DD.WellWorkover.Cloud/AsbCloudWebApi/Extentions.cs

using AsbCloudApp.Data;
using System.Collections.Generic;
using System.Linq;
using System.Security.Claims;

namespace Microsoft.AspNetCore.Mvc 
{
    public static class Extentions
    {
        public static int? GetCompanyId(this ClaimsPrincipal user)
        {
            var claimIdCompany = user.FindFirst(nameof(UserDto.IdCompany));
            if (claimIdCompany is null)
                return null;

            return int.TryParse(claimIdCompany.Value, out int uid)
                ? uid
                : null;
        }

        public static int? GetUserId(this ClaimsPrincipal user)
        {
            var userId = user.FindFirst(nameof(UserDto.Id));
            if (userId is null)
                return null;

            return int.TryParse(userId.Value, out int uid)
                ? uid
                : null;
        }

        public static IActionResult MakeBadRequest(this ControllerBase controller, string paramName, params string[] errors)
        {
            return controller.BadRequest(new
            {
                name = paramName,
                errors,
            });
        }

        public static BadRequestBuilder BadRequestBuilder(this ControllerBase controller, string paramName, params string[] errors)
            => new BadRequestBuilder(paramName, errors);
    }

    public class BadRequestBuilder
    {
        private readonly Dictionary<string, List<string>> body;

        private List<string> GetOrCreateNew(string paramName)
        {
            List<string> par;
            if (body.ContainsKey(paramName))
                par = body[paramName];
            else
            {
                par = new List<string>();
                body[paramName] = par;
            }
            return par;
        }

        public BadRequestBuilder(string paramName, params string[] errors)
        {
            body = new();
            body[paramName] = new List<string>(errors);
        }

        public BadRequestBuilder Add(string paramName, params string[] errors)
        {
            var par = GetOrCreateNew(paramName);
            par.AddRange(errors);
            return this;
        }

        public BadRequestObjectResult Build()
        {
            var o = body.Select(e => new { name = e.Key, errors = e.Value.ToArray() });

            return new BadRequestObjectResult(o);
        }

        public static implicit operator BadRequestObjectResult(BadRequestBuilder d) => d.Build();
    }
}