feat(config): migrate to INI + one-shot TOML conversion + calendar Selection

config.Load/Save now read/write config.ini; a pre-existing config.toml is
converted once (old file kept, reversible). New [calendar] section
(epiphany/ascension/corpus_christi) + Config.Selection() feeding the engine.
Config struct API unchanged, so daily-readings and web /settings keep working.

1 files changed, 39 insertions, 2 deletions

diff --git a/internal/config/config_test.go b/internal/config/config_test.go
index 53a3980..38c7604 100644
--- a/internal/config/config_test.go
+++ b/internal/config/config_test.go
@@ -19,7 +19,7 @@ func TestLoadSeeds(t *testing.T) {
 	if cfg.Lectionary != "new" {
 		t.Errorf("lectionary default wrong: %+v", cfg)
 	}
-	if _, err := os.Stat(filepath.Join(dir, "lectio", "config.toml")); err != nil {
+	if _, err := os.Stat(filepath.Join(dir, "lectio", "config.ini")); err != nil {
 		t.Error("config not seeded")
 	}
 }
@@ -201,7 +201,7 @@ func TestSiglaStyleDefaultsAndDialect(t *testing.T) {
 
 func TestSaveRoundTrip(t *testing.T) {
 	dir := t.TempDir()
-	path := filepath.Join(dir, "config.toml")
+	path := filepath.Join(dir, "config.ini")
 	t.Setenv("LECTIO_CONFIG", path)
 
 	cfg := Default()
@@ -224,6 +224,43 @@ func TestSaveRoundTrip(t *testing.T) {
 	}
 }
 
+func TestSelectionFromINI(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("LECTIO_CONFIG", filepath.Join(dir, "config.ini"))
+	os.WriteFile(filepath.Join(dir, "config.ini"),
+		[]byte("lectionary = new\n[calendar]\nepiphany = sunday\nascension = sunday\n"), 0o644)
+	cfg, err := Load()
+	if err != nil {
+		t.Fatal(err)
+	}
+	sel := cfg.Selection()
+	if sel.Form != "new" || sel.Epiphany != "sunday" || sel.Ascension != "sunday" || sel.CorpusChristi != "thursday" {
+		t.Fatalf("selection = %+v", sel)
+	}
+}
+
+func TestMigrateTOMLToINI(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("XDG_CONFIG_HOME", dir)
+	os.MkdirAll(filepath.Join(dir, "lectio"), 0o755)
+	// only the old TOML exists -> Load converts once and writes config.ini.
+	os.WriteFile(filepath.Join(dir, "lectio", "config.toml"),
+		[]byte("ui_language = \"pl\"\ndefault_version = \"wuj\"\n"), 0o644)
+	cfg, err := Load()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cfg.UILanguage != "pl" || cfg.DefaultVersion != "wuj" {
+		t.Errorf("migrated values wrong: %+v", cfg)
+	}
+	if _, err := os.Stat(filepath.Join(dir, "lectio", "config.ini")); err != nil {
+		t.Error("config.ini not written on migration")
+	}
+	if _, err := os.Stat(filepath.Join(dir, "lectio", "config.toml")); err != nil {
+		t.Error("old config.toml should be kept (reversible)")
+	}
+}
+
 func TestPartShown(t *testing.T) {
 	var empty Config
 	if !empty.PartShown("new", "psalm") {