# Module: Azaion.Services.ResourcesService

## Purpose
File-based resource management: upload, list, download (encrypted), clear, and installer retrieval from the server's filesystem.

## Public Interface

### IResourcesService
| Method | Signature | Description |
|--------|-----------|-------------|
| `GetInstaller` | `(string?, Stream?) GetInstaller(bool isStage)` | Returns the latest installer file (prod or stage) |
| `GetEncryptedResource` | `Task<Stream> GetEncryptedResource(string? dataFolder, string fileName, string key, CancellationToken ct)` | Reads a file and returns it AES-encrypted |
| `SaveResource` | `Task SaveResource(string? dataFolder, IFormFile data, CancellationToken ct)` | Saves an uploaded file to the resource folder |
| `ListResources` | `Task<IEnumerable<string>> ListResources(string? dataFolder, string? search, CancellationToken ct)` | Lists file names in a resource folder, optionally filtered |
| `ClearFolder` | `void ClearFolder(string? dataFolder)` | Deletes all files and subdirectories in the specified folder |

## Internal Logic
- **GetResourceFolder**: resolves the target directory. If `dataFolder` is null/empty, uses `ResourcesConfig.ResourcesFolder` directly; otherwise, appends it as a subdirectory.
- **GetInstaller**: scans the installer folder for files matching `"AzaionSuite.Iterative*"`, returns the first match as a `FileStream`.
- **GetEncryptedResource**: opens the file, encrypts via `Security.EncryptTo` extension into a `MemoryStream`, returns the encrypted stream.
- **SaveResource**: creates the folder if needed, deletes any existing file with the same name, then copies the uploaded file.
- **ListResources**: uses `DirectoryInfo.GetFiles` with optional search pattern.
- **ClearFolder**: iterates and deletes all files and subdirectories.

## Dependencies
- `IOptions<ResourcesConfig>` — folder paths
- `ILogger<ResourcesService>` — logs successful saves
- `BusinessException` — thrown for null file uploads
- `Security.EncryptTo` — stream encryption extension

## Consumers
- `Program.cs` — all `/resources/*` endpoints

## Data Models
None.

## Configuration
Uses `ResourcesConfig` (ResourcesFolder, SuiteInstallerFolder, SuiteStageInstallerFolder).

## External Integrations
Local filesystem for resource storage.

## Security
- Resources are encrypted per-user using a key derived from email + password + hardware hash
- File deletion overwrites existing files before writing new ones
- No path traversal protection on `dataFolder` parameter

## Tests
None.