package ical

import (
	"strings"
	"testing"
	"time"
	"unicode/utf8"

	"usoscal/internal/store"
)

func TestWrite(t *testing.T) {
	warsaw, err := time.LoadLocation("Europe/Warsaw")
	if err != nil {
		t.Fatal(err)
	}
	event := store.Event{
		UID:       "sm-90917229",
		Start:     time.Date(2026, 10, 9, 11, 45, 0, 0, warsaw),
		End:       time.Date(2026, 10, 9, 13, 15, 0, 0, warsaw),
		Title:     "Algebra liniowa z elementami matematyki dyskretnej",
		Kind:      "Laboratorium",
		Group:     "2",
		Room:      "602",
		Building:  "A1 - BM - Budowa Maszyn, budynek z zegarem",
		Address:   "ul. Piotrowo 3, 61-138 Poznań, Polska",
		Lecturers: "dr inż. Zażółć Gęślą-Jaźń",
		URL:       "https://usosweb.put.poznan.pl/kontroler.php?_action=x&gr_nr=2",
		UpdatedAt: time.Date(2026, 10, 1, 8, 0, 0, 0, time.UTC),
	}
	var out strings.Builder
	if err := Write(&out, "USOS", "usos.example", []store.Event{event}); err != nil {
		t.Fatal(err)
	}
	text := out.String()

	for _, rawLine := range strings.Split(strings.TrimSuffix(text, "\r\n"), "\r\n") {
		if len(rawLine) > lineLimit+1 {
			t.Errorf("line longer than the fold limit: %q", rawLine)
		}
		if !utf8.ValidString(rawLine) {
			t.Errorf("fold split a character: %q", rawLine)
		}
	}
	if strings.Contains(strings.ReplaceAll(text, "\r\n", ""), "\n") {
		t.Error("bare line feed in the output")
	}

	unfolded := strings.ReplaceAll(text, "\r\n ", "")
	for _, want := range []string{
		"UID:sm-90917229@usos.example\r\n",
		"DTSTART:20261009T094500Z\r\n",
		"DTEND:20261009T111500Z\r\n",
		"SUMMARY:Algebra liniowa z elementami matematyki dyskretnej (Laboratorium)\r\n",
		`LOCATION:602 (A1 - BM - Budowa Maszyn\, budynek z zegarem)\, ul. Piotrowo 3\, 61-138 Poznań\, Polska` + "\r\n",
		`DESCRIPTION:Laboratorium\, group 2\nLecturer: dr inż. Zażółć Gęślą-Jaźń\nhttps://usosweb.put.poznan.pl/kontroler.php?_action=x&gr_nr=2` + "\r\n",
		"END:VCALENDAR\r\n",
	} {
		if !strings.Contains(unfolded, want) {
			t.Errorf("missing %q in\n%s", want, unfolded)
		}
	}
}

func TestSparseEvent(t *testing.T) {
	event := store.Event{UID: "x", Title: "Spotkanie", Kind: "Spotkanie", Start: time.Unix(0, 0), End: time.Unix(60, 0)}
	if got := Summary(event); got != "Spotkanie" {
		t.Errorf("Summary = %q", got)
	}
	if got := Location(event); got != "" {
		t.Errorf("Location = %q", got)
	}
	if got := Description(event); got != "Spotkanie" {
		t.Errorf("Description = %q", got)
	}
}