package main

import (
	"strings"
	"testing"
	"time"
)

func TestParseICal(t *testing.T) {
	t.Run("Complex", func(t *testing.T) {
		i, err := ParseICal(strings.NewReader(icsWithTZ))
		if err != nil {
			t.Fatalf("Parse failed: %s", err)
		}

		if i.Summary() != "WithTZ" {
			t.Error("Summary is wrong.")
		}
		if i.UID() != "e726899a5ca4c9e478842669bac9688144bb95d9" {
			t.Error("UID is wrong")
		}
		if i.Start().Format(ICAL_TIME) != "20180411T170000" {
			t.Error("Start time wrong")
		}
		if i.End().Format(ICAL_TIME) != "20180411T210000" {
			t.Error("End time wrong")
		}
		// No "Z" at the end --> local time zone.
		if i.Start().Location() != time.Local {
			t.Error("Timezone is wrong")
		}
	})
	t.Run("Simple", func(t *testing.T) {
		i, err := ParseICal(strings.NewReader(icsSimple))
		if err != nil {
			t.Fatalf("Parse failed: %s", err)
		}

		if i.Summary() != "Anon" {
			t.Error("Summary is wrong.")
		}
		if i.Start().Format(ICAL_TIME) != "20180308T113000" {
			t.Error("Start time wrong")
		}
		if i.End().Format(ICAL_TIME) != "20180308T130000" {
			t.Error("End time wrong")
		}
		// "Z" at the end --> UTC.
		if i.Start().Location() != time.UTC {
			t.Error("Start time should be UTC")
		}
	})
	t.Run("First event only", func(t *testing.T) {
		i, err := ParseICal(strings.NewReader(icsMultiEvents))
		if err != nil {
			t.Fatalf("Parse failed: %s", err)
		}

		if i.Summary() != "First" {
			t.Error("Summary is wrong.")
		}
		if i.UID() != "123" {
			t.Error("UID is wrong.")
		}

		// Check that our sub slice is correct:
		if i.eventData[0] != "UID:123" {
			t.Error("First line is wrong")
		}
		if i.eventData[len(i.eventData)-1] != "LAST-MODIFIED:20180401T182238Z" {
			t.Error("Last line is wrong")
		}
	})
	t.Run("Whole day", func(t *testing.T) {
		i, err := ParseICal(strings.NewReader(icsWithDateOnly))
		if err != nil {
			t.Fatalf("Parse failed: %s", err)
		}

		start := i.Start()
		end := i.End()

		expectedStart := time.Date(2018, 4, 7, 0, 0, 0, 0, time.Local)
		expectedEnd := time.Date(2018, 4, 9, 0, 0, 0, 0, time.Local)

		if !start.Equal(expectedStart) {
			t.Errorf("Unexpected start time (%s != %s)", start, expectedStart)
		}
		if !end.Equal(expectedEnd) {
			t.Errorf("Unexpected end time (%s != %s)", end, expectedEnd)
		}
	})
}

func TestICal_Update(t *testing.T) {
	newStart := time.Date(2019, 10, 05, 10, 25, 0, 0, time.UTC)
	newEnd := time.Date(2019, 10, 05, 10, 55, 30, 0, time.UTC)

	t.Run("Values updated", func(t *testing.T) {
		ical, _ := ParseICal(strings.NewReader(icsSimple))
		ical.Update(newStart, newEnd, false)

		if ical.Start() != newStart {
			t.Error("Start not updated correctly")
		}
		if ical.End() != newEnd {
			t.Error("End not updated correctly")
		}

		if ical.getTimeField("DTSTAMP").Sub(time.Now()) > 5*time.Second {
			t.Error("Timestamp doesn't seem to be updated")
		}
	})

	t.Run("Other values untouched", func(t *testing.T) {
		// Use a ICal structure with dummy/unknown fields but also without
		// DTSTAMP or LAST-MODIFIED, so we can do a string comparison against
		// known values.
		ical, _ := ParseICal(strings.NewReader(`BEGIN:VCALENDAR
PRODID:-//some//thing//EN
VERSION:2.0
UNKNOWN:FIELD
SOME;MORE:STUFF
BEGIN:VEVENT
UID:WHATEVERID
SUMMARY:Summary
CLASS:PUBLIC
DTSTART:20180308T113000Z
DTEND:20180308T130000Z
CREATED:20180401T182238Z
END:VEVENT
EVEN;MORE:STUFF
END:VCALENDAR`))

		ical.Update(newStart, newEnd, false)

		if ical.String() != `BEGIN:VCALENDAR
PRODID:-//some//thing//EN
VERSION:2.0
UNKNOWN:FIELD
SOME;MORE:STUFF
BEGIN:VEVENT
UID:WHATEVERID
SUMMARY:Summary
CLASS:PUBLIC
DTSTART:20191005T102500Z
DTEND:20191005T105530Z
CREATED:20180401T182238Z
END:VEVENT
EVEN;MORE:STUFF
END:VCALENDAR` {

			t.Error("The resulting ICS seems wrong.")
		}
	})

	t.Run("Values wholeDay", func(t *testing.T) {
		newStart := time.Date(2019, 1, 2, 0, 0, 0, 0, time.Local)
		newEnd := time.Date(2019, 1, 3, 0, 0, 0, 0, time.Local)

		ical, _ := ParseICal(strings.NewReader(icsSimple))
		ical.Update(newStart, newEnd, true)

		if ical.Start() != newStart {
			t.Error("Start not updated correctly")
		}
		if ical.End() != newEnd {
			t.Error("End not updated correctly")
		}

		if ical.getTimeField("DTSTAMP").Sub(time.Now()) > 5*time.Second {
			t.Error("Timestamp doesn't seem to be updated")
		}
	})
}

const icsWithTZ = `BEGIN:VCALENDAR
PRODID:-//Ximian//NONSGML Evolution Calendar//EN
VERSION:2.0
CALSCALE:GREGORIAN
BEGIN:VTIMEZONE
TZID:/freeassociation.sourceforge.net/Europe/Berlin
X-LIC-LOCATION:Europe/Berlin
BEGIN:DAYLIGHT
TZNAME:CEST
DTSTART:19160429T230000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;UNTIL=19160430T220000Z;BYMONTH=4;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZNAME:CET
DTSTART:19161007T010000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;UNTIL=19160930T230000Z;BYMONTH=10;BYDAY=1SU
END:STANDARD
BEGIN:DAYLIGHT
TZNAME:CEST
DTSTART:19170416T020000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;UNTIL=19180415T010000Z;BYMONTH=4;BYDAY=3MO
END:DAYLIGHT
BEGIN:STANDARD
TZNAME:CET
DTSTART:19170917T030000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;UNTIL=19180916T010000Z;BYMONTH=9;BYDAY=3MO
END:STANDARD
BEGIN:DAYLIGHT
TZNAME:CEST
DTSTART:19400402T020000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;UNTIL=19400401T010000Z;BYMONTH=4;BYDAY=1MO
END:DAYLIGHT
BEGIN:STANDARD
TZNAME:CET
DTSTART:19421105T030000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;UNTIL=19421102T010000Z;BYMONTH=11;BYDAY=1MO
END:STANDARD
BEGIN:DAYLIGHT
TZNAME:CEST
DTSTART:19430326T020000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;UNTIL=19430329T010000Z;BYMONTH=3;BYDAY=-1MO
END:DAYLIGHT
BEGIN:STANDARD
TZNAME:CET
DTSTART:19431001T030000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;UNTIL=19441002T010000Z;BYMONTH=10;BYDAY=1MO
END:STANDARD
BEGIN:DAYLIGHT
TZNAME:CEST
DTSTART:19440402T020000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;UNTIL=19450402T000000Z;BYMONTH=4;BYDAY=1MO
END:DAYLIGHT
BEGIN:DAYLIGHT
TZNAME:CEMT
DTSTART:19450524T020000
TZOFFSETFROM:+0200
TZOFFSETTO:+0300
RRULE:FREQ=YEARLY;UNTIL=19450523T230000Z;BYMONTH=5;BYDAY=-2TH
END:DAYLIGHT
BEGIN:DAYLIGHT
TZNAME:CEST
DTSTART:19450924T030000
TZOFFSETFROM:+0300
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;UNTIL=19450924T020000Z;BYMONTH=9;BYDAY=-1MO
END:DAYLIGHT
BEGIN:STANDARD
TZNAME:CET
DTSTART:19451118T030000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;UNTIL=19451118T020000Z;BYMONTH=11;BYDAY=3SU
END:STANDARD
BEGIN:STANDARD
TZNAME:CET
DTSTART:19460102T000000
TZOFFSETFROM:+0100
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;UNTIL=19451231T220000Z;BYMONTH=1;BYDAY=1TU
END:STANDARD
BEGIN:DAYLIGHT
TZNAME:CEST
DTSTART:19460408T020000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;UNTIL=19460414T010000Z;BYMONTH=4;BYDAY=2SU
END:DAYLIGHT
BEGIN:STANDARD
TZNAME:CET
DTSTART:19461001T030000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;UNTIL=19461007T010000Z;BYMONTH=10;BYDAY=1MO
END:STANDARD
BEGIN:DAYLIGHT
TZNAME:CEST
DTSTART:19470401T030000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;UNTIL=19470406T010000Z;BYMONTH=4;BYDAY=1SU
END:DAYLIGHT
BEGIN:DAYLIGHT
TZNAME:CEMT
DTSTART:19470513T030000
TZOFFSETFROM:+0200
TZOFFSETTO:+0300
RRULE:FREQ=YEARLY;UNTIL=19470511T000000Z;BYMONTH=5;BYDAY=2SU
END:DAYLIGHT
BEGIN:DAYLIGHT
TZNAME:CEST
DTSTART:19470624T030000
TZOFFSETFROM:+0300
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;UNTIL=19470629T020000Z;BYMONTH=6;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZNAME:CET
DTSTART:19471007T030000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;UNTIL=19491002T020000Z;BYMONTH=10;BYDAY=1SU
END:STANDARD
BEGIN:DAYLIGHT
TZNAME:CEST
DTSTART:19480415T020000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;UNTIL=19480418T010000Z;BYMONTH=4;BYDAY=3SU
END:DAYLIGHT
BEGIN:DAYLIGHT
TZNAME:CEST
DTSTART:19490408T020000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;UNTIL=19490410T010000Z;BYMONTH=4;BYDAY=2SU
END:DAYLIGHT
BEGIN:STANDARD
TZNAME:CET
DTSTART:19800102T000000
TZOFFSETFROM:+0100
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;UNTIL=19791231T220000Z;BYMONTH=1;BYDAY=1TU
END:STANDARD
BEGIN:DAYLIGHT
TZNAME:CEST
DTSTART:19800401T020000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;UNTIL=19800406T010000Z;BYMONTH=4;BYDAY=1SU
END:DAYLIGHT
BEGIN:STANDARD
TZNAME:CET
DTSTART:19800930T030000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;UNTIL=19950924T010000Z;BYMONTH=9;BYDAY=-1SU
END:STANDARD
BEGIN:DAYLIGHT
TZNAME:CEST
DTSTART:19810325T020000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZNAME:CET
DTSTART:19961028T030000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
UID:e726899a5ca4c9e478842669bac9688144bb95d9
DTSTAMP:20180312T092638Z
DTSTART;TZID=/freeassociation.sourceforge.net/Europe/Berlin:20180411T170000
 
DTEND;TZID=/freeassociation.sourceforge.net/Europe/Berlin:20180411T210000
SEQUENCE:2
SUMMARY:WithTZ
TRANSP:OPAQUE
CLASS:PUBLIC
CREATED:20180313T074119Z
LAST-MODIFIED:20180313T074119Z
END:VEVENT
END:VCALENDAR`

const icsWithDateOnly = `BEGIN:VCALENDAR
PRODID:+//IDN bitfire.at//DAVdroid/1.10.1.1-gplay ical4j/2.x
VERSION:2.0
BEGIN:VEVENT
DTSTAMP:20180308T192428Z
UID:b3cf0d84-b746-420c-8642-3b107ddfd834
SUMMARY:WholeDay
DTSTART;VALUE=DATE:20180407
DTEND;VALUE=DATE:20180409
STATUS:CONFIRMED
TRANSP:TRANSPARENT
CLASS:PUBLIC
END:VEVENT
END:VCALENDAR`

const icsSimple = `BEGIN:VCALENDAR
PRODID:-//aksdb//calanonsync//EN
VERSION:2.0
BEGIN:VEVENT
UID:0A6768CB8B086C58F2942757C6E515DF
SUMMARY:Anon
CLASS:PUBLIC
DTSTART:20180308T113000Z
DTEND:20180308T130000Z
CREATED:20180401T182238Z
DTSTAMP:20180401T182238Z
LAST-MODIFIED:20180401T182238Z
END:VEVENT
END:VCALENDAR`

const icsMultiEvents = `BEGIN:VCALENDAR
PRODID:-//some//thing//EN
VERSION:2.0
BEGIN:VEVENT
UID:123
SUMMARY:First
CLASS:PUBLIC
DTSTART:20180308T113000Z
DTEND:20180308T130000Z
CREATED:20180401T182238Z
DTSTAMP:20180401T182238Z
LAST-MODIFIED:20180401T182238Z
END:VEVENT
BEGIN:VEVENT
UID:456
SUMMARY:Second
CLASS:PUBLIC
DTSTART:20180309T113000Z
DTEND:20180309T130000Z
CREATED:20180401T182238Z
DTSTAMP:20180401T182238Z
LAST-MODIFIED:20180401T182239Z
END:VEVENT
END:VCALENDAR`