namespace Cardone.Backoffice.ImageSearch.Controllers

open Microsoft.AspNetCore.Mvc
open Microsoft.AspNetCore.Authorization
open Microsoft.AspNetCore.Diagnostics
open System

type ErrorViewModel (message : string) =
    member __.Message with get() = message
    new() = ErrorViewModel(null)

[<Route("error")>]
type ErrorController() =
    inherit ControllerBase()

    let getDeepestExceptionMessage (ex : Exception) =
        let rec getDeepestException (ex : exn) =
            match ex.InnerException with
                | null -> ex
                | _ -> getDeepestException(ex.InnerException)
        getDeepestException(ex).Message

    [<AllowAnonymous>]
    member this.Index() =
        let ex =
            match this.HttpContext.Features.Get<IExceptionHandlerFeature>() with
                | null -> None
                | value when (not << isNull) value.Error  -> Some value.Error
                | _ -> None
        let errorViewModel =
            ex
             |> Option.map (getDeepestExceptionMessage >> ErrorViewModel)
             |> Option.defaultValue (ErrorViewModel("Произошла непредвиденная ошибка"))
        this.BadRequest(errorViewModel)