From d4e63d90e4afb9a446bca2f352533f1a505006d6 Mon Sep 17 00:00:00 2001
From: pietervdvn <pietervdvn@posteo.net>
Date: Sun, 10 Oct 2021 00:53:14 +0200
Subject: [PATCH] When a logged-in user opens a popup, the latest data will be
 downloaded and tags are updated to prevent duplicate work, fix #505

---
 .gitignore                                 |   1 +
 Logic/Actors/SelectedElementTagsUpdater.ts | 100 +++++++++++++++++++++
 Logic/Osm/Actions/ChangeDescription.ts     |   2 +
 State.ts                                   |   3 +
 4 files changed, 106 insertions(+)
 create mode 100644 Logic/Actors/SelectedElementTagsUpdater.ts

diff --git a/.gitignore b/.gitignore
index f2ff425f8..b2ad34580 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,3 +17,4 @@ missing_translations.txt
 .DS_Store
 Svg.ts
 data/
+Folder.DotSettings.user
diff --git a/Logic/Actors/SelectedElementTagsUpdater.ts b/Logic/Actors/SelectedElementTagsUpdater.ts
new file mode 100644
index 000000000..bb46734d2
--- /dev/null
+++ b/Logic/Actors/SelectedElementTagsUpdater.ts
@@ -0,0 +1,100 @@
+/**
+ * This actor will download the latest version of the selected element from OSM and update the tags if necessary.
+ */
+import {UIEventSource} from "../UIEventSource";
+import {ElementStorage} from "../ElementStorage";
+import {Changes} from "../Osm/Changes";
+import {OsmObject} from "../Osm/OsmObject";
+import {OsmConnection} from "../Osm/OsmConnection";
+
+export default class SelectedElementTagsUpdater {
+
+    constructor(state: {
+        selectedElement: UIEventSource<any>,
+        allElements: ElementStorage,
+        changes: Changes,
+        osmConnection: OsmConnection
+    }) {
+
+
+        state.osmConnection.isLoggedIn.addCallbackAndRun(isLoggedIn => {
+            if(isLoggedIn){
+                SelectedElementTagsUpdater.installCallback(state)
+                return true;
+            }
+        })
+
+    }
+    
+    private static installCallback(state: {
+        selectedElement: UIEventSource<any>,
+        allElements: ElementStorage,
+        changes: Changes,
+        osmConnection: OsmConnection
+    }) {
+
+
+        state.selectedElement.addCallbackAndRunD(s => {
+            const id = s.properties?.id
+            OsmObject.DownloadObjectAsync(id).then(obj => {
+                SelectedElementTagsUpdater.applyUpdate(state, obj, id)
+            }).catch(e => {
+                console.error("Could not update tags of ", id, "due to", e)
+            })
+        });
+
+    }
+
+    private static applyUpdate(state: {
+                                   selectedElement: UIEventSource<any>,
+                                   allElements: ElementStorage,
+                                   changes: Changes,
+                                   osmConnection: OsmConnection
+                               }, obj: OsmObject, id: string
+    ) {
+        const pendingChanges = state.changes.pendingChanges.data
+            .filter(change => change.type === obj.type && change.id === obj.id)
+            .filter(change => change.tags !== undefined);
+        const latestTags = obj.tags
+        console.log("Applying updates of ", id, " got tags", latestTags, "and still have to apply changes: ", pendingChanges)
+
+        for (const pendingChange of pendingChanges) {
+            const tagChanges = pendingChange.tags;
+            for (const tagChange of tagChanges) {
+                const key = tagChange.k
+                const v = tagChange.v
+                if (v === undefined || v === "") {
+                    delete latestTags[key]
+                } else {
+                    latestTags[key] = v
+                }
+            }
+        }
+
+        // With the changes applied, we merge them onto the upstream object
+        let somethingChanged = false;
+        const currentTagsSource = state.allElements.getEventSourceById(id);
+        const currentTags = currentTagsSource.data
+        for (const key in latestTags) {
+            let osmValue = latestTags[key]
+            
+            if(typeof osmValue === "number"){
+                osmValue = ""+osmValue
+            }
+            
+            const localValue = currentTags[key]
+            if (localValue !== osmValue) {
+                console.log("Local value:", localValue, "upstream", osmValue)
+                somethingChanged = true;
+                currentTags[key] = osmValue
+            }
+        }
+        if (somethingChanged) {
+            console.log("Detected upstream changes to the object when opening it, updating...")
+            currentTagsSource.ping()
+        }
+
+    }
+
+
+}
\ No newline at end of file
diff --git a/Logic/Osm/Actions/ChangeDescription.ts b/Logic/Osm/Actions/ChangeDescription.ts
index 1787d1b1b..55ced2f2a 100644
--- a/Logic/Osm/Actions/ChangeDescription.ts
+++ b/Logic/Osm/Actions/ChangeDescription.ts
@@ -18,6 +18,8 @@ export interface ChangeDescription {
     /**
      * All changes to tags
      * v = "" or v = undefined to erase this tag
+     * 
+     * Note that this list will only contain the _changes_ to the tags, not the full set of tags
      */
     tags?: { k: string, v: string }[],
 
diff --git a/State.ts b/State.ts
index 7279136b3..cdc61c57e 100644
--- a/State.ts
+++ b/State.ts
@@ -18,6 +18,7 @@ import FilteredLayer from "./Models/FilteredLayer";
 import ChangeToElementsActor from "./Logic/Actors/ChangeToElementsActor";
 import LayoutConfig from "./Models/ThemeConfig/LayoutConfig";
 import {BBox} from "./Logic/BBox";
+import SelectedElementTagsUpdater from "./Logic/Actors/SelectedElementTagsUpdater";
 
 /**
  * Contains the global state: a bunch of UI-event sources
@@ -376,6 +377,8 @@ export default class State {
         new ChangeToElementsActor(this.changes, this.allElements)
 
         new PendingChangesUploader(this.changes, this.selectedElement);
+        
+        new SelectedElementTagsUpdater(this)
 
         this.mangroveIdentity = new MangroveIdentity(
             this.osmConnection.GetLongPreference("identity", "mangrove")