using System.Collections.Concurrent;
using System.Net;
using Newtonsoft.Json.Linq;

namespace dy.net.service
{
    public class DyQrCodeService
    {
        private static readonly ConcurrentDictionary<string, QrSession> _sessions = new();

        private class QrSession
        {
            public CookieContainer CookieJar { get; set; } = new();
            public DateTime CreatedAt { get; set; } = DateTime.Now;
            public string? FinalCookies { get; set; }
            public string? SecUserId { get; set; }
        }

        private const string Fp = "kj5j6uhv_tvKYUFA0_qzgZ_4l9c_9Amt_DCywEfwbVFCJ";
        private const string NextUrl = "https://creator.douyin.com/content/manage";
        private const string Service = "https://creator.douyin.com";
        private const string Aid = "2906";
        private const string Ua = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36";
        private const string Referer = "https://creator.douyin.com/";

        public async Task<(string token, string qrBase64)> GetQrCodeAsync()
        {
            var jar = new CookieContainer();
            using var client = BuildClient(jar, autoRedirect: true);

            var url = $"https://sso.douyin.com/get_qrcode/?next={Uri.EscapeDataString(NextUrl)}&aid={Aid}&service={Uri.EscapeDataString(Service)}&is_vcd=1&fp={Fp}";
            var response = await client.GetStringAsync(url);
            var json = JObject.Parse(response);

            var token = json["data"]?["token"]?.ToString()
                ?? throw new Exception("获取二维码失败：响应中无 token");
            var qrBase64 = json["data"]?["qrcode"]?.ToString()
                ?? throw new Exception("获取二维码失败：响应中无图片");

            _sessions[token] = new QrSession { CookieJar = jar };
            CleanExpiredSessions();

            return (token, qrBase64);
        }

        public async Task<(int status, string? cookies, string? secUserId)> CheckStatusAsync(string token)
        {
            if (!_sessions.TryGetValue(token, out var session))
                return (-1, null, null);

            if (DateTime.Now - session.CreatedAt > TimeSpan.FromMinutes(10))
            {
                _sessions.TryRemove(token, out _);
                return (-1, null, null);
            }

            if (session.FinalCookies != null)
                return (3, session.FinalCookies, session.SecUserId);

            using var client = BuildClient(session.CookieJar, autoRedirect: false);

            var serviceParam = Uri.EscapeDataString($"{Service}/?logintype=user&loginapp=douyin&jump={NextUrl}");
            var url = $"https://sso.douyin.com/check_qrconnect/?next={Uri.EscapeDataString(NextUrl)}&token={token}&service={serviceParam}&loginapp=douyin&jump={Uri.EscapeDataString(NextUrl)}&correct_service={serviceParam}&aid={Aid}&is_vcd=1&fp={Fp}";
            var response = await client.GetStringAsync(url);
            var json = JObject.Parse(response);

            var statusStr = json["data"]?["status"]?.ToString() ?? "1";
            int.TryParse(statusStr, out int statusCode);

            if (statusCode == 3)
            {
                var redirectUrl = json["data"]?["redirect_url"]?.ToString();
                if (!string.IsNullOrEmpty(redirectUrl))
                {
                    try
                    {
                        using var followClient = BuildClient(session.CookieJar, autoRedirect: true);
                        await followClient.GetAsync(redirectUrl);
                        session.FinalCookies = ExtractCookieString(session.CookieJar);
                        session.SecUserId = await GetSecUserIdAsync(session.CookieJar);
                    }
                    catch (Exception ex)
                    {
                        Serilog.Log.Error($"跟进登录重定向失败: {ex.Message}");
                    }
                }
            }

            return (statusCode, session.FinalCookies, session.SecUserId);
        }

        public (string cookies, string secUserId) GetSessionResult(string token)
        {
            if (_sessions.TryGetValue(token, out var session))
                return (session.FinalCookies ?? "", session.SecUserId ?? "");
            return ("", "");
        }

        public void RemoveSession(string token) => _sessions.TryRemove(token, out _);

        private static HttpClient BuildClient(CookieContainer jar, bool autoRedirect)
        {
            var handler = new HttpClientHandler
            {
                CookieContainer = jar,
                AllowAutoRedirect = autoRedirect,
                UseCookies = true
            };
            var client = new HttpClient(handler);
            client.DefaultRequestHeaders.Add("User-Agent", Ua);
            client.DefaultRequestHeaders.Add("Referer", Referer);
            return client;
        }

        private static string ExtractCookieString(CookieContainer jar)
        {
            var domains = new[] { "https://www.douyin.com", "https://creator.douyin.com", "https://sso.douyin.com" };
            var all = new Dictionary<string, string>();
            foreach (var domain in domains)
            {
                foreach (Cookie c in jar.GetCookies(new Uri(domain)))
                    all[c.Name] = c.Value;
            }
            return string.Join("; ", all.Select(kv => $"{kv.Key}={kv.Value}"));
        }

        private static async Task<string?> GetSecUserIdAsync(CookieContainer jar)
        {
            try
            {
                using var client = BuildClient(jar, autoRedirect: true);
                var resp = await client.GetStringAsync("https://creator.douyin.com/web/api/userinfo/");
                var json = JObject.Parse(resp);
                return json["data"]?["sec_uid"]?.ToString()
                    ?? json["data"]?["sec_user_id"]?.ToString()
                    ?? json["sec_uid"]?.ToString();
            }
            catch (Exception ex)
            {
                Serilog.Log.Error($"获取 sec_user_id 失败: {ex.Message}");
                return null;
            }
        }

        private static void CleanExpiredSessions()
        {
            var expired = _sessions
                .Where(kv => DateTime.Now - kv.Value.CreatedAt > TimeSpan.FromMinutes(10))
                .Select(kv => kv.Key).ToList();
            foreach (var key in expired)
                _sessions.TryRemove(key, out _);
        }
    }
}