// 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 Azure.Provisioning.Primitives;
using Azure.Provisioning.ServiceBus;
 
namespace Aspire.Hosting.Azure;
 
/// <summary>
/// Represents an Azure Service Bus resource.
/// </summary>
/// <param name="name">The name of the resource.</param>
/// <param name="configureInfrastructure">Callback to configure the Azure Service Bus resource.</param>
public class AzureServiceBusResource(string name, Action<AzureResourceInfrastructure> configureInfrastructure)
    : AzureProvisioningResource(name, configureInfrastructure), IResourceWithConnectionString, IResourceWithAzureFunctionsConfig, IResourceWithEndpoints
{
    internal List<AzureServiceBusQueueResource> Queues { get; } = [];
    internal List<AzureServiceBusTopicResource> Topics { get; } = [];
 
    /// <summary>
    /// Gets the "serviceBusEndpoint" output reference from the bicep template for the Azure Storage resource.
    /// </summary>
    public BicepOutputReference ServiceBusEndpoint => new("serviceBusEndpoint", this);
 
    /// <summary>
    /// Gets the "serviceBusHostName" output reference from the bicep template for the Azure Storage resource.
    /// </summary>
    internal BicepOutputReference ServiceBusHostName => new("serviceBusHostName", this);
 
    /// <summary>
    /// Gets the "name" output reference for the resource.
    /// </summary>
    public BicepOutputReference NameOutputReference => new("name", this);
 
    internal EndpointReference EmulatorEndpoint => new(this, "emulator");
 
    /// <summary>
    /// Gets a value indicating whether the Azure Service Bus resource is running in the local emulator.
    /// </summary>
    public bool IsEmulator => this.IsContainer();
 
    /// <summary>
    /// Gets the host name for the Service Bus namespace.
    /// </summary>
    public ReferenceExpression HostName =>
        IsEmulator ?
            ReferenceExpression.Create($"{EmulatorEndpoint.Property(EndpointProperty.Host)}") :
            ReferenceExpression.Create($"{ServiceBusHostName}");
 
    /// <summary>
    /// Gets the port for the Service Bus namespace.
    /// </summary>
    /// <remarks>
    /// In container mode, resolves to the container's primary endpoint port.
    /// In Azure mode, return null.
    /// </remarks>
    public ReferenceExpression? Port =>
        IsEmulator ?
            ReferenceExpression.Create($"{EmulatorEndpoint.Property(EndpointProperty.Port)}") :
            null;
 
    /// <summary>
    /// Gets the connection URI expression for the Service Bus namespace.
    /// </summary>
    /// <remarks>
    /// Format: <c>sb://{host}</c>.
    /// </remarks>
    public ReferenceExpression UriExpression =>
        IsEmulator ?
            ReferenceExpression.Create($"sb://{EmulatorEndpoint.Property(EndpointProperty.HostAndPort)}") :
            ReferenceExpression.Create($"{ServiceBusEndpoint}");
 
    /// <summary>
    /// Gets the connection string template for the manifest for the Azure Service Bus endpoint.
    /// </summary>
    public ReferenceExpression ConnectionStringExpression =>
        IsEmulator
            ? ReferenceExpression.Create($"Endpoint=sb://{EmulatorEndpoint.Property(EndpointProperty.HostAndPort)};SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=SAS_KEY_VALUE;UseDevelopmentEmulator=true;")
            : ReferenceExpression.Create($"{ServiceBusEndpoint}");
 
    void IResourceWithAzureFunctionsConfig.ApplyAzureFunctionsConfiguration(IDictionary<string, object> target, string connectionName)
        => ApplyAzureFunctionsConfiguration(target, connectionName);
 
    /// <inheritdoc/>
    public override ProvisionableResource AddAsExistingResource(AzureResourceInfrastructure infra)
    {
        var bicepIdentifier = this.GetBicepIdentifier();
        var resources = infra.GetProvisionableResources();
        
        // Check if a ServiceBusNamespace with the same identifier already exists
        var existingNamespace = resources.OfType<ServiceBusNamespace>().SingleOrDefault(sbNamespace => sbNamespace.BicepIdentifier == bicepIdentifier);
        
        if (existingNamespace is not null)
        {
            return existingNamespace;
        }
        
        // Create and add new resource if it doesn't exist
        var sbNamespace = ServiceBusNamespace.FromExisting(bicepIdentifier);
 
        if (!TryApplyExistingResourceAnnotation(
            this,
            infra,
            sbNamespace))
        {
            sbNamespace.Name = NameOutputReference.AsProvisioningParameter(infra);
        }
 
        infra.Add(sbNamespace);
        return sbNamespace;
    }
 
    internal ReferenceExpression GetConnectionString(string? queueOrTopicName, string? subscriptionName)
    {
        if (string.IsNullOrEmpty(queueOrTopicName) && string.IsNullOrEmpty(subscriptionName))
        {
            return ConnectionStringExpression;
        }
 
        var builder = new ReferenceExpressionBuilder();
 
        if (IsEmulator)
        {
            builder.AppendFormatted(ConnectionStringExpression);
        }
        else
        {
            builder.Append($"Endpoint={ConnectionStringExpression}");
        }
 
        // Add EntityPath for child resources (queues, topics, subscriptions)
        if (!string.IsNullOrEmpty(queueOrTopicName))
        {
            builder.Append($";EntityPath={queueOrTopicName}");
 
            if (!string.IsNullOrEmpty(subscriptionName))
            {
                builder.Append($"/Subscriptions/{subscriptionName}");
            }
        }
 
        return builder.Build();
    }
 
    internal void ApplyAzureFunctionsConfiguration(IDictionary<string, object> target, string connectionName, string? queueOrTopicName = null, string? subscriptionName = null)
    {
        if (IsEmulator)
        {
            // Injected to support Azure Functions listener initialization.
            target[$"{connectionName}"] = ConnectionStringExpression;
            // Injected to support Aspire client integration for Service Bus in Azure Functions projects.
            target[$"Aspire__Azure__Messaging__ServiceBus__{connectionName}__ConnectionString"] = GetConnectionString(queueOrTopicName, subscriptionName);
        }
        else
        {
            // Injected to support Azure Functions listener initialization.
            target[$"{connectionName}__fullyQualifiedNamespace"] = ServiceBusEndpoint;
            // Injected to support Aspire client integration for Service Bus in Azure Functions projects.
            target[$"Aspire__Azure__Messaging__ServiceBus__{connectionName}__FullyQualifiedNamespace"] = ServiceBusEndpoint;
            if (queueOrTopicName is not null)
            {
                target[$"Aspire__Azure__Messaging__ServiceBus__{connectionName}__QueueOrTopicName"] = queueOrTopicName;
            }
            if (subscriptionName is not null)
            {
                target[$"Aspire__Azure__Messaging__ServiceBus__{connectionName}__SubscriptionName"] = subscriptionName;
            }
        }
    }
 
    IEnumerable<KeyValuePair<string, ReferenceExpression>> IResourceWithConnectionString.GetConnectionProperties()
    {
        yield return new("Host", HostName);
 
        if (Port is not null)
        {
            yield return new("Port", Port);
        }
 
        yield return new("Uri", UriExpression);
 
        if (IsEmulator)
        {
            yield return new("ConnectionString", ConnectionStringExpression);
        }
    }
}