// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Diagnostics;
using System.Text.Json.Serialization;
using k8s.Models;
 
namespace Aspire.Hosting.Dcp.Model;
 
internal sealed class ServiceSpec
{
    // The desired address for the service to run on
    [JsonPropertyName("address")]
    public string? Address { get; set; }
 
    // The desired port for the service to run on
    [JsonPropertyName("port")]
    public int? Port { get; set; }
 
    // The network protocol to be used for the service. Defaults to TCP.
    [JsonPropertyName("protocol")]
    public string Protocol { get; set; } = PortProtocol.TCP;
 
    // The mode for address allocation
    [JsonPropertyName("addressAllocationMode")]
    public string AddressAllocationMode { get; set; } = AddressAllocationModes.Localhost;
}
 
internal sealed record ServiceStatus : V1Status
{
    // The actual address the service is running on
    [JsonPropertyName("effectiveAddress")]
    public string? EffectiveAddress { get; set; }
 
    // The actual port the service is running on
    [JsonPropertyName("effectivePort")]
    public int? EffectivePort { get; set; }
 
    // The current state of the service
    [JsonPropertyName("state")]
    public string? State { get; set; }
}
 
internal static class ServiceState
{
    // The service is not ready to accept connection. EffectiveAddress and EffectivePort do not contain final data.
    public const string NotReady = "NotReady";
 
    // The service is ready to accept connections.
    public const string Ready = "Ready";
}
 
internal static class AddressAllocationModes
{
    // Bind only to 127.0.0.1
    public const string IPv4ZeroOne = "IPv4ZeroOne";
 
    // Bind to any 127.*.*.* loopback address range
    public const string IPv4Loopback = "IPv4Loopback";
 
    // Bind to IPv6 ::1
    public const string IPv6 = "IPv6ZeroOne";
 
    // Bind to "localhost", which is all loopback devices on the machine.
    public const string Localhost = "Localhost";
 
    // Don't use a proxy, instead bind to the first Endpoint.
    public const string Proxyless = "Proxyless";
}
 
[DebuggerDisplay("Service {Metadata.Name} State={Status?.State}")]
internal sealed class Service : CustomResource<ServiceSpec, ServiceStatus>, IKubernetesStaticMetadata
{
    [JsonConstructor]
    public Service(ServiceSpec spec) : base(spec) { }
 
    public static Service Create(string name)
    {
        var s = new Service(new ServiceSpec());
 
        s.Kind = Dcp.ServiceKind;
        s.ApiVersion = Dcp.GroupVersion.ToString();
        s.Metadata.Name = name;
        s.Metadata.NamespaceProperty = string.Empty;
 
        return s;
    }
 
    public int? AllocatedPort => Spec.Port ?? Status?.EffectivePort;
    public string? AllocatedAddress => Spec.Address ?? Status?.EffectiveAddress;
    public bool HasCompleteAddress => AllocatedPort > 0 && !string.IsNullOrEmpty(AllocatedAddress);
 
    public string? EndpointName => Metadata.Annotations?.TryGetValue(EndpointNameAnnotation, out var value) is true ? value : null;
 
    public void ApplyAddressInfoFrom(Service other)
    {
        Spec.Port = other.Spec.Port;
        Spec.Address = other.Spec.Address;
        if (Status is null)
        {
            Status = new();
        }
        if (other.Status?.EffectiveAddress is not null)
        {
            Status.EffectiveAddress = other.Status.EffectiveAddress;
        }
        if (other.Status?.EffectivePort is not null)
        {
            Status.EffectivePort = other.Status.EffectivePort;
        }
    }
 
    public static string ObjectKind => Dcp.ServiceKind;
}