using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Threading.Tasks;
using xModels.Base;
using xModels.Dtos;

namespace xDataService.Interfaces {
    /// <summary>
    /// a Base Repository Interface for Manipulate 
    /// an Entity in DataBase 
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public interface IXBaseRepository<T, TKey> : IDisposable
    where T : XBaseEntity<TKey> {
        //
        #region Add ...
        /// <summary>
        /// add a new Entity ...
        /// </summary>
        /// <param name="item"></param>
        /// <param name="saveChanges"></param>
        /// <returns></returns>
        Task<T> AddAsync (
            T item,
            bool saveChanges = true
        );

        /// <summary>
        /// add or update an Entity (add if not exists/update if exists) ...
        /// </summary>
        /// <param name="item"></param>
        /// <param name="saveChanges"></param>
        /// <returns></returns>
        Task<T> AddOrUpdateAsync (
            T item,
            bool saveChanges = true
        );

        /// <summary>
        /// add a range of new Entities ...
        /// </summary>
        /// <param name="items"></param>
        /// <param name="saveChanges"></param>
        /// <returns></returns>
        Task AddRangeAsync (
            IEnumerable<T> items,
            bool saveChanges = true
        );
        #endregion

        //
        #region Remove ...
        /// <summary>
        /// remove an Entity by it's Id ...
        /// </summary>
        /// <param name="id"></param>
        /// <param name="softDelete"></param>
        /// <param name="saveChanges"></param>
        /// <returns></returns>
        Task<T> RemoveAsync (
            TKey id,
            bool softDelete = true,
            bool saveChanges = true
        );

        /// <summary>
        /// remove an Entity ...
        /// </summary>
        /// <param name="item"></param>
        /// <param name="softDelete"></param>
        /// <param name="saveChanges"></param>
        /// <returns></returns>
        Task<T> RemoveAsync (
            T item,
            bool softDelete = true,
            bool saveChanges = true
        );

        /// <summary>
        /// remove a range of exists Entities ...
        /// </summary>
        /// <param name="items"></param>
        /// <param name="softDelete"></param>
        /// <param name="saveChanges"></param>
        /// <returns></returns>
        Task RemoveRangeAsync (
            IEnumerable<T> items,
            bool softDelete = true,
            bool saveChanges = true
        );
        #endregion

        //
        #region Retrieve ...
        /// <summary>
        /// retrieve whole items as queryable ...
        /// </summary>
        /// <returns></returns>
        IQueryable<T> AsQueryable ();

        /// <summary>
        /// retrieve an Entity by it's Id ...
        /// </summary>
        /// <param name="id"></param>
        /// <param name="ignoreSoftDeleteds"></param>
        /// <param name="containsDetail"></param>
        /// <returns></returns>
        Task<T> GetAsync (
            TKey id,
            bool ignoreSoftDeleteds = true,
            bool containsDetail = false
        );

        /// <summary>
        /// retrieve all exists Entities ...
        /// </summary>
        /// <param name="ignoreSoftDeleteds"></param>
        /// <param name="containsDetail"></param>
        /// <returns></returns>
        Task<IEnumerable<T>> GetAllAsync (
            bool ignoreSoftDeleteds = true,
            bool containsDetail = false
        );

        /// <summary>
        /// find an Entity by providing a Conditional Expression ...
        /// </summary>
        /// <param name="whereClause"></param>
        /// <param name="ignoreSoftDeleteds"></param>
        /// <param name="containsDetail"></param>
        /// <returns></returns>
        Task<T> FindOneAsync (
            Expression<Func<T, bool>> whereClause,
            bool ignoreSoftDeleteds = true,
            bool containsDetail = false
        );

        /// <summary>
        /// find a collection of Entities by proving a Conditional Expression ...
        /// </summary>
        /// <param name="whereClause"></param>
        /// <param name="ignoreSoftDeleteds"></param>
        /// <param name="containsDetail"></param>
        /// <returns></returns>
        Task<IEnumerable<T>> FindManyAsync (
            Expression<Func<T, bool>> whereClause,
            bool ignoreSoftDeleteds = true,
            bool containsDetail = false
        );

        /// <summary>
        /// retrieve Entities based on XQuery Pagination structure ...
        /// </summary>
        /// <param name="query"></param>
        /// <param name="ignoreSoftDeleteds"></param>
        /// <returns></returns>
        Task<XQueryResult<T>> QueryAsync (
            XQuery query,
            bool ignoreSoftDeleteds = true
        );

        /// <summary>
        /// retrieve Entities based on XQuery Pagination structure by providing a Conditional Expression ...
        /// </summary>
        /// <param name="whereClause"></param>
        /// <param name="query"></param>
        /// <param name="ignoreSoftDeleteds"></param>
        /// <returns></returns>
        Task<XQueryResult<T>> ConditionalQueryAsync (
            Expression<Func<T, bool>> whereClause,
            XQuery query,
            bool ignoreSoftDeleteds = true
        );
        #endregion

        //
        #region Update ...
        /// <summary>
        /// Update an Entity values ...
        /// </summary>
        /// <param name="id"></param>
        /// <param name="item"></param>
        /// <param name="saveChanges"></param>
        /// <returns></returns>
        Task<T> UpdateAsync (
            TKey id,
            T item,
            bool saveChanges = true
        );

        /// <summary>
        /// Update a range of Entities ...
        /// </summary>
        /// <param name="items"></param>
        /// <param name="saveChanges"></param>
        /// <returns></returns>
        Task<bool> UpdateRangeAsync (
            IEnumerable<T> items,
            bool saveChanges = true
        );
        #endregion

        //
        #region Count ...
        /// <summary>
        /// count all exists Entities ...
        /// </summary>
        /// <param name="ignoreSoftDeleteds"></param>
        /// <returns></returns>
        Task<int> CountAsync (bool ignoreSoftDeleteds = true);

        /// <summary>
        /// count all exists Entities Pages by providing page size ...
        /// </summary>
        /// <param name="pageSize"></param>
        /// <param name="totalItems"></param>
        /// <returns></returns>
        Task<int> PagesCountAsync (
            int pageSize,
            int? totalItems = null
        );
        #endregion

        //
        #region Exists ...
        /// <summary>
        /// Check an Entity exists or not ...
        /// </summary>
        /// <param name="id"></param>
        /// <param name="ignoreSoftDeleteds"></param>
        /// <returns></returns>
        Task<bool> IsExistsAsync (
            TKey id,
            bool ignoreSoftDeleteds = true
        );
        #endregion

        //
        #region Unit Of Work ...
        /// <summary>
        /// Save all unsaved Transactions on DbContext ...
        /// used fo Unit Of Works Design Pattern ...
        /// </summary>
        /// <returns></returns>
        Task<int> SaveChangesAsync ();
        #endregion

        //
        #region Key ...
        TKey GetKey (T item);

        void SetKey (
            ref T item,
            TKey id
        );

        Task<T> HandleKeyAsync (T item);
        #endregion

        //
        #region Detach ...
        void Detach (T item);

        void Detach (IEnumerable<T> items);

        void Detach (XQueryResult<T> query);

        void Detach (XPageResponse<T> page);
        #endregion
    }
}