/*******************************************************************************
 * 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 it.polito.verigraph.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 it.polito.verigraph.mcnet.components.NetContext;
import it.polito.verigraph.mcnet.components.Network;
import it.polito.verigraph.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()];
        //Constraintprivate_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));
    }
}