/*******************************************************************************
 * Copyright (c) 2017 Politecnico di Torino and others.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Apache License, Version 2.0
 * which accompanies this distribution, and is available at
 * http://www.apache.org/licenses/LICENSE-2.0
 *******************************************************************************/

package mcnet.netobjs;


import java.util.ArrayList;
import java.util.List;

import com.microsoft.z3.BoolExpr;
import com.microsoft.z3.Context;
import com.microsoft.z3.DatatypeExpr;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.Solver;

import mcnet.components.NetContext;
import mcnet.components.Network;
import mcnet.components.NetworkObject;
/**
 * NAT Model object
 *
 */
public class PolitoNat extends NetworkObject{
	List<BoolExpr> constraints;
	Context ctx;
	DatatypeExpr nat;
	List<DatatypeExpr> private_addresses;
	List<NetworkObject> private_node;
	Network net;
	NetContext nctx;
	FuncDecl private_addr_func ;

	public PolitoNat(Context ctx, Object[]... args) {
		super(ctx, args);
	}

	@Override
	protected void init(Context ctx, Object[]... args) {
		this.ctx = ctx;
		isEndHost=false;
   		constraints = new ArrayList<BoolExpr>();
        z3Node = ((NetworkObject)args[0][0]).getZ3Node();
        nat = z3Node;
        net = (Network)args[0][1];
        nctx = (NetContext)args[0][2];
        private_addresses = new ArrayList<DatatypeExpr>();
        private_node = new ArrayList<NetworkObject>();
        net.saneSend(this);
    }

	@Override
	public DatatypeExpr getZ3Node() {
		return nat;
	}

	@Override
	protected void addConstraints(Solver solver) {
			BoolExpr[] constr = new BoolExpr[constraints.size()];
		    solver.add(constraints.toArray(constr));
	}

	/*
	private void addPrivateAdd(List<DatatypeExpr> address){
		private_addresses.addAll(address);
	}
	*/

	public List<DatatypeExpr> getPrivateAddress(){
		return private_addresses;
	}

    public void natModel(DatatypeExpr natIp){
    	Expr x = ctx.mkConst("x", nctx.node);
    	Expr y = ctx.mkConst("y", nctx.node);
    	Expr z = ctx.mkConst("z", nctx.node);

    	Expr p_0 = ctx.mkConst("p_0", nctx.packet);
    	Expr p_1 = ctx.mkConst("p_1", nctx.packet);
    	Expr p_2 = ctx.mkConst("p_2", nctx.packet);

    	IntExpr t_0 = ctx.mkIntConst("t_0");
    	IntExpr t_1 = ctx.mkIntConst("t_1");
    	IntExpr t_2 = ctx.mkIntConst("t_2");

//    	private_addr_func = ctx.mkFuncDecl("private_addr_func", nctx.address, ctx.mkBoolSort());
    	private_addr_func = ctx.mkFuncDecl(nat + "_nat_func", nctx.address, ctx.mkBoolSort());

    	//Constraint1
//    	"send(nat, x, p_0, t_0) && !private_addr_func(p_0.dest) ->
//    	p_0.src == ip_politoNat &&
//    	(exist y, p_1,t_1 :
//    	   (recv(y, nat, p_1, t_1) && t_1 < t_0 &&
//    	    private_addr_func(p1.src) &&
//    	    p_1.origin == p_0.origin &&
//    	    same for p_1.<dest,orig_body,body,seq,proto,emailFrom,url,options> == p_0.<...>) "
    	constraints.add( ctx.mkForall(new Expr[]{t_0, p_0, x},
    		ctx.mkImplies(
    				ctx.mkAnd((BoolExpr)nctx.send.apply(nat, x, p_0, t_0),
    						ctx.mkNot((BoolExpr)private_addr_func.apply(nctx.pf.get("dest").apply(p_0)))),
    				ctx.mkAnd(
    						ctx.mkEq(nctx.pf.get("src").apply(p_0),natIp),
    						ctx.mkExists(new Expr[]{y, p_1, t_1},
    								ctx.mkAnd(
    									(BoolExpr)nctx.recv.apply(y, nat, p_1, t_1),
    									ctx.mkLt(t_1 , t_0),
    									(BoolExpr)private_addr_func.apply(nctx.pf.get("src").apply(p_1)),
    									ctx.mkEq(nctx.pf.get("origin").apply(p_1),nctx.pf.get("origin").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("dest").apply(p_1),nctx.pf.get("dest").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("orig_body").apply(p_1),nctx.pf.get("orig_body").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("body").apply(p_1),nctx.pf.get("body").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("seq").apply(p_1),nctx.pf.get("seq").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("proto").apply(p_1),nctx.pf.get("proto").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("emailFrom").apply(p_1),nctx.pf.get("emailFrom").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("url").apply(p_1),nctx.pf.get("url").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("options").apply(p_1),nctx.pf.get("options").apply(p_0))),1,null,null,null,null))),1,null,null,null,null));

    	//Constraint2
//    	send(nat, x, p_0, t_0) && private_addr_func(p_0.dest) ->
//    	!private_addr_func(p_0.src) &&
//    	(exist y, p_1,t_1 :
//    	  (recv(y, nat, p_1, t_1) && t_1 < t_0 &&
//    	   !private_addr_func(p1.src) &&
//    	   p_1.dest == ip_politoNat &&
//    	   p_1.origin == p_0.origin &&
//    	   same for p_1.<src,orig_body,body,seq,proto,emailFrom,url,options> == p_0.<...>)
    	constraints.add( ctx.mkForall(new Expr[]{x, p_0, t_0},
    			ctx.mkImplies(
    				ctx.mkAnd((BoolExpr)nctx.send.apply(nat, x, p_0, t_0),
    					(BoolExpr)private_addr_func.apply(nctx.pf.get("dest").apply(p_0))),
    					ctx.mkAnd(
    						ctx.mkNot((BoolExpr)private_addr_func.apply(nctx.pf.get("src").apply(p_0))),
    						ctx.mkExists(new Expr[]{y, p_1, t_1},
    							ctx.mkAnd(
    									ctx.mkLt(t_1 , t_0),
    									(BoolExpr)nctx.recv.apply(y, nat, p_1, t_1),
    									ctx.mkNot((BoolExpr)private_addr_func.apply(nctx.pf.get("src").apply(p_1))),
    									ctx.mkEq(nctx.pf.get("dest").apply(p_1),natIp),
    									ctx.mkEq(nctx.pf.get("src").apply(p_1),nctx.pf.get("src").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("origin").apply(p_0),nctx.pf.get("origin").apply(p_1)),
    									ctx.mkEq(nctx.pf.get("orig_body").apply(p_1),nctx.pf.get("orig_body").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("body").apply(p_1),nctx.pf.get("body").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("seq").apply(p_1),nctx.pf.get("seq").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("proto").apply(p_1),nctx.pf.get("proto").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("emailFrom").apply(p_1),nctx.pf.get("emailFrom").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("url").apply(p_1),nctx.pf.get("url").apply(p_0)),
    									ctx.mkEq(nctx.pf.get("options").apply(p_1),nctx.pf.get("options").apply(p_0)),
    									ctx.mkExists(new Expr[]{z, p_2, t_2},
    										ctx.mkAnd(
    												ctx.mkLt(t_2 , t_1),
    												(BoolExpr)nctx.recv.apply(z, nat, p_2, t_2),
    												(BoolExpr)private_addr_func.apply(nctx.pf.get("src").apply(p_2)),
    												ctx.mkEq(nctx.pf.get("src").apply(p_1),nctx.pf.get("dest").apply(p_2)),
    												ctx.mkEq(nctx.pf.get("src").apply(p_0),nctx.pf.get("dest").apply(p_2)),
    												ctx.mkEq(nctx.pf.get("src").apply(p_2),nctx.pf.get("dest").apply(p_0))),1,null,null,null,null)),1,null,null,null,null))),1,null,null,null,null));
    }

    public void setInternalAddress(ArrayList<DatatypeExpr> internalAddress){
    	List<BoolExpr> constr = new ArrayList<BoolExpr>();
    	Expr n_0 = ctx.mkConst("nat_node", nctx.address);

    	for(DatatypeExpr n : internalAddress){
    		constr.add(ctx.mkEq(n_0,n));
    	}
    	BoolExpr[] constrs = new BoolExpr[constr.size()];
    	//Constraint		private_addr_func(n_0) == or(n_0==n foreach internal address)
    	constraints.add(ctx.mkForall(new Expr[]{n_0}, ctx.mkEq(private_addr_func.apply(n_0),ctx.mkOr(constr.toArray(constrs))),1,null,null,null,null));
    }
}