From 558471237a005f4963c32b5db053dcbd53d4a1d5 Mon Sep 17 00:00:00 2001
From: AnimeGitB <AnimeGitB@bigblueball.in>
Date: Wed, 12 Oct 2022 21:57:26 +1030
Subject: [PATCH] Add DynamicFloat class

---
 .../grasscutter/data/common/DynamicFloat.java | 74 +++++++++++++++++++
 .../java/emu/grasscutter/utils/JsonUtils.java | 42 ++++++++++-
 2 files changed, 115 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/emu/grasscutter/data/common/DynamicFloat.java

diff --git a/src/main/java/emu/grasscutter/data/common/DynamicFloat.java b/src/main/java/emu/grasscutter/data/common/DynamicFloat.java
new file mode 100644
index 000000000..65c1be88f
--- /dev/null
+++ b/src/main/java/emu/grasscutter/data/common/DynamicFloat.java
@@ -0,0 +1,74 @@
+package emu.grasscutter.data.common;
+
+import java.util.List;
+
+import it.unimi.dsi.fastutil.floats.FloatArrayList;
+import it.unimi.dsi.fastutil.objects.Object2FloatArrayMap;
+import it.unimi.dsi.fastutil.objects.Object2FloatMap;
+import lombok.val;
+
+public class DynamicFloat {
+    public static class StackOp {
+        enum Op {CONSTANT, KEY, ADD, SUB, MUL, DIV};
+        public Op op;
+        public float fValue;
+        public String sValue;
+
+        public StackOp(String s) {
+            switch (s.toUpperCase()) {
+                case "ADD" -> this.op = Op.ADD;
+                case "SUB" -> this.op = Op.SUB;
+                case "MUL" -> this.op = Op.MUL;
+                case "DIV" -> this.op = Op.DIV;
+                default -> {
+                    this.op = Op.KEY;
+                    this.sValue = s;
+                }
+            }
+        }
+
+        public StackOp(float f) {
+            this.op = Op.CONSTANT;
+            this.fValue = f;
+        }
+    }
+    private List<StackOp> ops;
+    private boolean dynamic = false;
+    private float constant = 0f;
+
+    public DynamicFloat(float constant) {
+        this.constant = constant;
+    }
+
+    public DynamicFloat(String key) {
+        this.dynamic = true;
+        this.ops = List.of(new StackOp(key));
+    }
+
+    public DynamicFloat(List<StackOp> ops) {
+        this.dynamic = true;
+        this.ops = ops;
+    }
+
+    public float get() {
+        return this.get(new Object2FloatArrayMap<String>());
+    }
+
+    public float get(Object2FloatMap<String> props) {
+        if (!dynamic)
+            return constant;
+
+        val fl = new FloatArrayList();
+        for (var op : this.ops) {
+            switch (op.op) {
+                case CONSTANT -> fl.push(op.fValue);
+                case KEY -> fl.push(props.getOrDefault(op.sValue, 0f));
+                case ADD -> fl.push(fl.popFloat() + fl.popFloat());
+                case SUB -> fl.push(-fl.popFloat() + fl.popFloat());  // [f0, f1, f2] -> [f0, f1-f2]  (opposite of RPN order)
+                case MUL -> fl.push(fl.popFloat() * fl.popFloat());
+                case DIV -> fl.push((1f/fl.popFloat()) * fl.popFloat());  // [f0, f1, f2] -> [f0, f1/f2]
+            }
+        }
+        return fl.popFloat();  // well-formed data will always have only one value left at this point
+    }
+}
diff --git a/src/main/java/emu/grasscutter/utils/JsonUtils.java b/src/main/java/emu/grasscutter/utils/JsonUtils.java
index 5742b87f1..bcd95fb9b 100644
--- a/src/main/java/emu/grasscutter/utils/JsonUtils.java
+++ b/src/main/java/emu/grasscutter/utils/JsonUtils.java
@@ -7,6 +7,7 @@ import java.io.Reader;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 
@@ -14,10 +15,49 @@ import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonSyntaxException;
+import com.google.gson.TypeAdapter;
 import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+
+import emu.grasscutter.data.common.DynamicFloat;
+import lombok.val;
 
 public final class JsonUtils {
-    static final Gson gson = new GsonBuilder().setPrettyPrinting().create();
+    // Adapters
+    static class DynamicFloatAdapter extends TypeAdapter<DynamicFloat> {
+        @Override
+        public DynamicFloat read(JsonReader reader) throws IOException {
+            switch (reader.peek()) {
+                case STRING:
+                    return new DynamicFloat(reader.nextString());
+                case NUMBER:
+                    return new DynamicFloat((float) reader.nextDouble());
+                case BEGIN_ARRAY:
+                    reader.beginArray();
+                    val opStack = new ArrayList<DynamicFloat.StackOp>();
+                    while (reader.hasNext()) {
+                        opStack.add(switch (reader.peek()) {
+                            case STRING -> new DynamicFloat.StackOp(reader.nextString());
+                            case NUMBER -> new DynamicFloat.StackOp((float) reader.nextDouble());
+                            default -> throw new IOException("Invalid DynamicFloat definition - " + reader.peek().name());
+                        });
+                    }
+                    reader.endArray();
+                    return new DynamicFloat(opStack);
+                default:
+                    throw new IOException("Invalid DynamicFloat definition - " + reader.peek().name());
+            }
+        }
+
+        @Override
+        public void write(JsonWriter writer, DynamicFloat f) {};
+    }
+
+    static final Gson gson = new GsonBuilder()
+        .setPrettyPrinting()
+        .registerTypeAdapter(DynamicFloat.class, new DynamicFloatAdapter())
+        .create();
 
     @Deprecated(forRemoval = true)
     public static Gson getGsonFactory() {