refactor: pass ModelInfo instead of model name string through provider interface

bulkgen/config.py

@@ -4,11 +4,14 @@ from __future__ import annotations
 
 import enum
 from pathlib import Path
-from typing import Self
+from typing import TYPE_CHECKING, Self
 
 import yaml
 from pydantic import BaseModel, model_validator
 
+if TYPE_CHECKING:
+    from bulkgen.providers.models import ModelInfo
+
 
 class TargetType(enum.Enum):
     """The kind of artifact a target produces."""
@@ -65,14 +68,29 @@ def infer_target_type(target_name: str) -> TargetType:
     raise ValueError(msg)
 
 
-def resolve_model(target_name: str, target: TargetConfig, defaults: Defaults) -> str:
-    """Return the effective model for a target (explicit or default by type)."""
+def resolve_model(
+    target_name: str, target: TargetConfig, defaults: Defaults
+) -> ModelInfo:
+    """Return the effective model for a target (explicit or default by type).
+
+    Raises :class:`ValueError` if the resolved model name is not in the registry.
+    """
+    from bulkgen.providers.models import ALL_MODELS
+
     if target.model is not None:
-        return target.model
-    target_type = infer_target_type(target_name)
-    if target_type is TargetType.IMAGE:
-        return defaults.image_model
-    return defaults.text_model
+        model_name = target.model
+    else:
+        target_type = infer_target_type(target_name)
+        model_name = (
+            defaults.image_model
+            if target_type is TargetType.IMAGE
+            else defaults.text_model
+        )
+    for model in ALL_MODELS:
+        if model.name == model_name:
+            return model
+    msg = f"Unknown model '{model_name}' for target '{target_name}'"
+    raise ValueError(msg)
 
 
 def load_config(config_path: Path) -> ProjectConfig: