Option to only download missing Artwork

Add command line option to restrict downloaded images to games without official artwork.

README.md

@@ -35,6 +35,8 @@ again when you get more games or want to update the category overlays.
     * *(optional)* Append `--types <preference>` to choose your preferences between animated steam covers or static ones Available choices : `animated`,`static`. Default : `static`. You can use `animated,static` to download both while preferring animated covers, and `static,animated` for preferring static covers.
     * *(optional)* Append `--styles <preference>` to choose your preferences between the different covers styles from steamgriddb. Available choices : `material`,`white_logo`,`alternate`,`blurred`,`no_logo`. Default: `alternate`. You can also input multiple comma-separated choices in the same manners of the `--types` argument.
     * *(optional)* Append `--appids <appid1,appid2>` to only process the specified appID(s)
+    * *(optional)* Append `--onlymissingartwork` to only download artworks missing on the official servers.
+    * *(tip)* Run with `--help` to see all available options.
 6. Read the report and open Steam in grid view to check the results.
 
 ---

download.go

@@ -313,16 +313,24 @@ const steamCdnURLFormat = `cdn.akamai.steamstatic.com/steam/apps/%v/`
 // sources. Returns the final response received and a flag indicating if it was
 // from a Google search (useful because we want to log the lower quality
 // images).
-func getImageAlternatives(game *Game, artStyle string, artStyleExtensions []string, skipSteam bool, steamGridDBApiKey string, steamGridFilter string, IGDBApiKey string, skipGoogle bool) (response *http.Response, from string, err error) {
+func getImageAlternatives(game *Game, artStyle string, artStyleExtensions []string, skipSteam bool, steamGridDBApiKey string, steamGridFilter string, IGDBApiKey string, skipGoogle bool, onlyMissingArtwork bool) (response *http.Response, from string, err error) {
 	from = "steam server"
 	if !skipSteam {
 		response, err = tryDownload(fmt.Sprintf(akamaiURLFormat+artStyleExtensions[2], game.ID))
 		if err == nil && response != nil {
+			if onlyMissingArtwork {
+				// Abort if image is available
+				return nil, "", nil
+			}
 			return
 		}
 
 		response, err = tryDownload(fmt.Sprintf(steamCdnURLFormat+artStyleExtensions[2], game.ID))
 		if err == nil && response != nil {
+			if onlyMissingArtwork {
+				// Abort if image is available
+				return nil, "", nil
+			}
 			return
 		}
 	}
@@ -365,8 +373,8 @@ func getImageAlternatives(game *Game, artStyle string, artStyleExtensions []stri
 // DownloadImage tries to download the game images, saving it in game.ImageBytes. Returns
 // flags indicating if the operation succeeded and if the image downloaded was
 // from a search.
-func DownloadImage(gridDir string, game *Game, artStyle string, artStyleExtensions []string, skipSteam bool, steamGridDBApiKey string, steamGridFilter string, IGDBApiKey string, skipGoogle bool) (string, error) {
-	response, from, err := getImageAlternatives(game, artStyle, artStyleExtensions, skipSteam, steamGridDBApiKey, steamGridFilter, IGDBApiKey, skipGoogle)
+func DownloadImage(gridDir string, game *Game, artStyle string, artStyleExtensions []string, skipSteam bool, steamGridDBApiKey string, steamGridFilter string, IGDBApiKey string, skipGoogle bool, onlyMissingArtwork bool) (string, error) {
+	response, from, err := getImageAlternatives(game, artStyle, artStyleExtensions, skipSteam, steamGridDBApiKey, steamGridFilter, IGDBApiKey, skipGoogle, onlyMissingArtwork)
 	if response == nil || err != nil {
 		return "", err
 	}

steamgrid.go

@@ -59,6 +59,7 @@ func startApplication() {
 	skipLogo := flag.Bool("skiplogo", false, "Skip search and processing logo artwork")
 	nonSteamOnly := flag.Bool("nonsteamonly", false, "Only search artwork for Non-Steam-Games")
 	appIDs := flag.String("appids", "", "Comma separated list of appIds that should be processed")
+	onlyMissingArtwork := flag.Bool("onlymissingartwork", false, "Only download artworks missing on the official servers")
 	flag.Parse()
 	if flag.NArg() == 1 {
 		steamDir = &flag.Args()[0]
@@ -193,7 +194,7 @@ func startApplication() {
 				// Download if missing.
 				///////////////////////
 				if game.ImageSource == "" {
-					from, err := DownloadImage(gridDir, game, artStyle, artStyleExtensions, *skipSteam, *steamGridDBApiKey, steamGridFilter, *IGDBApiKey, *skipGoogle)
+					from, err := DownloadImage(gridDir, game, artStyle, artStyleExtensions, *skipSteam, *steamGridDBApiKey, steamGridFilter, *IGDBApiKey, *skipGoogle, *onlyMissingArtwork)
 					if err != nil && err.Error() == "SteamGridDB authorization token is missing or invalid" {
 						// Wrong api key
 						*steamGridDBApiKey = ""