/*******************************************************************************
 * 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 org.simantics.db.Resource;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.impl.ClusterI;
import org.simantics.db.impl.IntAllocatorI;
import org.simantics.db.impl.Modifier;
import org.simantics.db.impl.ResourceImpl;
import org.simantics.db.impl.graph.ReadGraphImpl;
import org.simantics.db.procedure.AsyncContextMultiProcedure;
import org.simantics.db.procedure.AsyncMultiProcedure;

final class TableIntArraySet {
    public static final int HeaderSize = 1; 
    private static final int SIZE_OFFSET = -1;
    static int create(final int[] ints, IntAllocatorI allocator)
    throws DatabaseException {
        final int LENGTH = ints.length*2;
        if (LENGTH <1)
            throw new DatabaseException("Illegal argument to create TableIntArraySet.");
        int newBase = allocator.allocate(LENGTH + HeaderSize) + HeaderSize;
        int[] table = allocator.getTable();
        table[newBase + SIZE_OFFSET] = -LENGTH;
        for (int i=0; i<ints.length; ++i) {
            if (0 == ints[i])
                throw new DatabaseException("Illegal value to create TableIntArraySet.");
            table[newBase+i] = ints[i];
        }
        for (int i=ints.length; i<LENGTH; ++i) {
            table[newBase+i] = 0;
        }
        return newBase;
    }
    static boolean isArraySet(int[] table, int base) {
        return table[base + SIZE_OFFSET] < 0;
    }
    static class Ints {
        int[] ints;
        boolean found;
        Ints() {
            this.ints = null;
            this.found = false;
        }
    }
    static Ints getIntsIfValueNotFound(int[] table, int base, int aValue) {
        final int REAL_SIZE = -table[base + SIZE_OFFSET];
        assert(REAL_SIZE > 0);
        Ints it = new Ints();
        int i;
        for (i=0; i<REAL_SIZE; ++i) {
            if (0 == table[base+i])
                break;
            else if (aValue == table[base+i]) {
                it.found = true;
                return it;
            }
        }
        int size = i;
        assert(size > 0);
        it.ints = new int[size+1];
        for (i=0; i<size; ++i)
            it.ints[i] = table[base+i];
        it.ints[i] = aValue;
        return it;
    }
    /**
     * @param table
     * @param base
     * @param object
     * @param allocator
     * @return new base if object was actually added.
     */
    static int addInt(int[] table, int base, final int object, IntAllocatorI allocator) {
        final int size = -table[base + SIZE_OFFSET];
        assert(size > 0);
        int i;
        for (i=0; i<size; ++i) {
            if (object == table[base+i])
                return 0;
            else if (0 == table[base+i])
                break;
        }
        if (i < size) {
            assert(0 == table[base+i]);
            table[base+i] = object;
            return base;
        }
        final int newSize = size + 1;
        int newBase = allocator.allocate(newSize + HeaderSize) + HeaderSize;
        int[] newTable = allocator.getTable();
        newTable[newBase + SIZE_OFFSET] = -newSize;
        System.arraycopy(table, base, newTable, newBase, size);
        newTable[newBase+size] = object;
        return newBase;
    }       
    
    static int removeInt(int[] table, int base, int object) {
        final int size = -table[base + SIZE_OFFSET];
        assert(size > 0);
        int i;
        for (i=0; i<size; ++i)
            if (object == table[base+i])
                break;
            else if (0 == table[base+i])
                return i; // not found
        if (i == size)
            return i; // not found
        int end = size - 1;
        for (;end>i; --end)
        	if (0 != table[base + end])
        		break;
        table[base + i] = table[base + end];
        table[base + end] = 0;
        return end;
    }

    static int removeIntLast(int[] table, int base)
    throws DatabaseException {
        final int size = getSize(table, base);
        if (size != 1)
            throw new DatabaseException("Illegal call of TableIntArraySet.removeLastint");
        int t = table[base];
        table[base] = 0;
        return t;
    }

    static int getSize(int[] table, int base) {
        final int size = -table[base + SIZE_OFFSET];
        assert(size > 0);
        int i;
        for (i=0; i<size; ++i)
            if (0 == table[base+i])
                break;
        return i;
    }
    
    static int getAllocatedSize(int[] table, int base) {
        final int size = -table[base + SIZE_OFFSET];
        assert(size>0);
        return size + HeaderSize;
    }
    
    static void foreachInt(final int[] table, final int base, ReadGraphImpl graph, AsyncMultiProcedure<Resource> procedure, Modifier modifier) throws DatabaseException {
    	
        final int size = -table[base + SIZE_OFFSET];
        assert(size>0);
        for (int i=0; i<size; ++i) {

        	int pRef = table[base+i];
            if (0 == pRef)
                break;
            int key = modifier.execute(pRef);
            procedure.execute(graph, new ResourceImpl(graph.getResourceSupport(), key));
            
        }
        
		procedure.finished(graph);
//		graph.state.dec(0);
        
    }

    static <C> void foreachInt(final int[] table, final int base, ReadGraphImpl graph, C context, AsyncContextMultiProcedure<C, Resource> procedure, Modifier modifier) throws DatabaseException {
    	
        final int size = -table[base + SIZE_OFFSET];
        assert(size>0);
        for (int i=0; i<size; ++i) {

        	int pRef = table[base+i];
            if (0 == pRef)
                break;
            int key = modifier.execute(pRef);
            procedure.execute(graph, context, new ResourceImpl(graph.getResourceSupport(), key));
            
        }
        
		procedure.finished(graph);
//		graph.state.dec(0);
        
    }
    
    static int getSingleInt(final int[] table, final int base, Modifier modifier) throws DatabaseException {

    	int result = 0;
    	
        final int size = -table[base + SIZE_OFFSET];
        assert(size>0);
        for (int i=0; i<size; ++i) {

        	int pRef = table[base+i];
            if (0 == pRef)
                break;
            int key = modifier.execute(pRef);
            if(result == 0) result = key;
            else result = -1;
            
        }

        return result;
        
//        if(result == -1) return 0;
//        else return result;
        
    }

    static <Context> boolean foreachInt(final int[] table, final int base
    		, final ClusterI.ObjectProcedure<Context> procedure, final Context context, final Modifier modifier) throws DatabaseException {
        final int size = -table[base + SIZE_OFFSET];
        assert(size>0);
        for (int i=0; i<size; ++i) {
            int pRef = table[base+i];
            if (0 == pRef)
                break;
            int key;
            if (null == modifier)
                key = pRef;
            else
                key = modifier.execute(pRef);
            if (procedure.execute(context, key))
                return true; // loop broken by procedure
        }
        return false; // loop finished
    }
}