package soot.dava.toolkits.base.AST.transformations;

/*-
 * #%L
 * Soot - a J*va Optimization Framework
 * %%
 * Copyright (C) 2005 Nomair A. Naeem
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 2.1 of the
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Lesser Public License for more details.
 * 
 * You should have received a copy of the GNU General Lesser Public
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/lgpl-2.1.html>.
 * #L%
 */

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

import soot.G;
import soot.dava.internal.AST.ASTCondition;
import soot.dava.internal.AST.ASTDoWhileNode;
import soot.dava.internal.AST.ASTIfElseNode;
import soot.dava.internal.AST.ASTIfNode;
import soot.dava.internal.AST.ASTLabeledBlockNode;
import soot.dava.internal.AST.ASTMethodNode;
import soot.dava.internal.AST.ASTNode;
import soot.dava.internal.AST.ASTOrCondition;
import soot.dava.internal.AST.ASTStatementSequenceNode;
import soot.dava.internal.AST.ASTSynchronizedBlockNode;
import soot.dava.internal.AST.ASTUnconditionalLoopNode;
import soot.dava.internal.AST.ASTWhileNode;
import soot.dava.internal.asg.AugmentedStmt;
import soot.dava.internal.javaRep.DAbruptStmt;
import soot.jimple.ReturnStmt;
import soot.jimple.ReturnVoidStmt;
import soot.jimple.Stmt;

/*
  Nomair A. Naeem 21-FEB-2005
  The class is responsible to do the following transformation on the AST
  if(cond1){              if(cond1 || cond2)
     A                            A
  }                       }
  if(cond2){
     A
  }

  Notice that this kind of conversion is only possible if A is an
  abrupt edge like:
     a, break label_0;
     b, continue label_0;
     c, return;

  i.e. we need to make sure that the A bodies are single statements
  and that too an abrupt control flow

  Also note that in the new aggregated or condition it is very important
  that cond2 be checked AFTER cond1 has been checked and failed.
  The reason for this being side effects that these conditions can cause.

*/
public class OrAggregatorThree {

  public static void checkAndTransform(ASTNode node, ASTIfNode ifOne, ASTIfNode ifTwo, int nodeNumber, int subBodyNumber) {

    if (!(node instanceof ASTIfElseNode)) {
      // these are the nodes which always have one subBody
      List<Object> subBodies = node.get_SubBodies();
      if (subBodies.size() != 1) {
        // there is something wrong
        throw new RuntimeException("Please report this benchmark to the programmer");
      }
      List<Object> onlySubBody = (List<Object>) subBodies.get(0);

      /*
       * The onlySubBody contains the Two consective if nodes at location given by nodeNumber and nodeNumber+1
       */

      // match the pattern and get the newBody
      List<Object> newBody = createNewNodeBody(onlySubBody, nodeNumber, ifOne, ifTwo);

      if (newBody == null) {
        // something went wrong, pattern didnt match or some other problem
        return;
      }
      if (node instanceof ASTMethodNode) {
        ((ASTMethodNode) node).replaceBody(newBody);
        G.v().ASTTransformations_modified = true;
        // System.out.println("OR AGGREGATOR THREE");
      } else if (node instanceof ASTSynchronizedBlockNode) {
        ((ASTSynchronizedBlockNode) node).replaceBody(newBody);
        G.v().ASTTransformations_modified = true;
        // System.out.println("OR AGGREGATOR THREE");
      } else if (node instanceof ASTLabeledBlockNode) {
        ((ASTLabeledBlockNode) node).replaceBody(newBody);
        G.v().ASTTransformations_modified = true;
        // System.out.println("OR AGGREGATOR THREE");
      } else if (node instanceof ASTUnconditionalLoopNode) {
        ((ASTUnconditionalLoopNode) node).replaceBody(newBody);
        G.v().ASTTransformations_modified = true;
        // System.out.println("OR AGGREGATOR THREE");
      } else if (node instanceof ASTIfNode) {
        ((ASTIfNode) node).replaceBody(newBody);
        G.v().ASTTransformations_modified = true;
        // System.out.println("OR AGGREGATOR THREE");
      } else if (node instanceof ASTWhileNode) {
        ((ASTWhileNode) node).replaceBody(newBody);
        G.v().ASTTransformations_modified = true;
        // System.out.println("OR AGGREGATOR THREE");
      } else if (node instanceof ASTDoWhileNode) {
        ((ASTDoWhileNode) node).replaceBody(newBody);
        G.v().ASTTransformations_modified = true;
        // System.out.println("OR AGGREGATOR THREE");
      } else {
        // there is no other case something is wrong if we get here
        return;
      }
    } else {
      // its an ASTIfElseNode
      // if its an ASIfElseNode then check which Subbody has the labeledBlock
      if (subBodyNumber != 0 && subBodyNumber != 1) {
        // something bad is happening dont do nothin
        // System.out.println("Error-------not modifying AST");
        return;
      }
      List<Object> subBodies = node.get_SubBodies();
      if (subBodies.size() != 2) {
        // there is something wrong
        throw new RuntimeException("Please report this benchmark to the programmer");
      }

      List<Object> toModifySubBody = (List<Object>) subBodies.get(subBodyNumber);

      /*
       * The toModifySubBody contains the two consective if nodes in question at location given by the nodeNumber and
       * nodeNumer+1
       */
      List<Object> newBody = createNewNodeBody(toModifySubBody, nodeNumber, ifOne, ifTwo);
      if (newBody == null) {
        // something went wrong, the pattern didnt match or something else
        return;
      }
      if (subBodyNumber == 0) {
        // the if body was modified
        // System.out.println("OR AGGREGATOR THREE");
        G.v().ASTTransformations_modified = true;
        ((ASTIfElseNode) node).replaceBody(newBody, (List<Object>) subBodies.get(1));
      } else if (subBodyNumber == 1) {
        // else body was modified
        // System.out.println("OR AGGREGATOR THREE");
        G.v().ASTTransformations_modified = true;
        ((ASTIfElseNode) node).replaceBody((List<Object>) subBodies.get(0), newBody);
      }

    } // end of ASTIfElseNode
  }

  /*
   * This method does the following: 1, check that the OrAggregatorThree pattern matches for node ifOne and ifTwo 2, if
   * pattern does not match return null 3, if pattern matches create and return a newSubBody which has: a, ifOne with its
   * condition ORED with that of ifTwo b, ifTwo has been removed from the subBody
   */

  public static List<Object> createNewNodeBody(List<Object> oldSubBody, int nodeNumber, ASTIfNode ifOne, ASTIfNode ifTwo) {
    if (!matchPattern(ifOne, ifTwo)) {
      // pattern did not match
      return null;
    }

    // create a new SubBody
    List<Object> newSubBody = new ArrayList<Object>();

    // this is an iterator of ASTNodes
    Iterator<Object> it = oldSubBody.iterator();

    // copy to newSubBody all nodes until you get to nodeNumber
    int index = 0;
    while (index != nodeNumber) {
      if (!it.hasNext()) {
        return null;
      }
      newSubBody.add(it.next());
      index++;
    }

    // at this point the iterator is pointing to the ASTIFNode
    // just to make sure check this
    ASTNode isItIfOne = (ASTNode) it.next();

    if (!(isItIfOne instanceof ASTIfNode)) {
      // something is wrong
      return null;
    }

    // get the next node that should also be an ASTIfNode
    ASTNode isItIfTwo = (ASTNode) it.next();
    if (!(isItIfTwo instanceof ASTIfNode)) {
      // something is wrong
      return null;
    }

    // double check by invoking matchPattern on these
    // if speed is an issue this check can be removed
    if (!matchPattern((ASTIfNode) isItIfOne, (ASTIfNode) isItIfTwo)) {
      // pattern did not match
      return null;
    }

    // we are sure that we have the two nodes

    // create new node
    ASTIfNode firstOne = (ASTIfNode) isItIfOne;
    ASTIfNode secondOne = (ASTIfNode) isItIfTwo;

    // create new condition
    ASTCondition firstCond = firstOne.get_Condition();
    ASTCondition secondCond = secondOne.get_Condition();

    ASTCondition newCond = new ASTOrCondition(firstCond, secondCond);

    ASTIfNode newNode = new ASTIfNode(firstOne.get_Label(), newCond, firstOne.getIfBody());

    // add the new node
    newSubBody.add(newNode);

    // add any remaining nodes in the oldSubBody to the new one
    while (it.hasNext()) {
      newSubBody.add(it.next());
    }

    // newSubBody is ready return it
    return newSubBody;
  }

  /*
   * Given two IfNodes as input the pattern checks the following: a, each if node has a single ASTSTatementSequenceNode in
   * the body b, Each StatementSequenceNode is a single statement c, The statement is the same in both nodes d, The statement
   * is an abrupt control flow statement
   */
  private static boolean matchPattern(ASTIfNode one, ASTIfNode two) {
    List<Object> subBodiesOne = one.get_SubBodies();
    List<Object> subBodiesTwo = two.get_SubBodies();

    if (subBodiesOne.size() != 1 || subBodiesTwo.size() != 1) {
      // these are both if nodes they should always have one subBody
      return false;
    }
    List onlySubBodyOne = (List) subBodiesOne.get(0);
    List onlySubBodyTwo = (List) subBodiesTwo.get(0);

    if (onlySubBodyOne.size() != 1 || onlySubBodyTwo.size() != 1) {
      // these subBodies are expected to have a single StatementSequenceNode
      return false;
    }

    ASTNode onlyASTNodeOne = (ASTNode) onlySubBodyOne.get(0);
    ASTNode onlyASTNodeTwo = (ASTNode) onlySubBodyTwo.get(0);

    if (!(onlyASTNodeOne instanceof ASTStatementSequenceNode) || !(onlyASTNodeTwo instanceof ASTStatementSequenceNode)) {
      // need both of these nodes to be StatementSequnceNodes
      return false;
    }

    ASTStatementSequenceNode stmtSeqOne = (ASTStatementSequenceNode) onlyASTNodeOne;
    ASTStatementSequenceNode stmtSeqTwo = (ASTStatementSequenceNode) onlyASTNodeTwo;

    List<AugmentedStmt> stmtsOne = stmtSeqOne.getStatements();
    List<AugmentedStmt> stmtsTwo = stmtSeqTwo.getStatements();

    if (stmtsOne.size() != 1 || stmtsTwo.size() != 1) {
      // there should only be one statement
      return false;
    }

    AugmentedStmt asOne = stmtsOne.get(0);
    AugmentedStmt asTwo = stmtsTwo.get(0);

    Stmt s1 = asOne.get_Stmt();
    Stmt s2 = asTwo.get_Stmt();

    if (s1.toString().compareTo(s2.toString()) != 0) {
      // the two stmts are not the same
      return false;
    }

    // check if they are abrupt statements
    if (s1 instanceof DAbruptStmt && s2 instanceof DAbruptStmt) {
      // takes care of break <label> and continue <label>
      return true;
    } else if (s1 instanceof ReturnStmt && s2 instanceof ReturnStmt) {
      // takes care of return <var>
      return true;
    } else if (s1 instanceof ReturnVoidStmt && s2 instanceof ReturnVoidStmt) {
      // takes care of return;
      return true;
    } else {
      return false;
    }
  }
}
