/**************************************************************************
 * EntityPath.java
 *
 * $Revision: 1.14 $
 * $Date: 2006/03/03 13:52:21 $
 *
 * Copyright (C) 2001 CERN - European Organization for Nuclear Research
 * All rights reserved.
 **************************************************************************/

package com.c2kernel.lookup;

import java.util.ArrayList;

import com.c2kernel.common.ObjectNotFoundException;


/**
* Extends Path to enforce SystemKey structure and support int form
*
* @version $Revision: 1.14 $ $Date: 2006/03/03 13:52:21 $
* @author  $Author: abranson $
**/
public class ItemPath extends Path
{
    // no of components in a syskey
    public static final int elementNo = 3;
    // no of digits in a syskey component
    public static final int elementLen = 3;
    // maximum possible int syskey
    public static final int maxSysKey = (int)Math.pow(10, elementNo*elementLen)-1;
    protected static String mTypeRoot;
    /*
     * From syskey int
     * Note no EntityPath constructors allow setting of CONTEXT or ENTITY:
     * The object decides that for itself from the number of components
     */

    public ItemPath(int syskey) throws InvalidItemPathException {
        super();
        setSysKey(syskey);
    }

    /*
    */
    public ItemPath()
    {
        super();
    }


    /*
    */
    public ItemPath(String[] path) throws InvalidItemPathException
    {
        super(path, Path.CONTEXT); // dummy - it will get replaced in checkSysPath()
        checkSysPath();
    }

    /*
    */
    public ItemPath(String path) throws InvalidItemPathException
    {
        super(path, Path.CONTEXT);
        checkSysPath();
    }

    /*
    */
    public ItemPath(ItemPath parent, String child) throws InvalidItemPathException {
        super(parent, child);
        checkSysPath();
    }

    // EntityPaths root in /entity
    @Override
	public String getRoot() {
        return "entity";
    }

    @Override
	public ItemPath getEntity() throws ObjectNotFoundException {
        return this;
    }

    public byte[] getOID() {
        if (mSysKey == Path.INVALID) return null;
        return String.valueOf(mSysKey).getBytes();
    }

    /*************************************************************************/

    /** Returns int form of syskey (if possible)
    */
    @Override
	public int getSysKey() {
        if (mSysKey == Path.INVALID && mType == Path.ENTITY)
            try {
                if (mPath.length != elementNo)
                    throw new InvalidItemPathException("Incorrect number of components for a system key");
                mSysKey = 0;
                for (String keypart : mPath) {
                    if (keypart.length()!=elementLen+1)
                        throw new InvalidItemPathException("Component '"+keypart+"' is not the correct size for a system key");
                    for(int j=1; j<elementLen+1; j++) // skip the 'd' prefix
                    {
                        char c = keypart.charAt(j);
                        if((c >= '0') && (c <='9'))
                            mSysKey = mSysKey*10 + c - '0';
                        else
                            throw new InvalidItemPathException("Component '"+keypart+"' contained a non-numeric char (excluding first char 'd').");

                    }
                }
            } catch (InvalidItemPathException ex) {
                mSysKey = Path.INVALID;
            }
        return mSysKey;
    }

    /** Sets path from int syskey
    */
    public void setSysKey(int sysKey) throws InvalidItemPathException
    {
        if (sysKey < 0 || sysKey > maxSysKey)
            throw new InvalidItemPathException("System key "+sysKey+" out of range");
        String stringPath = Integer.toString(sysKey);
        ArrayList<String> newKey = new ArrayList<String>();
        for (int i=0; i<elementNo; i++) {
            StringBuffer nextComponent = new StringBuffer("d");
            int start = stringPath.length()-elementLen;
            if (start < 0) {
                nextComponent.append("000000".substring(0,Math.abs(start))).append(stringPath);
                stringPath = "";
            }
            else {
                nextComponent.append(stringPath.substring(start));
                stringPath = stringPath.substring(0, start);
            }
            newKey.add(0, nextComponent.toString());
        }

        mPath = (newKey.toArray(mPath));
        mSysKey = sysKey;
        mStringPath = null;
        mType = Path.ENTITY;
        checkSysPath();
    }

    public void checkSysPath() throws InvalidItemPathException {
        if (mPath.length > elementNo)
            throw new InvalidItemPathException("EntityPath cannot have more than "+elementNo+" components: "+toString());
        if (mPath.length == elementNo)
            mType = Path.ENTITY;
        else
            mType = Path.CONTEXT;
    }
}