namespace AyaNova
{
    using Swashbuckle.AspNetCore.Swagger;
    using Swashbuckle.AspNetCore.SwaggerGen;
    using System.Linq;

    /// <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 );
                var routeInfo = description.RouteInfo;

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

                if ( routeInfo == null )
                {
                    continue;
                }

                if ( parameter.Default == null )
                {
                    parameter.Default = routeInfo.DefaultValue;
                }

                parameter.Required |= !routeInfo.IsOptional;
            }
        }
    }
}