// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using Aspire.Azure.Common;
using Aspire.Azure.Messaging.ServiceBus;
using Azure.Core;
using Azure.Core.Extensions;
using Azure.Messaging.ServiceBus;
using HealthChecks.AzureServiceBus;
using HealthChecks.AzureServiceBus.Configuration;
using Microsoft.Extensions.Azure;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Diagnostics.HealthChecks;
 
namespace Microsoft.Extensions.Hosting;
 
/// <summary>
/// Provides extension methods for registering <see cref="ServiceBusClient"/> as a singleton in the services provided by the <see cref="IHostApplicationBuilder"/>.
/// </summary>
public static class AspireServiceBusExtensions
{
    private const string DefaultConfigSectionName = "Aspire:Azure:Messaging:ServiceBus";
 
    /// <summary>
    /// Registers <see cref="ServiceBusClient"/> as a singleton in the services provided by the <paramref name="builder"/>.
    /// </summary>
    /// <param name="builder">The <see cref="IHostApplicationBuilder" /> to read config from and add services to.</param>
    /// <param name="connectionName">A name used to retrieve the connection string from the ConnectionStrings configuration section.</param>
    /// <param name="configureSettings">An optional method that can be used for customizing the <see cref="AzureMessagingServiceBusSettings"/>. It's invoked after the settings are read from the configuration.</param>
    /// <param name="configureClientBuilder">An optional method that can be used for customizing the <see cref="IAzureClientBuilder{TClient, TOptions}"/>.</param>
    /// <remarks>Reads the configuration from "Aspire:Azure:Messaging:ServiceBus" section.</remarks>
    /// <exception cref="InvalidOperationException">Thrown when neither <see cref="AzureMessagingServiceBusSettings.ConnectionString"/> nor <see cref="AzureMessagingServiceBusSettings.FullyQualifiedNamespace"/> is provided.</exception>
    public static void AddAzureServiceBusClient(
        this IHostApplicationBuilder builder,
        string connectionName,
        Action<AzureMessagingServiceBusSettings>? configureSettings = null,
        Action<IAzureClientBuilder<ServiceBusClient, ServiceBusClientOptions>>? configureClientBuilder = null)
    {
        new MessageBusComponent().AddClient(builder, DefaultConfigSectionName, configureSettings, configureClientBuilder, connectionName, serviceKey: null);
    }
 
    /// <summary>
    /// Registers <see cref="ServiceBusClient"/> as a singleton for given <paramref name="name"/> in the services provided by the <paramref name="builder"/>.
    /// </summary>
    /// <param name="builder">The <see cref="IHostApplicationBuilder" /> to read config from and add services to.</param>
    /// <param name="name">The name of the component, which is used as the <see cref="ServiceDescriptor.ServiceKey"/> of the service and also to retrieve the connection string from the ConnectionStrings configuration section.</param>
    /// <param name="configureSettings">An optional method that can be used for customizing the <see cref="AzureMessagingServiceBusSettings"/>. It's invoked after the settings are read from the configuration.</param>
    /// <param name="configureClientBuilder">An optional method that can be used for customizing the <see cref="IAzureClientBuilder{TClient, TOptions}"/>.</param>
    /// <remarks>Reads the configuration from "Aspire:Azure:Messaging:ServiceBus:{name}" section.</remarks>
    /// <exception cref="InvalidOperationException">Thrown when neither <see cref="AzureMessagingServiceBusSettings.ConnectionString"/> nor <see cref="AzureMessagingServiceBusSettings.FullyQualifiedNamespace"/> is provided.</exception>
    public static void AddKeyedAzureServiceBusClient(
        this IHostApplicationBuilder builder,
        string name,
        Action<AzureMessagingServiceBusSettings>? configureSettings = null,
        Action<IAzureClientBuilder<ServiceBusClient, ServiceBusClientOptions>>? configureClientBuilder = null)
    {
        ArgumentException.ThrowIfNullOrEmpty(name);
 
        new MessageBusComponent().AddClient(builder, DefaultConfigSectionName, configureSettings, configureClientBuilder, connectionName: name, serviceKey: name);
    }
 
    private sealed class MessageBusComponent : AzureComponent<AzureMessagingServiceBusSettings, ServiceBusClient, ServiceBusClientOptions>
    {
        protected override IAzureClientBuilder<ServiceBusClient, ServiceBusClientOptions> AddClient(
            AzureClientFactoryBuilder azureFactoryBuilder, AzureMessagingServiceBusSettings settings,
            string connectionName, string configurationSectionName)
        {
            return ((IAzureClientFactoryBuilderWithCredential)azureFactoryBuilder).RegisterClientFactory<ServiceBusClient, ServiceBusClientOptions>((options, cred) =>
            {
                var connectionString = settings.ConnectionString;
                if (string.IsNullOrEmpty(connectionString) && string.IsNullOrEmpty(settings.FullyQualifiedNamespace))
                {
                    throw new InvalidOperationException($"A ServiceBusClient could not be configured. Ensure valid connection information was provided in 'ConnectionStrings:{connectionName}' or specify a 'ConnectionString' or 'Namespace' in the '{configurationSectionName}' configuration section.");
                }
 
                return !string.IsNullOrEmpty(connectionString) ?
                    new ServiceBusClient(connectionString, options) :
                    new ServiceBusClient(settings.FullyQualifiedNamespace, cred, options);
            }, requiresCredential: false);
        }
 
        protected override IHealthCheck CreateHealthCheck(ServiceBusClient client, AzureMessagingServiceBusSettings settings)
            => !string.IsNullOrEmpty(settings.HealthCheckQueueName)
                    ? new AzureServiceBusQueueHealthCheck(new AzureServiceBusQueueHealthCheckOptions(settings.HealthCheckQueueName)
                    {
                        FullyQualifiedNamespace = settings.FullyQualifiedNamespace,
                        ConnectionString = settings.ConnectionString,
                        Credential = settings.Credential
                    })
                    : new AzureServiceBusTopicHealthCheck(new AzureServiceBusTopicHealthCheckOptions(settings.HealthCheckTopicName!)
                    {
                        FullyQualifiedNamespace = settings.FullyQualifiedNamespace,
                        ConnectionString = settings.ConnectionString,
                        Credential = settings.Credential
                    });
 
        protected override void BindClientOptionsToConfiguration(IAzureClientBuilder<ServiceBusClient, ServiceBusClientOptions> clientBuilder, IConfiguration configuration)
        {
#pragma warning disable IDE0200 // Remove unnecessary lambda expression - needed so the ConfigBinder Source Generator works
            clientBuilder.ConfigureOptions(options => configuration.Bind(options));
#pragma warning restore IDE0200
        }
 
        protected override void BindSettingsToConfiguration(AzureMessagingServiceBusSettings settings, IConfiguration config)
        {
            config.Bind(settings);
        }
 
        protected override bool GetHealthCheckEnabled(AzureMessagingServiceBusSettings settings)
            => !string.IsNullOrEmpty(settings.HealthCheckQueueName) || !string.IsNullOrEmpty(settings.HealthCheckTopicName);
 
        protected override TokenCredential? GetTokenCredential(AzureMessagingServiceBusSettings settings)
            => settings.Credential;
 
        protected override bool GetMetricsEnabled(AzureMessagingServiceBusSettings settings)
            => false;
 
        protected override bool GetTracingEnabled(AzureMessagingServiceBusSettings settings)
            => !settings.DisableTracing;
    }
}