feat: usos sign-in, private calendar feed and timetable archive

internal/ical/ical.go

@@ -0,0 +1,114 @@
+package ical
+
+import (
+	"io"
+	"strings"
+	"time"
+	"unicode/utf8"
+
+	"usoscal/internal/store"
+)
+
+const (
+	stamp     = "20060102T150405Z"
+	lineLimit = 75
+)
+
+func Summary(event store.Event) string {
+	if event.Kind == "" || event.Kind == event.Title {
+		return event.Title
+	}
+	return event.Title + " (" + event.Kind + ")"
+}
+
+func Location(event store.Event) string {
+	place := event.Room
+	switch {
+	case place != "" && event.Building != "":
+		place += " (" + event.Building + ")"
+	case place == "":
+		place = event.Building
+	}
+	return joinNonEmpty(", ", place, event.Address)
+}
+
+func Description(event store.Event) string {
+	about := event.Kind
+	if event.Group != "" {
+		about = joinNonEmpty(", ", about, "group "+event.Group)
+	}
+	lecturers := ""
+	if event.Lecturers != "" {
+		lecturers = "Lecturer: " + event.Lecturers
+	}
+	return joinNonEmpty("\n", about, lecturers, event.URL)
+}
+
+func Write(w io.Writer, name, host string, events []store.Event) error {
+	var b strings.Builder
+	line(&b, "BEGIN:VCALENDAR")
+	line(&b, "VERSION:2.0")
+	line(&b, "PRODID:-//usoscal//EN")
+	line(&b, "CALSCALE:GREGORIAN")
+	line(&b, "METHOD:PUBLISH")
+	line(&b, "X-WR-CALNAME:"+escape(name))
+	line(&b, "X-WR-TIMEZONE:Europe/Warsaw")
+	line(&b, "REFRESH-INTERVAL;VALUE=DURATION:PT6H")
+	line(&b, "X-PUBLISHED-TTL:PT6H")
+	for _, event := range events {
+		line(&b, "BEGIN:VEVENT")
+		line(&b, "UID:"+event.UID+"@"+host)
+		line(&b, "DTSTAMP:"+utc(event.UpdatedAt))
+		line(&b, "LAST-MODIFIED:"+utc(event.UpdatedAt))
+		line(&b, "DTSTART:"+utc(event.Start))
+		line(&b, "DTEND:"+utc(event.End))
+		line(&b, "SUMMARY:"+escape(Summary(event)))
+		if location := Location(event); location != "" {
+			line(&b, "LOCATION:"+escape(location))
+		}
+		if description := Description(event); description != "" {
+			line(&b, "DESCRIPTION:"+escape(description))
+		}
+		if event.URL != "" {
+			line(&b, "URL:"+event.URL)
+		}
+		line(&b, "END:VEVENT")
+	}
+	line(&b, "END:VCALENDAR")
+	_, err := io.WriteString(w, b.String())
+	return err
+}
+
+func utc(t time.Time) string {
+	return t.UTC().Format(stamp)
+}
+
+func joinNonEmpty(separator string, parts ...string) string {
+	kept := parts[:0:0]
+	for _, part := range parts {
+		if part != "" {
+			kept = append(kept, part)
+		}
+	}
+	return strings.Join(kept, separator)
+}
+
+var escaper = strings.NewReplacer(`\`, `\\`, ";", `\;`, ",", `\,`, "\r\n", `\n`, "\n", `\n`, "\r", "")
+
+func escape(text string) string {
+	return escaper.Replace(text)
+}
+
+func line(b *strings.Builder, content string) {
+	for len(content) > lineLimit {
+		cut := lineLimit
+		for cut > 0 && !utf8.RuneStart(content[cut]) {
+			cut--
+		}
+		b.WriteString(content[:cut])
+		b.WriteString("\r\n ")
+		content = content[cut:]
+	}
+	b.WriteString(content)
+	b.WriteString("\r\n")
+}

internal/ical/ical_test.go

@@ -0,0 +1,76 @@
+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)
+	}
+}