using System.Net;
using FluentValidation;
using Prefab.Domain.Exceptions;
using Prefab.Endpoints;
using Prefab.Web.Client.Models;
using Prefab.Web.Client.Models.Shared;
using Prefab.Web.Client.Pages;
using Prefab.Web.Client.Services;

namespace Prefab.Web.Gateway;

public static class Categories
{
    public class Endpoints : IEndpointRegistrar
    {
        public void MapEndpoints(IEndpointRouteBuilder endpoints)
        {
            endpoints.MapGet("/bff/categories/page",
                    async (ICategoriesPageService service, CancellationToken cancellationToken) =>
                    {
                        var result = await service.GetPage(cancellationToken);
                        var status = result.Problem?.StatusCode ?? (result.IsSuccess
                            ? StatusCodes.Status200OK
                            : StatusCodes.Status500InternalServerError);
                        return Results.Json(result, statusCode: status);
                    })
                .WithTags(nameof(Categories));
        }
    }

    public class PageService(Prefab.Shared.Catalog.IModuleClient moduleClient) : ICategoriesPageService
    {
        public async Task<Result<CategoriesPageModel>> GetPage(CancellationToken cancellationToken)
        {
            try
            {
                var response = await moduleClient.Category.GetCategories(cancellationToken);

                var model = new CategoriesPageModel
                {
                    Categories = response.Categories.Select(x => new CategoryListItemModel
                    {
                        Id = x.Id,
                        Name = x.Name,
                        ParentName = x.ParentName
                    })
                };

                return Result<CategoriesPageModel>.Success(model);
            }
            catch (Exception exception)
            {
                var problem = exception switch
                {
                    ValidationException validationException => ResultProblem.FromValidation(validationException),
                    DomainException domainException => ResultProblem.Unexpected(domainException.Message, domainException, HttpStatusCode.UnprocessableEntity),
                    _ => ResultProblem.Unexpected("Failed to retrieve categories.", exception)
                };

                return Result<CategoriesPageModel>.Failure(problem);
            }
        }
    }
}