"""
Detection Function Wrappers

Provides unified detection function signatures for different backends:
- Direct service access (for HF Spaces / local)
- API client access (for production service-oriented architecture)

This eliminates duplication of detection logic across app.py and ui/gradio_interface.py
"""

import os
import requests
import base64
import io
from PIL import Image
from typing import Tuple, Optional
import traceback

from detection.service_factory import get_detection_service
from detection import ocr_handler, response_builder


def detect_with_service(
    image: Image.Image,
    confidence_threshold: float,
    line_thickness: int,
    enable_clip: bool,
    enable_ocr: bool,
    enable_blip: bool,
    ocr_only: bool,
    blip_scope_choice: str,
    preprocess: bool = False,
    preprocess_mode_choice: str = "RF-DETR Optimized (Recommended)",
    preprocess_preset: str = "standard"
) -> Tuple[Optional[Image.Image], str, Optional[dict]]:
    """
    Detect UI elements using detection service directly (no API)
    
    Used by: app.py (HF Spaces / local mode)
    
    Returns:
        Tuple of (annotated_image, summary_text, json_payload)
    """
    try:
        if image is None:
            return None, "❌ Please upload an image first.", None

        # Map BLIP scope choice to internal value
        scope_value = "all" if (blip_scope_choice or "").lower().startswith("all") else "icons"
        
        # Map preprocessing mode choice to internal value
        preprocess_mode = "rfdetr" if "RF-DETR" in preprocess_mode_choice else "generic"

        # OCR-only path
        if ocr_only:
            detections = ocr_handler.process_ocr_only(image)
            annotated = ocr_handler.annotate_ocr_detections(
                image,
                detections,
                thickness=line_thickness,
                return_format="pil"
            )
            
            json_payload = response_builder.build_ocr_only_response(
                detections=detections,
                image_width=image.width,
                image_height=image.height,
                annotated_image=None,
                confidence_threshold=confidence_threshold,
                line_thickness=line_thickness
            )
            
            summary_text = response_builder.format_summary_text(
                detections=detections,
                parameters=json_payload["parameters"],
                ocr_only=True
            )
            
            return annotated, summary_text, json_payload

        # Standard detection path
        service = get_detection_service()
        
        # Run analysis (pass parameters directly to avoid race conditions)
        analysis = service.analyze(
            image,
            confidence_threshold=confidence_threshold,
            extract_text=enable_ocr,
            use_clip=enable_clip,
            use_blip=enable_blip,
            merge_global_ocr=True,
            blip_scope=scope_value,
            preprocess=preprocess,
            preprocess_mode=preprocess_mode,
            preprocess_preset=preprocess_preset
        )

        # Generate annotated image
        annotated = service.get_prediction_image(
            image,
            confidence_threshold=confidence_threshold,
            extract_content=True,
            thickness=line_thickness,
            return_format="pil",
            analysis=analysis
        )

        # Build JSON response
        json_payload = {
            "success": True,
            "detections": analysis["detections"],
            "total_detections": len(analysis["detections"]),
            "image_size": analysis["image_size"],
            "parameters": {
                "confidence_threshold": confidence_threshold,
                "enable_clip": enable_clip,
                "enable_ocr": enable_ocr,
                "enable_blip": enable_blip,
                "blip_scope": scope_value if enable_blip else None,
                "ocr_only": False,
                "line_thickness": line_thickness
            },
            "type_distribution": response_builder.build_type_distribution(analysis["detections"]) if enable_clip else None
        }
        
        # Build summary text
        summary_text = response_builder.format_summary_text(
            detections=analysis["detections"],
            parameters=json_payload["parameters"],
            ocr_only=False
        )

        return annotated, summary_text, json_payload
        
    except Exception as e:
        error_msg = f"""❌ **Error during detection:**

```
{str(e)}

{traceback.format_exc()}
```
"""
        print(error_msg)
        return None, error_msg, None


def detect_with_api(
    image: Image.Image,
    confidence_threshold: float,
    line_thickness: int,
    enable_clip: bool,
    enable_ocr: bool,
    enable_blip: bool,
    ocr_only: bool,
    blip_scope_choice: str,
    preprocess: bool = False,
    preprocess_mode_choice: str = "RF-DETR Optimized (Recommended)",
    preprocess_preset: str = "standard",
    api_url: str = "http://localhost:8000"
) -> Tuple[Optional[Image.Image], str, Optional[dict]]:
    """
    Detect UI elements by calling the API
    
    Used by: app_ui.py (service-oriented mode)
    
    Returns:
        Tuple of (annotated_image, summary_text, json_payload)
    """
    try:
        if image is None:
            return None, "❌ Please upload an image first.", None

        # Map BLIP scope choice to internal value
        scope_value = "all" if (blip_scope_choice or "").lower().startswith("all") else "icons"
        
        # Map preprocessing mode choice to internal value
        preprocess_mode = "rfdetr" if "RF-DETR" in preprocess_mode_choice else "generic"

        # Prepare image for upload
        img_byte_arr = io.BytesIO()
        image.save(img_byte_arr, format='PNG')
        img_byte_arr.seek(0)

        # Prepare form data
        files = {
            'image': ('image.png', img_byte_arr, 'image/png')
        }
        data = {
            'confidence_threshold': confidence_threshold,
            'line_thickness': line_thickness,
            'enable_clip': str(enable_clip).lower(),
            'enable_ocr': str(enable_ocr).lower(),
            'enable_blip': str(enable_blip).lower(),
            'blip_scope': scope_value,
            'ocr_only': str(ocr_only).lower(),
            'preprocess': str(preprocess).lower(),
            'preprocess_mode': preprocess_mode,
            'preprocess_preset': preprocess_preset
        }

        # Call API
        try:
            response = requests.post(
                f"{api_url}/detect",
                files=files,
                data=data,
                timeout=120
            )
            response.raise_for_status()
        except requests.exceptions.ConnectionError:
            return None, f"""❌ **Connection Error**

Cannot connect to API server at `{api_url}`

**To fix this:**
1. Make sure the API server is running:
   ```bash
   python app_api.py
   ```
2. The API should be accessible at http://localhost:8000
3. Check that no firewall is blocking the connection

**Current API URL:** {api_url}
You can change this by setting the `CU1_API_URL` environment variable.
""", None
        except requests.exceptions.Timeout:
            return None, f"""❌ **Timeout Error**

The API request timed out after 120 seconds.

This might happen with:
- Very large images
- First run (models need to download)
- CPU-only processing (slower than GPU)

**Try:**
- Using a smaller image
- Waiting for model downloads to complete
- Checking API server logs for errors
""", None
        except requests.exceptions.HTTPError as e:
            error_detail = "Unknown error"
            try:
                error_json = response.json()
                error_detail = error_json.get("detail", str(e))
            except:
                error_detail = str(e)
            return None, f"""❌ **API Error ({response.status_code})**

{error_detail}

**API URL:** {api_url}
""", None

        # Parse response
        json_payload = response.json()
        
        if not json_payload.get("success", False):
            return None, f"❌ Detection failed: {json_payload.get('error', 'Unknown error')}", json_payload

        # Decode annotated image
        annotated_image = None
        if "annotated_image" in json_payload and json_payload["annotated_image"]:
            try:
                img_data = base64.b64decode(json_payload["annotated_image"]["base64"])
                annotated_image = Image.open(io.BytesIO(img_data))
            except Exception as e:
                print(f"Failed to decode annotated image: {e}")

        # Build summary text using response_builder
        summary_text = response_builder.format_summary_text(
            detections=json_payload.get("detections", []),
            parameters=json_payload.get("parameters", {}),
            ocr_only=json_payload.get("parameters", {}).get("ocr_only", False)
        )

        return annotated_image, summary_text, json_payload
        
    except Exception as e:
        error_msg = f"""❌ **Error during detection:**

```
{str(e)}

{traceback.format_exc()}
```

**API URL:** {api_url}
"""
        print(error_msg)
        return None, error_msg, None