using AutoMapper;
using BlackRock.Reporting.API.Models;
using MediatR;

namespace BlackRock.Reporting.API.Mediator
{
    public class QueryResults<T>
    {
        public int TotalItems { get; set; }
        public IEnumerable<T> Items { get; set; }
    }
    public class UserQuery
    {
        public string SortBy { get; set; }
        public bool IsSortAscending { get; set; }
        public int Page { get; set; }
        public int PageSize { get; set; }
    }


    public class GetAllUsersQuery : IRequest<Result<QueryResults<UserDto>>>
    {
        public UserQuery Filter { get; }
        public GetAllUsersQuery(UserQuery filter)
        {
            this.Filter = filter;
        }
    }

    public class GetAllUsersQueryHandlers : IRequestHandler<GetAllUsersQuery, Result<QueryResults<UserDto>>>
    {
        private readonly ILogger<GetAllUsersQueryHandlers> logger;
        private readonly IMapper mapper;
        public GetAllUsersQueryHandlers(ILogger<GetAllUsersQueryHandlers> logger, IMapper mapper)
        {
            this.mapper = mapper;
            this.logger = logger;
        }
        public async Task<Result<QueryResults<UserDto>>> Handle(GetAllUsersQuery command, CancellationToken cancellationToken)
        {
            if (command.Filter == null)
                throw new ArgumentNullException($"Parameter {nameof(command.Filter)} must not be null");
            logger.LogInformation("Getting user ...");
            try
            {
                var users = new List<User>();
                users.Add(new (){Id = new Guid(), Name = "John", Email = "john.done@dilig.net"}); // Demonstration purpose
                // var users = await repository.GetAllUsersByFilterAsync(command.Filter);
                var usersDto = mapper.Map<IEnumerable<User>, IEnumerable<UserDto>>(users);
                var data = new QueryResults<UserDto> { Items = usersDto, TotalItems = users.Count };
                return new Result<QueryResults<UserDto>> { Data = data };
            }
            catch (Exception ex)
            {
                return new Result<QueryResults<UserDto>> { IsSuccess = false, Error = "Faild to fetch data from DB." };
            }
        }
    }
}