admin/_docs/02_document/components/04_resource_management/description.md

Resource Management

1. High-Level Overview

Purpose: Server-side file storage management — upload, list, download (with per-user AES encryption), folder clearing, and installer distribution.

Architectural Pattern: Service layer — filesystem operations with encryption applied at the service boundary.

Upstream dependencies: Data Layer (ResourcesConfig), Authentication & Security (encryption via Security.EncryptTo).

Downstream consumers: Admin API (resource endpoints).

2. Internal Interfaces

Interface: IResourcesService

Method	Input	Output	Async	Error Types
GetInstaller	bool isStage	(string?, Stream?)	No	None (returns nulls if not found)
GetEncryptedResource	string? dataFolder, string fileName, string key, CancellationToken	Stream	Yes	FileNotFoundException
SaveResource	string? dataFolder, IFormFile data, CancellationToken	void	Yes	BusinessException(NoFileProvided)
ListResources	string? dataFolder, string? search, CancellationToken	IEnumerable<string>	Yes	DirectoryNotFoundException
ClearFolder	string? dataFolder	void	No	None

Input DTOs:

GetResourceRequest:
  Password: string (required, min 8 chars)
  Hardware: string (required, not empty)
  FileName: string (required, not empty)

CheckResourceRequest:
  Hardware: string (required)

3. External API Specification

N/A — exposed through Admin API.

4. Data Access Patterns

No database access. All operations are filesystem-based.

Storage Estimates

Resources are stored as flat files in configured directories. Size depends on uploaded content (AI models, DLLs, installers — potentially hundreds of MB per file).

5. Implementation Details

State Management: Stateless — reads/writes directly to filesystem.

Key Dependencies: None beyond BCL (System.IO).

Error Handling Strategy:

• SaveResource throws BusinessException(NoFileProvided) for null uploads.
• Missing files/directories throw standard .NET I/O exceptions.
• ClearFolder silently returns if directory doesn't exist.
• GetInstaller returns (null, null) tuple if installer file is not found.

6. Extensions and Helpers

Helper	Purpose	Used By
Security.EncryptTo	AES stream encryption	GetEncryptedResource
Security.GetApiEncryptionKey	Key derivation	Admin API (before calling GetEncryptedResource)

7. Caveats & Edge Cases

Known limitations:

• No path traversal protection: dataFolder parameter is concatenated directly with ResourcesFolder. A malicious dataFolder like ../../etc could access arbitrary filesystem paths.
• SaveResource deletes existing file before writing — no versioning or backup.
• GetEncryptedResource loads the entire encrypted file into a MemoryStream — memory-intensive for large files.
• ListResources wraps a synchronous DirectoryInfo.GetFiles in Task.FromResult — not truly async.

Performance bottlenecks:

• Full file encryption to memory before streaming response: memory usage scales with file size.
• ClearFolder iterates and deletes files synchronously.

8. Dependency Graph

Must be implemented after: Data Layer (ResourcesConfig), Authentication & Security (encryption).

Can be implemented in parallel with: User Management.

Blocks: Admin API.

9. Logging Strategy

Log Level	When	Example
INFO	Successful file save	Resource {data.FileName} Saved Successfully

Log format: String interpolation via Serilog.

Log storage: Console + rolling file (via Serilog configured in Program.cs).

Modules Covered

• Services/ResourcesService
• Common/Requests/GetResourceRequest (includes CheckResourceRequest)
• Common/Configs/ResourcesConfig