# Image Caching Implementation

## Objective
Implement a robust image caching system that downloads card images to the server when creating a draft room, ensuring all players can see images reliably via local serving.

## Changes
1.  **Backend - Image Service (`src/server/services/CardService.ts`)**:
    *   Created `CardService` class.
    *   Implements `cacheImages` which downloads images from external URLs to `src/server/public/cards`.
    *   Uses a concurrency limit (5) to avoid rate limiting.
    *   Checks for existence before downloading to avoid redundant work.

2.  **Backend - Server Setup (`src/server/index.ts`)**:
    *   Enabled static file serving for `/cards` endpoint mapping to `src/server/public/cards`.
    *   Added `POST /api/cards/cache` endpoint that accepts a list of cards and triggers cache logic.
    *   Increased JSON body limit to 50mb to handle large set payloads.

3.  **Frontend - Lobby Manager (`LobbyManager.tsx`)**:
    *   Updated `handleCreateRoom` workflow.
    *   **Pre-Creation**: Extracts all unique cards from generated packs.
    *   **Cache Request**: Sends list to `/api/cards/cache`.
    *   **Transformation**: Updates local pack data to point `image` property to the local server URL (`/cards/{scryfallId}.jpg`) instead of remote Scryfall URL.
    *   This ensures that when `create_room` is emitted, the room state on the server (and thus all connected clients) contains valid local URLs.

4.  **Fixes**:
    *   Addressed `GameRoom.tsx` crash by replacing `require` with dynamic imports (or static if preloaded) and fixing clipboard access.
    *   Fixed TS imports in server index.

## Status
-   **Image Caching**: Functional. Creating a room now triggers a download process on the terminal.
-   **Local Serving**: Cards should now load instantly from the server for all peers.

## How to Verify
1.  Generate packs in Draft Management.
2.  Create a Room. Watch server logs for "Cached image: ..." messages.
3.  Join room.
4.  Start Draft. Images should appear.