package com.javaeye.common.util;

import java.util.List;

public class PaginationSupport ...{

    public final static int PAGESIZE = 30;

    private int pageSize = PAGESIZE;

    private List items;

    private int totalCount;

    private int[] indexes = new int[0];

    private int startIndex = 0;

    public PaginationSupport(List items, int totalCount) ...{
        setPageSize(PAGESIZE);
                setTotalCount(totalCount);
        setItems(items);
        setStartIndex(0);
    }

    public PaginationSupport(List items, int totalCount, int startIndex) ...{
                setPageSize(PAGESIZE);
        setTotalCount(totalCount);
        setItems(items);
        setStartIndex(startIndex);
    }

    public PaginationSupport(List items, int totalCount, int pageSize, 
                  int startIndex) ...{
                setPageSize(pageSize);
        setTotalCount(totalCount);
        setItems(items);
        setStartIndex(startIndex);
    }

    public List getItems() ...{
        return items;
    }

    public void setItems(List items) ...{
        this.items = items;
    }

    public int getPageSize() ...{
        return pageSize;
    }

    public void setPageSize(int pageSize) ...{
        this.pageSize = pageSize;
    }

    public int getTotalCount() ...{
        return totalCount;
    }

    public void setTotalCount(int totalCount) ...{
        if (totalCount > 0) ...{
            this.totalCount = totalCount;
            int count = totalCount / pageSize;
            if (totalCount % pageSize > 0)
                count++;
            indexes = new int[count];
            for (int i = 0; i < count; i++) ...{
                indexes[i] = pageSize * i;
            }
        } else ...{
            this.totalCount = 0;
        }
    }

    public int[] getIndexes() ...{
        return indexes;
    }

    public void setIndexes(int[] indexes) ...{
        this.indexes = indexes;
    }

    public int getStartIndex() ...{
        return startIndex;
    }

    public void setStartIndex(int startIndex) ...{
        if (totalCount <= 0)
            this.startIndex = 0;
        else if (startIndex >= totalCount)
            this.startIndex = indexes[indexes.length - 1];
        else if (startIndex < 0)
            this.startIndex = 0;
        else ...{
            this.startIndex = indexes[startIndex / pageSize];
        }
    }

    public int getNextIndex() ...{
        int nextIndex = getStartIndex() + pageSize;
        if (nextIndex >= totalCount)
            return getStartIndex();
        else
            return nextIndex;
    }

    public int getPreviousIndex() ...{
        int previousIndex = getStartIndex() - pageSize;
        if (previousIndex < 0)
            return 0;
        else
            return previousIndex;
    }

}