Use attachment preview urls

This changes the preview urls to use the concrete attachment ids. This
way browsers have it easier to switch the preview image when the
attachment position is changed.

modules/webapp/src/main/elm/Api.elm

@@ -144,6 +144,7 @@ import Api.Model.InviteResult exposing (InviteResult)
 import Api.Model.ItemDetail exposing (ItemDetail)
 import Api.Model.ItemFtsSearch exposing (ItemFtsSearch)
 import Api.Model.ItemInsights exposing (ItemInsights)
+import Api.Model.ItemLight exposing (ItemLight)
 import Api.Model.ItemLightList exposing (ItemLightList)
 import Api.Model.ItemProposals exposing (ItemProposals)
 import Api.Model.ItemSearch exposing (ItemSearch)
@@ -1503,8 +1504,20 @@ deleteAllItems flags ids receive =
 --- Item
 
 
-itemPreviewURL : String -> String
+itemPreviewURL : ItemLight -> String
-itemPreviewURL itemId =
+itemPreviewURL item =
+    let
+        makeUrl a =
+            "/api/v1/sec/attachment/" ++ a.id ++ "/preview?withFallback=true"
+    in
+    List.sortBy .position item.attachments
+        |> List.head
+        |> Maybe.map makeUrl
+        |> Maybe.withDefault (itemBasePreviewURL item.id)
+
+
+itemBasePreviewURL : String -> String
+itemBasePreviewURL itemId =
     "/api/v1/sec/item/" ++ itemId ++ "/preview?withFallback=true"
 
 

modules/webapp/src/main/elm/Comp/ItemCardList.elm

@@ -238,7 +238,7 @@ viewItem cfg settings item =
             div [ class "image" ]
                 [ img
                     [ class "preview-image"
-                    , src (Api.itemPreviewURL item.id)
+                    , src (Api.itemPreviewURL item)
                     , Data.UiSettings.cardPreviewSize settings
                     ]
                     []