feat(bible): user corpus discovery + override registry

4 files changed, 165 insertions, 2 deletions

diff --git a/internal/bible/bible.go b/internal/bible/bible.go
index 1bc8983..ac746e1 100644
--- a/internal/bible/bible.go
+++ b/internal/bible/bible.go
@@ -2,6 +2,7 @@ package bible
 
 import (
 	"embed"
+	"os"
 	"sort"
 	"strconv"
 	"strings"
@@ -32,8 +33,14 @@ func load(version string) *corpus {
 	if c, ok := corpora[version]; ok {
 		return c
 	}
-	data, err := corporaFS.ReadFile("corpora/" + version + ".tsv")
-	if err != nil {
+	var data []byte
+	if p := userTSVPath(version); p != "" {
+		data, _ = os.ReadFile(p)
+	}
+	if data == nil {
+		data, _ = corporaFS.ReadFile("corpora/" + version + ".tsv")
+	}
+	if data == nil {
 		corpora[version] = &corpus{books: map[string]map[int][]Verse{}}
 		return corpora[version]
 	}
diff --git a/internal/bible/registry.go b/internal/bible/registry.go
new file mode 100644
index 0000000..2ab721b
--- /dev/null
+++ b/internal/bible/registry.go
@@ -0,0 +1,110 @@
+package bible
+
+import (
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"sync"
+)
+
+var (
+	regMu      sync.Mutex
+	userDir    string
+	regBuilt   bool
+	regMeta    map[string]CorpusMeta // code -> meta (user overrides embed)
+	regUserTSV map[string]string     // code -> user .tsv path (override source)
+)
+
+// SetUserCorporaDir sets the drop-in dir and invalidates the registry cache.
+// Empty string disables user corpora (used by tests).
+func SetUserCorporaDir(dir string) {
+	regMu.Lock()
+	userDir = dir
+	regBuilt = false
+	regMu.Unlock()
+
+	corporaMu.Lock()
+	corpora = map[string]*corpus{} // drop cached loads so overrides take effect
+	corporaMu.Unlock()
+}
+
+func buildRegistry() {
+	if regBuilt {
+		return
+	}
+	regMeta = map[string]CorpusMeta{}
+	regUserTSV = map[string]string{}
+	// embedded first
+	ents, _ := corporaFS.ReadDir("corpora")
+	for _, e := range ents {
+		if code, ok := strings.CutSuffix(e.Name(), ".ini"); ok {
+			if m, ok := embeddedCorpusMeta(code); ok {
+				regMeta[code] = m
+			}
+		}
+	}
+	// user dir overrides
+	if userDir != "" {
+		ents, _ := os.ReadDir(userDir)
+		for _, e := range ents {
+			name := e.Name()
+			if code, ok := strings.CutSuffix(name, ".tsv"); ok {
+				regUserTSV[code] = filepath.Join(userDir, name)
+				if _, have := regMeta[code]; !have {
+					regMeta[code] = CorpusMeta{Code: code, PsalmSystem: "vulgate"}
+				}
+			}
+		}
+		for _, e := range ents {
+			if code, ok := strings.CutSuffix(e.Name(), ".ini"); ok {
+				data, err := os.ReadFile(filepath.Join(userDir, e.Name()))
+				if err == nil {
+					regMeta[code] = parseCorpusMeta(code, data)
+				}
+			}
+		}
+	}
+	regBuilt = true
+}
+
+// Corpora returns all known corpora, sorted by code.
+func Corpora() []CorpusMeta {
+	regMu.Lock()
+	defer regMu.Unlock()
+	buildRegistry()
+	out := make([]CorpusMeta, 0, len(regMeta))
+	for _, m := range regMeta {
+		out = append(out, m)
+	}
+	sort.Slice(out, func(i, j int) bool { return out[i].Code < out[j].Code })
+	return out
+}
+
+// Meta returns a corpus's metadata.
+func Meta(code string) (CorpusMeta, bool) {
+	regMu.Lock()
+	defer regMu.Unlock()
+	buildRegistry()
+	m, ok := regMeta[code]
+	return m, ok
+}
+
+// CorporaForLang returns corpora whose lang == lang, sorted by code.
+func CorporaForLang(lang string) []CorpusMeta {
+	var out []CorpusMeta
+	for _, m := range Corpora() {
+		if m.Lang == lang {
+			out = append(out, m)
+		}
+	}
+	return out
+}
+
+// userTSVPath returns the override .tsv path for code, or "".
+func userTSVPath(code string) string {
+	regMu.Lock()
+	defer regMu.Unlock()
+	buildRegistry()
+	return regUserTSV[code]
+}
diff --git a/internal/bible/registry_test.go b/internal/bible/registry_test.go
new file mode 100644
index 0000000..0e9aab2
--- /dev/null
+++ b/internal/bible/registry_test.go
@@ -0,0 +1,35 @@
+package bible
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestUserCorpusOverride(t *testing.T) {
+	dir := t.TempDir()
+	os.WriteFile(filepath.Join(dir, "drb.tsv"), []byte("Genesis\tGn\t1\t1\t1\tUSER TEXT\n"), 0o644)
+	os.WriteFile(filepath.Join(dir, "drb.ini"), []byte("lang = en\nname = User DRB\npsalm_system = drb\n"), 0o644)
+	SetUserCorporaDir(dir)
+	t.Cleanup(func() { SetUserCorporaDir("") })
+
+	if got := Verses("drb", "Genesis", 1); len(got) == 0 || got[0].Text != "USER TEXT" {
+		t.Fatalf("user drb.tsv did not override embed: %+v", got)
+	}
+	m, _ := Meta("drb")
+	if m.Name != "User DRB" {
+		t.Fatalf("user sidecar not used: %+v", m)
+	}
+}
+
+func TestUserCorpusNewCode(t *testing.T) {
+	dir := t.TempDir()
+	os.WriteFile(filepath.Join(dir, "fr-x.tsv"), []byte("Genesis\tGn\t1\t1\t1\tAu commencement\n"), 0o644)
+	os.WriteFile(filepath.Join(dir, "fr-x.ini"), []byte("lang = fr\nname = Test FR\npsalm_system = vulgate\n"), 0o644)
+	SetUserCorporaDir(dir)
+	t.Cleanup(func() { SetUserCorporaDir("") })
+
+	if l := CorporaForLang("fr"); len(l) != 1 || l[0].Code != "fr-x" {
+		t.Fatalf("new fr corpus not registered: %+v", l)
+	}
+}
diff --git a/internal/config/config.go b/internal/config/config.go
index 0f99a3a..55abd72 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -274,6 +274,17 @@ func CalendarsDir() (string, error) {
 	return filepath.Join(filepath.Dir(p), "calendars"), nil
 }
 
+// CorporaDir is the user directory for drop-in bible corpora (<code>.tsv +
+// <code>.ini), alongside calendars/ under the lectio config dir. Mirrors
+// CalendarsDir exactly (verified: it uses configPath() then filepath.Dir).
+func CorporaDir() (string, error) {
+	p, _, err := configPath()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(filepath.Dir(p), "corpora"), nil
+}
+
 // BooksPath returns the path to the optional user books.ini (in the same
 // directory as the config file). There is no embedded seed on disk -- absence
 // means "use the built-in defaults".