/*
 * Copyright 2000-2015 JetBrains s.r.o.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jetbrains.java.decompiler.modules.decompiler.exps;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.jetbrains.java.decompiler.code.CodeConstants;
import org.jetbrains.java.decompiler.main.TextBuffer;
import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
import org.jetbrains.java.decompiler.modules.decompiler.vars.CheckTypesResult;
import org.jetbrains.java.decompiler.struct.gen.VarType;
import org.jetbrains.java.decompiler.struct.match.MatchEngine;
import org.jetbrains.java.decompiler.struct.match.MatchNode;
import org.jetbrains.java.decompiler.util.InterpreterUtil;
import org.jetbrains.java.decompiler.util.ListStack;

public class FunctionExprent extends Exprent {

  public static final int FUNCTION_ADD = 0;
  public static final int FUNCTION_SUB = 1;
  public static final int FUNCTION_MUL = 2;
  public static final int FUNCTION_DIV = 3;

  public static final int FUNCTION_AND = 4;
  public static final int FUNCTION_OR = 5;
  public static final int FUNCTION_XOR = 6;

  public static final int FUNCTION_REM = 7;

  public static final int FUNCTION_SHL = 8;
  public static final int FUNCTION_SHR = 9;
  public static final int FUNCTION_USHR = 10;

  public static final int FUNCTION_BIT_NOT = 11;
  public static final int FUNCTION_BOOL_NOT = 12;
  public static final int FUNCTION_NEG = 13;

  public final static int FUNCTION_I2L = 14;
  public final static int FUNCTION_I2F = 15;
  public final static int FUNCTION_I2D = 16;
  public final static int FUNCTION_L2I = 17;
  public final static int FUNCTION_L2F = 18;
  public final static int FUNCTION_L2D = 19;
  public final static int FUNCTION_F2I = 20;
  public final static int FUNCTION_F2L = 21;
  public final static int FUNCTION_F2D = 22;
  public final static int FUNCTION_D2I = 23;
  public final static int FUNCTION_D2L = 24;
  public final static int FUNCTION_D2F = 25;
  public final static int FUNCTION_I2B = 26;
  public final static int FUNCTION_I2C = 27;
  public final static int FUNCTION_I2S = 28;

  public final static int FUNCTION_CAST = 29;
  public final static int FUNCTION_INSTANCEOF = 30;

  public final static int FUNCTION_ARRAY_LENGTH = 31;

  public final static int FUNCTION_IMM = 32;
  public final static int FUNCTION_MMI = 33;

  public final static int FUNCTION_IPP = 34;
  public final static int FUNCTION_PPI = 35;

  public final static int FUNCTION_IIF = 36;

  public final static int FUNCTION_LCMP = 37;
  public final static int FUNCTION_FCMPL = 38;
  public final static int FUNCTION_FCMPG = 39;
  public final static int FUNCTION_DCMPL = 40;
  public final static int FUNCTION_DCMPG = 41;

  public static final int FUNCTION_EQ = 42;
  public static final int FUNCTION_NE = 43;
  public static final int FUNCTION_LT = 44;
  public static final int FUNCTION_GE = 45;
  public static final int FUNCTION_GT = 46;
  public static final int FUNCTION_LE = 47;

  public static final int FUNCTION_CADD = 48;
  public static final int FUNCTION_COR = 49;

  public static final int FUNCTION_STR_CONCAT = 50;

  private static final VarType[] TYPES = { VarType.VARTYPE_LONG, VarType.VARTYPE_FLOAT, VarType.VARTYPE_DOUBLE, VarType.VARTYPE_INT,
      VarType.VARTYPE_FLOAT, VarType.VARTYPE_DOUBLE, VarType.VARTYPE_INT, VarType.VARTYPE_LONG, VarType.VARTYPE_DOUBLE, VarType.VARTYPE_INT,
      VarType.VARTYPE_LONG, VarType.VARTYPE_FLOAT, VarType.VARTYPE_BYTE, VarType.VARTYPE_CHAR, VarType.VARTYPE_SHORT };

  private static final String[] OPERATORS = { " + ", " - ", " * ", " / ", " & ", " | ", " ^ ", " % ", " << ", " >> ", " >>> ", " == ", " != ", " < ",
      " >= ", " > ", " <= ", " && ", " || ", " + " };

  private static final int[] PRECEDENCE = { 3, // FUNCTION_ADD
      3, // FUNCTION_SUB
      2, // FUNCTION_MUL
      2, // FUNCTION_DIV
      7, // FUNCTION_AND
      9, // FUNCTION_OR
      8, // FUNCTION_XOR
      2, // FUNCTION_REM
      4, // FUNCTION_SHL
      4, // FUNCTION_SHR
      4, // FUNCTION_USHR
      1, // FUNCTION_BIT_NOT
      1, // FUNCTION_BOOL_NOT
      1, // FUNCTION_NEG
      1, // FUNCTION_I2L
      1, // FUNCTION_I2F
      1, // FUNCTION_I2D
      1, // FUNCTION_L2I
      1, // FUNCTION_L2F
      1, // FUNCTION_L2D
      1, // FUNCTION_F2I
      1, // FUNCTION_F2L
      1, // FUNCTION_F2D
      1, // FUNCTION_D2I
      1, // FUNCTION_D2L
      1, // FUNCTION_D2F
      1, // FUNCTION_I2B
      1, // FUNCTION_I2C
      1, // FUNCTION_I2S
      1, // FUNCTION_CAST
      6, // FUNCTION_INSTANCEOF
      0, // FUNCTION_ARRAY_LENGTH
      1, // FUNCTION_IMM
      1, // FUNCTION_MMI
      1, // FUNCTION_IPP
      1, // FUNCTION_PPI
      12, // FUNCTION_IFF
      -1, // FUNCTION_LCMP
      -1, // FUNCTION_FCMPL
      -1, // FUNCTION_FCMPG
      -1, // FUNCTION_DCMPL
      -1, // FUNCTION_DCMPG
      6, // FUNCTION_EQ = 41;
      6, // FUNCTION_NE = 42;
      5, // FUNCTION_LT = 43;
      5, // FUNCTION_GE = 44;
      5, // FUNCTION_GT = 45;
      5, // FUNCTION_LE = 46;
      10, // FUNCTION_CADD = 47;
      11, // FUNCTION_COR = 48;
      3 // FUNCTION_STR_CONCAT = 49;
  };

  private static final Set<Integer> ASSOCIATIVITY = new HashSet<>(
      Arrays.asList(FUNCTION_ADD, FUNCTION_MUL, FUNCTION_AND, FUNCTION_OR, FUNCTION_XOR, FUNCTION_CADD, FUNCTION_COR, FUNCTION_STR_CONCAT));

  private int funcType;
  private VarType implicitType;
  private final List<Exprent> lstOperands;

  public FunctionExprent(int funcType, ListStack<Exprent> stack, Set<Integer> bytecodeOffsets) {
    this(funcType, new ArrayList<>(), bytecodeOffsets);

    if (funcType >= FUNCTION_BIT_NOT && funcType <= FUNCTION_PPI && funcType != FUNCTION_CAST && funcType != FUNCTION_INSTANCEOF) {
      lstOperands.add(stack.pop());
    } else if (funcType == FUNCTION_IIF) {
      throw new RuntimeException("no direct instantiation possible");
    } else {
      Exprent expr = stack.pop();
      lstOperands.add(stack.pop());
      lstOperands.add(expr);
    }
  }

  public FunctionExprent(int funcType, List<Exprent> operands, Set<Integer> bytecodeOffsets) {
    super(EXPRENT_FUNCTION);
    this.funcType = funcType;
    this.lstOperands = operands;

    addBytecodeOffsets(bytecodeOffsets);
  }

  public FunctionExprent(int funcType, Exprent operand, Set<Integer> bytecodeOffsets) {
    this(funcType, new ArrayList<>(1), bytecodeOffsets);
    lstOperands.add(operand);
  }

  @Override
  public VarType getExprType() {
    VarType exprType = null;

    if (funcType <= FUNCTION_NEG || funcType == FUNCTION_IPP || funcType == FUNCTION_PPI || funcType == FUNCTION_IMM || funcType == FUNCTION_MMI) {

      VarType type1 = lstOperands.get(0).getExprType();
      VarType type2 = null;
      if (lstOperands.size() > 1) {
        type2 = lstOperands.get(1).getExprType();
      }

      switch (funcType) {
      case FUNCTION_IMM:
      case FUNCTION_MMI:
      case FUNCTION_IPP:
      case FUNCTION_PPI:
        exprType = implicitType;
        break;
      case FUNCTION_BOOL_NOT:
        exprType = VarType.VARTYPE_BOOLEAN;
        break;
      case FUNCTION_SHL:
      case FUNCTION_SHR:
      case FUNCTION_USHR:
      case FUNCTION_BIT_NOT:
      case FUNCTION_NEG:
        exprType = getMaxVarType(new VarType[] { type1 });
        break;
      case FUNCTION_ADD:
      case FUNCTION_SUB:
      case FUNCTION_MUL:
      case FUNCTION_DIV:
      case FUNCTION_REM:
        exprType = getMaxVarType(new VarType[] { type1, type2 });
        break;
      case FUNCTION_AND:
      case FUNCTION_OR:
      case FUNCTION_XOR:
        if (type1.type == CodeConstants.TYPE_BOOLEAN & type2.type == CodeConstants.TYPE_BOOLEAN) {
          exprType = VarType.VARTYPE_BOOLEAN;
        } else {
          exprType = getMaxVarType(new VarType[] { type1, type2 });
        }
      }
    } else if (funcType == FUNCTION_CAST) {
      exprType = lstOperands.get(1).getExprType();
    } else if (funcType == FUNCTION_IIF) {
      Exprent param1 = lstOperands.get(1);
      Exprent param2 = lstOperands.get(2);
      VarType supertype = VarType.getCommonSupertype(param1.getExprType(), param2.getExprType());

      if (param1.type == Exprent.EXPRENT_CONST && param2.type == Exprent.EXPRENT_CONST && supertype.type != CodeConstants.TYPE_BOOLEAN
          && VarType.VARTYPE_INT.isSuperset(supertype)) {
        exprType = VarType.VARTYPE_INT;
      } else {
        exprType = supertype;
      }
    } else if (funcType == FUNCTION_STR_CONCAT) {
      exprType = VarType.VARTYPE_STRING;
    } else if (funcType >= FUNCTION_EQ || funcType == FUNCTION_INSTANCEOF) {
      exprType = VarType.VARTYPE_BOOLEAN;
    } else if (funcType >= FUNCTION_ARRAY_LENGTH) {
      exprType = VarType.VARTYPE_INT;
    } else {
      exprType = TYPES[funcType - FUNCTION_I2L];
    }

    return exprType;
  }

  @Override
  public int getExprentUse() {
    if (funcType >= FUNCTION_IMM && funcType <= FUNCTION_PPI) {
      return 0;
    } else {
      int ret = Exprent.MULTIPLE_USES | Exprent.SIDE_EFFECTS_FREE;
      for (Exprent expr : lstOperands) {
        ret &= expr.getExprentUse();
      }
      return ret;
    }
  }

  @Override
  public CheckTypesResult checkExprTypeBounds() {
    CheckTypesResult result = new CheckTypesResult();

    Exprent param1 = lstOperands.get(0);
    VarType type1 = param1.getExprType();
    Exprent param2 = null;
    VarType type2 = null;

    if (lstOperands.size() > 1) {
      param2 = lstOperands.get(1);
      type2 = param2.getExprType();
    }

    switch (funcType) {
    case FUNCTION_IIF:
      VarType supertype = getExprType();
      if (supertype == null) {
        supertype = getExprType();
      }
      result.addMinTypeExprent(param1, VarType.VARTYPE_BOOLEAN);
      result.addMinTypeExprent(param2, VarType.getMinTypeInFamily(supertype.typeFamily));
      result.addMinTypeExprent(lstOperands.get(2), VarType.getMinTypeInFamily(supertype.typeFamily));
      break;
    case FUNCTION_I2L:
    case FUNCTION_I2F:
    case FUNCTION_I2D:
    case FUNCTION_I2B:
    case FUNCTION_I2C:
    case FUNCTION_I2S:
      result.addMinTypeExprent(param1, VarType.VARTYPE_BYTECHAR);
      result.addMaxTypeExprent(param1, VarType.VARTYPE_INT);
      break;
    case FUNCTION_IMM:
    case FUNCTION_IPP:
    case FUNCTION_MMI:
    case FUNCTION_PPI:
      result.addMinTypeExprent(param1, implicitType);
      result.addMaxTypeExprent(param1, implicitType);
      break;
    case FUNCTION_ADD:
    case FUNCTION_SUB:
    case FUNCTION_MUL:
    case FUNCTION_DIV:
    case FUNCTION_REM:
    case FUNCTION_SHL:
    case FUNCTION_SHR:
    case FUNCTION_USHR:
    case FUNCTION_LT:
    case FUNCTION_GE:
    case FUNCTION_GT:
    case FUNCTION_LE:
      result.addMinTypeExprent(param2, VarType.VARTYPE_BYTECHAR);
    case FUNCTION_BIT_NOT:
      // case FUNCTION_BOOL_NOT:
    case FUNCTION_NEG:
      result.addMinTypeExprent(param1, VarType.VARTYPE_BYTECHAR);
      break;
    case FUNCTION_AND:
    case FUNCTION_OR:
    case FUNCTION_XOR:
    case FUNCTION_EQ:
    case FUNCTION_NE: {
      if (type1.type == CodeConstants.TYPE_BOOLEAN) {
        if (type2.isStrictSuperset(type1)) {
          result.addMinTypeExprent(param1, VarType.VARTYPE_BYTECHAR);
        } else { // both are booleans
          boolean param1_false_boolean = type1.isFalseBoolean()
              || (param1.type == Exprent.EXPRENT_CONST && !((ConstExprent) param1).hasBooleanValue());
          boolean param2_false_boolean = type1.isFalseBoolean()
              || (param2.type == Exprent.EXPRENT_CONST && !((ConstExprent) param2).hasBooleanValue());

          if (param1_false_boolean || param2_false_boolean) {
            result.addMinTypeExprent(param1, VarType.VARTYPE_BYTECHAR);
            result.addMinTypeExprent(param2, VarType.VARTYPE_BYTECHAR);
          }
        }
      } else if (type2.type == CodeConstants.TYPE_BOOLEAN) {
        if (type1.isStrictSuperset(type2)) {
          result.addMinTypeExprent(param2, VarType.VARTYPE_BYTECHAR);
        }
      }
    }
    }

    return result;
  }

  @Override
  public List<Exprent> getAllExprents() {
    List<Exprent> lst = new ArrayList<>();
    lst.addAll(lstOperands);
    return lst;
  }

  @Override
  public Exprent copy() {
    List<Exprent> lst = new ArrayList<>();
    for (Exprent expr : lstOperands) {
      lst.add(expr.copy());
    }
    FunctionExprent func = new FunctionExprent(funcType, lst, bytecode);
    func.setImplicitType(implicitType);

    return func;
  }

  @Override
  public boolean equals(Object o) {
    if (o == this)
      return true;
    if (o == null || !(o instanceof FunctionExprent))
      return false;

    FunctionExprent fe = (FunctionExprent) o;
    return funcType == fe.getFuncType() && InterpreterUtil.equalLists(lstOperands, fe.getLstOperands()); // TODO: order of operands insignificant
  }

  @Override
  public void replaceExprent(Exprent oldExpr, Exprent newExpr) {
    for (int i = 0; i < lstOperands.size(); i++) {
      if (oldExpr == lstOperands.get(i)) {
        lstOperands.set(i, newExpr);
      }
    }
  }

  @Override
  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    tracer.addMapping(bytecode);

    if (funcType <= FUNCTION_USHR) {
      return wrapOperandString(lstOperands.get(0), false, indent, tracer).append(OPERATORS[funcType])
          .append(wrapOperandString(lstOperands.get(1), true, indent, tracer));
    }

    if (funcType >= FUNCTION_EQ) {
      return wrapOperandString(lstOperands.get(0), false, indent, tracer).append(OPERATORS[funcType - FUNCTION_EQ + 11])
          .append(wrapOperandString(lstOperands.get(1), true, indent, tracer));
    }

    switch (funcType) {
    case FUNCTION_BIT_NOT:
      return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("~");
    case FUNCTION_BOOL_NOT:
      return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("!");
    case FUNCTION_NEG:
      return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("-");
    case FUNCTION_CAST:
      return lstOperands.get(1).toJava(indent, tracer).enclose("(", ")").append(wrapOperandString(lstOperands.get(0), true, indent, tracer));
    case FUNCTION_ARRAY_LENGTH:
      Exprent arr = lstOperands.get(0);

      TextBuffer res = wrapOperandString(arr, false, indent, tracer);
      if (arr.getExprType().arrayDim == 0) {
        VarType objArr = VarType.VARTYPE_OBJECT.resizeArrayDim(1); // type family does not change
        res.enclose("((" + ExprProcessor.getCastTypeName(objArr) + ")", ")");
      }
      return res.append(".length");
    case FUNCTION_IIF:
      return wrapOperandString(lstOperands.get(0), true, indent, tracer).append("?")
          .append(wrapOperandString(lstOperands.get(1), true, indent, tracer)).append(":")
          .append(wrapOperandString(lstOperands.get(2), true, indent, tracer));
    case FUNCTION_IPP:
      return wrapOperandString(lstOperands.get(0), true, indent, tracer).append("++");
    case FUNCTION_PPI:
      return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("++");
    case FUNCTION_IMM:
      return wrapOperandString(lstOperands.get(0), true, indent, tracer).append("--");
    case FUNCTION_MMI:
      return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("--");
    case FUNCTION_INSTANCEOF:
      return wrapOperandString(lstOperands.get(0), true, indent, tracer).append(" instanceof ")
          .append(wrapOperandString(lstOperands.get(1), true, indent, tracer));
    case FUNCTION_LCMP: // shouldn't appear in the final code
      return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__lcmp__(").append(",")
          .append(wrapOperandString(lstOperands.get(1), true, indent, tracer)).append(")");
    case FUNCTION_FCMPL: // shouldn't appear in the final code
      return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__fcmpl__(").append(",")
          .append(wrapOperandString(lstOperands.get(1), true, indent, tracer)).append(")");
    case FUNCTION_FCMPG: // shouldn't appear in the final code
      return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__fcmpg__(").append(",")
          .append(wrapOperandString(lstOperands.get(1), true, indent, tracer)).append(")");
    case FUNCTION_DCMPL: // shouldn't appear in the final code
      return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__dcmpl__(").append(",")
          .append(wrapOperandString(lstOperands.get(1), true, indent, tracer)).append(")");
    case FUNCTION_DCMPG: // shouldn't appear in the final code
      return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__dcmpg__(").append(",")
          .append(wrapOperandString(lstOperands.get(1), true, indent, tracer)).append(")");
    }

    if (funcType <= FUNCTION_I2S) {
      return wrapOperandString(lstOperands.get(0), true, indent, tracer)
          .prepend("(" + ExprProcessor.getTypeName(TYPES[funcType - FUNCTION_I2L]) + ")");
    }

    //		return "<unknown function>";
    throw new RuntimeException("invalid function");
  }

  @Override
  public int getPrecedence() {
    return getPrecedence(funcType);
  }

  public static int getPrecedence(int func) {
    return PRECEDENCE[func];
  }

  public VarType getSimpleCastType() {
    return TYPES[funcType - FUNCTION_I2L];
  }

  private TextBuffer wrapOperandString(Exprent expr, boolean eq, int indent, BytecodeMappingTracer tracer) {
    int myprec = getPrecedence();
    int exprprec = expr.getPrecedence();

    boolean parentheses = exprprec > myprec;
    if (!parentheses && eq) {
      parentheses = (exprprec == myprec);
      if (parentheses) {
        if (expr.type == Exprent.EXPRENT_FUNCTION && ((FunctionExprent) expr).getFuncType() == funcType) {
          parentheses = !ASSOCIATIVITY.contains(funcType);
        }
      }
    }

    TextBuffer res = expr.toJava(indent, tracer);

    if (parentheses) {
      res.enclose("(", ")");
    }

    return res;
  }

  private static VarType getMaxVarType(VarType[] arr) {
    int[] types = new int[] { CodeConstants.TYPE_DOUBLE, CodeConstants.TYPE_FLOAT, CodeConstants.TYPE_LONG };
    VarType[] vartypes = new VarType[] { VarType.VARTYPE_DOUBLE, VarType.VARTYPE_FLOAT, VarType.VARTYPE_LONG };

    for (int i = 0; i < types.length; i++) {
      for (int j = 0; j < arr.length; j++) {
        if (arr[j].type == types[i]) {
          return vartypes[i];
        }
      }
    }

    return VarType.VARTYPE_INT;
  }

  // *****************************************************************************
  // getter and setter methods
  // *****************************************************************************

  public int getFuncType() {
    return funcType;
  }

  public void setFuncType(int funcType) {
    this.funcType = funcType;
  }

  public List<Exprent> getLstOperands() {
    return lstOperands;
  }

  public void setImplicitType(VarType implicitType) {
    this.implicitType = implicitType;
  }

  // *****************************************************************************
  // IMatchable implementation
  // *****************************************************************************

  public boolean match(MatchNode matchNode, MatchEngine engine) {

    if (!super.match(matchNode, engine)) {
      return false;
    }

    Integer type = (Integer) matchNode.getRuleValue(MatchProperties.EXPRENT_FUNCTYPE);
    if (type != null) {
      if (this.funcType != type.intValue()) {
        return false;
      }
    }

    return true;
  }

}
