package org.batfish.z3;

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

import org.batfish.z3.node.AclMatchExpr;
import org.batfish.z3.node.AndExpr;
import org.batfish.z3.node.DeclareRelExpr;
import org.batfish.z3.node.NumberedQueryExpr;
import org.batfish.z3.node.QueryExpr;
import org.batfish.z3.node.RuleExpr;
import org.batfish.z3.node.SaneExpr;

import com.microsoft.z3.BoolExpr;
import com.microsoft.z3.Context;
import com.microsoft.z3.Z3Exception;

public final class AclReachabilityQuerySynthesizer
      extends SatQuerySynthesizer<AclLine> {

   private final String _aclName;

   private final String _hostname;

   private final int _numLines;

   public AclReachabilityQuerySynthesizer(String hostname, String aclName,
         int numLines) {
      _hostname = hostname;
      _aclName = aclName;
      _numLines = numLines;
   }

   @Override
   public NodProgram getNodProgram(NodProgram baseProgram) throws Z3Exception {
      Context ctx = baseProgram.getContext();
      NodProgram program = new NodProgram(ctx);
      for (int line = 0; line < _numLines; line++) {
         AclMatchExpr matchAclLine = new AclMatchExpr(_hostname, _aclName,
               line);
         AndExpr queryConditions = new AndExpr();
         queryConditions.addConjunct(matchAclLine);
         queryConditions.addConjunct(SaneExpr.INSTANCE);
         NumberedQueryExpr queryRel = new NumberedQueryExpr(line);
         String queryRelName = queryRel.getRelations()
               .toArray(new String[] {})[0];
         List<Integer> sizes = new ArrayList<>();
         sizes.addAll(Synthesizer.PACKET_VAR_SIZES.values());
         DeclareRelExpr declaration = new DeclareRelExpr(queryRelName, sizes);
         baseProgram.getRelationDeclarations().put(queryRelName,
               declaration.toFuncDecl(ctx));
         RuleExpr queryRule = new RuleExpr(queryConditions, queryRel);
         List<BoolExpr> rules = program.getRules();
         rules.add(queryRule.toBoolExpr(baseProgram));
         QueryExpr query = new QueryExpr(queryRel);
         BoolExpr queryBoolExpr = query.toBoolExpr(baseProgram);
         program.getQueries().add(queryBoolExpr);
         _keys.add(new AclLine(_hostname, _aclName, line));
      }
      return program;
   }

   @Override
   public NodProgram synthesizeBaseProgram(Synthesizer synthesizer,
         Context ctx) {
      return synthesizer.synthesizeNodAclProgram(_hostname, _aclName, ctx);
   }

}