docs/MIGRATION_GUIDE.md

# Migration Guide - Old to New Structure

## Overview

This guide explains how to update your code imports from the old structure to the new reorganized structure.

## Old Structure vs New Structure

### Model Imports

#### BEFORE (Old Structure)
```python
from NETRA.violence_detector import ViolenceDetector
from NETRA.yolo_detector import YOLODetector
from NETRA.weapon_person_detector import WeaponPersonDetector
from NETRA.anomaly_detector import AnomalyDetector
from NETRA.video_capture import VideoCapture
from pose_detection import PoseDetection
```

#### AFTER (New Structure)
```python
from src.detectors import (
    ViolenceDetector,
    YOLODetector,
    WeaponPersonDetector,
    PoseDetection,
    AnomalyDetector,
)
from src.pipeline import VideoCapture
```

**Or use the main src module:**
```python
from src import (
    ViolenceDetector,
    YOLODetector,
    WeaponPersonDetector,
    PoseDetection,
    AnomalyDetector,
    VideoCapture,
)
```

### Configuration Imports

#### BEFORE (Hardcoded paths in code)
```python
# Scattered throughout app.py
violence_model_path = Path(__file__).parent.parent / "NETRA" / "model" / "violence_model.h5"
yolo_model_candidates = [
    Path(__file__).parent.parent / "ai_models" / "object_detection" / "yolov8n.pt",
    ...
]
```

#### AFTER (Centralized in config)
```python
from config import MODEL_PATHS, get_model_path, DETECTION_THRESHOLDS, PROCESSING_PARAMS

# Get a specific model path
violence_model = get_model_path('violence')

# Get threshold
yolo_threshold = DETECTION_THRESHOLDS['yolo']  # 0.25

# Get processing parameters
frame_skip = PROCESSING_PARAMS['frame_skip']  # 10
```

### Settings Imports

#### BEFORE (Config spread throughout app.py)
```python
app.config['SECRET_KEY'] = 'netra-surveillance-secret-key-2024'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///netra.db'
app.config['MAX_CONTENT_LENGTH'] = 500 * 1024 * 1024
```

#### AFTER (Centralized in config)
```python
from config import SECRET_KEY, DATABASE_URI, MAX_CONTENT_LENGTH

app.config['SECRET_KEY'] = SECRET_KEY
app.config['SQLALCHEMY_DATABASE_URI'] = DATABASE_URI
app.config['MAX_CONTENT_LENGTH'] = MAX_CONTENT_LENGTH
```

## Step-by-Step webapp/app.py Update

### Step 1: Update Imports (Top of file)

**REPLACE:**
```python
from NETRA.violence_detector import ViolenceDetector
from NETRA.yolo_detector import YOLODetector
from NETRA.weapon_person_detector import WeaponPersonDetector
from NETRA.anomaly_detector import AnomalyDetector
from NETRA.video_capture import VideoCapture
from pose_detection import PoseDetection
```

**WITH:**
```python
from src import (
    ViolenceDetector,
    YOLODetector,
    WeaponPersonDetector,
    PoseDetection,
    AnomalyDetector,
    VideoCapture,
)
from config import (
    MODEL_PATHS,
    get_model_path,
    DETECTION_THRESHOLDS,
    PROCESSING_PARAMS,
    SECRET_KEY,
    DATABASE_URI,
    MAX_CONTENT_LENGTH,
    UPLOAD_FOLDER,
    PROCESSED_FOLDER,
    INSTANCE_FOLDER,
)
```

### Step 2: Update sys.path (No longer needed!)

**REMOVE THIS:**
```python
sys.path.append(str(Path(__file__).parent.parent))
sys.path.append(str(Path(__file__).parent.parent / "NETRA"))
sys.path.append(str(Path(__file__).parent.parent / "detection logic"))
```

**INSTEAD:** Just add project root if needed:
```python
sys.path.insert(0, str(Path(__file__).parent.parent))
```

### Step 3: Update Configuration

**REPLACE:**
```python
app.config['SECRET_KEY'] = 'netra-surveillance-secret-key-2024'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///netra.db'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['UPLOAD_FOLDER'] = str(Path(__file__).parent / 'uploads')
app.config['PROCESSED_FOLDER'] = str(Path(app.config['UPLOAD_FOLDER']) / 'processed')
app.config['MAX_CONTENT_LENGTH'] = 500 * 1024 * 1024

os.makedirs(app.config['UPLOAD_FOLDER'], exist_ok=True)
os.makedirs(app.config['PROCESSED_FOLDER'], exist_ok=True)
```

**WITH:**
```python
app.config['SECRET_KEY'] = SECRET_KEY
app.config['SQLALCHEMY_DATABASE_URI'] = DATABASE_URI
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['UPLOAD_FOLDER'] = str(UPLOAD_FOLDER)
app.config['PROCESSED_FOLDER'] = str(PROCESSED_FOLDER)
app.config['MAX_CONTENT_LENGTH'] = MAX_CONTENT_LENGTH

# Folders already created by config/settings.py
```

### Step 4: Update Model Loading in ModelManager

**REPLACE hardcoded paths like:**
```python
violence_model_path = Path(__file__).parent.parent / "NETRA" / "model" / "violence_model.h5"
yolo_model_candidates = [...]
```

**WITH:**
```python
violence_model_path = get_model_path('violence')
yolo_model_path = get_model_path('yolo')
weapon_gun_path = get_model_path('weapon')
pose_model_path = get_model_path('pose')
anomaly_model_path = get_model_path('anomaly')
```

### Step 5: Update Detection Thresholds

**REPLACE:**
```python
detections = yolo_model.detect(frame, conf_threshold=0.25)
violence_result = violence_model.detect_violence(frame, confidence_threshold=0.6)
```

**WITH:**
```python
detections = yolo_model.detect(frame, conf_threshold=DETECTION_THRESHOLDS['yolo'])
violence_result = violence_model.detect_violence(frame, confidence_threshold=DETECTION_THRESHOLDS['violence'])
```

### Step 6: Update Video Processing Parameters

**REPLACE:**
```python
if frame_count % 10 == 0:  # Magic number
    results = video_processor.process_frame(frame)
```

**WITH:**
```python
if frame_count % PROCESSING_PARAMS['frame_skip'] == 0:
    results = video_processor.process_frame(frame)
```

## Benefits of Migration

✅ **Cleaner Imports** - All imports from organized src/ and config/
✅ **Centralized Configuration** - Single source of truth for paths and thresholds
✅ **Easier Maintenance** - Update model paths once in config/model_config.py
✅ **Better Scalability** - Easy to add new models or modules
✅ **Less Code Duplication** - No scattered hardcoded paths

## Testing After Migration

After updating app.py, verify:

```bash
# Test imports work
python -c "from src import YOLODetector; print('✓ Imports OK')"

# Test config loads
python -c "from config import get_all_available_models; print(get_all_available_models())"

# Test app starts
python webapp/app.py
```

## Summary of Changes

| What Changed | Was | Now |
|--------------|-----|-----|
| **Detector location** | `NETRA/` | `src/detectors/` |
| **Pipeline location** | `NETRA/` | `src/pipeline/` |
| **Model paths** | Hardcoded | `config/model_config.py` |
| **Settings** | Scattered | `config/settings.py` |
| **Models organization** | `ai_models/mixed` | `models/type/` |
| **Documentation** | `webapp/ARCHITECTURE.md` | `docs/` |

## If You Need Help

Refer to `docs/PROJECT_STRUCTURE.md` for detailed explanation of each component.