using System;
using System.Text.Json;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.ModelBinding;

namespace LCU.Library.Internal.DocumentModels.Converter
{
    public class FromJsonQueryAttribute : ModelBinderAttribute
    {
        public FromJsonQueryAttribute()
        {
            BinderType = typeof(JsonQueryBinder);
        }
    }

    public class JsonQueryBinder : IModelBinder
    {
        public JsonQueryBinder()
        {
        }

        public Task BindModelAsync(ModelBindingContext bindingContext)
        {
            var value = bindingContext.ValueProvider.GetValue(bindingContext.FieldName).FirstValue;
            if (value == null)
            {
                return Task.CompletedTask;
            }

            try
            {
                var parsed = JsonSerializer.Deserialize(
                    value,
                    bindingContext.ModelType,
                    new JsonSerializerOptions(JsonSerializerDefaults.Web)
                );
                bindingContext.Result = ModelBindingResult.Success(parsed);
            }
            catch (Exception e)
            {
                bindingContext.Result = ModelBindingResult.Failed();
            }

            return Task.CompletedTask;
        }
    }
}