using System;
using System.Configuration;
using System.Net.Http;
using System.Text;
using System.Threading;
using Newtonsoft.Json;
using RevitHttpControl.Models;

namespace RevitHttpControl.Services
{
    /// <summary>
    /// 批处理任务结果回调服务
    /// </summary>
    public static class TaskCallbackService
    {
        private const string DefaultEndpointPath = "/api/v1/plugin-callbacks/task-result";
        private const string DefaultSoftwareId = "revit";
        private static readonly TimeSpan[] RetryDelays =
        {
            TimeSpan.FromSeconds(1),
            TimeSpan.FromSeconds(3),
            TimeSpan.FromSeconds(5)
        };

        public static void NotifyTaskResult(TaskStatusResponse task)
        {
            if (task == null || (task.Status != TaskStatus.Completed && task.Status != TaskStatus.Failed))
            {
                return;
            }

            var baseAddress = ConfigurationManager.AppSettings["PluginCallbackBaseUrl"];
            var token = ConfigurationManager.AppSettings["PluginCallbackToken"];
            var softwareId = ConfigurationManager.AppSettings["PluginSoftwareId"];

            if (string.IsNullOrWhiteSpace(baseAddress) || string.IsNullOrWhiteSpace(token))
            {
                return;
            }

            if (string.IsNullOrWhiteSpace(softwareId))
            {
                softwareId = DefaultSoftwareId;
            }

            var callbackUrl = $"{baseAddress.TrimEnd('/')}{DefaultEndpointPath}";
            var payload = new TaskResultCallbackRequest
            {
                ExecutionId = task.ExecutionId,
                SoftwareId = softwareId,
                Status = task.Status == TaskStatus.Completed ? "success" : "failed",
                ErrorMessage = task.Status == TaskStatus.Failed
                    ? (string.IsNullOrWhiteSpace(task.ErrorMessage) ? "UNKNOWN_ERROR" : task.ErrorMessage)
                    : null,
                Result = task.Status == TaskStatus.Completed ? (task.Result ?? new { }) : new { },
                FinishedAt = (task.CompletedAt ?? DateTime.UtcNow).ToString("o"),
                Token = token
            };

            SendWithRetry(callbackUrl, payload);
        }

        private static void SendWithRetry(string callbackUrl, TaskResultCallbackRequest payload)
        {
            var json = JsonConvert.SerializeObject(payload);
            using (var httpClient = new HttpClient())
            {
                if (Post(httpClient, callbackUrl, json))
                {
                    return;
                }

                foreach (var delay in RetryDelays)
                {
                    Thread.Sleep(delay);
                    if (Post(httpClient, callbackUrl, json))
                    {
                        return;
                    }
                }
            }
        }

        private static bool Post(HttpClient httpClient, string callbackUrl, string json)
        {
            try
            {
                using (var content = new StringContent(json, Encoding.UTF8, "application/json"))
                using (var response = httpClient.PostAsync(callbackUrl, content).GetAwaiter().GetResult())
                {
                    return response.IsSuccessStatusCode;
                }
            }
            catch
            {
                return false;
            }
        }
    }
}