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>
    /// 飞书群机器人通知发送器（自定义机器人 Webhook，支持加签校验）
    /// 报文：msg_type=post 富文本，用 at 标签(user_id=open_id)真正 @ 人；加签时附 timestamp(秒)+sign（算法见 ImWebhookSigner.FeishuSign）
    /// </summary>
    public class FeishuNotifier : IAlertNotifier
    {
        private readonly HttpClient _httpClient;
        private readonly ILogger<FeishuNotifier> _logger;

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

        public NotifyChannelTypeEnum ChannelType => NotifyChannelTypeEnum.Feishu;

        public async Task<NotifyResult> SendAsync(AlertNotifyMessage message, string webhookUrl, string? secret, CancellationToken ct = default)
        {
            try
            {
                // 飞书 text 消息不支持结构化 @，必须用 post 富文本 + at 标签才能真正 @ 到人。
                // at 标签的 user_id 为飞书 open_id(ou_ 开头)；如需 @ 所有人，接收人填 "all"。
                var contentLines = new List<List<Dictionary<string, object>>>();
                foreach (var raw in (message.Content ?? string.Empty).Split('\n'))
                {
                    var line = raw.TrimEnd('\r');
                    if (line.Length == 0) continue;
                    contentLines.Add(new List<Dictionary<string, object>>
                    {
                        new Dictionary<string, object> { ["tag"] = "text", ["text"] = line }
                    });
                }
                if (message.AtMobiles.Count > 0)
                {
                    var atLine = new List<Dictionary<string, object>>
                    {
                        new Dictionary<string, object> { ["tag"] = "text", ["text"] = "关注人: " }
                    };
                    foreach (var openId in message.AtMobiles)
                    {
                        if (string.IsNullOrWhiteSpace(openId)) continue;
                        atLine.Add(new Dictionary<string, object> { ["tag"] = "at", ["user_id"] = openId.Trim() });
                    }
                    contentLines.Add(atLine);
                }

                var body = new Dictionary<string, object>
                {
                    ["msg_type"] = "post",
                    ["content"] = new Dictionary<string, object>
                    {
                        ["post"] = new Dictionary<string, object>
                        {
                            ["zh_cn"] = new Dictionary<string, object>
                            {
                                ["title"] = message.Title,
                                ["content"] = contentLines
                            }
                        }
                    }
                };

                // 加签：timestamp(秒) + sign
                if (!string.IsNullOrWhiteSpace(secret))
                {
                    long timestampSec = DateTimeOffset.Now.ToUnixTimeSeconds();
                    body["timestamp"] = timestampSec.ToString();
                    body["sign"] = ImWebhookSigner.FeishuSign(timestampSec, secret);
                }

                string json = JsonSerializer.Serialize(body);
                _logger.LogInformation("飞书推送(post富文本) @open_id=[{At}]", string.Join(",", message.AtMobiles));
                using var content = new StringContent(json, Encoding.UTF8, "application/json");
                using var response = await _httpClient.PostAsync(webhookUrl, content, ct);
                string respText = await response.Content.ReadAsStringAsync(ct);

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

                // 飞书返回 {"code":0,...}（旧版为 {"StatusCode":0,...}）
                using var doc = JsonDocument.Parse(respText);
                var root = doc.RootElement;
                bool ok = (root.TryGetProperty("code", out var code) && code.GetInt32() == 0)
                       || (root.TryGetProperty("StatusCode", out var sc) && sc.GetInt32() == 0);
                return ok ? NotifyResult.Ok() : NotifyResult.Fail(Truncate(respText));
            }
            catch (Exception ex)
            {
                return NotifyResult.Fail($"飞书推送异常: {NotifyError.Describe(ex)}");
            }
        }

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