/*

 * 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.ConstantPoolGen;

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

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.ClassGenerator;

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

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

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

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

import java.util.List;

/**

 * @author Jacek Ambroziak

 * @author Morten Jorgensen

 * @LastModified: Oct 2017

 */

final class DocumentCall extends FunctionCall {

    private Expression _arg1 = null;

    private Expression _arg2 = null;

    private Type       _arg1Type;

    /**

     * Default function call constructor

     */

    public DocumentCall(QName fname, List<Expression> arguments) {

        super(fname, arguments);

    }

    /**

     * Type checks the arguments passed to the document() function. The first

     * argument can be any type (we must cast it to a string) and contains the

     * URI of the document

     */

    public Type typeCheck(SymbolTable stable) throws TypeCheckError {

        // At least one argument - two at most

        final int ac = argumentCount();

        if ((ac < 1) || (ac > 2)) {

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

            throw new TypeCheckError(msg);

        }

        if (getStylesheet() == null) {

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

            throw new TypeCheckError(msg);

        }

        // Parse the first argument

        _arg1 = argument(0);

        if (_arg1 == null) {// should not happened

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

            throw new TypeCheckError(msg);

        }

        _arg1Type = _arg1.typeCheck(stable);

        if ((_arg1Type != Type.NodeSet) && (_arg1Type != Type.String)) {

            _arg1 = new CastExpr(_arg1, Type.String);

        }

        // Parse the second argument

        if (ac == 2) {

            _arg2 = argument(1);

            if (_arg2 == null) {// should not happened

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

                throw new TypeCheckError(msg);

            }

            final Type arg2Type = _arg2.typeCheck(stable);

            if (arg2Type.identicalTo(Type.Node)) {

                _arg2 = new CastExpr(_arg2, Type.NodeSet);

            } else if (arg2Type.identicalTo(Type.NodeSet)) {

                // falls through

            } else {

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

                throw new TypeCheckError(msg);

            }

        }

        return _type = Type.NodeSet;

    }

    /**

     * Translates the document() function call to a call to LoadDocument()'s

     * static method document().

     */

    public void translate(ClassGenerator classGen, MethodGenerator methodGen) {

        final ConstantPoolGen cpg = classGen.getConstantPool();

        final InstructionList il = methodGen.getInstructionList();

        final int ac = argumentCount();

        final int domField = cpg.addFieldref(classGen.getClassName(),

                                             DOM_FIELD,

                                             DOM_INTF_SIG);

        String docParamList = null;

        if (ac == 1) {

           // documentF(Object,String,AbstractTranslet,DOM)

           docParamList = "("+OBJECT_SIG+STRING_SIG+TRANSLET_SIG+DOM_INTF_SIG

                         +")"+NODE_ITERATOR_SIG;

        } else { //ac == 2; ac < 1 or as >2  was tested in typeChec()

           // documentF(Object,DTMAxisIterator,String,AbstractTranslet,DOM)

           docParamList = "("+OBJECT_SIG+NODE_ITERATOR_SIG+STRING_SIG

                         +TRANSLET_SIG+DOM_INTF_SIG+")"+NODE_ITERATOR_SIG;

        }

        final int docIdx = cpg.addMethodref(LOAD_DOCUMENT_CLASS, "documentF",

                                            docParamList);

        // The URI can be either a node-set or something else cast to a string

        _arg1.translate(classGen, methodGen);

        if (_arg1Type == Type.NodeSet) {

            _arg1.startIterator(classGen, methodGen);

        }

        if (ac == 2) {

            //_arg2 == null was tested in typeChec()

            _arg2.translate(classGen, methodGen);

            _arg2.startIterator(classGen, methodGen);

        }

        // Feck the rest of the parameters on the stack

        il.append(new PUSH(cpg, getStylesheet().getSystemId()));

        il.append(classGen.loadTranslet());

        il.append(DUP);

        il.append(new GETFIELD(domField));

        il.append(new INVOKESTATIC(docIdx));

    }

}