# Data Model

## Entity Overview

This system does not use a database. All data is stored as files on the filesystem and in-memory data structures. The primary entities are annotation images, labels, and ML models.

## Entities

### Annotation Image
- **Storage**: JPEG files on filesystem
- **Naming**: `{uuid}.jpg` (name assigned by Azaion platform)
- **Lifecycle**: Created → Seed/Validated → Augmented → Dataset → Model Training

### Annotation Label (YOLO format)
- **Storage**: Text files on filesystem
- **Naming**: `{uuid}.txt` (matches image name)
- **Format**: One line per detection: `{class_id} {center_x} {center_y} {width} {height}`
- **Coordinates**: All normalized to 0–1 range relative to image dimensions

### AnnotationClass
- **Storage**: `classes.json` (static file, 17 entries)
- **Fields**: Id (int), Name (str), ShortName (str), Color (hex str)
- **Weather expansion**: Each class × 3 weather modes → IDs offset by 0/20/40
- **Total slots**: 80 (51 used, 29 reserved as "Class-N" placeholders)

### Detection (inference)
- **In-memory only**: Created during inference postprocessing
- **Fields**: x, y, w, h (normalized), cls (int), confidence (float)

### Annotation (inference)
- **In-memory only**: Groups detections per video frame
- **Fields**: frame (image), time (ms), detections (list)

### AnnotationMessage (queue)
- **Wire format**: msgpack with positional integer keys
- **Fields**: createdDate, name, originalMediaName, time, imageExtension, detections (JSON string), image (bytes), createdRole, createdEmail, source, status

### ML Model
- **Formats**: .pt, .onnx, .engine, .rknn
- **Encryption**: AES-256-CBC before upload
- **Split storage**: .small part (API server) + .big part (CDN)
- **Naming**: `azaion.{ext}` for current model; `azaion.cc_{major}.{minor}_sm_{count}.engine` for GPU-specific TensorRT

## Filesystem Entity Relationships

```mermaid
erDiagram
    ANNOTATION_IMAGE ||--|| ANNOTATION_LABEL : "matches by filename stem"
    ANNOTATION_CLASS ||--o{ ANNOTATION_LABEL : "class_id references"
    ANNOTATION_IMAGE }o--|| DATASET_SPLIT : "copied into"
    ANNOTATION_LABEL }o--|| DATASET_SPLIT : "copied into"
    DATASET_SPLIT ||--|| TRAINING_RUN : "input to"
    TRAINING_RUN ||--|| MODEL_PT : "produces"
    MODEL_PT ||--|| MODEL_ONNX : "exported to"
    MODEL_PT ||--|| MODEL_ENGINE : "exported to"
    MODEL_PT ||--|| MODEL_RKNN : "exported to"
    MODEL_ONNX ||--|| ENCRYPTED_MODEL : "encrypted"
    MODEL_ENGINE ||--|| ENCRYPTED_MODEL : "encrypted"
    ENCRYPTED_MODEL ||--|| MODEL_SMALL : "split part"
    ENCRYPTED_MODEL ||--|| MODEL_BIG : "split part"
```

## Directory Layout (Data Lifecycle)

```
/azaion/
├── data-seed/              ← Unvalidated annotations (from operators)
│   ├── images/
│   └── labels/
├── data/                   ← Validated annotations (from validators/admins)
│   ├── images/
│   └── labels/
├── data-processed/         ← Augmented data (8× expansion)
│   ├── images/
│   └── labels/
├── data-corrupted/         ← Invalid labels (coords > 1.0)
│   ├── images/
│   └── labels/
├── data_deleted/           ← Soft-deleted annotations
│   ├── images/
│   └── labels/
├── data-sample/            ← Random sample for review
├── datasets/               ← Training datasets (dated)
│   └── azaion-{YYYY-MM-DD}/
│       ├── train/images/ + labels/
│       ├── valid/images/ + labels/
│       ├── test/images/ + labels/
│       └── data.yaml
└── models/                 ← Trained model artifacts
    ├── azaion.pt           ← Current best model
    ├── azaion.onnx         ← Current ONNX export
    └── azaion-{YYYY-MM-DD}/← Per-training-run results
        └── weights/
            └── best.pt
```

## Configuration Files

| File | Location | Contents |
|------|----------|---------|
| `config.yaml` | Project root | API credentials, queue config, directory paths |
| `cdn.yaml` | Project root | CDN endpoint + S3 access keys |
| `classes.json` | Project root | Annotation class definitions (17 classes) |
| `checkpoint.txt` | Project root | Last training checkpoint timestamp |
| `offset.yaml` | annotation-queue/ | Queue consumer offset |
| `data.yaml` | Per dataset | YOLO training config (class names, split paths) |
