/*

 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.

 */

/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You 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 com.sun.org.apache.xalan.internal.xsltc.compiler;

import com.sun.org.apache.bcel.internal.generic.BranchInstruction;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;

import com.sun.org.apache.bcel.internal.generic.INVOKESTATIC;

import com.sun.org.apache.bcel.internal.generic.InstructionList;

import com.sun.org.apache.bcel.internal.generic.PUSH;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.BooleanType;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.IntType;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodType;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.NodeSetType;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.NodeType;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.RealType;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ReferenceType;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;

import com.sun.org.apache.xalan.internal.xsltc.runtime.Operators;

/**

 * @author Jacek Ambroziak

 * @author Santiago Pericas-Geertsen

 * @LastModified: Oct 2017

 */

final class RelationalExpr extends Expression {

    private int _op;

    private Expression _left, _right;

    public RelationalExpr(int op, Expression left, Expression right) {

        _op = op;

        (_left = left).setParent(this);

        (_right = right).setParent(this);

    }

    public void setParser(Parser parser) {

        super.setParser(parser);

        _left.setParser(parser);

        _right.setParser(parser);

    }

    /**

     * Returns true if this expressions contains a call to position(). This is

     * needed for context changes in node steps containing multiple predicates.

     */

    public boolean hasPositionCall() {

        if (_left.hasPositionCall()) return true;

        if (_right.hasPositionCall()) return true;

        return false;

    }

    /**

     * Returns true if this expressions contains a call to last()

     */

    public boolean hasLastCall() {

            return (_left.hasLastCall() || _right.hasLastCall());

    }

    public boolean hasReferenceArgs() {

        return _left.getType() instanceof ReferenceType ||

            _right.getType() instanceof ReferenceType;

    }

    public boolean hasNodeArgs() {

        return _left.getType() instanceof NodeType ||

            _right.getType() instanceof NodeType;

    }

    public boolean hasNodeSetArgs() {

        return _left.getType() instanceof NodeSetType ||

            _right.getType() instanceof NodeSetType;

    }

    public Type typeCheck(SymbolTable stable) throws TypeCheckError {

        Type tleft = _left.typeCheck(stable);

        Type tright = _right.typeCheck(stable);

        //bug fix # 2838, cast to reals if both are result tree fragments

        if (tleft instanceof ResultTreeType &&

            tright instanceof ResultTreeType )

        {

            _right = new CastExpr(_right, Type.Real);

            _left = new CastExpr(_left, Type.Real);

            return _type = Type.Boolean;

        }

        // If one is of reference type, then convert the other too

        if (hasReferenceArgs()) {

            Type type = null;

            Type typeL = null;

            Type typeR = null;

            if (tleft instanceof ReferenceType) {

                if (_left instanceof VariableRefBase) {

                    VariableRefBase ref = (VariableRefBase)_left;

                    VariableBase var = ref.getVariable();

                    typeL = var.getType();

                }

            }

            if (tright instanceof ReferenceType) {

                if (_right instanceof VariableRefBase) {

                    VariableRefBase ref = (VariableRefBase)_right;

                    VariableBase var = ref.getVariable();

                    typeR = var.getType();

                }

            }

            // bug fix # 2838

            if (typeL == null)

                type = typeR;

            else if (typeR == null)

                type = typeL;

            else {

                type = Type.Real;

            }

            if (type == null) type = Type.Real;

            _right = new CastExpr(_right, type);

            _left = new CastExpr(_left, type);

            return _type = Type.Boolean;

        }

        if (hasNodeSetArgs()) {

            // Ensure that the node-set is the left argument

            if (tright instanceof NodeSetType) {

                final Expression temp = _right; _right = _left; _left = temp;

        _op = (_op == Operators.GT) ? Operators.LT :

            (_op == Operators.LT) ? Operators.GT :

            (_op == Operators.GE) ? Operators.LE : Operators.GE;

                tright = _right.getType();

            }

            // Promote nodes to node sets

            if (tright instanceof NodeType) {

                _right = new CastExpr(_right, Type.NodeSet);

            }

            // Promote integer to doubles to have fewer compares

            if (tright instanceof IntType) {

                _right = new CastExpr(_right, Type.Real);

            }

            // Promote result-trees to strings

            if (tright instanceof ResultTreeType) {

                _right = new CastExpr(_right, Type.String);

            }

            return _type = Type.Boolean;

        }

        // In the node-boolean case, convert node to boolean first

        if (hasNodeArgs()) {

            if (tleft instanceof BooleanType) {

                _right = new CastExpr(_right, Type.Boolean);

                tright = Type.Boolean;

            }

            if (tright instanceof BooleanType) {

                _left = new CastExpr(_left, Type.Boolean);

                tleft = Type.Boolean;

            }

        }

        // Lookup the table of primops to find the best match

    MethodType ptype = lookupPrimop(stable, Operators.getOpNames(_op),

                new MethodType(Type.Void, tleft, tright));

        if (ptype != null) {

            Type arg1 = ptype.argsType().get(0);

            if (!arg1.identicalTo(tleft)) {

                _left = new CastExpr(_left, arg1);

            }

            Type arg2 = ptype.argsType().get(1);

            if (!arg2.identicalTo(tright)) {

                _right = new CastExpr(_right, arg1);

            }

            return _type = ptype.resultType();

        }

        throw new TypeCheckError(this);

    }

    public void translate(ClassGenerator classGen, MethodGenerator methodGen) {

        if (hasNodeSetArgs() || hasReferenceArgs()) {

            final ConstantPoolGen cpg = classGen.getConstantPool();

            final InstructionList il = methodGen.getInstructionList();

            // Call compare() from the BasisLibrary

            _left.translate(classGen, methodGen);

            _left.startIterator(classGen, methodGen);

            _right.translate(classGen, methodGen);

            _right.startIterator(classGen, methodGen);

            il.append(new PUSH(cpg, _op));

            il.append(methodGen.loadDOM());

            int index = cpg.addMethodref(BASIS_LIBRARY_CLASS, "compare",

                                         "("

                                         + _left.getType().toSignature()

                                         + _right.getType().toSignature()

                                         + "I"

                                         + DOM_INTF_SIG

                                         + ")Z");

            il.append(new INVOKESTATIC(index));

        }

        else {

            translateDesynthesized(classGen, methodGen);

            synthesize(classGen, methodGen);

        }

    }

    public void translateDesynthesized(ClassGenerator classGen,

                                       MethodGenerator methodGen) {

        if (hasNodeSetArgs() || hasReferenceArgs()) {

            translate(classGen, methodGen);

            desynthesize(classGen, methodGen);

        }

        else {

            BranchInstruction bi = null;

            final InstructionList il = methodGen.getInstructionList();

            _left.translate(classGen, methodGen);

            _right.translate(classGen, methodGen);

            // TODO: optimize if one of the args is 0

            boolean tozero = false;

            Type tleft = _left.getType();

            if (tleft instanceof RealType) {

        il.append(tleft.CMP(_op == Operators.LT || _op == Operators.LE));

                tleft = Type.Int;

                tozero = true;

            }

            switch (_op) {

        case Operators.LT:

                bi = tleft.GE(tozero);

                break;

        case Operators.GT:

                bi = tleft.LE(tozero);

                break;

        case Operators.LE:

                bi = tleft.GT(tozero);

                break;

        case Operators.GE:

                bi = tleft.LT(tozero);

                break;

            default:

                ErrorMsg msg = new ErrorMsg(ErrorMsg.ILLEGAL_RELAT_OP_ERR,this);

                getParser().reportError(Constants.FATAL, msg);

            }

            _falseList.add(il.append(bi));              // must be backpatched

        }

    }

    public String toString() {

        return Operators.getOpNames(_op) + '(' + _left + ", " + _right + ')';

    }

}