using Common.Notify;
using Model.Entity.Inspection;
using Service.Interface;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Text;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;

namespace Service.Implement
{
    /// <summary>
    /// 钉钉群机器人通知发送器（自定义机器人 Webhook，支持加签校验）
    /// 报文：msgtype=markdown，at.atMobiles 支持 @手机号；
    /// 加签：URL 追加 timestamp(毫秒)+sign（算法见 ImWebhookSigner.DingTalkSign）
    /// </summary>
    public class DingTalkNotifier : IAlertNotifier
    {
        private readonly HttpClient _httpClient;
        private readonly ILogger<DingTalkNotifier> _logger;

        public DingTalkNotifier(HttpClient httpClient, ILogger<DingTalkNotifier> logger)
        {
            _httpClient = httpClient;
            _logger = logger;
        }

        public NotifyChannelTypeEnum ChannelType => NotifyChannelTypeEnum.DingTalk;

        public async Task<NotifyResult> SendAsync(AlertNotifyMessage message, string webhookUrl, string? secret, CancellationToken ct = default)
        {
            try
            {
                string url = webhookUrl;
                // 加签：URL 追加 timestamp 与 sign 参数
                if (!string.IsNullOrWhiteSpace(secret))
                {
                    long timestampMs = DateTimeOffset.Now.ToUnixTimeMilliseconds();
                    string sign = ImWebhookSigner.DingTalkSign(timestampMs, secret);
                    url += $"{(url.Contains('?') ? "&" : "?")}timestamp={timestampMs}&sign={sign}";
                }

                // markdown 正文中 @ 手机号需同时出现在 atMobiles 与正文里才会真正提醒
                var text = new StringBuilder();
                text.AppendLine($"### {message.Title}");
                text.AppendLine(message.Content);
                foreach (var mobile in message.AtMobiles)
                {
                    text.Append($"@{mobile} ");
                }

                var body = new Dictionary<string, object>
                {
                    ["msgtype"] = "markdown",
                    ["markdown"] = new Dictionary<string, object>
                    {
                        ["title"] = message.Title,
                        ["text"] = text.ToString()
                    },
                    ["at"] = new Dictionary<string, object>
                    {
                        ["atMobiles"] = message.AtMobiles,
                        ["isAtAll"] = false
                    }
                };

                string json = JsonSerializer.Serialize(body);
                _logger.LogInformation("钉钉推送 atMobiles=[{At}]", string.Join(",", message.AtMobiles));
                using var content = new StringContent(json, Encoding.UTF8, "application/json");
                using var response = await _httpClient.PostAsync(url, content, ct);
                string respText = await response.Content.ReadAsStringAsync(ct);

                if (!response.IsSuccessStatusCode)
                {
                    return NotifyResult.Fail($"HTTP {(int)response.StatusCode}: {Truncate(respText)}");
                }

                // 钉钉返回 {"errcode":0,"errmsg":"ok"}
                using var doc = JsonDocument.Parse(respText);
                bool ok = doc.RootElement.TryGetProperty("errcode", out var errcode) && errcode.GetInt32() == 0;
                return ok ? NotifyResult.Ok() : NotifyResult.Fail(Truncate(respText));
            }
            catch (Exception ex)
            {
                return NotifyResult.Fail($"钉钉推送异常: {NotifyError.Describe(ex)}");
            }
        }

        private static string Truncate(string s, int max = 200) =>
            string.IsNullOrEmpty(s) || s.Length <= max ? s : s.Substring(0, max) + "...";
    }
}