Migrate to onion architecture with dynamic controller loading

.env

@@ -1,5 +1,5 @@
 # Application settings
-APP_VERSION=v1.2.1
+APP_VERSION=v1.3.0
 FLASK_ENV=Production
 
 # Additional settings can be added here

asgi.py

@@ -1,6 +1,5 @@
 import uvicorn
-from src.app import app
+from src.api.app import app
 
 if __name__ == "__main__":
-    print("Starting Transparent Image Cropper FastAPI app on http://0.0.0.0:5000")
     uvicorn.run(app, host="0.0.0.0", port=5000)

requirements.txt

@@ -4,4 +4,5 @@ Pillow==11.3.0
 numpy==2.3.2
 python-dotenv==1.1.1
 jinja2==3.1.6
-python-multipart==0.0.20
+python-multipart==0.0.20
+colorlog==6.9.0

src/api/__init__.py

@@ -0,0 +1 @@
+# API layer: endpoints, interceptors, middlewares, etc.

src/api/app.py

@@ -0,0 +1,30 @@
+from fastapi import FastAPI
+from fastapi.staticfiles import StaticFiles
+from fastapi.templating import Jinja2Templates
+from src.api.router_registry import router_registry
+from dotenv import load_dotenv
+import os
+import logging
+from pathlib import Path
+
+logging.basicConfig(level=logging.INFO)
+load_dotenv()
+
+app = FastAPI(
+    title="Smart Image Cropper API",
+    description="API for automatically cropping transparent areas and backgrounds from images",
+    version="1.0.0"
+)
+
+base_dir = Path(__file__).parent.parent
+
+# Mount static files and templates using pathlib for cleaner paths
+static_dir = base_dir / "frontend"
+app.mount("/static", StaticFiles(directory=str(static_dir)), name="static")
+
+templates_dir = base_dir / "frontend" / "templates"
+templates = Jinja2Templates(directory=str(templates_dir))
+app.state.templates = templates
+
+# Auto-register all controllers
+router_registry.auto_register(app)

src/api/controllers/application_controller.py

@@ -0,0 +1,10 @@
+import os
+from fastapi import APIRouter
+
+router = APIRouter()
+
+@router.get("/api/app-info", tags=["App Info"])
+def app_info():
+    environment = os.environ.get('FLASK_ENV', 'unknown environment')
+    version = os.environ.get('APP_VERSION', 'unknown version')
+    return {"environment": environment, "version": version}

src/controllers/image_controller.py → src/api/controllers/image_processing_controller.py

@@ -1,44 +1,12 @@
-from fastapi import APIRouter, Request, UploadFile, File, HTTPException
-from fastapi.responses import JSONResponse, StreamingResponse, HTMLResponse
-from src.services.image_service import auto_crop_image
 import base64
 import io
-import os
+from fastapi import File, HTTPException, UploadFile
+from fastapi.responses import JSONResponse, StreamingResponse
+from src.application.services import image_service
+from fastapi import APIRouter
 
 router = APIRouter()
 
-@router.get("/", response_class=HTMLResponse, include_in_schema=False)
-def index(request: Request):
-    templates = request.app.state.templates
-    environment = os.environ.get('FLASK_ENV', 'unknown')
-    version = os.environ.get('APP_VERSION', 'unknown')
-    version_url = f"https://github.com/Pianonic/CropTransparent/releases/tag/{version}"
-    return templates.TemplateResponse("index.html", {
-        "request": request,
-        "environment": environment,
-        "version": version,
-        "version_url": version_url
-    })
-
-@router.get("/about", response_class=HTMLResponse, include_in_schema=False)
-def about(request: Request):
-    templates = request.app.state.templates
-    environment = os.environ.get('FLASK_ENV', 'unknown')
-    version = os.environ.get('APP_VERSION', 'unknown')
-    version_url = f"https://github.com/Pianonic/CropTransparent/releases/tag/{version}"
-    return templates.TemplateResponse("about.html", {
-        "request": request,
-        "environment": environment,
-        "version": version,
-        "version_url": version_url
-    })
-
-@router.get("/api/app-info", tags=["App Info"])
-def app_info():
-    environment = os.environ.get('FLASK_ENV', 'unknown environment')
-    version = os.environ.get('APP_VERSION', 'unknown version')
-    return {"environment": environment, "version": version}
-
 @router.post("/api/process", tags=["Image Processing"])
 async def process_image(file: UploadFile = File(...)):
     if not file:
@@ -47,7 +15,7 @@ async def process_image(file: UploadFile = File(...)):
         raise HTTPException(status_code=400, detail="No selected file")
     try:
         image_data = await file.read()
-        output_buffer, original_size, cropped_size, crop_method, background_info, output_format = auto_crop_image(image_data)
+        output_buffer, original_size, cropped_size, crop_method, background_info, output_format = image_service.auto_crop_image(image_data)
         encoded = base64.b64encode(output_buffer.getvalue()).decode('utf-8')
         output_buffer.seek(0)
         filename = file.filename or 'image.png'
@@ -108,7 +76,4 @@ async def download_image(data: dict):
             "Content-Disposition": f"attachment; filename={filename}"
         })
     except Exception as e:
-        raise HTTPException(status_code=500, detail=str(e))
-
-def register_routes(app):
-    app.include_router(router)
+        raise HTTPException(status_code=500, detail=str(e))

src/api/controllers/static_controller.py

@@ -0,0 +1,32 @@
+import os
+from fastapi import Request
+from fastapi.responses import HTMLResponse
+from fastapi import APIRouter
+
+router = APIRouter()
+
+@router.get("/", response_class=HTMLResponse, include_in_schema=False)
+def index(request: Request):
+    templates = request.app.state.templates
+    environment = os.environ.get('FLASK_ENV', 'unknown')
+    version = os.environ.get('APP_VERSION', 'unknown')
+    version_url = f"https://github.com/Pianonic/CropTransparent/releases/tag/{version}"
+    return templates.TemplateResponse("index.html", {
+        "request": request,
+        "environment": environment,
+        "version": version,
+        "version_url": version_url
+    })
+
+@router.get("/about", response_class=HTMLResponse, include_in_schema=False)
+def about(request: Request):
+    templates = request.app.state.templates
+    environment = os.environ.get('FLASK_ENV', 'unknown')
+    version = os.environ.get('APP_VERSION', 'unknown')
+    version_url = f"https://github.com/Pianonic/CropTransparent/releases/tag/{version}"
+    return templates.TemplateResponse("about.html", {
+        "request": request,
+        "environment": environment,
+        "version": version,
+        "version_url": version_url
+    })

src/api/router_registry.py

@@ -0,0 +1,73 @@
+import os
+import importlib
+import logging
+from pathlib import Path
+from typing import Optional
+from fastapi import FastAPI, APIRouter
+import colorlog
+
+# Configure FastAPI/Uvicorn-style colored logging
+handler = colorlog.StreamHandler()
+handler.setFormatter(colorlog.ColoredFormatter(
+    '%(log_color)sINFO%(reset)s:     %(message)s',
+    log_colors={
+        'DEBUG': 'blue',
+        'INFO': 'green',
+        'WARNING': 'yellow',
+        'ERROR': 'red',
+        'CRITICAL': 'bold_red',
+    }
+))
+
+logger = colorlog.getLogger(__name__)
+logger.addHandler(handler)
+logger.setLevel(logging.INFO)
+logger.propagate = False  # Prevent duplicate logs
+
+class RouterRegistry:
+    def __init__(self, controllers_path: str = "src.api.controllers"):
+        self.controllers_path = controllers_path
+        self.registered_count = 0
+
+    def auto_register(self, app: FastAPI, controllers_dir: Optional[Path] = None) -> int:
+        """Auto-discover and register all controller routers"""
+        if controllers_dir is None:
+            # Get the directory where this registry file is located
+            registry_file = Path(__file__).resolve()
+            # This file is in /api/router_registry.py, controllers are in /api/controllers/
+            controllers_dir = registry_file.parent / "controllers"
+
+        logger.info(f"Scanning controllers directory: {controllers_dir}")
+
+        if not controllers_dir.exists():
+            logger.warning(f"Controllers directory not found: {controllers_dir}")
+            return 0
+
+        self.registered_count = 0
+
+        for file_path in controllers_dir.glob("*.py"):
+            if file_path.name.startswith("__") or file_path.name.startswith("."):
+                continue
+
+            module_name = f"{self.controllers_path}.{file_path.stem}"
+
+            try:
+                module = importlib.import_module(module_name)
+
+                if hasattr(module, 'router') and isinstance(module.router, APIRouter):
+                    app.include_router(module.router)
+                    logger.info(f"Registered: {file_path.stem}")
+                    self.registered_count += 1
+                else:
+                    logger.debug(f"No router found in: {module_name}")
+
+            except ImportError as e:
+                logger.error(f"Import failed: {module_name} - {e}")
+            except Exception as e:
+                logger.error(f"Registration error: {module_name} - {e}")
+
+        logger.info(f"Successfully registered {self.registered_count} controller(s)")
+        return self.registered_count
+
+# Global instance for easy use
+router_registry = RouterRegistry()

src/application/__init__.py

@@ -0,0 +1 @@
+# Application layer: use cases and service interfaces

src/application/services/__init__.py

@@ -0,0 +1,5 @@
+"""Services package for image processing functionality."""
+
+from .image_service import auto_crop_image, crop_transparent_image, crop_by_background_color
+
+__all__ = ['auto_crop_image', 'crop_transparent_image', 'crop_by_background_color']

src/services/image_service.py → src/application/services/image_service.py

@@ -1,5 +1,4 @@
 from PIL import Image
-from PIL.Image import Image as PILImage
 import numpy as np
 import io