1 files changed, 154 insertions, 0 deletions
diff --git a/src/main/java/moe/nea/zwirn/Descriptor.java b/src/main/java/moe/nea/zwirn/Descriptor.java
new file mode 100644
index 0000000..a121264
--- /dev/null
+++ b/src/main/java/moe/nea/zwirn/Descriptor.java
@@ -0,0 +1,154 @@
+package moe.nea.zwirn;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public interface Descriptor {
+    Descriptor mapClassName(SimpleRemapper remapper);
+
+    String toJvmDescriptor();
+
+    interface Type extends Descriptor {
+        Type mapClassName(SimpleRemapper remapper);
+
+        static Type readType(GoodStringReader reader) {
+            if (reader.peekChar() == 'V') {
+                reader.nextChar();
+                return VoidType.VOID;
+            }
+            return Field.readField(reader);
+        }
+    }
+
+    interface Field extends Type {
+        Field mapClassName(SimpleRemapper remapper);
+
+        static Field readField(GoodStringReader reader) {
+            switch (reader.nextChar()) {
+                case 'L':
+                    return new Class(reader.readUntil(';').replace('/', '.'));
+                case 'Z':
+                    return DefaultField.BOOLEAN;
+                case 'B':
+                    return DefaultField.BYTE;
+                case 'I':
+                    return DefaultField.INT;
+                case 'D':
+                    return DefaultField.DOUBLE;
+                case 'J':
+                    return DefaultField.LONG;
+                case 'S':
+                    return DefaultField.SHORT;
+                case 'F':
+                    return DefaultField.FLOAT;
+                case 'C':
+                    return DefaultField.CHAR;
+                case '[':
+                    return new Array(readField(reader));
+            }
+            throw new IllegalStateException("Unknown type");
+        }
+    }
+
+    record Method(List<Field> argumentTypes, Type returnType) implements Descriptor {
+
+        @Override
+        public Descriptor mapClassName(SimpleRemapper remapper) {
+            List<Field> newArgumentTypes = new ArrayList<>(argumentTypes.size());
+            for (Field argumentType : argumentTypes) {
+                newArgumentTypes.add(argumentType.mapClassName(remapper));
+            }
+            return new Method(newArgumentTypes, returnType.mapClassName(remapper));
+        }
+
+        @Override
+        public String toJvmDescriptor() {
+            StringBuilder sb = new StringBuilder();
+            sb.append("(");
+            for (Field argumentType : argumentTypes) {
+                sb.append(argumentType.toJvmDescriptor());
+            }
+            sb.append(")");
+            sb.append(returnType.toJvmDescriptor());
+            return sb.toString();
+        }
+
+        public static Method readMethod(GoodStringReader reader) {
+            if (reader.nextChar() != '(')
+                throw new IllegalStateException("Expected (");
+            List<Field> argument = new ArrayList<>();
+            while (reader.peekChar() != ')') {
+                argument.add(Field.readField(reader));
+            }
+            reader.nextChar(); // Consume )
+            return new Method(argument, Type.readType(reader));
+        }
+    }
+
+    record Array(Field field) implements Field {
+
+        @Override
+        public String toJvmDescriptor() {
+            return "[" + field.toJvmDescriptor();
+        }
+
+        @Override
+        public Array mapClassName(SimpleRemapper remapper) {
+            return new Array(field.mapClassName(remapper));
+        }
+    }
+
+    record Class(String dottedName) implements Field {
+        @Override
+        public String toJvmDescriptor() {
+            return "L" + dottedName.replace('.', '/') + ";";
+        }
+
+        @Override
+        public Field mapClassName(SimpleRemapper remapper) {
+            return new Class(remapper.remapClass(dottedName));
+        }
+    }
+
+
+    enum VoidType implements Type {
+        VOID;
+
+        @Override
+        public String toJvmDescriptor() {
+            return "V";
+        }
+
+        @Override
+        public VoidType mapClassName(SimpleRemapper remapper) {
+            return this;
+        }
+    }
+
+    enum DefaultField implements Field {
+        BOOLEAN("Z"),
+        BYTE("B"),
+        INT("I"),
+        DOUBLE("D"),
+        LONG("J"),
+        SHORT("S"),
+        FLOAT("F"),
+        CHAR("C");
+        private final String jvmDescriptor;
+
+        DefaultField(String jvmDescriptor) {
+            this.jvmDescriptor = jvmDescriptor;
+        }
+
+        @Override
+        public String toJvmDescriptor() {
+            return jvmDescriptor;
+        }
+
+        @Override
+        public DefaultField mapClassName(SimpleRemapper remapper) {
+            return this;
+        }
+    }
+
+}