using Common.Notify;
using Model.Dto.Inspection;
using System.Text;
using System.Text.Json;

namespace AlertBridge
{
    /// <summary>
    /// 跨网告警转发程序（部署在可同时访问"工控内网 IOT_API"与"外网 IM Webhook"的跳板机上）
    /// 工作方式：轮询拉取内网发件箱（GET outbox/pull）→ 按报文推送飞书/钉钉/企微 → 回写结果（POST outbox/{id}/result）
    /// 报文自包含 WebhookUrl/Secret/内容，本程序无需访问数据库，配置仅需 appsettings.json 三项
    /// </summary>
    public class Program
    {
        private static string _apiBaseUrl = "http://localhost:5287";
        private static int _pollSeconds = 5;
        private static int _batchSize = 20;

        public static async Task Main(string[] args)
        {
            LoadConfig();

            using var http = new HttpClient { Timeout = TimeSpan.FromSeconds(30) };
            using var cts = new CancellationTokenSource();
            Console.CancelKeyPress += (_, e) => { e.Cancel = true; cts.Cancel(); };

            Log($"AlertBridge 启动，API 地址: {_apiBaseUrl}，轮询间隔: {_pollSeconds}s，批量: {_batchSize}");
            Log("按 Ctrl+C 停止");

            while (!cts.IsCancellationRequested)
            {
                try
                {
                    await PollOnceAsync(http, cts.Token);
                }
                catch (OperationCanceledException)
                {
                    break;
                }
                catch (Exception ex)
                {
                    Log($"轮询异常: {ex.Message}");
                }

                try { await Task.Delay(TimeSpan.FromSeconds(_pollSeconds), cts.Token); }
                catch (TaskCanceledException) { break; }
            }
            Log("AlertBridge 已停止");
        }

        /// <summary>
        /// 单次轮询：拉取 → 逐条推送 → 回写
        /// </summary>
        private static async Task PollOnceAsync(HttpClient http, CancellationToken ct)
        {
            string pullUrl = $"{_apiBaseUrl}/api/inspection/alert-notify/outbox/pull?batch={_batchSize}";
            string pullJson = await http.GetStringAsync(pullUrl, ct);

            var pullResult = JsonSerializer.Deserialize<ResultDto<List<AlertOutboxItemDto>>>(pullJson, JsonOpts);
            if (pullResult == null || pullResult.Code != 0 || pullResult.Data == null || pullResult.Data.Count == 0)
            {
                return;
            }

            Log($"拉取到 {pullResult.Data.Count} 条待推送消息");
            foreach (var item in pullResult.Data)
            {
                bool success = false;
                string? error = null;
                try
                {
                    var payload = JsonSerializer.Deserialize<AlertOutboxPayload>(item.Payload ?? "{}", JsonOpts);
                    if (payload == null || string.IsNullOrWhiteSpace(payload.WebhookUrl))
                    {
                        error = "Payload 为空或缺少 WebhookUrl";
                    }
                    else
                    {
                        (success, error) = await SendAsync(http, payload, ct);
                    }
                }
                catch (Exception ex)
                {
                    error = NotifyError.Describe(ex);
                }

                // 回写结果
                try
                {
                    var resultBody = JsonSerializer.Serialize(new { Success = success, ResultMsg = error }, JsonOpts);
                    using var content = new StringContent(resultBody, Encoding.UTF8, "application/json");
                    await http.PostAsync($"{_apiBaseUrl}/api/inspection/alert-notify/outbox/{item.Id}/result", content, ct);
                    Log($"消息 {item.Id} 推送{(success ? "成功" : $"失败: {error}")}，结果已回写");
                }
                catch (Exception ex)
                {
                    Log($"消息 {item.Id} 结果回写失败: {ex.Message}");
                }
            }
        }

        /// <summary>
        /// 按渠道类型推送（与主站 Notifier 报文格式保持一致）
        /// </summary>
        private static async Task<(bool success, string? error)> SendAsync(HttpClient http, AlertOutboxPayload p, CancellationToken ct)
        {
            string url = p.WebhookUrl!;
            object body;

            switch (p.ChannelType)
            {
                case 1: // 飞书：post 富文本 + at 标签(user_id=open_id) 真正 @ + 可选加签（timestamp 秒 + sign）
                {
                    var contentLines = new List<List<Dictionary<string, object>>>();
                    foreach (var raw in (p.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 (p.AtMobiles is { Count: > 0 })
                    {
                        var atLine = new List<Dictionary<string, object>>
                        {
                            new Dictionary<string, object> { ["tag"] = "text", ["text"] = "关注人: " }
                        };
                        foreach (var openId in p.AtMobiles)
                        {
                            if (string.IsNullOrWhiteSpace(openId)) continue;
                            atLine.Add(new Dictionary<string, object> { ["tag"] = "at", ["user_id"] = openId.Trim() });
                        }
                        contentLines.Add(atLine);
                    }

                    var feishuBody = new Dictionary<string, object>
                    {
                        ["msg_type"] = "post",
                        ["content"] = new Dictionary<string, object>
                        {
                            ["post"] = new Dictionary<string, object>
                            {
                                ["zh_cn"] = new Dictionary<string, object>
                                {
                                    ["title"] = p.Title ?? "设备告警",
                                    ["content"] = contentLines
                                }
                            }
                        }
                    };
                    if (!string.IsNullOrWhiteSpace(p.Secret))
                    {
                        long ts = DateTimeOffset.Now.ToUnixTimeSeconds();
                        feishuBody["timestamp"] = ts.ToString();
                        feishuBody["sign"] = ImWebhookSigner.FeishuSign(ts, p.Secret);
                    }
                    body = feishuBody;
                    break;
                }
                case 2: // 钉钉：markdown + at.atMobiles + URL 加签（timestamp 毫秒 + sign）
                {
                    if (!string.IsNullOrWhiteSpace(p.Secret))
                    {
                        long ts = DateTimeOffset.Now.ToUnixTimeMilliseconds();
                        url += $"{(url.Contains('?') ? "&" : "?")}timestamp={ts}&sign={ImWebhookSigner.DingTalkSign(ts, p.Secret)}";
                    }
                    var md = new StringBuilder();
                    md.AppendLine($"### {p.Title}");
                    md.AppendLine(p.Content);
                    foreach (var m in p.AtMobiles ?? new List<string>()) md.Append($"@{m} ");

                    body = new Dictionary<string, object>
                    {
                        ["msgtype"] = "markdown",
                        ["markdown"] = new Dictionary<string, object> { ["title"] = p.Title ?? "设备告警", ["text"] = md.ToString() },
                        ["at"] = new Dictionary<string, object> { ["atMobiles"] = p.AtMobiles ?? new List<string>(), ["isAtAll"] = false }
                    };
                    break;
                }
                case 3: // 企微：text + mentioned_mobile_list（无加签）
                {
                    var text = new StringBuilder();
                    text.AppendLine(p.Title);
                    text.AppendLine(p.Content);
                    body = new Dictionary<string, object>
                    {
                        ["msgtype"] = "text",
                        ["text"] = new Dictionary<string, object>
                        {
                            ["content"] = text.ToString(),
                            ["mentioned_mobile_list"] = p.AtMobiles ?? new List<string>()
                        }
                    };
                    break;
                }
                default:
                    return (false, $"未知渠道类型: {p.ChannelType}");
            }

            string json = JsonSerializer.Serialize(body, JsonOpts);
            using var content = new StringContent(json, Encoding.UTF8, "application/json");
            using var response = await http.PostAsync(url, content, ct);
            string respText = await response.Content.ReadAsStringAsync(ct);

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

            // 飞书返回 code/StatusCode，钉钉/企微返回 errcode，0 均为成功
            using var doc = JsonDocument.Parse(respText);
            var root = doc.RootElement;
            bool ok = (root.TryGetProperty("errcode", out var ec) && ec.GetInt32() == 0)
                   || (root.TryGetProperty("code", out var c) && c.GetInt32() == 0)
                   || (root.TryGetProperty("StatusCode", out var sc) && sc.GetInt32() == 0);
            return ok ? (true, null) : (false, Truncate(respText));
        }

        /// <summary>
        /// 读取 appsettings.json（免依赖 Microsoft.Extensions.Configuration，直接 JSON 解析）
        /// </summary>
        private static void LoadConfig()
        {
            try
            {
                string path = Path.Combine(AppContext.BaseDirectory, "appsettings.json");
                if (!File.Exists(path)) return;
                using var doc = JsonDocument.Parse(File.ReadAllText(path));
                var root = doc.RootElement;
                if (root.TryGetProperty("ApiBaseUrl", out var u)) _apiBaseUrl = u.GetString() ?? _apiBaseUrl;
                if (root.TryGetProperty("PollSeconds", out var p)) _pollSeconds = p.GetInt32();
                if (root.TryGetProperty("BatchSize", out var b)) _batchSize = b.GetInt32();
            }
            catch (Exception ex)
            {
                Log($"读取配置失败，使用默认值: {ex.Message}");
            }
        }

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

        private static void Log(string msg) => Console.WriteLine($"[{DateTime.Now:yyyy-MM-dd HH:mm:ss}] {msg}");

        private static readonly JsonSerializerOptions JsonOpts = new() { PropertyNameCaseInsensitive = true };

        /// <summary>
        /// 主站统一返回结构（仅取所需字段）
        /// </summary>
        private class ResultDto<T>
        {
            public int Code { get; set; }
            public string? Msg { get; set; }
            public T? Data { get; set; }
        }
    }
}