1 files changed, 112 insertions, 0 deletions
diff --git a/src/main/kotlin/mcprepack/ParseMethodDescriptor.kt b/src/main/kotlin/mcprepack/ParseMethodDescriptor.kt
new file mode 100644
index 0000000..a3d5717
--- /dev/null
+++ b/src/main/kotlin/mcprepack/ParseMethodDescriptor.kt
@@ -0,0 +1,112 @@
+package mcprepack
+
+import net.fabricmc.stitch.commands.tinyv2.TinyFile
+import java.io.StringReader
+
+sealed interface TypeDescriptor {
+    fun mapClassName(tinyFile: TinyFile): TypeDescriptor {
+        return when (this) {
+            is Class ->
+                Class(tinyFile.mapClassesByFirstNamespace()[this.name]?.classNames?.get(2) ?: this.name)
+
+            else -> this
+        }
+    }
+
+    fun toProguardString(): String {
+        return when (this) {
+            is Array -> this.elementType.toProguardString() + "[]"
+            Boolean -> "boolean"
+            Byte -> "byte"
+            Char -> "char"
+            is Class -> this.name.replace("/", ".")
+            Double -> "double"
+            Float -> "float"
+            Int -> "int"
+            Long -> "long"
+            Short -> "short"
+            Void -> "void"
+        }
+    }
+
+    sealed interface FieldDescriptor : TypeDescriptor
+    object Void : TypeDescriptor
+    object Double : FieldDescriptor
+    object Boolean : FieldDescriptor
+    object Float : FieldDescriptor
+    object Int : FieldDescriptor
+    object Long : FieldDescriptor
+    object Short : FieldDescriptor
+    object Byte : FieldDescriptor
+    object Char : FieldDescriptor
+    data class Class(val name: String) : FieldDescriptor
+    data class Array(val elementType: TypeDescriptor) : FieldDescriptor
+}
+
+data class FieldDescriptor(
+    val type: TypeDescriptor.FieldDescriptor
+) {
+    companion object {
+        fun parseFieldDescriptor(descriptor: String) =
+            FieldDescriptor(readType(StringReader(descriptor)) as? TypeDescriptor.FieldDescriptor ?: error("Cannot have void as a field type"))
+    }
+}
+
+data class MethodDescriptor(
+    val arguments: List<TypeDescriptor.FieldDescriptor>,
+    val returnType: TypeDescriptor
+) {
+    companion object {
+        fun parseMethodDescriptor(descriptor: String): MethodDescriptor {
+            val reader = StringReader(descriptor)
+            require(reader.readChar() == '(')
+            val arguments = mutableListOf<TypeDescriptor.FieldDescriptor>()
+            while (reader.peek() != ')') {
+                arguments.add(
+                    readType(reader) as? TypeDescriptor.FieldDescriptor ?: error("Cannot have void type as argument")
+                )
+            }
+            reader.readChar() // Consume the ')'
+            return MethodDescriptor(arguments, readType(reader))
+        }
+    }
+}
+
+fun StringReader.readChar() = CharArray(1).let {
+    if (read(it) < 0) null
+    else it[0]
+}
+
+fun StringReader.readUntil(search: Char): String? {
+    val s = StringBuilder()
+    while (true) {
+        val justRead = readChar() ?: return null
+        if (justRead == search) return s.toString()
+        s.append(justRead)
+    }
+}
+
+fun StringReader.peek(): Char? {
+    mark(0)
+    val x = readChar()
+    reset()
+    return x
+}
+
+
+fun readType(reader: StringReader): TypeDescriptor {
+    return when (reader.readChar()) {
+        'L' -> TypeDescriptor.Class(reader.readUntil(';') ?: error("Unfinished class type descriptor"))
+        'V' -> TypeDescriptor.Void
+        'Z' -> TypeDescriptor.Boolean
+        'B' -> TypeDescriptor.Byte
+        'I' -> TypeDescriptor.Int
+        'D' -> TypeDescriptor.Double
+        'J' -> TypeDescriptor.Long
+        'S' -> TypeDescriptor.Short
+        'F' -> TypeDescriptor.Float
+        'C' -> TypeDescriptor.Char
+        '[' -> TypeDescriptor.Array(readType(reader))
+        else -> error("Unknown or unfinished type descriptor")
+    }
+}