Prevent multiple downloads of the same thing

src/electron/ipc/download/ChartDownload.ts

@@ -41,6 +41,7 @@ export class ChartDownload {
   /** If this chart download needs to be retried */
   get hasFailed() { return this._hasFailed }
   get isArchive() { return this.data.driveData.isArchive }
+  get hash() { return this.data.driveData.filesHash }
 
   constructor(public versionID: number, private data: NewDownload) {
     this.updateGUI('', 'Waiting for other downloads to finish...', 'good')

src/electron/ipc/download/DownloadHandler.ts

@@ -19,6 +19,11 @@ class DownloadHandler implements IPCEmitHandler<'download'> {
   }
 
   private addDownload(data: Download) {
+    const filesHash = data.data.driveData.filesHash
+    if (this.currentDownload?.hash == filesHash || this.downloadQueue.isDownloadingLink(filesHash)) {
+      return
+    }
+
     const newDownload = new ChartDownload(data.versionID, data.data)
     this.addDownloadEventListeners(newDownload)
     if (this.currentDownload == undefined) {

src/electron/ipc/download/DownloadQueue.ts

@@ -6,6 +6,10 @@ export class DownloadQueue {
 
   downloadQueue: ChartDownload[] = []
 
+  isDownloadingLink(filesHash: string) {
+    return this.downloadQueue.some(download => download.hash == filesHash)
+  }
+
   isEmpty() {
     return this.downloadQueue.length == 0
   }