modify getChangesets and add getUndoItems list

Author: Achyut Kumar M

GoInfoGame/GoInfoGame/DataBase/DatabaseConnector.swift

@@ -9,6 +9,7 @@ import Foundation
 import RealmSwift
 import MapKit
 import osmapi
+import osmparser
 
 class DatabaseConnector {
     static let shared = DatabaseConnector()
@@ -446,12 +447,24 @@ class DatabaseConnector {
     /// - parameter synced: Optional variable of whether synced or non synced
     /// - Returns: an instance of `Results<StoredChangeset>`
     func getChangesets(synced: Bool = false) -> Results<StoredChangeset> {
-        
-        if (synced == true){
-            return  realm.objects(StoredChangeset.self).where({$0.changesetId != -1 })
+        let results: Results<StoredChangeset>
+        if synced {
+            results = realm.objects(StoredChangeset.self).where { $0.changesetId != -1 }
+        } else {
+            results = realm.objects(StoredChangeset.self).where { $0.changesetId == -1 }
         }
-        return realm.objects(StoredChangeset.self).where({$0.changesetId == -1 })
+        print("Found \(results.count) changesets for synced=\(synced)")
+        return results
+    }
+    
+    func getChangeset(for id: Int64, type: ElementType) -> StoredChangeset? {
+        let storedType: StoredElementEnum = (type == .way) ? .way : .node
+        let stringId = String(id)
+        return realm.objects(StoredChangeset.self)
+            .filter("elementId == %@ AND elementType == %@", stringId, storedType.rawValue)
+            .first
     }
+
     /// Assigns changesetId for a stored changeset
     /// - parameter obj: Internal id for the changeset in the database (unique ID)
     /// - parameter changesetId: Assigned changeset ID from the server

GoInfoGame/GoInfoGame/quests/QuestUndoManager.swift

@@ -43,6 +43,12 @@ class MapUndoManager {
             }
 
             updateTagsHandler?(id, current.tags.toDictionary(), .way)
+            
+            if let changeset = DatabaseConnector.shared.getChangeset(for: id, type: type) {
+                try? realm.write {
+                    realm.delete(changeset)
+                }
+            }
 
         case .node:
             guard let original = DatabaseConnector.shared.getNode(id: Int(id), version: .original),
@@ -56,15 +62,31 @@ class MapUndoManager {
                 original.tags.forEach { current.tags[$0.key] = $0.value }
 
                 current.point = original.point
-                current.version += 1
+             //   current.version += 1
             }
 
             updateTagsHandler?(id, current.tags.toDictionary(), .node)
+            
+            if let changeset = DatabaseConnector.shared.getChangeset(for: id, type: type) {
+                try? realm.write {
+                    realm.delete(changeset)
+                }
+            }
 
         default:
             print(" Unknown element type")
         }
     }
+    
+    func getUndoItems() -> [UndoItem] {
+        let changesets = DatabaseConnector.shared.getChangesets(synced: true)
+
+        return changesets.compactMap { cs in
+            guard let type = cs.elementType.toElementType() else { return nil }
+            let changedKeys = cs.tags.map { $0.key }
+            return UndoItem(elementId: Int(cs.elementId) ?? -1, type: type, changedKeys: changedKeys)
+        }
+    }
 }
 
 extension Map where Key == String, Value == String {
@@ -76,3 +98,13 @@ extension Map where Key == String, Value == String {
         return dict
     }
 }
+
+extension StoredElementEnum {
+    func toElementType() -> ElementType? {
+        switch self {
+        case .node: return .node
+        case .way: return .way
+        default: return nil
+        }
+    }
+}