feat(cli): 'lectio --liturgy/-L' prints the computed liturgical day offline

Uses the pure engine + embedded universal calendar; UI-language names, rank,
colour, cycles, and inline proper readings. Added the Assumption's propers.

4 files changed, 128 insertions, 0 deletions

diff --git a/internal/caldata/roman-calendar.ini b/internal/caldata/roman-calendar.ini
index dfaeb96..8ce49e0 100644
--- a/internal/caldata/roman-calendar.ini
+++ b/internal/caldata/roman-calendar.ini
@@ -61,6 +61,10 @@ colour = white
 name.en = The Assumption of the Blessed Virgin Mary
 name.pl = Wniebowzięcie Najświętszej Maryi Panny
 name.la = In Assumptione Beatae Mariae Virginis
+reading.first = Rev 11:19; 12:1-6.10
+reading.psalm = Ps 45:10-16
+reading.second = 1 Cor 15:20-27
+reading.gospel = Lk 1:39-56
 
 [all-saints]
 date = 11-01
diff --git a/internal/cli/cli.go b/internal/cli/cli.go
index d69bce0..6d09591 100644
--- a/internal/cli/cli.go
+++ b/internal/cli/cli.go
@@ -119,6 +119,7 @@ func Run(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	var width int
 	var list bool
 	var ref string
+	var liturgy bool
 
 	fs := flag.NewFlagSet("lectio", flag.ContinueOnError)
 	fs.SetOutput(stderr)
@@ -163,6 +164,8 @@ func Run(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	fs.StringVar(&output, "out", "", "write --md/--pdf output to FILE (default: stdout)")
 	fs.StringVar(&output, "output", "", "write --md/--pdf output to FILE (default: stdout)")
 	fs.StringVar(&calendar, "calendar", "", "export a month (YYYY-MM) as a printable A4 PDF calendar")
+	fs.BoolVar(&liturgy, "L", false, "print the computed liturgical day (offline calendar engine) and exit")
+	fs.BoolVar(&liturgy, "liturgy", false, "print the computed liturgical day (offline calendar engine) and exit")
 
 	if err := fs.Parse(rest); err != nil {
 		return 2
@@ -207,6 +210,10 @@ func Run(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 		cfg.UILanguage = config.NormalizeUILanguage(uiLang)
 	}
 
+	if liturgy {
+		return runLiturgy(cfg, date, stdout, stderr)
+	}
+
 	if citation || week || randV || randCh {
 		tbl, _ := bible.LoadBookTable(userBooksTOML())
 		switch {
diff --git a/internal/cli/liturgy.go b/internal/cli/liturgy.go
new file mode 100644
index 0000000..523531d
--- /dev/null
+++ b/internal/cli/liturgy.go
@@ -0,0 +1,84 @@
+package cli
+
+import (
+	"fmt"
+	"io"
+	"strings"
+	"time"
+
+	"github.com/lukaszkasprzak/lectio/internal/caldata"
+	"github.com/lukaszkasprzak/lectio/internal/calendar"
+	"github.com/lukaszkasprzak/lectio/internal/config"
+)
+
+// runLiturgy prints the computed liturgical day for date (default today) using
+// the offline calendar engine, and exits. It is the engine's demo/validation
+// surface; the daily-readings paths still use the scraper.
+func runLiturgy(cfg config.Config, date string, stdout, stderr io.Writer) int {
+	if date == "" {
+		date = today()
+	}
+	d, err := time.Parse("2006-01-02", date)
+	if err != nil {
+		fmt.Fprintf(stderr, "lectio: bad date %q (want YYYY-MM-DD)\n", date)
+		return 2
+	}
+	day := calendar.Compute(d.UTC(), cfg.Selection(), []calendar.Layer{caldata.Universal()})
+	printLiturgicalDay(stdout, cfg, day)
+	return 0
+}
+
+func printLiturgicalDay(out io.Writer, cfg config.Config, day calendar.LiturgicalDay) {
+	fmt.Fprintf(out, "%s  %s\n", day.Date.Format("2006-01-02"), day.Weekday.String())
+	fmt.Fprintf(out, "season:   %s (week %d · Sunday cycle %s · weekday cycle %s)\n",
+		day.Season, day.Week, day.SundayCycle, day.WeekdayCycle)
+	fmt.Fprintf(out, "observed: %s  [%s · %s]\n", celebrationName(cfg, day.Observed), rankLabel(day.Observed.Rank), day.Colour)
+	for _, o := range day.Others {
+		if n := celebrationName(cfg, o); n != "" {
+			fmt.Fprintf(out, "  also:   %s  [%s]\n", n, rankLabel(o.Rank))
+		}
+	}
+	for _, m := range day.Observed.Masses {
+		for _, r := range m.Readings {
+			label := r.Part
+			if m.Variant != "" {
+				label = m.Variant + " " + label
+			}
+			fmt.Fprintf(out, "  %-16s %s\n", label+":", r.Citation)
+		}
+	}
+}
+
+// celebrationName is the celebration's name in the UI language (falling back to
+// English, then a humanized slug for temporal days that carry no proper name).
+func celebrationName(cfg config.Config, c calendar.Celebration) string {
+	lang := "en"
+	if cfg.UILanguage == "pl" {
+		lang = "pl"
+	}
+	if n := c.Name[lang]; n != "" {
+		return n
+	}
+	if n := c.Name["en"]; n != "" {
+		return n
+	}
+	if c.Slug == "" {
+		return "(feria)"
+	}
+	return strings.ReplaceAll(c.Slug, "-", " ")
+}
+
+func rankLabel(r calendar.Rank) string {
+	switch r {
+	case calendar.RankSolemnity:
+		return "solemnity"
+	case calendar.RankFeast:
+		return "feast"
+	case calendar.RankMemorial:
+		return "memorial"
+	case calendar.RankOptional:
+		return "optional memorial"
+	default:
+		return "feria"
+	}
+}
diff --git a/internal/cli/liturgy_test.go b/internal/cli/liturgy_test.go
new file mode 100644
index 0000000..c3ab0b4
--- /dev/null
+++ b/internal/cli/liturgy_test.go
@@ -0,0 +1,33 @@
+package cli
+
+import (
+	"bytes"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/lukaszkasprzak/lectio/internal/config"
+)
+
+func TestRunLiturgy(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("LECTIO_CONFIG", filepath.Join(dir, "config.ini"))
+	cfg, err := config.Load()
+	if err != nil {
+		t.Fatal(err)
+	}
+	var buf bytes.Buffer
+	if code := runLiturgy(cfg, "2025-08-15", &buf, &buf); code != 0 {
+		t.Fatalf("exit code %d", code)
+	}
+	out := buf.String()
+	if !strings.Contains(out, "2025-08-15") {
+		t.Errorf("missing date:\n%s", out)
+	}
+	if !strings.Contains(strings.ToLower(out), "solemnity") || !strings.Contains(out, "Assumption") {
+		t.Errorf("2025-08-15 should be the Assumption solemnity:\n%s", out)
+	}
+	if !strings.Contains(out, "gospel:") {
+		t.Errorf("proper reading not shown:\n%s", out)
+	}
+}