Backend (#218)

* First pass of AI generated backend

* A backend and server_side_storage courtesy Copilot (Claude Sonnet 4)

* Addressing review comments

* Convert test to python unit test

* Adding test

* Fix so it correctly handles getting the root

Author: alan412

.gitignore

@@ -24,6 +24,7 @@ venv/
 .env.test.local
 .env.production.local
 .vscode 
+projects.db
 
 npm-debug.log*
 yarn-debug.log*

backend/README.md

@@ -0,0 +1,143 @@
+# Storage API
+
+A Flask-based REST API for providing storage capabilities (key-value pairs and file storage) using SQLite as the database.
+
+## Features
+
+- **Key-Value Storage**: Store and retrieve key-value pairs
+- **File Storage**: Store, retrieve, list, rename, and delete files and directories
+- **SQLite Database**: Persistent storage using SQLite
+- **CORS Support**: Cross-origin resource sharing for frontend integration
+
+## API Endpoints
+
+### Key-Value Storage (Entries)
+
+- `GET /entries/<entry_key>` - Fetch entry value by key (supports `?default=value` query param)
+- `POST /entries/<entry_key>` - Save entry value
+
+### File and Directory Operations
+
+- `GET /storage/<path>` - List directory contents (if path ends with `/`) or fetch file content (if path doesn't end with `/`)
+- `POST /storage/<path>` - Save file content (path must not end with `/`)
+- `DELETE /storage/<path>` - Delete file or directory
+- `POST /storage/rename` - Rename file or directory
+
+## Setup
+    1. cd <your repo>/backend
+    2. python3.12 -m venv ./venv
+    3. source ./venv/bin/activate
+    4. python3.12 -m pip install -r requirements.txt
+    5. deactivate
+
+## Running the Application
+    1. source ./venv/bin/activate
+    2. python main.py
+    3. The API will be available at `http://localhost:5001`
+
+## Example Usage
+
+### Key-Value Operations (Entries)
+
+#### Save an Entry
+```bash
+curl -X POST http://localhost:5001/entries/user_settings \
+  -H "Content-Type: application/json" \
+  -d '{"value": "{\"theme\": \"dark\", \"language\": \"en\"}"}'
+```
+
+#### Fetch an Entry
+```bash
+curl http://localhost:5001/entries/user_settings
+```
+
+#### Fetch an Entry with Default Value
+```bash
+curl "http://localhost:5001/entries/missing_key?default=default_value"
+```
+
+### File and Directory Operations
+
+#### Save a File
+```bash
+curl -X POST http://localhost:5001/storage/projects/robot1/main.py \
+  -H "Content-Type: application/json" \
+  -d '{"content": "# Robot main file\nprint(\"Hello Robot!\")"}'
+```
+
+#### Fetch a File
+```bash
+curl http://localhost:5001/storage/projects/robot1/main.py
+```
+
+#### List Files in Directory
+```bash
+curl http://localhost:5001/storage/projects/
+```
+
+#### Rename a File
+```bash
+curl -X POST http://localhost:5001/storage/rename \
+  -H "Content-Type: application/json" \
+  -d '{"old_path": "projects/robot1/main.py", "new_path": "projects/robot1/robot_main.py"}'
+```
+
+#### Rename a Directory
+```bash
+curl -X POST http://localhost:5001/storage/rename \
+  -H "Content-Type: application/json" \
+  -d '{"old_path": "projects/robot1/", "new_path": "projects/my_robot/"}'
+```
+
+#### Delete a File
+```bash
+curl -X DELETE http://localhost:5001/storage/projects/robot1/old_file.py
+```
+
+#### Delete a Directory
+```bash
+curl -X DELETE http://localhost:5001/storage/projects/old_project/
+```
+
+## Data Models
+
+### StorageEntry (Key-Value Storage)
+- `id`: Integer (Primary Key)
+- `entry_key`: String (Unique, Required)
+- `entry_value`: Text (Required)
+
+### StorageFile (File Storage)
+- `id`: Integer (Primary Key)
+- `file_path`: String (Unique, Required)
+- `file_content`: Text (Required)
+
+## Database
+
+The application creates a SQLite database file `storage.db` in the backend directory automatically when first run.
+
+## CORS Support
+
+The API includes CORS (Cross-Origin Resource Sharing) headers to allow frontend applications running on different ports to access the API. This is essential for development when the frontend runs on a different port than the backend.
+
+## Frontend Integration
+
+The server-side storage implementation in `src/storage/server_side_storage.ts` provides a TypeScript interface that connects to this Flask backend. It implements the `Storage` interface with methods for:
+
+- Key-value storage (`saveEntry`, `fetchEntry`)
+- File operations (`saveFile`, `fetchFileContentText`, `list`, `rename`, `delete`)
+
+Example usage in TypeScript:
+```typescript
+import { ServerSideStorage } from './storage/server_side_storage';
+
+const storage = new ServerSideStorage();
+
+// Save and fetch key-value data
+await storage.saveEntry('user_settings', JSON.stringify({theme: 'dark'}));
+const settings = await storage.fetchEntry('user_settings', '{}');
+
+// File operations
+await storage.saveFile('projects/robot1/main.py', 'print("Hello Robot!")');
+const content = await storage.fetchFileContentText('projects/robot1/main.py');
+const files = await storage.list('projects/');
+```