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

/*-
 * #%L
 * Soot - a J*va Optimization Framework
 * %%
 * Copyright (C) 2006 Nomair A. Naeem (nomair.naeem@mail.mcgill.ca)
 * %%
 * 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.HashSet;
import java.util.List;

import soot.BooleanType;
import soot.ByteType;
import soot.CharType;
import soot.DoubleType;
import soot.FloatType;
import soot.IntType;
import soot.Local;
import soot.LongType;
import soot.RefType;
import soot.ShortType;
import soot.SootClass;
import soot.SootField;
import soot.SootFieldRef;
import soot.SootMethod;
import soot.Type;
import soot.Value;
import soot.dava.DavaBody;
import soot.dava.DecompilationException;
import soot.dava.internal.AST.ASTMethodNode;
import soot.dava.internal.AST.ASTNode;
import soot.dava.internal.AST.ASTStatementSequenceNode;
import soot.dava.internal.AST.ASTTryNode;
import soot.dava.internal.asg.AugmentedStmt;
import soot.dava.internal.javaRep.DInstanceFieldRef;
import soot.dava.internal.javaRep.DIntConstant;
import soot.dava.internal.javaRep.DStaticFieldRef;
import soot.dava.internal.javaRep.DVariableDeclarationStmt;
import soot.dava.toolkits.base.AST.analysis.DepthFirstAdapter;
import soot.dava.toolkits.base.AST.structuredAnalysis.MustMayInitialize;
import soot.dava.toolkits.base.AST.traversals.AllVariableUses;
import soot.grimp.internal.GAssignStmt;
import soot.jimple.DefinitionStmt;
import soot.jimple.DoubleConstant;
import soot.jimple.FloatConstant;
import soot.jimple.InvokeExpr;
import soot.jimple.LongConstant;
import soot.jimple.NullConstant;
import soot.jimple.Stmt;
import soot.jimple.internal.JimpleLocal;
import soot.tagkit.DoubleConstantValueTag;
import soot.tagkit.FloatConstantValueTag;
import soot.tagkit.IntegerConstantValueTag;
import soot.tagkit.LongConstantValueTag;
import soot.tagkit.StringConstantValueTag;

/**
 * Maintained by: Nomair A. Naeem
 */
/**
 * CHANGE LOG: 30th January 2006: Class was created to get rid of the field might not be initialized error that used to show
 * up when recompiling decompiled code Will be throughly covered in "Programmer Friendly Code" Sable Tech Report (2006)
 *
 */
/**
 * This class makes sure there is an initialization of all final variables (static or non static). If we cant guarantee
 * initialization (may be initialized on multiple paths but not all) then we remove the final keyword
 */
public class FinalFieldDefinition {
  // extends DepthFirstAdapter{
  SootClass sootClass;

  SootMethod sootMethod;

  DavaBody davaBody;

  List<SootField> cancelFinalModifier;

  public FinalFieldDefinition(ASTMethodNode node) {
    davaBody = node.getDavaBody();
    sootMethod = davaBody.getMethod();
    sootClass = sootMethod.getDeclaringClass();

    String subSignature = sootMethod.getName();
    if (subSignature.compareTo("<clinit>") != 0 && subSignature.compareTo("<init>") != 0) {
      // dont care about these since we want only static block and
      // constructors
      // System.out.println("\n\nName"+sootMethod.getName()+"
      // SubSignature:"+sootMethod.getSubSignature());
      return;
    }

    // create a list of interesting vars
    ArrayList<SootField> interesting = findFinalFields();
    if (interesting.isEmpty()) {
      // no final fields of interest
      return;
    }

    cancelFinalModifier = new ArrayList<SootField>();
    analyzeMethod(node, interesting);
    for (SootField field : cancelFinalModifier) {
      field.setModifiers((soot.Modifier.FINAL ^ 0xFFFF) & field.getModifiers());
    }
  }

  /*
   * this method finds all the final fields in this class and assigns them to the finalFields list
   *
   * Note this stores a list of SootFields!!!
   *
   * Fields which are initialized in their declaration should not be added
   */
  public ArrayList<SootField> findFinalFields() {

    // first thing is to get a list of all final fields in the class
    ArrayList<SootField> interestingFinalFields = new ArrayList<SootField>();
    for (SootField tempField : sootClass.getFields()) {
      if (tempField.isFinal()) {

        // if its static final and method is static add
        if (tempField.isStatic() && sootMethod.getName().compareTo("<clinit>") == 0) {
          interestingFinalFields.add(tempField);
        }

        // if its non static and final and method is constructor add
        if (!tempField.isStatic() && sootMethod.getName().compareTo("<init>") == 0) {
          interestingFinalFields.add(tempField);
        }
      }
    }
    return interestingFinalFields;
  }

  public void analyzeMethod(ASTMethodNode node, List<SootField> varsOfInterest) {
    MustMayInitialize must = new MustMayInitialize(node, MustMayInitialize.MUST);

    for (SootField interest : varsOfInterest) {
      // check for constant value tags
      Type fieldType = interest.getType();
      if (fieldType instanceof DoubleType && interest.hasTag(DoubleConstantValueTag.NAME)) {
        continue;
      } else if (fieldType instanceof FloatType && interest.hasTag(FloatConstantValueTag.NAME)) {
        continue;
      } else if (fieldType instanceof LongType && interest.hasTag(LongConstantValueTag.NAME)) {
        continue;
      } else if (fieldType instanceof CharType && interest.hasTag(IntegerConstantValueTag.NAME)) {
        continue;
      } else if (fieldType instanceof BooleanType && interest.hasTag(IntegerConstantValueTag.NAME)) {
        continue;
      } else if ((fieldType instanceof IntType || fieldType instanceof ByteType || fieldType instanceof ShortType)
          && interest.hasTag(IntegerConstantValueTag.NAME)) {
        continue;
      } else if (interest.hasTag(StringConstantValueTag.NAME)) {
        continue;
      }

      if (must.isMustInitialized(interest)) {
        // was initialized on all paths couldnt ask for more
        continue;
      }

      // System.out.println("SootField: "+interest+" not initialized.
      // checking may analysis");
      MustMayInitialize may = new MustMayInitialize(node, MustMayInitialize.MAY);
      if (may.isMayInitialized(interest)) {
        // System.out.println("It is initialized on some path just not
        // all paths\n");
        List defs = must.getDefs(interest);
        if (defs == null) {
          throw new RuntimeException("Sootfield: " + interest + " is mayInitialized but the defs is null");
        }

        handleAssignOnSomePaths(node, interest, defs);
      } else {
        // not initialized on any path., assign default
        // System.out.println("Final field is not initialized on any
        // path--------ASSIGN DEFAULT VALUE");
        assignDefault(node, interest);
      }
    }
  }

  /*
   * One gets to this method only if there was NO definition of a static final field in the static body At the same time no
   * TAG with a constant value matched, so we know the static final was not initialized at declaration time If this happens:
   * though it shouldnt unless u come from non-java compilers...insert default value initialization into the static
   * method...right at the end to make things easy
   */
  public void assignDefault(ASTMethodNode node, SootField f) {

    // create initialization stmt
    AugmentedStmt defaultStmt = createDefaultStmt(f);

    if (defaultStmt == null) {
      return;
    }

    List<Object> subBodies = node.get_SubBodies();
    if (subBodies.size() != 1) {
      throw new RuntimeException("SubBodies size of method node not equal to 1");
    }

    List<Object> body = (List<Object>) subBodies.get(0);

    // check if the bodys last node is an ASTStatementSequenceNode where we
    // might be able to add

    boolean done = false;
    if (!body.isEmpty()) {
      ASTNode lastNode = (ASTNode) body.get(body.size() - 1);
      if (lastNode instanceof ASTStatementSequenceNode) {
        List<AugmentedStmt> stmts = ((ASTStatementSequenceNode) lastNode).getStatements();
        if (!stmts.isEmpty()) {
          Stmt s = stmts.get(0).get_Stmt();
          if (!(s instanceof DVariableDeclarationStmt)) {
            // can add statement here
            stmts.add(defaultStmt);

            ASTStatementSequenceNode newNode = new ASTStatementSequenceNode(stmts);
            // replace this node with the original node

            body.remove(body.size() - 1);
            body.add(newNode);

            node.replaceBody(body);
            done = true;
          }
        }
      }
    }
    if (!done) {
      List<AugmentedStmt> newBody = new ArrayList<AugmentedStmt>();
      newBody.add(defaultStmt);

      ASTStatementSequenceNode newNode = new ASTStatementSequenceNode(newBody);
      body.add(newNode);

      node.replaceBody(body);
    }

  }

  public AugmentedStmt createDefaultStmt(Object field) {

    Value ref = null;
    Type fieldType = null;
    if (field instanceof SootField) {
      // have to make a static field ref
      SootFieldRef tempFieldRef = ((SootField) field).makeRef();

      fieldType = ((SootField) field).getType();
      if (((SootField) field).isStatic()) {
        ref = new DStaticFieldRef(tempFieldRef, true);
      } else {
        ref = new DInstanceFieldRef(new JimpleLocal("this", fieldType), tempFieldRef, new HashSet<Object>());
      }

    } else if (field instanceof Local) {
      ref = (Local) field;
      fieldType = ((Local) field).getType();
    }

    GAssignStmt assignStmt = null;

    if (fieldType instanceof RefType) {
      assignStmt = new GAssignStmt(ref, NullConstant.v());
    } else if (fieldType instanceof DoubleType) {
      assignStmt = new GAssignStmt(ref, DoubleConstant.v(0));
    } else if (fieldType instanceof FloatType) {
      assignStmt = new GAssignStmt(ref, FloatConstant.v(0));
    } else if (fieldType instanceof LongType) {
      assignStmt = new GAssignStmt(ref, LongConstant.v(0));
    } else if (fieldType instanceof IntType || fieldType instanceof ByteType || fieldType instanceof ShortType
        || fieldType instanceof CharType || fieldType instanceof BooleanType) {

      assignStmt = new GAssignStmt(ref, DIntConstant.v(0, fieldType));
    }

    if (assignStmt != null) {
      // System.out.println("AssignStmt is"+assignStmt);
      AugmentedStmt as = new AugmentedStmt(assignStmt);
      return as;
    } else {
      return null;
    }

  }

  /*
   * A sootfield gets to this method if it was an interesting field i.e static final for clinit and only final but non static
   * for init and there was atleast one place that this var was defined but it was not defined on all paths and hence the
   * recompilation will result in an error
   *
   * try{ staticFinal = defined; } catch(Exception e){}
   */

  public void handleAssignOnSomePaths(ASTMethodNode node, SootField field, List defs) {

    if (defs.size() != 1) {
      // give up by removing "final" if there are more than one defs
      cancelFinalModifier.add(field);
    } else {
      // if there is only one definition

      // see if there is no use of def
      AllVariableUses varUses = new AllVariableUses(node);
      node.apply(varUses);

      List allUses = varUses.getUsesForField(field);

      if (allUses != null && !allUses.isEmpty()) {
        /*
         * if the number of uses is not 0 then we dont want to get into trying to delay initialization just before
         * assignment. Easier to remove "final"
         */
        cancelFinalModifier.add(field);
      } else {
        /*
         * we have a final field with 1 def and 0 uses but is not initialized on all paths we can try to delay initialization
         * using an indirect approach STMT0 TYPE DavaTemp_fieldName; STMT1 DavaTemp_fieldname = DEFAULT try{ try{ field = ...
         * STMT2 DavaTemp_fieldname = ... } X catch(...){ }catch(..){ .... .... } } STMT3 field = Dava_tempVar
         *
         * Notice the following code will try to place the field assignment as close to the original assignment as possible.
         *
         * TODO: However there might still be issues with delaying this assignment e.g. what if the place marked by X (more
         * specifically between the original def and the new def includes a method invocation which access the delayed field.
         *
         * Original Comment February 2nd, 2006: Laurie mentioned that apart from direct uses we also have to be conservative
         * about method calls since we are dealing with fields here What if some method was invoked and it tried to use a
         * field whose initialization we are about to delay. This can be done by implementing a small analysis. (See end of
         * this class file.
         *
         * TODO: SHOULD BE CHECKED FOR CODE BETWEEN THE OLD DEF AND THE NEW ASSIGNMENT Currently checks from some point till
         * end of method
         *
         * MethodCallFinder myMethodCallFinder = new MethodCallFinder( (GAssignStmt) defs.get(0));
         * node.apply(myMethodCallFinder); if (myMethodCallFinder.anyMethodCalls()) { // there was some method call after the
         * definition stmt so // we cant continue // remove the final modifier and leave //System.out.println(
         * "Method invoked somewhere after definition"); cancelFinalModifier.add(field); return; }
         */

        // Creating STMT0
        Type localType = field.getType();
        Local newLocal = new JimpleLocal("DavaTemp_" + field.getName(), localType);

        DVariableDeclarationStmt varStmt = new DVariableDeclarationStmt(localType, davaBody);

        varStmt.addLocal(newLocal);
        AugmentedStmt as = new AugmentedStmt(varStmt);

        // System.out.println("Var Decl stmt"+as);

        // STORE IT IN Methods Declaration Node
        ASTStatementSequenceNode declNode = node.getDeclarations();
        List<AugmentedStmt> stmts = declNode.getStatements();
        stmts.add(as);

        declNode = new ASTStatementSequenceNode(stmts);

        List<Object> subBodies = node.get_SubBodies();
        if (subBodies.size() != 1) {
          throw new DecompilationException("ASTMethodNode does not have one subBody");
        }

        List<Object> body = (List<Object>) subBodies.get(0);

        body.remove(0);
        body.add(0, declNode);

        node.replaceBody(body);

        node.setDeclarations(declNode);

        // STMT1 initialization
        AugmentedStmt initialization = createDefaultStmt(newLocal);
        /*
         * The first node in a method is the declarations we know there is a second node because originaly the field was
         * initialized on some path
         */
        if (body.size() < 2) {
          throw new RuntimeException("Size of body is less than 1");
        }

        /*
         * If the second node is a stmt seq we put STMT1 there otherwise we create a new stmt seq node
         */

        ASTNode nodeSecond = (ASTNode) body.get(1);
        if (nodeSecond instanceof ASTStatementSequenceNode) {
          // the second node is a stmt seq node just add the stmt here
          List<AugmentedStmt> stmts1 = ((ASTStatementSequenceNode) nodeSecond).getStatements();
          stmts1.add(initialization);
          nodeSecond = new ASTStatementSequenceNode(stmts1);
          // System.out.println("Init added in exisiting node");
          body.remove(1);
        } else {
          // System.out.println("had to add new node");
          List<AugmentedStmt> tempList = new ArrayList<AugmentedStmt>();
          tempList.add(initialization);
          nodeSecond = new ASTStatementSequenceNode(tempList);
        }
        body.add(1, nodeSecond);
        node.replaceBody(body);

        // STMT2
        // done by simply replacing the leftop in the original stmt
        ((GAssignStmt) defs.get(0)).setLeftOp(newLocal);

        // STMT3

        // have to make a field ref
        SootFieldRef tempFieldRef = (field).makeRef();

        Value ref;
        if (field.isStatic()) {
          ref = new DStaticFieldRef(tempFieldRef, true);
        } else {
          ref = new DInstanceFieldRef(new JimpleLocal("this", field.getType()), tempFieldRef, new HashSet<Object>());
          // throw new RuntimeException("STOPPED");
        }

        GAssignStmt assignStmt = new GAssignStmt(ref, newLocal);
        AugmentedStmt assignStmt1 = new AugmentedStmt(assignStmt);

        /*
         * 14th February 2006 Should add this statement to the first place in the code where we will have a mustInitialize
         * satisfied
         */

        // the def is at (GAssignStmt) defs.get(0)
        // its parent is ASTStatementSequence and its parent is now needed
        soot.dava.toolkits.base.AST.traversals.ASTParentNodeFinder parentFinder
            = new soot.dava.toolkits.base.AST.traversals.ASTParentNodeFinder();
        node.apply(parentFinder);

        Object parent = parentFinder.getParentOf(defs.get(0));
        if (!(parent instanceof ASTStatementSequenceNode)) {
          throw new DecompilationException("Parent of stmt was not a stmt seq node");
        }

        Object grandParent = parentFinder.getParentOf(parent);
        if (grandParent == null) {
          throw new DecompilationException("Parent of stmt seq node was null");
        }

        // so we have the parent stmt seq node and the grandparent node
        // so it is the grandparent which is causing the error in MUSTINitialize
        // we should move our assign right after the grandParent is done

        MustMayInitialize must = new MustMayInitialize(node, MustMayInitialize.MUST);
        while (!must.isMustInitialized(field)) {

          // System.out.println("not must initialized");
          Object parentOfGrandParent = parentFinder.getParentOf(grandParent);
          if (!(grandParent instanceof ASTMethodNode) && parentOfGrandParent == null) {
            throw new DecompilationException("Parent of non method node was null");
          }
          boolean notResolved = false;
          // look for grandParent in parentOfGrandParent
          ASTNode ancestor = (ASTNode) parentOfGrandParent;
          for (Object next : ancestor.get_SubBodies()) {
            List<ASTStatementSequenceNode> ancestorSubBody;
            if (ancestor instanceof ASTTryNode) {
              ancestorSubBody = (List<ASTStatementSequenceNode>) ((ASTTryNode.container) next).o;
            } else {
              ancestorSubBody = (List<ASTStatementSequenceNode>) next;
            }

            if (ancestorSubBody.indexOf(grandParent) > -1) {
              // grandParent is present in this body
              int index = ancestorSubBody.indexOf(grandParent);
              // check the next index

              if (index + 1 < ancestorSubBody.size() && ancestorSubBody.get(index + 1) instanceof ASTStatementSequenceNode) {
                // there is an stmt seq node node after the grandParent
                ASTStatementSequenceNode someNode = ancestorSubBody.get(index + 1);

                // add the assign stmt here

                List<AugmentedStmt> stmtsLast = (someNode).getStatements();
                List<AugmentedStmt> newStmts = new ArrayList<AugmentedStmt>();
                newStmts.add(assignStmt1);
                newStmts.addAll(stmtsLast);
                someNode.setStatements(newStmts);
                // System.out.println("here1");
                // check if problem is solved else remove the assign and change parents
                must = new MustMayInitialize(node, MustMayInitialize.MUST);
                if (!must.isMustInitialized(field)) {
                  // problem not solved remove the stmt just added
                  someNode.setStatements(stmtsLast);
                  notResolved = true;
                }
              } else {
                // create a new stmt seq node and add it here
                List<AugmentedStmt> tempList = new ArrayList<AugmentedStmt>();
                tempList.add(assignStmt1);
                ASTStatementSequenceNode lastNode = new ASTStatementSequenceNode(tempList);
                ancestorSubBody.add(index + 1, lastNode);
                // node.replaceBody(body);
                // System.out.println("here2");
                // check if problem is solved else remove the assign and change parents
                must = new MustMayInitialize(node, MustMayInitialize.MUST);
                if (!must.isMustInitialized(field)) {
                  // problem not solved remove the stmt just added
                  ancestorSubBody.remove(index + 1);
                  notResolved = true;
                }
              }
              break;// break the loop going through subBodies
            } // if ancestor was found
          } // next subBody
          if (notResolved) {
            // meaning we still dont have must initialization
            // we should put assign in one level above than current
            grandParent = parentFinder.getParentOf(grandParent);
            // System.out.println("Going one level up");
          }
        } // while ! ismustinitialized
      }
    }
  }
}

/*
 * TODO: Change the analysis below to find method calls between GAssignStmt def and the new Assign Stmt.
 */

class MethodCallFinder extends DepthFirstAdapter {

  GAssignStmt def;

  boolean foundIt = false;

  boolean anyMethodCalls = false;

  public MethodCallFinder(GAssignStmt def) {
    this.def = def;
  }

  public MethodCallFinder(boolean verbose, GAssignStmt def) {
    super(verbose);
    this.def = def;
  }

  @Override
  public void outDefinitionStmt(DefinitionStmt s) {
    if (s instanceof GAssignStmt) {
      if (((GAssignStmt) s).equals(def)) {
        foundIt = true;
        // System.out.println("Found it" + s);
      }
    }
  }

  @Override
  public void inInvokeExpr(InvokeExpr ie) {
    // System.out.println("In invoke Expr");
    if (foundIt) {
      // System.out.println("oops invoking something after definition");
      anyMethodCalls = true;
    }
  }

  /*
   * Method will return false if there were no method calls made after the definition stmt
   */
  public boolean anyMethodCalls() {
    return anyMethodCalls;
    // return false;
  }
}
