package ru.dbotthepony.kstarbound.lua

@Retention(AnnotationRetention.RUNTIME)
@Target(AnnotationTarget.PROPERTY, AnnotationTarget.FUNCTION)
annotation class LuaExposed

interface ILuaIndex {
	fun luaIndex(index: Any?): Any?
}

interface ILuaNewIndex {
	fun luaIndex(index: Any?, value: Any?)
}

class JVM2LuaWrapper<R : Any>(val value: R) {
	private abstract class LuaBinding<in R : Any> {
		abstract fun invoke(receiver: R, values: Array<Any?>): Any?
		abstract fun read(receiver: R): Any?
		abstract fun write(receiver: R, value: Any?)
	}

	private class LuaFunctionBinding<in R : Any>(private val func: (R, Array<Any?>) -> Any?) : LuaBinding<R>() {
		override fun invoke(receiver: R, values: Array<Any?>): Any? {
			return func.invoke(receiver, values)
		}

		override fun read(receiver: R) {
			throw UnsupportedOperationException("attempt to index a function value")
		}

		override fun write(receiver: R, value: Any?) {
			throw UnsupportedOperationException("attempt to new index a function value")
		}
	}

	private class LuaPropertyBinding<in R : Any>(private val read: (R) -> Any?, private val write: ((R, Any?) -> Unit)?) : LuaBinding<R>() {
		override fun invoke(receiver: R, values: Array<Any?>): Any? {
			throw UnsupportedOperationException("attempt to call a value")
		}

		override fun read(receiver: R): Any? {
			return read.invoke(receiver)
		}

		override fun write(receiver: R, value: Any?) {
			if (write == null)
				throw UnsupportedOperationException("attempt to new index a read-only value")

			write.invoke(receiver, value)
		}
	}

	companion object {
		//private val decls =
	}
}