# Module: hardware_service

## Purpose
Collects hardware fingerprint information (CPU, GPU, RAM, drive serial) from the host machine for use in hardware-bound encryption key derivation.

## Public Interface

| Function | Signature | Returns |
|----------|-----------|---------|
| `get_hardware_info` | `() -> str` | Formatted string: `CPU: {cpu}. GPU: {gpu}. Memory: {memory}. DriveSerial: {drive_serial}` |

## Internal Logic
- Detects OS via `os.name` (`nt` for Windows, else Linux)
- **Windows**: PowerShell commands to query `Win32_Processor`, `Win32_VideoController`, `Win32_OperatingSystem`, disk serial
- **Linux**: `lscpu`, `lspci`, `free`, `/sys/block/sda/device/` serial
- Parses multi-line output: first line = CPU, second = GPU, second-to-last = memory, last = drive serial
- Handles multiple GPUs by taking first GPU and last two lines for memory/drive

## Dependencies
- `os`, `subprocess` (stdlib)

## Consumers
api_client (used in `load_bytes` to generate hardware string for encryption)

## Data Models
None.

## Configuration
None.

## External Integrations
Executes OS-level shell commands to query hardware.

## Security
The hardware fingerprint is used as input to `Security.get_hw_hash()` and subsequently `Security.get_api_encryption_key()`, binding API encryption to the specific machine.

## Tests
None.