package org.ngbw.web.model;

import java.util.Comparator;
import java.util.List;


public interface Page<T>
{
    /**
     * Sort the backing collection with the supplied Comparator.
     * Resets the page number to the first page of the newly sorted collection.
     * voids the elements for query and criteria based page implementations
     */
    void sortElements ( Comparator<T> comparator );


    /**
     * Set pageNumber to the pageNumber of the next Page
     * voids the elements for query and criteria based page implementations
     */
    void next ();


    /**
     * Set pageNumber to the pageNumber of the previous Page
     * voids the elements for query and criteria based page implementations
     */
    void previous ();


    /**
     * Set pageNumber to the pageNumber of the first Page
     * voids the elements for query and criteria based page implementations
     */
    void first ();


    /**
     * Set pageNumber to the pageNumber of the last Page
     * voids the elements for query and criteria based page implementations
     * <p>
     */
    void last ();


    /**
     * Set pageNumber to the submitted pageNumber
     * voids the elements for query and criteria based page implementations
     * 
     * @param pageNumber
     */
    void setPageNumber ( int pageNumber );


    /**
     * Set pageSize to the submitted pageSize
     * voids the elements for query and criteria based page implementations
     */
    void setPageSize ( int pageSize );


    /**
     * @returns true if this page is the first page
     */
    boolean isFirstPage ();


    /**
     * @returns true if this page is the last page
     */
    boolean isLastPage ();


    /**
     * @returns true if this page has a next page
     */
    boolean hasNextPage ();


    /**
     * @returns true if this page has a previous page
     */
    boolean hasPreviousPage ();


    /**
     * @returns true whether a page with this number (0 based) exists
     */
    boolean hasPageWithNumber ( int pageNumber );


    /**
     * @returns true whether a page with this number label (1 based) exists
     */
    boolean hasPageWithLabel ( String pageNumberLabel );


    /**
     * @return page number of this page 0-based
     */
    int getPageNumber ();


    /**
     * @return page number of this page 1-based
     */
    String getPageNumberLabel ();


    /**
     * @return page number of the last page 0-based
     */
    int getLastPageNumber ();


    /**
     * @return page number of the last page 1-based
     */
    String getLastPageNumberLabel ();


    /**
     * @return page number of the next page 0-based
     */
    int getNextPageNumber ();


    /**
     * @return page number of the next page 1-based
     */
    String getNextPageNumberLabel ();


    /**
     * @return page number of the previous page 0-based
     */
    int getPreviousPageNumber ();


    /**
     * @return page number of the previous page 1-based
     */
    String getPreviousPageNumberLabel ();


    /**
     * @return list of all elements on this page
     */
    List<T> getThisPageElements ();


    /**
     * @return all elements in the backing list
     */
    List<T> getAllElements ();


    /**
     * A page element corresponds to a row in the result list
     * and has getters for the values for all columns
     * and the Long value for the id property
     *
     * @param index
     *
     * @return the page element with this index (0-based)
     */
    T getPageElement ( int index );


    /**
     * @return number of elements per page
     */
    int getPageSize ();


    /**
     * @return number of elements actually displayed on this page
     */
    int getThisPageNumberOfElements ();


    /**
     * @return total number of elements
     */
    int getTotalNumberOfElements ();


    /**
     * @return (row) number of the first element this page 1-based
     */
    int getThisPageFirstElementNumber ();


    /**
     * @return (row) number of the last element this page 1-based
     */
    int getThisPageLastElementNumber ();


    /**
     * @return List of pageNumberLabels (page 1 - last)
     */
    List<String> getPageNumberLabels ();

}