using System.Linq;
using Swashbuckle.AspNetCore.Swagger;
using Swashbuckle.AspNetCore.SwaggerGen;

namespace Volo.Abp.Identity.HttpApi.Host
{
    /// <summary>
    /// Represents the Swagger/Swashbuckle operation filter used to document the implicit API version parameter.
    /// </summary>
    /// <remarks>This <see cref="IOperationFilter"/> is only required due to bugs in the <see cref="SwaggerGenerator"/>.
    /// Once they are fixed and published, this class can be removed.</remarks>
    public class SwaggerDefaultValues : IOperationFilter
    {
        /// <summary>
        /// Applies the filter to the specified operation using the given context.
        /// </summary>
        /// <param name="operation">The operation to apply the filter to.</param>
        /// <param name="context">The current operation filter context.</param>
        public void Apply(Operation operation, OperationFilterContext context)
        {
            // REF: https://github.com/domaindrivendev/Swashbuckle.AspNetCore/issues/412
            // REF: https://github.com/domaindrivendev/Swashbuckle.AspNetCore/pull/413
            foreach (var parameter in operation.Parameters.OfType<NonBodyParameter>())
            {
                var description = context.ApiDescription.ParameterDescriptions.First(p => p.Name == parameter.Name);

                if (parameter.Description == null)
                {
                    parameter.Description = description.ModelMetadata.Description;
                }

                if (parameter.Default == null)
                {
                    parameter.Default = description.RouteInfo?.DefaultValue;
                }

                parameter.Required |= description.RouteInfo?.IsOptional == true;
            }
        }
    }
}