using Microsoft.AspNetCore.Mvc.ApiExplorer;
using Swashbuckle.AspNetCore.SwaggerGen;

namespace IOL.GreatOffice.Api.Utilities;

/// <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(OpenApiOperation operation, OperationFilterContext context) {
		var apiDescription = context.ApiDescription;

		operation.Deprecated |= apiDescription.IsDeprecated();

		// REF: https://github.com/domaindrivendev/Swashbuckle.AspNetCore/issues/1752#issue-663991077
		foreach (var responseType in context.ApiDescription.SupportedResponseTypes) {
			// REF: https://github.com/domaindrivendev/Swashbuckle.AspNetCore/blob/b7cf75e7905050305b115dd96640ddd6e74c7ac9/src/Swashbuckle.AspNetCore.SwaggerGen/SwaggerGenerator/SwaggerGenerator.cs#L383-L387
			var responseKey = responseType.IsDefaultResponse ? "default" : responseType.StatusCode.ToString();
			var response = operation.Responses[responseKey];

			foreach (var contentType in response.Content.Keys) {
				if (responseType.ApiResponseFormats.All(x => x.MediaType != contentType)) {
					response.Content.Remove(contentType);
				}
			}
		}

		if (operation.Parameters == null) {
			return;
		}

		// REF: https://github.com/domaindrivendev/Swashbuckle.AspNetCore/issues/412
		// REF: https://github.com/domaindrivendev/Swashbuckle.AspNetCore/pull/413
		foreach (var parameter in operation.Parameters) {
			var description = apiDescription.ParameterDescriptions.First(p => p.Name == parameter.Name);

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

			if (parameter.Schema.Default == null && description.DefaultValue != null) {
				// REF: https://github.com/Microsoft/aspnet-api-versioning/issues/429#issuecomment-605402330
				var json = JsonSerializer.Serialize(description.DefaultValue, description.ModelMetadata.ModelType);
				parameter.Schema.Default = OpenApiAnyFactory.CreateFromJson(json);
			}

			parameter.Required |= description.IsRequired;
		}
	}
}