# One-Time Secret Sharing Service

A secure API backend for a one-time secret sharing service built with FastAPI and SQLite.

## Features

- Create and share secrets securely
- Secrets can only be viewed once
- Automatic deletion after viewing or expiration
- Customizable time-to-live (TTL) for secrets
- Background cleanup of expired secrets
- Encrypted storage of secrets

## API Endpoints

### Health Check

```
GET /health
```

Returns the health status of the API and database connection.

### Create a Secret

```
POST /api/v1/secrets
```

Create a new secret and get a token to access it.

**Request Body:**
```json
{
  "content": "Your secret message here",
  "ttl_hours": 24  // Optional, defaults to 24 hours
}
```

**Response:**
```json
{
  "token": "unique-token-id",
  "expires_at": "2023-07-28T10:00:00.000Z",
  "message": "Secret stored successfully"
}
```

### Retrieve a Secret

```
GET /api/v1/secrets/{token}
```

Retrieve a secret using its token. The secret is deleted immediately after retrieval.

**Response:**
```json
{
  "content": "Your secret message here",
  "message": "Secret retrieved successfully"
}
```

**Error Responses:**
- `404 Not Found` - Secret not found, already viewed, or expired

## Setup and Installation

### Prerequisites

- Python 3.8+
- SQLite

### Environment Variables

The application uses the following environment variables:

- `SECRET_KEY`: Secret key for encryption (defaults to "development_secret_key" in development)

### Environment Detection

The application automatically detects the environment it's running in:

- In local development, it uses the project directory for database storage
- In container deployment, it uses the `/app/storage/db` directory
- Database permissions are automatically set to ensure write access

### Installation

1. Clone the repository
2. Create a virtual environment and activate it:
   ```bash
   python -m venv venv
   source venv/bin/activate  # On Windows: venv\Scripts\activate
   ```
3. Install dependencies:
   ```bash
   pip install -r requirements.txt
   ```

### Database Setup

Run Alembic migrations to set up the database:

```bash
alembic upgrade head
```

The SQLite database will be created automatically in the `storage/db` directory with the proper permissions. The application will ensure that both the directory and the database file have appropriate write permissions.

### Running the Application

Start the application with uvicorn:

```bash
uvicorn main:app --host 0.0.0.0 --port 8000 --reload
```

The API will be available at `http://localhost:8000`.

- API Documentation: `http://localhost:8000/docs`
- ReDoc Documentation: `http://localhost:8000/redoc`
- OpenAPI Specification: `http://localhost:8000/openapi.json`

## Security Considerations

- Secrets are encrypted before storage
- Secrets are automatically deleted after viewing
- Expired secrets are cleaned up regularly
- The service uses a TTL (time-to-live) mechanism to ensure secrets don't persist indefinitely

## Development

### Project Structure

```
.
├── alembic.ini                  # Alembic configuration
├── app/                         # Application code
│   ├── api/                     # API endpoints
│   │   └── routes/              # Route definitions
│   ├── core/                    # Core application code
│   │   └── config.py            # Application configuration
│   ├── db/                      # Database related code
│   │   └── session.py           # Database session setup
│   ├── models/                  # SQLAlchemy models
│   │   ├── base.py              # Base model
│   │   └── secret.py            # Secret model
│   ├── schemas/                 # Pydantic schemas
│   │   └── secret.py            # Secret schemas
│   └── services/                # Business logic
│       ├── encryption.py        # Encryption service
│       └── secret_service.py    # Secret service
├── main.py                      # Application entry point
├── migrations/                  # Alembic migrations
│   └── versions/                # Migration scripts
├── README.md                    # This file
└── requirements.txt             # Python dependencies
```