using OrderCriterias;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ManagerInterfaces
{
    /// <summary>
    /// All methods to handle chapters
    /// /!\ all methods returns a task
    /// </summary>
    /// <typeparam name="T">a DTO, Entity or Model chapter</typeparam>
    public interface IChapterManager<T>
    {
        /// <summary>
        /// get the number of T element
        /// </summary>
        /// <returns>the number of T element</returns>
        public int getNbElements();
        /// <summary>
        /// add a chapter
        /// </summary>
        /// <param name="chapter">chapter to add</param>
        /// <returns>
        /// the chapter added or the chapter that correspond
        /// to it and that is already in the database
        /// </returns>
        Task<T> addChapter(T chapter);
        /// <summary>
        /// remove a chapter
        /// </summary>
        /// <param name="chapter">the chapter to remove</param>
        /// <returns>
        /// the chapter removed or null if
        /// the chapter does not exist
        /// </returns>
        Task<T?> removeChapter(T chapter);
        /// <summary>
        /// remove a chapter
        /// </summary>
        /// <param name="id">the identifier of the chapter to remove</param>
        /// <returns>
        /// the chapter removed or null if
        /// the chapter does not exist
        /// </returns>
        Task<T?> removeChapter(uint id);
        /// <summary>
        /// get a chapter
        /// </summary>
        /// <param name="id">the identifier of the chapter to remove</param>
        /// <returns>
        /// the chapter that correspond
        /// to the id or null if the
        /// chapter does not exist
        /// </returns>
        Task<T?> getChapter(uint id);
        /// <summary>
        /// get a part of all chapters
        /// </summary>
        /// <param name="nb">the actual page</param>
        /// <param name="count">number of T element in a page</param>
        /// <param name="orderCriteria">the order criteria</param>
        /// <returns>
        /// a set of the number of page and
        /// all T element in the database for
        /// the page nb (or null if the page
        /// does not exist (<=> (nb-1)*count outside
        /// boundaries (0, getNbElement()-1)))
        /// </returns>
        Task<(int nbPages, IEnumerable<T>? chapters)> getChapters(int nb, int count, ChapterOrderCriteria orderCriteria = ChapterOrderCriteria.ById);
    }
}
