/*
 * 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 org.apache.xerces.impl.xs.models;

import java.util.Vector;

import org.apache.xerces.impl.xs.SubstitutionGroupHandler;
import org.apache.xerces.impl.xs.XMLSchemaException;
import org.apache.xerces.impl.xs.XSConstraints;
import org.apache.xerces.impl.xs.XSElementDecl;
import org.apache.xerces.xni.QName;

XSAllCM implements XSCMValidator and handles <all>.
Author:
Pavani Mukthipudi, Sun Microsystems Inc.
@xerces.internal
Version:
$Id: XSAllCM.java 806363 2009-08-20 21:18:48Z mrglavas $/**
 * XSAllCM implements XSCMValidator and handles &lt;all&gt;.
 *
 * @xerces.internal 
 *
 * @author Pavani Mukthipudi, Sun Microsystems Inc.
 * @version $Id: XSAllCM.java 806363 2009-08-20 21:18:48Z mrglavas $
 */
public class XSAllCM implements XSCMValidator {

    //
    // Constants
    //

    // start the content model: did not see any children
    private static final short STATE_START = 0;
    private static final short STATE_VALID = 1;
    private static final short STATE_CHILD = 1;


    //
    // Data
    //

    private final XSElementDecl fAllElements[];
    private final boolean fIsOptionalElement[];
    private final boolean fHasOptionalContent;
    private int fNumElements = 0;

    //
    // Constructors
    //

    public XSAllCM (boolean hasOptionalContent, int size) {
        fHasOptionalContent = hasOptionalContent;
        fAllElements = new XSElementDecl[size];
        fIsOptionalElement = new boolean[size];
    }

    public void addElement (XSElementDecl element, boolean isOptional) {
        fAllElements[fNumElements] = element;
        fIsOptionalElement[fNumElements] = isOptional;
        fNumElements++;
    }


    //
    // XSCMValidator methods
    //

    
This methods to be called on entering a first element whose type
has this content model. It will return the initial state of the
content model
Returns:
Start state of the content model/**
     * This methods to be called on entering a first element whose type
     * has this content model. It will return the initial state of the
     * content model
     *
     * @return Start state of the content model
     */
    public int[] startContentModel() {

        int[] state = new int[fNumElements + 1];

        for (int i = 0; i <= fNumElements; i++) {
            state[i] = STATE_START;
        }
        return state;
    }

    // convinient method: when error occurs, to find a matching decl
    // from the candidate elements.
    Object findMatchingDecl(QName elementName, SubstitutionGroupHandler subGroupHandler) {
        Object matchingDecl = null;
        for (int i = 0; i < fNumElements; i++) {
            matchingDecl = subGroupHandler.getMatchingElemDecl(elementName, fAllElements[i]);
            if (matchingDecl != null)
                break;
        }
        return matchingDecl;
    }

    
The method corresponds to one transition in the content model.
Params:
elementName – 
currentState –  Current state
Returns:
an element decl object/**
     * The method corresponds to one transition in the content model.
     *
     * @param elementName
     * @param currentState  Current state
     * @return an element decl object
     */
    public Object oneTransition (QName elementName, int[] currentState, SubstitutionGroupHandler subGroupHandler) {

        // error state
        if (currentState[0] < 0) {
            currentState[0] = XSCMValidator.SUBSEQUENT_ERROR;
            return findMatchingDecl(elementName, subGroupHandler);
        }

        // seen child
        currentState[0] = STATE_CHILD;
        
        Object matchingDecl = null;

        for (int i = 0; i < fNumElements; i++) {
            // we only try to look for a matching decl if we have not seen
            // this element yet.
            if (currentState[i+1] != STATE_START)
                continue;
            matchingDecl = subGroupHandler.getMatchingElemDecl(elementName, fAllElements[i]);
            if (matchingDecl != null) {
                // found the decl, mark this element as "seen".
                currentState[i+1] = STATE_VALID;
                return matchingDecl;
            }
        }

        // couldn't find the decl, change to error state.
        currentState[0] = XSCMValidator.FIRST_ERROR;
        return findMatchingDecl(elementName, subGroupHandler);
    }


    
The method indicates the end of list of children
Params:
currentState –  Current state of the content model
Returns:
true if the last state was a valid final state/**
     * The method indicates the end of list of children
     *
     * @param currentState  Current state of the content model
     * @return true if the last state was a valid final state
     */
    public boolean endContentModel (int[] currentState) {

        int state = currentState[0];

        if (state == XSCMValidator.FIRST_ERROR || state == XSCMValidator.SUBSEQUENT_ERROR) {
            return false;
        }

        // If <all> has minOccurs of zero and there are
        // no children to validate, it is trivially valid
        if (fHasOptionalContent && state == STATE_START) {
            return true;
        }

        for (int i = 0; i < fNumElements; i++) {
            // if one element is required, but not present, then error
            if (!fIsOptionalElement[i] && currentState[i+1] == STATE_START)
                return false;
        }

        return true;
    }

    
check whether this content violates UPA constraint.
Params:
subGroupHandler – the substitution group handler
Returns:
true if this content model contains other or list wildcard/**
     * check whether this content violates UPA constraint.
     *
     * @param subGroupHandler the substitution group handler
     * @return true if this content model contains other or list wildcard
     */
    public boolean checkUniqueParticleAttribution(SubstitutionGroupHandler subGroupHandler) throws XMLSchemaException {
        // check whether there is conflict between any two leaves
        for (int i = 0; i < fNumElements; i++) {
            for (int j = i+1; j < fNumElements; j++) {
                if (XSConstraints.overlapUPA(fAllElements[i], fAllElements[j], subGroupHandler)) {
                    // REVISIT: do we want to report all errors? or just one?
                    throw new XMLSchemaException("cos-nonambig", new Object[]{fAllElements[i].toString(),
                                                                              fAllElements[j].toString()});
                }
            }
        }

        return false;
    }

    
Check which elements are valid to appear at this point. This method also
works if the state is in error, in which case it returns what should
have been seen.
Params:
state –  the current state
Returns:
      a Vector whose entries are instances of
              either XSWildcardDecl or XSElementDecl./**
     * Check which elements are valid to appear at this point. This method also
     * works if the state is in error, in which case it returns what should
     * have been seen.
     * 
     * @param state  the current state
     * @return       a Vector whose entries are instances of
     *               either XSWildcardDecl or XSElementDecl.
     */
    public Vector whatCanGoHere(int[] state) {
        Vector ret = new Vector();
        for (int i = 0; i < fNumElements; i++) {
            // we only try to look for a matching decl if we have not seen
            // this element yet.
            if (state[i+1] == STATE_START)
                ret.addElement(fAllElements[i]);
        }
        return ret;
    }
    
    public int [] occurenceInfo(int[] state) {
        return null;
    }
    
    public String getTermName(int termId) {
        return null;
    }

    public boolean isCompactedForUPA() {
        return false;
    }
} // class XSAllCM