fix: update template_loader to handle both source and installed modes

gitignore_generator/template_loader.py

@@ -1,6 +1,7 @@
 """Template loader for gitignore-generator."""
 
 import json
+import os
 from pathlib import Path
 from typing import Dict, List, Optional, Set
 
@@ -15,10 +16,22 @@ class TemplateLoader:
         self._templates_index: Optional[Dict] = None
         self._custom_templates: Dict[str, str] = {}
 
+    def _get_templates_dir(self) -> Path:
+        """Get the templates directory, handling both source and installed modes."""
+        templates_dir = config.template_dir
+        if templates_dir.exists() and (templates_dir / "templates.json").exists():
+            return templates_dir
+        module_dir = Path(__file__).parent
+        package_templates = module_dir / "templates"
+        if package_templates.exists() and (package_templates / "templates.json").exists():
+            return package_templates
+        return templates_dir
+
     def _load_templates_index(self) -> Dict:
         """Load the templates index file."""
         if self._templates_index is None:
-            index_path = config.template_dir / "templates.json"
+            templates_dir = self._get_templates_dir()
+            index_path = templates_dir / "templates.json"
             if index_path.exists():
                 with open(index_path, "r") as f:
                     self._templates_index = json.load(f)
@@ -29,7 +42,8 @@ class TemplateLoader:
 
     def _save_templates_index(self) -> None:
         """Save the templates index file."""
-        index_path = config.template_dir / "templates.json"
+        templates_dir = self._get_templates_dir()
+        index_path = templates_dir / "templates.json"
         with open(index_path, "w") as f:
             json.dump(self._templates_index, f, indent=2)
 
@@ -72,6 +86,14 @@ class TemplateLoader:
             for template_file in custom_dir.glob("*.gitignore"):
                 self._custom_templates[template_file.stem] = str(template_file)
 
+    def _get_template_path(self, template_name: str, category: str) -> Optional[Path]:
+        """Get the path to a template file."""
+        templates_dir = self._get_templates_dir()
+        template_path = templates_dir / category / f"{template_name}.gitignore"
+        if template_path.exists():
+            return template_path
+        return None
+
     def load_template(self, template_name: str, category: Optional[str] = None) -> Optional[str]:
         """Load a template by name."""
         self._load_custom_templates()
@@ -89,8 +111,8 @@ class TemplateLoader:
             categories = ["languages", "ides"]
 
         for cat in categories:
-            template_path = config.template_dir / cat / f"{template_name}.gitignore"
-            if template_path.exists():
+            template_path = self._get_template_path(template_name, cat)
+            if template_path is not None:
                 with open(template_path, "r") as f:
                     return f.read()
 
@@ -139,8 +161,8 @@ class TemplateLoader:
             return True
 
         for cat in ["languages", "ides"]:
-            template_path = config.template_dir / cat / f"{template_name}.gitignore"
-            if template_path.exists():
+            template_path = self._get_template_path(template_name, cat)
+            if template_path is not None:
                 return True
 
         return False