/*******************************************************************************
 * 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 com.microsoft.z3.Sort;

import mcnet.components.NetContext;
import mcnet.components.Network;
import mcnet.components.NetworkObject;
/**Cache Model
 *
 */
public class PolitoCache extends NetworkObject{

		List<BoolExpr> constraints;
		Context ctx;
		DatatypeExpr politoCache;
		Network net;
		NetContext nctx;
		FuncDecl isInBlacklist;

		public PolitoCache(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();
	        politoCache = z3Node;
	        net = (Network)args[0][1];
	        nctx = (NetContext)args[0][2];
	        //net.saneSend(this);
	    }

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

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

	    public void installCache (NetworkObject[] internalNodes){
	    	Expr n_0 = ctx.mkConst("politoCache_"+politoCache+"_n_0", nctx.node);
	    	Expr n_1 = ctx.mkConst("politoCache_"+politoCache+"_n_1", nctx.node);
	    	Expr n_2 = ctx.mkConst("politoCache_"+politoCache+"_n_2", nctx.node);
	    	Expr p_0 = ctx.mkConst("politoCache_"+politoCache+"_p_0", nctx.packet);
	    	Expr p_1 = ctx.mkConst("politoCache_"+politoCache+"_p_1", nctx.packet);
	    	Expr p_2 = ctx.mkConst("politoCache_"+politoCache+"_p_2", nctx.packet);

	    	IntExpr t_0 = ctx.mkIntConst("politoCache_"+politoCache+"_t_0");
	    	IntExpr t_1 = ctx.mkIntConst("politoCache_"+politoCache+"_t_1");
	    	IntExpr t_2 = ctx.mkIntConst("politoCache_"+politoCache+"_t_2");

	    	Expr a_0 = ctx.mkConst(politoCache+"politoCache_a_0", nctx.node);
	    	IntExpr u_0 = ctx.mkIntConst("politoCache_"+politoCache+"_u_0");

	    	FuncDecl isInternalNode = ctx.mkFuncDecl(politoCache+"_isInternalNode", nctx.node, ctx.mkBoolSort());
	    	FuncDecl isInCache = ctx.mkFuncDecl(politoCache+"_isInCache", new Sort[]{ctx.mkIntSort(),ctx.mkIntSort()}, ctx.mkBoolSort());

	    	assert(internalNodes.length!=0); //No internal nodes => Should never happen

	    	//Modeling the behavior of the isInternalNode() and isInCache() functions
	    	BoolExpr[] internalNodesConstraint = new BoolExpr[internalNodes.length];
	    	for(int w=0;w<internalNodesConstraint.length;w++)
	    		internalNodesConstraint[w]= (ctx.mkEq(a_0,internalNodes[w].getZ3Node()));

	    	//Constraint1		if(isInternalNode(a_0) == or(listadeinodiinterni) ? True : false
	    	constraints.add(
	    			 ctx.mkForall(new Expr[]{a_0},
	    					 ctx.mkIff((BoolExpr)isInternalNode.apply(a_0), ctx.mkOr(internalNodesConstraint)),1,null,null,null,null));

//	    	constraints.add(ctx.mkForall(new Expr[]{a_0}, ctx.mkEq(isInternalNode.apply(a_0),ctx.mkOr(internalNodesConstraint)),1,null,null,null,null));

//	    	constraints.add(ctx.mkForall(new Expr[]{u_0, t_0},
//                     ctx.mkITE(ctx.mkExists(new Expr[]{t_1, t_2, p_1, p_2, n_1, n_2},
//	                        	ctx.mkAnd(ctx.mkLt(t_1, t_2),
//	                                ctx.mkLt(t_1, t_0),
//	                                ctx.mkLt(t_2, t_0),
//	                                (BoolExpr)nctx.recv.apply(n_1, politoCache, p_1, t_1),
//	                                (BoolExpr)nctx.recv.apply(n_2, politoCache, p_2, t_2),
//	                                ctx.mkEq(nctx.pf.get("proto").apply(p_1),ctx.mkInt(nctx.HTTP_REQUEST)),
//	                                ctx.mkEq(nctx.pf.get("proto").apply(p_2),ctx.mkInt(nctx.HTTP_RESPONSE)),
//	                                (BoolExpr)isInternalNode.apply(n_1),
//	                                ctx.mkNot((BoolExpr)isInternalNode.apply(n_2)),
//	                                ctx.mkEq(nctx.pf.get("url").apply(p_1),u_0),
//	                                ctx.mkEq(nctx.pf.get("url").apply(p_2),u_0)),1,null,null,null,null),
//                    		 ctx.mkEq(isInCache.apply(u_0,t_0),ctx.mkBool(true)),ctx.mkEq(isInCache.apply(u_0,t_0),ctx.mkBool(false))),1,null,null,null,null));
//

	    	//Constraint2	isInCache(u_0,t_0), exist t_1, t_2, p_1, p_2, n_1, n_2 :
	    	//						    	(   t_1< t_2 < t_0 && recv(n_1, politoCache, p_1, t_1) && recv(n_2, politoCache, p_2, t_2))) &&
	    	//	        						p_1.proto == HTTP_REQ &&  p_2.proto == HTTP_RESP &&
	    	//	        						isInternalNode(n_1) && !isInternalNode(n_2) &&
	    	//	        						p_1.url == u_0 &&  p_2.url == u_0 )
	    	constraints.add(
	    			ctx.mkForall(new Expr[]{u_0, t_0},
	    			 ctx.mkImplies((BoolExpr)isInCache.apply(u_0, t_0),
	    					 ctx.mkExists(new Expr[]{t_1,t_2,p_1,p_2,n_1, n_2},
	    							 ctx.mkAnd(
	    									 ctx.mkLt(t_1, t_2),
	    									 ctx.mkLt(t_1, t_0),
	    									 ctx.mkLt(t_2, t_0),
	    									 (BoolExpr)nctx.recv.apply(n_1, politoCache, p_1, t_1),
	    									 (BoolExpr)nctx.recv.apply(n_2, politoCache, p_2, t_2),
	    									 ctx.mkEq(nctx.pf.get("proto").apply(p_1), ctx.mkInt(nctx.HTTP_REQUEST)),
	    									 ctx.mkEq(nctx.pf.get("proto").apply(p_2), ctx.mkInt(nctx.HTTP_RESPONSE)),
	    									 (BoolExpr)isInternalNode.apply(n_1),
	    									 ctx.mkNot((BoolExpr)isInternalNode.apply(n_2)),
	    									 ctx.mkEq(nctx.pf.get("url").apply(p_1), u_0),
	    									 ctx.mkEq(nctx.pf.get("url").apply(p_2), u_0)),1,null,null,null,null)),1,null,null,null,null));
//	    	//Always in cache
//	    	constraints.add(ctx.mkForall(new Expr[]{u_0, t_0},ctx.mkEq(isInCache.apply(u_0,t_0),ctx.mkBool(true)),1,null,null,null,null));

	    	//Constraint3	Modeling the behavior of the cache
	    	//				send(politoCache, n_0, p, t_0) && !isInternalNode(n_0) ->
			//	    			(exist t_1,n_1 :
			//	    		    (t_1 < t_0 && recv(n_1, politoCache, p, t_1) &&
			//	    		     p.proto == HTTP_REQ &&  !isInCache(p.url,t_0))
	    	constraints.add(
	    			ctx.mkForall(new Expr[]{n_0,p_0, t_0},
	   	    			 ctx.mkImplies(
	   	    					 ctx.mkAnd((BoolExpr)nctx.send.apply(politoCache,n_0,p_0,t_0),ctx.mkNot((BoolExpr)isInternalNode.apply(n_0))),
	   	    					 ctx.mkAnd(ctx.mkExists(new Expr[]{t_1, n_1},
	   	    							 ctx.mkAnd(
	   	    									 ctx.mkLt(t_1, t_0),
	   	    									 (BoolExpr)isInternalNode.apply(n_1),
	   	    									 (BoolExpr)nctx.recv.apply(n_1, politoCache, p_0, t_1)),1,null,null,null,null),
	   	    									 ctx.mkEq(nctx.pf.get("proto").apply(p_0), ctx.mkInt(nctx.HTTP_REQUEST)),
	   	    									 ctx.mkNot((BoolExpr)isInCache.apply(nctx.pf.get("url").apply(p_0), t_0)))),1,null,null,null,null));

	    	//Constraint4		send(politoCache, n_0, p, t_0) && isInternalNode(n_0) ->
			//	    			(exist p_1,t_1 :
			//	    		    	(t_1 < t_0 && recv(n_0, politoCache, p_1, t_1) &&
			//	    		     	p_1.proto == HTTP_REQ && p.proto == HTTP_RESP &&
			//	    		     	p_1.url == p.url &&  p.src == p_1.dest && p.dest==p_1.src
			//	    		     	&& isInCache(p.url,t_0))
	    	constraints.add(
	    			ctx.mkForall(new Expr[]{n_0,p_0, t_0},
	   	    			 ctx.mkImplies(
	   	    					 ctx.mkAnd((BoolExpr)nctx.send.apply(politoCache,n_0,p_0,t_0),(BoolExpr)isInternalNode.apply(n_0)),
	   	    					 ctx.mkAnd(ctx.mkExists(new Expr[]{p_1, t_1},
	   	    							 ctx.mkAnd(
	   	    									 ctx.mkLt(t_1, t_0),
	   	    									(BoolExpr)nctx.recv.apply(n_0, politoCache, p_1, t_1),
	   	    									 ctx.mkEq(nctx.pf.get("proto").apply(p_1), ctx.mkInt(nctx.HTTP_REQUEST)),
	   	    									 ctx.mkEq(nctx.pf.get("url").apply(p_1), nctx.pf.get("url").apply(p_0))),1,null,null,null,null),
	   	    							 ctx.mkEq(nctx.pf.get("proto").apply(p_0), ctx.mkInt(nctx.HTTP_RESPONSE)),
	   	    							 ctx.mkEq(nctx.pf.get("src").apply(p_0), nctx.pf.get("dest").apply(p_1)),
	   	    							 ctx.mkEq(nctx.pf.get("dest").apply(p_0), nctx.pf.get("src").apply(p_1)),
		    							(BoolExpr)isInCache.apply(nctx.pf.get("url").apply(p_0), t_0))),1,null,null,null,null));
	    }
}