refactor(webui): replace direct VOICES_INTERNAL/DEFAULT_SUPERTONIC_VOICES with get_metadata API

- Add get_default_voice() helper to tts_backend_registry
- Replace all VOICES_INTERNAL imports in WebUI with get_metadata().voices
- Replace all DEFAULT_SUPERTONIC_VOICES imports in conversion_runner with get_metadata().voices
- Remove unused VOICES_INTERNAL import from voices.py

Core modules (voice_profiles, voice_formulas, voice_cache) already used
get_metadata(). This completes the WebUI migration.

abogen/tts_backend_registry.py

@@ -79,6 +79,12 @@ def get_metadata(backend_id: str) -> TTSBackendMetadata:
     return _registry.get_metadata(backend_id)
 
 
+def get_default_voice(backend_id: str, fallback: str = "") -> str:
+    """Return the first voice of a backend, or *fallback* if none."""
+    voices = get_metadata(backend_id).voices
+    return voices[0] if voices else fallback
+
+
 def create_backend(backend_id: str, **kwargs: Any) -> TTSBackend:
     """Create a TTS backend instance by provider id."""
     return _registry.create_backend(backend_id, **kwargs)

abogen/webui/conversion_runner.py

@@ -20,7 +20,7 @@ import numpy as np
 import soundfile as sf
 import static_ffmpeg
 
-from abogen.constants import VOICES_INTERNAL
+from abogen.tts_backend_registry import get_metadata
 from abogen.epub3.exporter import build_epub3_package
 from abogen.kokoro_text_normalization import ApostropheConfig, normalize_for_pipeline, HAS_NUM2WORDS
 from abogen.normalization_settings import (
@@ -47,7 +47,7 @@ from abogen.voice_formulas import extract_voice_ids, get_new_voice
 from abogen.voice_profiles import load_profiles, normalize_profile_entry
 from abogen.pronunciation_store import increment_usage
 from abogen.llm_client import LLMClientError
-from abogen.tts_backends.supertonic import DEFAULT_SUPERTONIC_VOICES
+
 
 from .service import Job, JobStatus
 
@@ -68,11 +68,11 @@ def _supertonic_voice_from_spec(spec: Any, fallback: str) -> str:
         raw = "M1"
 
     upper = raw.upper()
-    if upper in DEFAULT_SUPERTONIC_VOICES:
+    if upper in get_metadata("supertonic").voices:
         return upper
 
     fallback_upper = fallback_raw.upper() if fallback_raw else ""
-    if fallback_upper in DEFAULT_SUPERTONIC_VOICES:
+    if fallback_upper in get_metadata("supertonic").voices:
         return fallback_upper
 
     return "M1"
@@ -123,7 +123,7 @@ def _infer_provider_from_spec(value: Any, fallback: str = "kokoro") -> str:
     if not raw:
         return fallback
     upper = raw.upper()
-    if upper in DEFAULT_SUPERTONIC_VOICES:
+    if upper in get_metadata("supertonic").voices:
         return "supertonic"
     if "*" in raw or "+" in raw:
         return "kokoro"
@@ -576,7 +576,7 @@ def _spec_to_voice_ids(spec: Any) -> Set[str]:
             return set(extract_voice_ids(text))
         except ValueError:
             return set()
-    if text in VOICES_INTERNAL:
+    if text in get_metadata("kokoro").voices:
         return {text}
     return set()
 
@@ -640,7 +640,7 @@ def _collect_required_voice_ids(job: Job) -> Set[str]:
             for key in ("resolved_voice", "voice_formula", "voice"):
                 voices.update(_spec_to_voice_ids(payload.get(key)))
 
-    voices.update(VOICES_INTERNAL)
+    voices.update(get_metadata("kokoro").voices)
     return voices
 
 
@@ -1803,8 +1803,8 @@ def run_conversion_job(job: Job) -> None:
                     fallback_key = next(iter(voice_cache.keys()), "")
                     if fallback_key and fallback_key != "__custom_mix":
                         intro_voice_spec = fallback_key.split(":", 1)[-1]
-                if not intro_voice_spec and VOICES_INTERNAL:
-                    intro_voice_spec = VOICES_INTERNAL[0]
+                if not intro_voice_spec:
+                    intro_voice_spec = get_default_voice("kokoro")
 
                 if intro_voice_spec:
                     intro_provider, _, intro_voice_choice, intro_speed, intro_steps = resolve_voice_choice(
@@ -2237,8 +2237,8 @@ def run_conversion_job(job: Job) -> None:
                 if fallback_key and fallback_key != "__custom_mix":
                     # `voice_cache` keys are internal and include provider prefixes.
                     outro_voice_spec = fallback_key.split(":", 1)[-1]
-            if not outro_voice_spec and VOICES_INTERNAL:
-                outro_voice_spec = VOICES_INTERNAL[0]
+            if not outro_voice_spec:
+                outro_voice_spec = get_default_voice("kokoro")
 
             if outro_text and outro_voice_spec:
                 outro_start_time = current_time

abogen/webui/routes/utils/form.py

@@ -32,7 +32,7 @@ from abogen.webui.routes.utils.common import split_profile_spec
 from abogen.utils import calculate_text_length
 from abogen.voice_profiles import serialize_profiles, normalize_profile_entry
 from abogen.chunking import ChunkLevel, build_chunks_for_chapters
-from abogen.constants import VOICES_INTERNAL
+from abogen.tts_backend_registry import get_default_voice
 from abogen.speaker_configs import get_config
 from abogen.kokoro_text_normalization import normalize_roman_numeral_titles
 from dataclasses import dataclass
@@ -616,8 +616,8 @@ def apply_book_step_form(
         custom_formula = ""
 
     base_voice_spec = resolved_default_voice or narrator_voice_raw
-    if not base_voice_spec and VOICES_INTERNAL:
-        base_voice_spec = VOICES_INTERNAL[0]
+    if not base_voice_spec:
+        base_voice_spec = get_default_voice("kokoro")
 
     voice_choice, resolved_language, selected_profile = resolve_voice_choice(
         pending.language,
@@ -796,8 +796,8 @@ def build_pending_job_from_extraction(
         profile_selection = inferred_profile
 
     base_voice = base_voice_input or resolved_default_voice or str(default_voice_setting).strip()
-    if not base_voice and VOICES_INTERNAL:
-        base_voice = VOICES_INTERNAL[0]
+    if not base_voice:
+        base_voice = get_default_voice("kokoro")
     selected_speaker_config = (form.get("speaker_config") or "").strip()
     speaker_config_payload = get_config(selected_speaker_config) if selected_speaker_config else None
 

abogen/webui/routes/utils/settings.py

@@ -6,8 +6,8 @@ from abogen.constants import (
     LANGUAGE_DESCRIPTIONS,
     SUBTITLE_FORMATS,
     SUPPORTED_SOUND_FORMATS,
-    VOICES_INTERNAL,
 )
+from abogen.tts_backend_registry import get_default_voice
 from abogen.normalization_settings import (
     DEFAULT_LLM_PROMPT,
     environment_llm_defaults,
@@ -174,7 +174,7 @@ def settings_defaults() -> Dict[str, Any]:
         "subtitle_format": "srt",
         "save_mode": "default_output" if has_output_override() else "save_next_to_input",
         "default_speaker": "",
-        "default_voice": VOICES_INTERNAL[0] if VOICES_INTERNAL else "",
+        "default_voice": get_default_voice("kokoro"),
         "supertonic_total_steps": 5,
         "supertonic_speed": 1.0,
         "replace_single_newlines": False,

abogen/webui/routes/utils/voice.py

@@ -17,8 +17,8 @@ from abogen.constants import (
     SUPPORTED_SOUND_FORMATS,
     SUPPORTED_LANGUAGES_FOR_SUBTITLE_GENERATION,
     SAMPLE_VOICE_TEXTS,
-    VOICES_INTERNAL,
 )
+from abogen.tts_backend_registry import get_metadata
 from abogen.speaker_configs import list_configs
 from abogen.tts_backend_registry import create_backend
 from abogen.webui.conversion_runner import _select_device, _to_float32, SAMPLE_RATE, SPLIT_PATTERN
@@ -285,7 +285,7 @@ def filter_voice_catalog(
 def build_voice_catalog() -> List[Dict[str, str]]:
     catalog: List[Dict[str, str]] = []
     gender_map = {"f": "Female", "m": "Male"}
-    for voice_id in VOICES_INTERNAL:
+    for voice_id in get_metadata("kokoro").voices:
         prefix, _, rest = voice_id.partition("_")
         language_code = prefix[0] if prefix else "a"
         gender_code = prefix[1] if len(prefix) > 1 else ""
@@ -590,7 +590,7 @@ def template_options() -> Dict[str, Any]:
     voice_catalog = build_voice_catalog()
     return {
         "languages": LANGUAGE_DESCRIPTIONS,
-        "voices": VOICES_INTERNAL,
+        "voices": get_metadata("kokoro").voices,
         "subtitle_formats": SUBTITLE_FORMATS,
         "supported_langs_for_subs": SUPPORTED_LANGUAGES_FOR_SUBTITLE_GENERATION,
         "output_formats": SUPPORTED_SOUND_FORMATS,

abogen/webui/routes/voices.py

@@ -17,7 +17,7 @@ from abogen.speaker_configs import (
     save_configs,
     delete_config,
 )
-from abogen.constants import VOICES_INTERNAL
+
 
 voices_bp = Blueprint("voices", __name__)