it is done

core/src/mindustry/io/versions/LegacyTypeTable.java

@@ -0,0 +1,145 @@
+package mindustry.io.versions;
+
+import arc.func.Prov;
+import mindustry.entities.type.Bullet;
+import mindustry.entities.effect.*;
+import mindustry.entities.type.Player;
+import mindustry.entities.type.base.*;
+
+/*
+Latest data: [build 81]
+
+0 = Player
+1 = Fire
+2 = Puddle
+3 = MinerDrone
+4 = RepairDrone
+5 = BuilderDrone
+6 = GroundUnit
+7 = GroundUnit
+8 = GroundUnit
+9 = GroundUnit
+10 = GroundUnit
+11 = FlyingUnit
+12 = FlyingUnit
+13 = Revenant
+
+Before removal of lightining/bullet: [build 80]
+
+0 = Player
+1 = Fire
+2 = Puddle
+3 = Bullet
+4 = Lightning
+5 = MinerDrone
+6 = RepairDrone
+7 = BuilderDrone
+8 = GroundUnit
+9 = GroundUnit
+10 = GroundUnit
+11 = GroundUnit
+12 = GroundUnit
+13 = FlyingUnit
+14 = FlyingUnit
+15 = Revenant
+
+Before addition of new units: [build 79 and below]
+
+0 = Player
+1 = Fire
+2 = Puddle
+3 = Bullet
+4 = Lightning
+5 = RepairDrone
+6 = GroundUnit
+7 = GroundUnit
+8 = GroundUnit
+9 = GroundUnit
+10 = GroundUnit
+11 = FlyingUnit
+12 = FlyingUnit
+13 = BuilderDrone
+14 = Revenant
+ */
+public class LegacyTypeTable{
+    /*
+    0 = Player
+1 = Fire
+2 = Puddle
+3 = Draug
+4 = Spirit
+5 = Phantom
+6 = Dagger
+7 = Crawler
+8 = Titan
+9 = Fortress
+10 = Eruptor
+11 = Wraith
+12 = Ghoul
+13 = Revenant
+     */
+    private static final Prov[] build81Table = {
+        Player::new,
+        Fire::new,
+        Puddle::new,
+        MinerDrone::new,
+        RepairDrone::new,
+        BuilderDrone::new,
+        GroundUnit::new,
+        GroundUnit::new,
+        GroundUnit::new,
+        GroundUnit::new,
+        GroundUnit::new,
+        FlyingUnit::new,
+        FlyingUnit::new,
+        HoverUnit::new
+    };
+
+    private static final Prov[] build80Table = {
+        Player::new,
+        Fire::new,
+        Puddle::new,
+        Bullet::new,
+        Lightning::new,
+        MinerDrone::new,
+        RepairDrone::new,
+        BuilderDrone::new,
+        GroundUnit::new,
+        GroundUnit::new,
+        GroundUnit::new,
+        GroundUnit::new,
+        GroundUnit::new,
+        FlyingUnit::new,
+        FlyingUnit::new,
+        HoverUnit::new
+    };
+
+    private static final Prov[] build79Table = {
+        Player::new,
+        Fire::new,
+        Puddle::new,
+        Bullet::new,
+        Lightning::new,
+        RepairDrone::new,
+        GroundUnit::new,
+        GroundUnit::new,
+        GroundUnit::new,
+        GroundUnit::new,
+        GroundUnit::new,
+        FlyingUnit::new,
+        FlyingUnit::new,
+        BuilderDrone::new,
+        HoverUnit::new
+    };
+
+    public static Prov[] getTable(int build){
+        if(build == -1 || build == 81){
+            //return most recent one since that's probably it; not guaranteed
+            return build81Table;
+        }else if(build == 80){
+            return build80Table;
+        }else{
+            return build79Table;
+        }
+    }
+}

core/src/mindustry/io/versions/Save1.java

@@ -0,0 +1,32 @@
+package mindustry.io.versions;
+
+import arc.func.*;
+import mindustry.entities.traits.*;
+
+import java.io.*;
+
+public class Save1 extends Save2{
+
+    public Save1(){
+        version = 1;
+    }
+
+    @Override
+    public void readEntities(DataInput stream) throws IOException{
+        Prov[] table = LegacyTypeTable.getTable(lastReadBuild);
+
+        byte groups = stream.readByte();
+
+        for(int i = 0; i < groups; i++){
+            int amount = stream.readInt();
+            for(int j = 0; j < amount; j++){
+                readChunk(stream, true, in -> {
+                    byte typeid = in.readByte();
+                    byte version = in.readByte();
+                    SaveTrait trait = (SaveTrait)table[typeid].get();
+                    trait.readSave(in, version);
+                });
+            }
+        }
+    }
+}

core/src/mindustry/io/versions/Save2.java

@@ -0,0 +1,35 @@
+package mindustry.io.versions;
+
+import mindustry.ctype.ContentType;
+import mindustry.entities.traits.*;
+import mindustry.io.*;
+import mindustry.type.TypeID;
+
+import java.io.*;
+
+import static mindustry.Vars.content;
+
+public class Save2 extends SaveVersion{
+
+    public Save2(){
+        super(2);
+    }
+
+    @Override
+    public void readEntities(DataInput stream) throws IOException{
+        byte groups = stream.readByte();
+
+        for(int i = 0; i < groups; i++){
+            int amount = stream.readInt();
+            for(int j = 0; j < amount; j++){
+                //TODO throw exception on read fail
+                readChunk(stream, true, in -> {
+                    byte typeid = in.readByte();
+                    byte version = in.readByte();
+                    SaveTrait trait = (SaveTrait)content.<TypeID>getByID(ContentType.typeid, typeid).constructor.get();
+                    trait.readSave(in, version);
+                });
+            }
+        }
+    }
+}

core/src/mindustry/io/versions/Save3.java

@@ -0,0 +1,9 @@
+package mindustry.io.versions;
+
+import mindustry.io.*;
+
+public class Save3 extends SaveVersion{
+    public Save3(){
+        super(3);
+    }
+}