package org.batfish.question;

import java.util.Collections;
import java.util.TreeSet;

import org.batfish.common.Answerer;
import org.batfish.common.plugin.IBatfish;
import org.batfish.datamodel.IpAccessList;
import org.batfish.datamodel.answers.AnswerElement;
import org.batfish.datamodel.collections.NamedStructureEquivalenceSets;
import org.batfish.datamodel.questions.Question;
import org.batfish.question.CompareSameNameQuestionPlugin.CompareSameNameAnswerElement;
import org.batfish.question.CompareSameNameQuestionPlugin.CompareSameNameAnswerer;
import org.batfish.question.CompareSameNameQuestionPlugin.CompareSameNameQuestion;
import com.fasterxml.jackson.annotation.JsonProperty;

public class AclReachabilityQuestionPlugin extends QuestionPlugin {

   public static class AclReachabilityAnswerer extends Answerer {

      public AclReachabilityAnswerer(Question question, IBatfish batfish) {
         super(question, batfish);
      }

      @Override
      public AnswerElement answer() {
         AclReachabilityQuestion question = (AclReachabilityQuestion) _question;
         // get comparesamename results for acls
         CompareSameNameQuestion csnQuestion = new CompareSameNameQuestion();
         csnQuestion.setNodeRegex(question.getNodeRegex());
         csnQuestion.setNamedStructTypes(new TreeSet<>(
               Collections.singleton(IpAccessList.class.getSimpleName())));
         csnQuestion.setSingletons(true);
         CompareSameNameAnswerer csnAnswerer = new CompareSameNameAnswerer(
               csnQuestion, _batfish);
         CompareSameNameAnswerElement csnAnswer = csnAnswerer.answer();
         NamedStructureEquivalenceSets<?> aclEqSets = csnAnswer
               .getEquivalenceSets().get(IpAccessList.class.getSimpleName());

         return _batfish.answerAclReachability(question.getAclNameRegex(),
               aclEqSets);
      }

   }

   // <question_page_comment>
   /**
    * Identifies unreachable lines in ACLs.
    * <p>
    * Report ACLs with unreachable lines, as well as reachability of each line
    * within the ACL. Unreachable lines can indicate erroneous configuration.
    *
    * @type AclReachability onefile
    *
    * @param aclNameRegex
    *           Regular expression for names of the ACLs to analyze. Default
    *           value is '.*' (i.e., all ACLs).
    *
    * @param nodeRegex
    *           Regular expression for names of nodes to include. Default value
    *           is '.*' (all nodes).
    *
    * @example bf_answer("AclReachability", aclNameRegex='OUTSIDE_TO_INSIDE.*')
    *          Analyzes only ACLs whose names start with 'OUTSIDE_TO_INSIDE'.
    */
   public static class AclReachabilityQuestion extends Question {

      private static final String ACL_NAME_REGEX_VAR = "aclNameRegex";

      private static final String NODE_REGEX_VAR = "nodeRegex";

      private String _aclNameRegex;

      private String _nodeRegex;

      public AclReachabilityQuestion() {
         _nodeRegex = ".*";
         _aclNameRegex = ".*";
      }

      @JsonProperty(ACL_NAME_REGEX_VAR)
      public String getAclNameRegex() {
         return _aclNameRegex;
      }

      @Override
      public boolean getDataPlane() {
         return false;
      }

      @Override
      public String getName() {
         return "aclreachability";
      }

      @JsonProperty(NODE_REGEX_VAR)
      public String getNodeRegex() {
         return _nodeRegex;
      }

      @Override
      public boolean getTraffic() {
         return false;
      }

      @Override
      public String prettyPrint() {
         String retString = String.format("%s %s%s=\"%s\" %s=\"%s\"", getName(),
               prettyPrintBase(), ACL_NAME_REGEX_VAR, _aclNameRegex,
               NODE_REGEX_VAR, _nodeRegex);
         return retString;
      }

      @JsonProperty(ACL_NAME_REGEX_VAR)
      public void setAclNameRegex(String regex) {
         _aclNameRegex = regex;
      }

      @JsonProperty(NODE_REGEX_VAR)
      public void setNodeRegex(String regex) {
         _nodeRegex = regex;
      }

   }

   @Override
   protected Answerer createAnswerer(Question question, IBatfish batfish) {
      return new AclReachabilityAnswerer(question, batfish);
   }

   @Override
   protected Question createQuestion() {
      return new AclReachabilityQuestion();
   }

}