package org.luaj.luajc;

import org.luaj.vm2.LuaValue;
import org.luaj.vm2.Varargs;
import org.luaj.vm2.lib.TwoArgFunction;
import org.luaj.vm2.lib.VarArgFunction;

public class SampleMainChunk extends VarArgFunction {

	static final LuaValue $print = valueOf("print");
	static final LuaValue $foo = valueOf("foo");
	
	LuaValue[] rw_ENV;  // The environment when it is read-write
//	LuaValue ro_ENV;  // The environment when it is read-only in all sub-functions
	
	LuaValue[] rw_openup1;  // upvalue that we create and modify in "slot" 1, passed to sub-function in initer.
	LuaValue[] rw_openup2;  // array is instantiated on first set or before supply to closure, after that value is get, set.
	LuaValue[] rw_openup3;  // closing these nulls them out, sub-functions still retain references to array & can use
	LuaValue ro_openup4;  // open upvalue that is read-only once it is supplied to an inner function.
	LuaValue ro_openup5;  // closing this also nulls it out.
	
	// Must have this in the main chunk so it can be loaded and instantiated on all platforms.
	public SampleMainChunk() {
	}
	
	public void initupvalue1(LuaValue[] v) {
		this.rw_ENV = v;
	}

	public Varargs invoke(Varargs args) {
		rw_ENV[0].get($print).call($foo);
		
		rw_ENV[0].set($print, new InnerFunction(rw_openup3, rw_openup1, ro_openup5));
		
		return null;
	}
	
	static class InnerFunction extends TwoArgFunction {
		static final LuaValue $print = valueOf("print"); // A constant, named for what it is.
		static final LuaValue $foo = valueOf("foo");
		
		final LuaValue[] rw_upvalue1;  // from enclosing function, corresponds to upvaldesc not instack.
		final LuaValue[] rw_upvalue2;  // from enclosing function, corresponds to upvaldesc not instack.
		final LuaValue ro_upvalue3;  // from enclosing function, but read-only everywhere.

		LuaValue[] rw_openup1;  // closing these nulls them out, sub-functions still retain references to array & can use
		LuaValue ro_openup2;  // open upvalue that is read-only once it is supplied to an inner function.

		InnerFunction(LuaValue[] rw_upvalue1, LuaValue[] rw_upvalue2, LuaValue ro_upvalue3) {
			this.rw_upvalue1 = rw_upvalue1;
			this.rw_upvalue2 = rw_upvalue2;
			this.ro_upvalue3 = ro_upvalue3;
		}

		public LuaValue call(LuaValue arg1, LuaValue arg2) {
			return NIL;
		}
		
	}

}