using System;
using System.Linq;
using xModels.Dtos;
using System.Threading;
using xCommons.Extensions;
using xIdentityModels.Dtos;
using xExceptions.Constants;
using System.Threading.Tasks;
using xIdentityModels.Models;
using System.Linq.Expressions;
using xDataService.Extensions;
using System.Collections.Generic;
using xIdentityModels.Extensions;
using xIdentityHelper.Extensions;
using Microsoft.EntityFrameworkCore;
using System.Runtime.CompilerServices;
using Microsoft.EntityFrameworkCore.Query;
using Microsoft.EntityFrameworkCore.ChangeTracking;

namespace xIds.Providers
{
    public partial class XApplicationProvider
    {
        //
        #region Application ...
        /// <summary>
        /// Add Specified Item ...
        /// </summary>
        /// <param name="item"></param>
        /// <param name="userInfo"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public async Task<XApplicationDto> AddApplicationAsync(
            XApplicationDto item,
            XUserClaimsInfoDto userInfo = null,
            CancellationToken cancellationToken = default
        )
        {
            //
            // Validate ...
            if (!item.IsValidForAdd())
            {
                XException.InvalidArgs.Throw();
            }

            //
            // Permission ...
            if (userInfo.IsNullOrDefault())
            {
                XException.NotAllowed.Throw();
            }

            //
            item.OwnerId = userInfo.UserId;
            item.CreatedOn = DateTime.UtcNow;

            //
            var entity = item.MapConvert<XApplication, XApplicationDto>();
            if (entity.Id.IsValidIntId())
            {
                entity.Id = -1;
            }

            //
            var entry = await dbContext.Applications.AddAsync(
                entity: entity,
                cancellationToken: cancellationToken
            );
            var changes = await dbContext.SaveChangesAsync(cancellationToken);

            //
            if (
                changes <= 0 ||
                entry.IsNull() ||
                entry.Entity.IsNullOrDefault()
            )
            {
                XException.ActionFailed.Throw();
            }

            //
            var result = await EnrichAsync(
                source: entry.Entity,
                cancellationToken: cancellationToken
            );
            return result;
        }

        /// <summary>
        /// Update Specified Item ...
        /// </summary>
        /// <param name="id"></param>
        /// <param name="item"></param>
        /// <param name="userInfo"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public async Task<XApplicationDto> UpdateApplicationAsync(
            int id,
            XApplicationDto item,
            XUserClaimsInfoDto userInfo = null,
            CancellationToken cancellationToken = default
        )
        {
            //
            // Validate ...
            if (
                id != item.Id ||
                !id.IsValidIntId() ||
                item.IsNullOrDefault() ||
                userInfo.IsNullOrDefault()
            )
            {
                XException.InvalidArgs.Throw();
            }

            //
            // Retrieve Exists Entity ...
            var exists = await dbContext.Applications
                .FirstOrDefaultAsync(x => x.Id == id && !x.Deleted);
            if (exists.IsNullOrDefault())
            {
                XException.NotFound.Throw();
            }

            //
            // Permission Checking ...
            if (!IsOwned(exists, userInfo))
            {
                XException.NotAllowed.Throw();
            }

            //
            // Update Data on Exists Entity ...
            exists = exists.UpdateData(
                updateWith: item,
                propertyWhiteList: [
                    nameof(XApplication.Name),
                    nameof(XApplication.Type),
                    nameof(XApplication.OwnerId),
                    nameof(XApplication.IsActive),
                    nameof(XApplication.CreatedOn),
                    nameof(XApplication.UpdatedAt),
                    nameof(XApplication.Description),
                ]
            );

            //
            var entry = dbContext.Applications.Attach(exists);
            entry.State = EntityState.Modified;

            //
            var changes = await dbContext.SaveChangesAsync(cancellationToken);
            if (
                changes <= 0 ||
                entry.IsNull() ||
                entry.Entity.IsNullOrDefault()
            )
            {
                XException.ActionFailed.Throw();
            }

            //
            var result = await EnrichAsync(
                source: entry.Entity,
                cancellationToken: cancellationToken
            );
            return result;
        }

        /// <summary>
        /// Remove Specified Item ...
        /// </summary>
        /// <param name="id"></param>
        /// <param name="softDelete"></param>
        /// <param name="userInfo"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public async Task<XApplicationDto> RemoveApplicationAsync(
            int id,
            bool softDelete = true,
            XUserClaimsInfoDto userInfo = null,
            CancellationToken cancellationToken = default
        )
        {
            //
            // Validate ...
            if (
                !id.IsValidIntId() ||
                userInfo.IsNullOrDefault()
            )
            {
                XException.InvalidArgs.Throw();
            }

            //
            // Retrieve Exists Entity ...
            var exists = await dbContext.Applications
                .FirstOrDefaultAsync(x => x.Id == id && !x.Deleted);
            if (exists.IsNullOrDefault())
            {
                XException.NotFound.Throw();
            }

            //
            // Permission Checking ...
            if (!IsOwned(exists, userInfo))
            {
                XException.NotAllowed.Throw();
            }

            //
            EntityEntry<XApplication> entry = null;
            if (softDelete)
            {
                //
                exists.Deleted = true;
                entry = dbContext.Applications.Update(exists);
            }
            else
            {
                entry = dbContext.Applications.Remove(exists);
            }

            //
            var changes = await dbContext.SaveChangesAsync(cancellationToken);
            if (
                changes <= 0 ||
                entry.IsNull() ||
                entry.Entity.IsNull()
            )
            {
                XException.ActionFailed.Throw();
            }

            //
            var result = await EnrichAsync(
                source: entry.Entity,
                cancellationToken: cancellationToken
            );
            return result;
        }

        /// <summary>
        /// Retrieve an Item by Providing it's ID ...
        /// </summary>
        /// <param name="id"></param>
        /// <param name="ignoreSoftDeleteds"></param>
        /// <param name="userInfo"></param>
        /// <param name="includeBuilder"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public async Task<XApplicationDto> GetApplicationAsync(
            int id,
            bool ignoreSoftDeleteds = true,
            XUserClaimsInfoDto userInfo = null,
            Func<IQueryable<XApplication>, IIncludableQueryable<XApplication, object>> includeBuilder = null,
            CancellationToken cancellationToken = default
        )
        {
            //
            // Validate ...
            if (!id.IsValidIntId() ||
                userInfo.IsNullOrDefault())
            {
                XException.InvalidArgs.Throw();
            }

            //
            // Prepare Condition ...
            Expression<Func<XApplication, bool>> predicate = x =>
                x.OwnerId != userInfo.UserId ||
                !ignoreSoftDeleteds || !x.Deleted;
            if (userInfo.IsAdmin())
            {
                //
                predicate = x =>
                    !ignoreSoftDeleteds || !x.Deleted;
            }

            //
            // Retrieve Queryable ...
            var queryable = GetApplicationsQeryable(
                orderBuilder: null,
                predicate: predicate,
                includeBuilder: includeBuilder
            );

            //
            var entity = await queryable.FirstOrDefaultAsync(
                predicate: x => x.Id == id,
                cancellationToken: cancellationToken
            );

            //
            var result = await EnrichAsync(
                source: entity,
                cancellationToken: cancellationToken
            );
            return result;
        }

        /// <summary>
        /// Retrieve all Items ...
        /// </summary>
        /// <param name="ignoreSoftDeleteds"></param>
        /// <param name="userInfo"></param>
        /// <param name="orderBuilder"></param>
        /// <param name="includeBuilder"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public async Task<IEnumerable<XApplicationDto>> GetAllApplicationAsync(
            bool ignoreSoftDeleteds = true,
            XUserClaimsInfoDto userInfo = null,
            Func<IQueryable<XApplication>, IOrderedQueryable<XApplication>> orderBuilder = null,
            Func<IQueryable<XApplication>, IIncludableQueryable<XApplication, object>> includeBuilder = null,
            CancellationToken cancellationToken = default
        )
        {
            //
            // Validate ...
            if (userInfo.IsNullOrDefault())
            {
                XException.InvalidArgs.Throw();
            }

            //
            // Prepare Condition ...
            Expression<Func<XApplication, bool>> predicate = x =>
                x.OwnerId == userInfo.UserId &&
                (!ignoreSoftDeleteds || !x.Deleted);
            if (userInfo.IsAdmin())
            {
                //
                predicate = x =>
                    !ignoreSoftDeleteds || !x.Deleted;
            }

            //
            // Retrieve Queryable ...
            var queryable = GetApplicationsQeryable(
                predicate: predicate,
                orderBuilder: orderBuilder,
                includeBuilder: includeBuilder
            );

            //
            var items = await queryable.ToListAsync(cancellationToken);
            var result = await EnrichRangeAsync(
                sources: items,
                cancellationToken: cancellationToken
            );

            //
            return result;
        }

        /// <summary>
        /// Retrieve all Items as Async Enumerable ...
        /// </summary>
        /// <param name="ignoreSoftDeleteds"></param>
        /// <param name="userInfo"></param>
        /// <param name="orderBuilder"></param>
        /// <param name="includeBuilder"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public async IAsyncEnumerable<XApplicationDto> GetAllApplicationAsAsyncEnumerable(
            bool ignoreSoftDeleteds = true,
            XUserClaimsInfoDto userInfo = null,
            Func<IQueryable<XApplication>, IOrderedQueryable<XApplication>> orderBuilder = null,
            Func<IQueryable<XApplication>, IIncludableQueryable<XApplication, object>> includeBuilder = null,
            [EnumeratorCancellation]
            CancellationToken cancellationToken = default
        )
        {
            //
            // Validate ...
            if (userInfo.IsNullOrDefault())
            {
                XException.InvalidArgs.Throw();
            }

            //
            // Prepare Condition ...
            Expression<Func<XApplication, bool>> predicate = x =>
                x.OwnerId == userInfo.UserId &&
                (!ignoreSoftDeleteds || !x.Deleted);
            if (userInfo.IsAdmin())
            {
                //
                predicate = x =>
                    !ignoreSoftDeleteds || !x.Deleted;
            }

            //
            // Retrieve Queryable ...
            var queryable = GetApplicationsQeryable(
                predicate: predicate,
                orderBuilder: orderBuilder,
                includeBuilder: includeBuilder
            );

            //
            var enumerator = queryable.AsAsyncEnumerable();
            await foreach (var item in enumerator)
            {
                //
                // Handle Cancellation Token ...
                if (cancellationToken.IsCancellationRequested)
                {
                    yield break;
                }

                //
                var dto = await EnrichAsync(
                    source: item,
                    cancellationToken: cancellationToken
                );

                yield return dto;
            }
        }

        /// <summary>
        /// Find an Item By Providing a Conditional Expression ...
        /// </summary>
        /// <param name="predicate"></param>
        /// <param name="ignoreSoftDeleteds"></param>
        /// <param name="userInfo"></param>
        /// <param name="includeBuilder"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public async Task<XApplicationDto> FindOneApplicationAsync(
            Expression<Func<XApplication, bool>> predicate,
            bool ignoreSoftDeleteds = true,
            XUserClaimsInfoDto userInfo = null,
            Func<IQueryable<XApplication>, IIncludableQueryable<XApplication, object>> includeBuilder = null,
            CancellationToken cancellationToken = default
        )
        {
            //
            // Validate ...
            if (userInfo.IsNullOrDefault())
            {
                XException.InvalidArgs.Throw();
            }

            //
            Expression<Func<XApplication, bool>> _predicate = x => !ignoreSoftDeleteds || !x.Deleted;
            if (!userInfo.IsAdmin())
            {
                _predicate = x =>
                    x.OwnerId == userInfo.UserId &&
                    (!ignoreSoftDeleteds || !x.Deleted);
            }

            //
            var queryable = GetApplicationsQeryable(
                orderBuilder: null,
                predicate: _predicate,
                includeBuilder: includeBuilder
            );

            //
            var entity = (await queryable
                .ToListAsync(cancellationToken))
                .FirstOrDefault(x => predicate.Compile()(x));

            //
            var result = await EnrichAsync(
                source: entity,
                cancellationToken: cancellationToken
            );
            return result;
        }

        /// <summary>
        /// Find a Collection of Items By Providing a Conditional Expression ...
        /// </summary>
        /// <param name="predicate"></param>
        /// <param name="ignoreSoftDeleteds"></param>
        /// <param name="userInfo"></param>
        /// <param name="orderBuilder"></param>
        /// <param name="includeBuilder"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public async Task<IEnumerable<XApplicationDto>> FindManyApplicationAsync(
            Expression<Func<XApplication, bool>> predicate,
            bool ignoreSoftDeleteds = true,
            XUserClaimsInfoDto userInfo = null,
            Func<IQueryable<XApplication>, IOrderedQueryable<XApplication>> orderBuilder = null,
            Func<IQueryable<XApplication>, IIncludableQueryable<XApplication, object>> includeBuilder = null,
            CancellationToken cancellationToken = default
        )
        {
            //
            // Validate ...
            if (userInfo.IsNullOrDefault())
            {
                XException.InvalidArgs.Throw();
            }

            //
            Expression<Func<XApplication, bool>> _predicate = x => !ignoreSoftDeleteds || !x.Deleted;
            if (!userInfo.IsAdmin())
            {
                _predicate = x =>
                    x.OwnerId == userInfo.UserId &&
                    (!ignoreSoftDeleteds || !x.Deleted);
            }

            //
            var queryable = GetApplicationsQeryable(
                orderBuilder: null,
                predicate: _predicate,
                includeBuilder: includeBuilder
            );

            //
            var entities = (await queryable
                .ToListAsync(cancellationToken))
                .Where(x => predicate.Compile()(x));

            //
            var result = await EnrichRangeAsync(
                sources: entities,
                cancellationToken: cancellationToken
            );
            return result;
        }

        /// <summary>
        /// Retrieve Items based on XQuery Pagination Structure ...
        /// </summary>
        /// <param name="query"></param>
        /// <param name="ignoreSoftDeleteds"></param>
        /// <param name="userInfo"></param>
        /// <param name="predicate"></param>
        /// <param name="orderBuilder"></param>
        /// <param name="includeBuilder"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public async Task<XQueryResult<XApplicationDto>> QueryApplicationAsync(
            XQuery query,
            bool ignoreSoftDeleteds = true,
            XUserClaimsInfoDto userInfo = null,
            Expression<Func<XApplication, bool>> predicate = null,
            Func<IQueryable<XApplication>, IOrderedQueryable<XApplication>> orderBuilder = null,
            Func<IQueryable<XApplication>, IIncludableQueryable<XApplication, object>> includeBuilder = null,
            CancellationToken cancellationToken = default
        )
        {
            //
            // Normalize Query ...
            query = NormalizeQuery(query, configuration);

            //
            var items = await GetAllApplicationAsync(
                userInfo: userInfo,
                orderBuilder: orderBuilder,
                includeBuilder: includeBuilder,
                cancellationToken: cancellationToken,
                ignoreSoftDeleteds: ignoreSoftDeleteds
            );
            var totalItemsCount = items.Count();

            //
            // Apply Filter ...
            if (!query.Filter.IsNullOrEmpty())
            {
                //
                items = items
                    .ApplyFilter(query.Filter);
            }
            int filteredItemsCount = items.Count();

            //
            // Count Pages ...
            var totalPagesCount = query.CountPages(totalItemsCount);
            var filteredPagesCount = query.CountPages(filteredItemsCount);

            //
            // Apply Paging and Sorting ...
            if (totalItemsCount > 0 &&
                filteredItemsCount > 0
            )
            {
                //
                // Apply Sorting ...
                items = items
                    .ToList()
                    .ApplySorting(
                        query.SortBy,
                        query.IsAscending
                    );

                //
                // Apply Paging ...
                items = items
                    .ToList()
                    .ApplyPaging(
                        query.Page,
                        query.PageSize
                    );
            }

            //
            // Prepare Result ...
            var result = new XQueryResult<XApplicationDto>
            {
                Page = query.Page,
                Items = [.. items],
                PageSize = query.PageSize,
                TotalPages = totalPagesCount,
                TotalItems = totalItemsCount,
                TotalFilteredPages = filteredPagesCount,
                TotalFilteredItems = filteredItemsCount
            };

            //
            return result;
        }
        #endregion
    }
}