using System;
using Consul;
using Microsoft.AspNetCore.Builder; 
using Microsoft.Extensions.Hosting;

namespace Aurora.Core.Api
{
    public class ServiceEntity
    {
        public string IP { get; set; }
        public int Port { get; set; }
        public string ServiceName { get; set; }
        public string ConsulIP { get; set; }
        public int ConsulPort { get; set; }
    }
    public static class AppBuilderExtensions
    {
        public static IApplicationBuilder RegisterConsul(this IApplicationBuilder app, IHostApplicationLifetime lifetime, ServiceEntity serviceEntity)
        {
            var consulClient = new ConsulClient(x => x.Address = new Uri($"http://{serviceEntity.ConsulIP}:{serviceEntity.ConsulPort}"));//请求注册的 Consul 地址
            var httpCheck = new AgentServiceCheck()
            {
                DeregisterCriticalServiceAfter = TimeSpan.FromSeconds(5),//服务启动多久后注册
                Interval = TimeSpan.FromSeconds(10),//健康检查时间间隔，或者称为心跳间隔
                HTTP = $"http://{serviceEntity.IP}:{serviceEntity.Port}/api/health",//健康检查地址
                Timeout = TimeSpan.FromSeconds(5)
            };

            // Register service with consul
            var registration = new AgentServiceRegistration()
            {
                Checks = new[] { httpCheck },
                ID = Guid.NewGuid().ToString(),
                Name = serviceEntity.ServiceName,
                Address = serviceEntity.IP,
                Port = serviceEntity.Port,
                Tags = new[] { $"urlprefix-/{serviceEntity.ServiceName}" }//添加 urlprefix-/servicename 格式的 tag 标签，以便 Fabio 识别
            };

            consulClient.Agent.ServiceRegister(registration).Wait();//服务启动时注册，内部实现其实就是使用 Consul API 进行注册（HttpClient发起）
            lifetime.ApplicationStopping.Register(() =>
            {
                consulClient.Agent.ServiceDeregister(registration.ID).Wait();//服务停止时取消注册
            });

            return app;
        }
    }
}