# Phase 1: Data Model & Setup

## Objective
Establish the database schema and directory infrastructure that underpin the entire drive system. This is a prerequisite for all subsequent work.

## Concepts

### Drives and Containers
Users organize storage into named "Drives". Each drive acts as a logical folder scoped to the owner.

```text
{data_directory}/drives/{user_id}/{drive_name}/{opaque_hash}
```

- `{drive_name}`: Human-readable scope (e.g., "My Projects").
- `{opaque_hash}`: Auto-generated alphanumeric string (UUID or SHA prefix).

### Disk Hashing Strategy
Physical filenames are opaque hashes that do not map deterministically to database IDs, preventing enumeration attacks on the filesystem level. Renaming files updates only the database record; the physical file remains untouched.

## Tasks

### 1.1 Define Database Models

Append the following models to `backend/src/database.py`:

```python
class Drive(models.Model):
    id = fields.IntField(pk=True)
    user = fields.ForeignKeyField("models.User", related_name="drives")
    name = fields.CharField(max_length=255)
    created_at = fields.DatetimeField(auto_now_add=True)

class DriveFile(models.Model):
    id = fields.IntField(pk=True)
    drive = fields.ForeignKeyField("models.Drive", related_name="files")
    
    filename = fields.CharField(max_length=500)       # Readable name (DB only)
    disk_hash = fields.CharField(max_length=64)       # Internal disk identifier
    mime_type = fields.CharField(max_length=255)      # Content type
    size_bytes = fields.BigIntField()                 # Physical size
    
    accessed_at = fields.DatetimeField(null=True)     # Last access timestamp
    created_at = fields.DatetimeField(auto_now_add=True)
    
    class Meta:
        table = "drive_files"
```

**Design Notes:**
- Ownership is enforced via foreign key chain (`User` → `Drive` → `File`).
- Indexes on `drive_id` and `user_id` ensure fast listing queries.

### 1.2 Run Migrations

Execute:
```bash
python -m tortoise.makemigrations --config tortoise_config --name add_drives
python -m tortoise.migrate --config tortoise_config
```

### 1.3 Initialize Directory Structure

In `backend/src/app.py`, call the drive initialization during startup:
```python
await app.init_drives(data_directory)
```

Ensure this happens after any DB connection is established so that `DRIVES_ROOT` can reference the data path correctly.