/*******************************************************************************
 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
 * in Industry THTH ry.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.db.procore.cluster;

import java.util.Arrays;
import java.util.Map;
import java.util.TreeMap;

import org.simantics.db.exception.DatabaseException;
import org.simantics.db.exception.ValidationException;
import org.simantics.db.impl.ClusterI.ObjectProcedure;
import org.simantics.db.impl.ClusterI.Procedure;
import org.simantics.db.impl.ClusterSupport;
import org.simantics.db.impl.Modifier;
import org.simantics.db.impl.Table;
import org.simantics.db.impl.TableFactory;
import org.simantics.db.impl.TableSizeListener;

public final class ValueTableSmall extends Table<byte[]> {
    private static final boolean DEBUG = ClusterImpl.DEBUG;
    public ValueTableSmall(TableSizeListener sizeListener, int[] header, int headerBase) {
        super(TableFactory.getByteFactory(), sizeListener, header, headerBase);
    }
    public ValueTableSmall(TableSizeListener sizeListener, int[] header, int headerBase, byte[] bytes) {
        super(TableFactory.getByteFactory(), sizeListener, header, headerBase, bytes);
    }
    private static final class IndexAndSize {
    	int index; // Real index (zero based) to start of value data.
    	short size; // Size of value data.
    }
    private IndexAndSize checkIndexAndGetRealIndex(int index) {
    	if (index < ZERO_SHIFT) // Index starts with ZERO_SHIFT.
            throw new IllegalArgumentException("Underflow, index=" + index);
    	int tableSize = getTableSize();
    	if (index >= tableSize) // Element size is at least two (one byte length and one byte data).
            throw new IllegalArgumentException("Overflow, index=" + index);
    	int i = index + offset;
    	byte[] table = getTable();
    	IndexAndSize is = new IndexAndSize();
    	is.size = table[i++]; 
    	if (is.size == 0)
    		throw new IllegalArgumentException("Removed, index=" + index);
    	if (is.size < 0) // two byte size
    		is.size = (short)(((is.size & 0x7F) << 8) | (table[i++] & 0xFF));
    	is.index = i;
    	if (is.index + is.size > tableSize) // Element size too big.
    		throw new IllegalArgumentException("Illegal size, index=" + is.index + " size=" + is.size);
    	return is;
    }
    public byte[] getValue(int valueIndex) {
    	IndexAndSize is = checkIndexAndGetRealIndex(valueIndex);
    	byte[] value = new byte[is.size];
        System.arraycopy(table, is.index, value, 0, is.size);
        if (DEBUG)
            System.out.println("ValueTableSmall.getValue " + valueIndex + " " + Arrays.toString(value));
    	return value;
    }
    char[] getString(int valueIndex) {
        IndexAndSize is = checkIndexAndGetRealIndex(valueIndex);
        final int size = is.size-1;
        char[] t = new char[size];
        int start = is.index;
        for(int i=0; i<size; i++, ++start)
            t[i] = (char)table[start];
        return t;
    }
    int setValue(int valueIndex, byte[] value, int offset, int length) {
    	if (valueIndex != 0) // Modify old value.
    		removeValue(valueIndex);
    	return createValue(value, offset, length); 
    }
    int createValue(byte[] value, int voffset, int vsize) {
    	if (vsize < 1 || vsize > (1<<15)-1)
    		throw new IllegalArgumentException("Illegal internal value size=" + vsize + ".");
    	int size = vsize;
    	if (vsize > 0x7F)
    		size += 2;
    	else
    		size += 1;
        int valueIndex = createNewElement(size);
        int i = checkIndexAndGetRealIndex(valueIndex, 1);
    	if (vsize > 0x7F) {
    		table[i++] = (byte)((vsize >>> 8) | 1<<7); // msb
    		table[i++] = (byte)(vsize & 0xFF); // lsb
    	} else
    		table[i++] = (byte)vsize;
    	System.arraycopy(value, voffset, table, i, vsize);
        return valueIndex;
    }
    void removeValue(int valueIndex) {
    	IndexAndSize is = checkIndexAndGetRealIndex(valueIndex);
    	int length = is.size;
    	int index = is.index;
    	if (is.size > 0x7F) {
    		length += 2;
    		index -= 2;
        	table[index+1] = 0;
    	} else {
    		length += 1;
    		index -= 1;
    	}
    	table[index] = 0;
     	deleteOldElement(valueIndex, length);
    }
//    boolean isEqual(int valueIndex, byte[] value, int voffset, int vsize) {
//        return isEqual(valueIndex, value, 0, value.length);
//    }
    private TreeMap<Integer, Integer> valueMap =
        new TreeMap<Integer, Integer>();
    
    private int VALUE_SIZE = 0;
    private int VALUE_OFFSET = 0;
    public void checkValueInit()
    throws DatabaseException {
        valueMap.clear();
        final int s = getTableSize();
        final int c = getTableCapacity();
        if (s < 0 || s > c)
            throw new ValidationException("Illegal value table size=" + s + " cap=" + c);
        VALUE_SIZE = s;
        VALUE_OFFSET = getTableBase() - ValueTableSmall.ZERO_SHIFT; 
    }
    public void checkValue(int capacity, int index)
    throws DatabaseException {
        if (0 == capacity && 0 == index)
            return;
        if (capacity < 1)
            throw new ValidationException("Illegal resource value capacity=" + capacity);
        if (index < 1)
            throw new ValidationException("Illegal resource value index=" + index);
        if (VALUE_SIZE < capacity + index + VALUE_OFFSET)
            throw new ValidationException("Illegal resource value c=" + capacity +
                    " i=" + index + " ts=" + VALUE_SIZE + " off=" + VALUE_OFFSET);
        // Duplicate index is allowed because new index is created only if new size is greater than old.
        Integer valueCap = valueMap.get(index);
        if (null == valueCap)
            valueMap.put(index, capacity);
        else if (capacity > valueCap)
            valueMap.put(index, capacity);
        else
            valueMap.put(index, valueCap);
    }
    public void checkValueFini()
    throws DatabaseException {
        int last = 0;
        for (Map.Entry<Integer, Integer> e : valueMap.entrySet()) {
            int i = e.getKey();
            int c = e.getValue();
            int cur = VALUE_OFFSET + i;
            if (last > cur)
                throw new ValidationException("Index error with resource value c=" + c +
                        " i=" + i + " ts=" + VALUE_SIZE + " off=" + VALUE_OFFSET);
            last = cur + c;
        }
    }
    @Override
    public <Context> boolean foreach(int setIndex, Procedure procedure, Context context, ClusterSupport support, Modifier modifier) throws DatabaseException {
        throw new UnsupportedOperationException();
    }

}