using NObfs.Tree;
using NObfs.Dump;
using System;

namespace NObfs {
	public module NObfs {
		public Main() : void {
			def Expr(expr : NExpr) {
				| Var(var) => var : object
				| Number(num) => num : object
				| x => x
			}
			
			def tree = Dump.DumpTree;
			// NExpr.Print(tree)
			def stateDeobfsVar = Walk(
				tree,
				fun(expr : NExpr) {
					| Switch(expr, _) => Expr(expr)
					| _ => null
				}
			);
			Console.WriteLine(
				"Deobfs state == {0}",
				stateDeobfsVar
			);
			def (stateObfsVar, stateOff) = Walk(
				tree,
				fun(expr : NExpr) {
					| Assign(left, right) =>
						match(left) {
							| Var(var) when var == stateDeobfsVar =>
								match(right) {
									| Arith(type_, left, right) =>
										(
											Expr(left) :> string,
											match(type_) {
												| Add =>   Expr(right) :> long
												| Sub => -(Expr(right) :> long)
												| _ => throw Exception("WTF?")
											}
										) : object
									| _ => null
								}
							| _ => null
						}
					| _ => null
				}
			) :> string * long;
			
			Console.WriteLine(
				"Obfs state == {0}",
				stateObfsVar
			);
			Console.WriteLine(
				"State offset == {0}",
				stateOff
			);
		}
		
		Walk(tree : NExpr, func : NExpr -> object) : object {
			def WalkList(exprs, func) {
				match(exprs) {
					| [] => null
					| head :: tail =>
						def ret = Walk(head, func);
						if(ret == null)
							WalkList(tail, func)
						else
							ret
				}
			}
			
			def WalkCases(exprs, func) {
				match(exprs) {
					| [] => null
					| (_, head) :: tail =>
						def ret = Walk(head, func);
						if(ret == null)
							WalkCases(tail, func)
						else
							ret
				}
			}
			
			def ret = func(tree);
			if(ret == null) {
				match(tree) {
					| Loc(_, body) => Walk(body, func)
					| Block(exprs) => WalkList(exprs, func)
					| If(_, then, else_) =>
						def ret = Walk(then, func);
						if(ret == null)
							Walk(else_, func)
						else
							ret
					| Switch(_, cases) => WalkCases(cases, func)
					| While(_, body) => Walk(body, func)
					| _ => null
				}
			} else
				ret
		}
	}
}