// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using Aspire.Hosting.ApplicationModel;
using Aspire.Hosting.Azure;
using Aspire.Hosting.Azure.SignalR;
using Azure.Provisioning;
using Azure.Provisioning.SignalR;
 
namespace Aspire.Hosting;
 
/// <summary>
/// Provides extension methods for adding the Azure SignalR resources to the application model.
/// </summary>
public static class AzureSignalRExtensions
{
    private const string EmulatorEndpointName = "emulator";
 
    /// <summary>
    /// Adds an Azure SignalR resource to the application model.
    /// </summary>
    /// <param name="builder">The <see cref="IDistributedApplicationBuilder"/>.</param>
    /// <param name="name">The name of the resource. This name will be used as the connection string name when referenced in a dependency.</param>
    /// <returns>A reference to the <see cref="IResourceBuilder{T}"/>.</returns>
    public static IResourceBuilder<AzureSignalRResource> AddAzureSignalR(this IDistributedApplicationBuilder builder, [ResourceName] string name) => AddAzureSignalR(builder, name, AzureSignalRServiceMode.Default);
 
    /// <summary>
    /// Adds an Azure SignalR resource to the application model.
    /// </summary>
    /// <param name="builder">The <see cref="IDistributedApplicationBuilder"/>.</param>
    /// <param name="name">The name of the resource. This name will be used as the connection string name when referenced in a dependency.</param>
    /// <param name="serviceMode">The service mode of the resource.</param>
    /// <returns>A reference to the <see cref="IResourceBuilder{T}"/>.</returns>
    public static IResourceBuilder<AzureSignalRResource> AddAzureSignalR(this IDistributedApplicationBuilder builder, [ResourceName] string name, AzureSignalRServiceMode serviceMode)
    {
        builder.AddAzureProvisioning();
 
        var configureInfrastructure = (AzureResourceInfrastructure infrastructure) =>
        {
            var service = new SignalRService(infrastructure.AspireResource.GetBicepIdentifier())
            {
                Kind = SignalRServiceKind.SignalR,
                Sku = new SignalRResourceSku()
                {
                    Name = "Free_F1",
                    Capacity = 1
                },
                Features =
                [
                    new SignalRFeature()
                    {
                        Flag = SignalRFeatureFlag.ServiceMode,
                        Value = serviceMode.ToString()
                    }
                ],
                CorsAllowedOrigins = ["*"],
                Tags = { { "aspire-resource-name", infrastructure.AspireResource.Name } }
            };
            infrastructure.Add(service);
 
            infrastructure.Add(new ProvisioningOutput("hostName", typeof(string)) { Value = service.HostName });
 
            var principalTypeParameter = new ProvisioningParameter(AzureBicepResource.KnownParameters.PrincipalType, typeof(string));
            infrastructure.Add(principalTypeParameter);
            var principalIdParameter = new ProvisioningParameter(AzureBicepResource.KnownParameters.PrincipalId, typeof(string));
            infrastructure.Add(principalIdParameter);
 
            infrastructure.Add(service.CreateRoleAssignment(SignalRBuiltInRole.SignalRAppServer, principalTypeParameter, principalIdParameter));
 
            if (serviceMode == AzureSignalRServiceMode.Serverless)
            {
                infrastructure.Add(service.CreateRoleAssignment(SignalRBuiltInRole.SignalRRestApiOwner, principalTypeParameter, principalIdParameter));
            }
        };
 
        var resource = new AzureSignalRResource(name, configureInfrastructure);
        return builder.AddResource(resource)
                      .WithManifestPublishingCallback(resource.WriteToManifest);
    }
 
    /// <summary>
    /// Configures an Azure SignalR resource to be emulated. This resource requires an <see cref="AzureSignalRResource"/> to be added to the application model. Please note that the resource will be emulated in <b>Serverless mode</b>.
    /// </summary>
    /// <remarks>
    /// This version of the package defaults to the <inheritdoc cref="SignalREmulatorContainerImageTags.Tag"/> tag of the <inheritdoc cref="SignalREmulatorContainerImageTags.Registry"/>/<inheritdoc cref="SignalREmulatorContainerImageTags.Image"/> container image.
    /// </remarks>
    /// <param name="builder">The Azure SignalR resource builder.</param>
    /// <param name="configureContainer">Callback that exposes underlying container used for emulation to allow for customization.</param>
    /// <returns>A reference to the <see cref="IResourceBuilder{T}"/>.</returns>
    public static IResourceBuilder<AzureSignalRResource> RunAsEmulator(this IResourceBuilder<AzureSignalRResource> builder, Action<IResourceBuilder<AzureSignalREmulatorResource>>? configureContainer = null)
    {
        if (builder.ApplicationBuilder.ExecutionContext.IsPublishMode)
        {
            return builder;
        }
 
        builder
            .WithEndpoint(name: EmulatorEndpointName, targetPort: 8888, scheme: "http")
            .WithAnnotation(new ContainerImageAnnotation
            {
                Registry = SignalREmulatorContainerImageTags.Registry,
                Image = SignalREmulatorContainerImageTags.Image,
                Tag = SignalREmulatorContainerImageTags.Tag
            });
        if (configureContainer != null)
        {
            var surrogate = new AzureSignalREmulatorResource(builder.Resource);
            var surrogateBuilder = builder.ApplicationBuilder.CreateResourceBuilder(surrogate);
            configureContainer(surrogateBuilder);
        }
        return builder.WithHttpHealthCheck(endpointName: EmulatorEndpointName, path: "/api/health");
    }
}