+			time.Date(2021, 5, 27, 0, 0, 0, 0, time.UTC),
+			time.Date(2021, 5, 28, 0, 0, 0, 0, time.UTC),
+			time.Date(2021, 5, 27, 0, 0, 0, 0, time.UTC),
+			time.Date(2021, 5, 28, 0, 0, 0, 0, time.UTC)},
+	}
+
+	assertTime := func(evtUid string, exp time.Time, timeFunc func() (given time.Time, err error)) {
+		given, err := timeFunc()
+		if err == nil {
+			if !exp.Equal(given) {
+				t.Errorf("no match on '%s', expected=%v != given=%v", evtUid, exp, given)
+			}
+		} else {
+			t.Errorf("get time on uid '%s', %v", evtUid, err)
+		}
+	}
+	evts := cal.Events()
+
+	for _, tt := range tests {
+		t.Run(tt.uid, func(t *testing.T) {
+			var evt *VEvent
+			for _, e := range evts {
+				if strings.EqualFold(e.Id(), tt.uid) {
+					evt = e
+				}
+			}
+
+			if evt == nil {
+				t.Errorf("event UID not found, %s", tt.uid)
+				return
+			}
+
+			assertTime(tt.uid, tt.start, evt.GetStartAt)
+			assertTime(tt.uid, tt.end, evt.GetEndAt)
+			assertTime(tt.uid, tt.allDayStart, evt.GetAllDayStartAt)
+			assertTime(tt.uid, tt.allDayEnd, evt.GetAllDayEndAt)
+		})
+	}
+}
+
 func TestCalendarStream(t *testing.T) {
 	i := `
 ATTENDEE;RSVP=TRUE;ROLE=REQ-PARTICIPANT;CUTYPE=GROUP:

components.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"regexp"
 	"strconv"
 	"strings"
 	"time"
@@ -55,40 +56,46 @@ func (c *VEvent) Serialize() string {
 }
 
 const (
-	icalTimeFormat       = "20060102T150405Z"
-	icalAllDayTimeFormat = "20060102"
+	icalTimestampFormatUtc   = "20060102T150405Z"
+	icalTimestampFormatLocal = "20060102T150405"
+	icalDateFormatUtc        = "20060102Z"
+	icalDateFormatLocal      = "20060102"
+)
+
+var (
+	timeStampVariations = regexp.MustCompile("^([0-9]{8})?([TZ])?([0-9]{6})?(Z)?$")
 )
 
 func (event *VEvent) SetCreatedTime(t time.Time, props ...PropertyParameter) {
-	event.SetProperty(ComponentPropertyCreated, t.UTC().Format(icalTimeFormat), props...)
+	event.SetProperty(ComponentPropertyCreated, t.UTC().Format(icalTimestampFormatUtc), props...)
 }
 
 func (event *VEvent) SetDtStampTime(t time.Time, props ...PropertyParameter) {
-	event.SetProperty(ComponentPropertyDtstamp, t.UTC().Format(icalTimeFormat), props...)
+	event.SetProperty(ComponentPropertyDtstamp, t.UTC().Format(icalTimestampFormatUtc), props...)
 }
 
 func (event *VEvent) SetModifiedAt(t time.Time, props ...PropertyParameter) {
-	event.SetProperty(ComponentPropertyLastModified, t.UTC().Format(icalTimeFormat), props...)
+	event.SetProperty(ComponentPropertyLastModified, t.UTC().Format(icalTimestampFormatUtc), props...)
 }
 
 func (event *VEvent) SetSequence(seq int, props ...PropertyParameter) {
 	event.SetProperty(ComponentPropertySequence, strconv.Itoa(seq), props...)
 }
 
 func (event *VEvent) SetStartAt(t time.Time, props ...PropertyParameter) {
-	event.SetProperty(ComponentPropertyDtStart, t.UTC().Format(icalTimeFormat), props...)
+	event.SetProperty(ComponentPropertyDtStart, t.UTC().Format(icalTimestampFormatUtc), props...)
 }
 
 func (event *VEvent) SetAllDayStartAt(t time.Time, props ...PropertyParameter) {
-	event.SetProperty(ComponentPropertyDtStart, t.UTC().Format(icalAllDayTimeFormat), props...)
+	event.SetProperty(ComponentPropertyDtStart, t.UTC().Format(icalDateFormatUtc), props...)
 }
 
 func (event *VEvent) SetEndAt(t time.Time, props ...PropertyParameter) {
-	event.SetProperty(ComponentPropertyDtEnd, t.UTC().Format(icalTimeFormat), props...)
+	event.SetProperty(ComponentPropertyDtEnd, t.UTC().Format(icalTimestampFormatUtc), props...)
 }
 
 func (event *VEvent) SetAllDayEndAt(t time.Time, props ...PropertyParameter) {
-	event.SetProperty(ComponentPropertyDtEnd, t.UTC().Format(icalAllDayTimeFormat), props...)
+	event.SetProperty(ComponentPropertyDtEnd, t.UTC().Format(icalDateFormatUtc), props...)
 }
 
 // SetDuration updates the duration of an event.
@@ -111,29 +118,87 @@ func (event *VEvent) SetDuration(d time.Duration) error {
 	return errors.New("start or end not yet defined")
 }
 
-func (event *VEvent) getTimeProp(componentProperty ComponentProperty, tFormat string) (time.Time, error) {
+func (event *VEvent) getTimeProp(componentProperty ComponentProperty, expectAllDay bool) (time.Time, error) {
 	timeProp := event.GetProperty(componentProperty)
 	if timeProp == nil {
 		return time.Time{}, errors.New("property not found")
 	}
+
 	timeVal := timeProp.BaseProperty.Value
-	return time.Parse(tFormat, timeVal)
+	matched := timeStampVariations.FindStringSubmatch(timeVal)
+	if matched == nil {
+		return time.Time{}, fmt.Errorf("time value not matched, got '%s'", timeVal)
+	}
+	tOrZGrp := matched[2]
+	zGrp := matched[4]
+	grp1len := len(matched[1])
+	grp3len := len(matched[3])
+
+	tzId, tzIdOk := timeProp.ICalParameters["TZID"]
+	var propLoc *time.Location
+	if tzIdOk {
+		if len(tzId) != 1 {
+			return time.Time{}, errors.New("expected only one TZID")
+		}
+		var tzErr error
+		propLoc, tzErr = time.LoadLocation(tzId[0])
+		if tzErr != nil {
+			return time.Time{}, tzErr
+		}
+	}
+	dateStr := matched[1]
+
+	if expectAllDay {
+		if grp1len > 0 {
+			if tOrZGrp == "Z" || zGrp == "Z" {
+				return time.ParseInLocation(icalDateFormatUtc, dateStr+"Z", time.UTC)
+			} else {
+				if propLoc == nil {
+					return time.ParseInLocation(icalDateFormatLocal, dateStr, time.Local)
+				} else {
+					return time.ParseInLocation(icalDateFormatLocal, dateStr, propLoc)
+				}
+			}
+		}
+
+		return time.Time{}, fmt.Errorf("time value matched but unsupported all-day timestamp, got '%s'", timeVal)
+	}
+
+	if grp1len > 0 && grp3len > 0 && tOrZGrp == "T" && zGrp == "Z" {
+		return time.ParseInLocation(icalTimestampFormatUtc, timeVal, time.UTC)
+	} else if grp1len > 0 && grp3len > 0 && tOrZGrp == "T" && zGrp == "" {
+		if propLoc == nil {
+			return time.ParseInLocation(icalTimestampFormatLocal, timeVal, time.Local)
+		} else {
+			return time.ParseInLocation(icalTimestampFormatLocal, timeVal, propLoc)
+		}
+	} else if grp1len > 0 && grp3len == 0 && tOrZGrp == "Z" && zGrp == "" {
+		return time.ParseInLocation(icalDateFormatUtc, dateStr + "Z", time.UTC)
+	} else if grp1len > 0 && grp3len == 0 && tOrZGrp == "" && zGrp == "" {
+		if propLoc == nil {
+			return time.ParseInLocation(icalDateFormatLocal, dateStr, time.Local)
+		} else {
+			return time.ParseInLocation(icalDateFormatLocal, dateStr, propLoc)
+		}
+	}
+
+	return time.Time{}, fmt.Errorf("time value matched but not supported, got '%s'", timeVal)
 }
 
 func (event *VEvent) GetStartAt() (time.Time, error) {
-	return event.getTimeProp(ComponentPropertyDtStart, icalTimeFormat)
+	return event.getTimeProp(ComponentPropertyDtStart, false)
 }
 
 func (event *VEvent) GetEndAt() (time.Time, error) {
-	return event.getTimeProp(ComponentPropertyDtEnd, icalTimeFormat)
+	return event.getTimeProp(ComponentPropertyDtEnd, false)
 }
 
 func (event *VEvent) GetAllDayStartAt() (time.Time, error) {
-	return event.getTimeProp(ComponentPropertyDtStart, icalAllDayTimeFormat)
+	return event.getTimeProp(ComponentPropertyDtStart, true)
 }
 
 func (event *VEvent) GetAllDayEndAt() (time.Time, error) {
-	return event.getTimeProp(ComponentPropertyDtEnd, icalAllDayTimeFormat)
+	return event.getTimeProp(ComponentPropertyDtEnd, true)
 }
 
 type TimeTransparency string

testdata/timeparsing.ics

@@ -0,0 +1,53 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:DAVx5/4.0-gplay ical4j/3.1.0
+BEGIN:VTIMEZONE
+TZID:Europe/Copenhagen
+LAST-MODIFIED:20201010T011803Z
+BEGIN:STANDARD
+DTSTART:19961027T030000
+RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
+TZNAME:CET
+TZOFFSETFROM:+0200
+TZOFFSETTO:+0100
+END:STANDARD
+BEGIN:DAYLIGHT
+DTSTART:19810329T020000
+RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
+TZNAME:CEST
+TZOFFSETFROM:+0100
+TZOFFSETTO:+0200
+END:DAYLIGHT
+END:VTIMEZONE
+BEGIN:VEVENT
+UID:269cf715-4e14-4a10-8753-f2feeb9d060e
+DTSTART;TZID=Europe/Copenhagen:20211207T140000
+DTEND;TZID=Europe/Copenhagen:20211207T150000
+SUMMARY:Form 3
+END:VEVENT
+BEGIN:VEVENT
+UID:53634aed-1b7d-4d85-aa38-ede76a2e4fe3
+DTSTART:20220122T170000Z
+DTEND:20220122T200000Z
+SUMMARY:Form #2
+END:VEVENT
+BEGIN:VEVENT
+UID:be7c9690-d42a-40ef-b82f-1634dc5033b4
+DTSTART:19980118T230000
+DTEND:19980119T230000
+DTSTAMP:20210624T080748Z
+SUMMARY:Form #1
+END:VEVENT
+BEGIN:VEVENT
+UID:fb54680e-7f69-46d3-9632-00aed2469f7b
+DTSTART;VALUE=DATE:20210627
+DTEND;VALUE=DATE:20210628
+SUMMARY:Unknown local date, with 'VALUE'
+END:VEVENT
+BEGIN:VEVENT
+UID:62475ad0-a76c-4fab-8e68-f99209afcca6
+DTSTART:20210527Z
+DTEND:20210528Z
+SUMMARY:Unknown UTC date
+END:VEVENT
+END:VCALENDAR