using System.Net;
using System.Text;
using System.Text.Json;
using ErvCollector.Storage;
using ErvProtocol;

namespace ErvCollector.Http
{
    // 대시보드 서빙 + 모니터링/제어 HTTP API
    //   GET  /                → wwwroot/index.html
    //   GET  /api/latest      → 현장별 최신 상태 JSON
    //   POST /api/control     → 제어 (헤더 X-Auth-Token 필요, 토큰 설정 시)
    public sealed class ControlServer
    {
        readonly HttpListener _listener = new();
        readonly SiteHub _hub;
        readonly HistoryDb _history;
        readonly string _token;
        readonly string[] _sites;
        readonly string _webRoot;

        public event Action<string>? Log;

        public ControlServer(string prefix, string token, IEnumerable<string> sites, SiteHub hub, HistoryDb history)
        {
            _hub = hub;
            _history = history;
            _token = token ?? "";
            _sites = sites.ToArray();
            _webRoot = Path.Combine(AppContext.BaseDirectory, "wwwroot");
            _listener.Prefixes.Add(prefix.EndsWith('/') ? prefix : prefix + "/");
        }

        public void Start()
        {
            _listener.Start();
            if (string.IsNullOrEmpty(_token))
                Log?.Invoke("경고: 제어 토큰이 비어있음 → 인증 없이 제어 허용(개발용). 운영 시 Http.Token 설정 권장");
            _ = AcceptLoop();
        }

        async Task AcceptLoop()
        {
            while (_listener.IsListening)
            {
                HttpListenerContext ctx;
                try { ctx = await _listener.GetContextAsync(); }
                catch { break; }
                _ = Task.Run(() => Handle(ctx));
            }
        }

        void Handle(HttpListenerContext ctx)
        {
            try
            {
                var req = ctx.Request;
                string path = req.Url?.AbsolutePath ?? "/";

                if (req.HttpMethod == "GET" && (path == "/" || path == "/index.html"))
                    ServeFile(ctx, "index.html", "text/html; charset=utf-8");
                else if (req.HttpMethod == "GET" && path == "/api/latest")
                    Json(ctx, 200, BuildLatestJson());
                else if (req.HttpMethod == "GET" && path == "/api/history")
                    HandleHistory(ctx);
                else if (req.HttpMethod == "GET" && path == "/api/dates")
                    HandleDates(ctx);
                else if (req.HttpMethod == "POST" && path == "/api/control")
                    HandleControl(ctx);
                else if (req.HttpMethod == "GET" && path.StartsWith("/"))
                    ServeFile(ctx, path.TrimStart('/'), GuessMime(path));
                else
                    Text(ctx, 404, "not found");
            }
            catch (Exception ex)
            {
                try { Text(ctx, 500, "error: " + ex.Message); } catch { }
            }
        }

        void HandleControl(HttpListenerContext ctx)
        {
            // 인증
            if (!string.IsNullOrEmpty(_token))
            {
                var h = ctx.Request.Headers["X-Auth-Token"];
                if (h != _token) { Json(ctx, 401, "{\"ok\":false,\"error\":\"unauthorized\"}"); return; }
            }

            string body;
            using (var r = new StreamReader(ctx.Request.InputStream, Encoding.UTF8)) body = r.ReadToEnd();

            string site, action;
            byte[]? frame;
            try
            {
                using var doc = JsonDocument.Parse(body);
                var root = doc.RootElement;
                site = root.GetProperty("site").GetString() ?? "";
                action = root.GetProperty("action").GetString() ?? "";
                int V(string n, int def = 0) => root.TryGetProperty(n, out var e) ? e.GetInt32() : def;

                frame = action switch
                {
                    "power"   => CtrlFrame.Power(V("value")),
                    "runmode" => CtrlFrame.RunModeCmd(V("value")),
                    "fan"     => CtrlFrame.Fan(V("value")),
                    "submode" => CtrlFrame.SubMode(V("type"), V("value")),
                    "hood"    => CtrlFrame.Hood(V("value")),
                    "preset"  => CtrlFrame.Preset(V("value")),
                    "hyst"    => CtrlFrame.HystValue(V("preset"), V("pm25"), V("pm10"), V("voc"), V("co2")),
                    "hystthr" => CtrlFrame.HystThr(V("preset"), V("pollutant"), V("l1"), V("l2"), V("l3"), V("l4")),
                    "damper"  => CtrlFrame.Damper(V("room"), V("type"), V("value")),   // type 0=급기/1=배기 (미지정 시 0)
                    "led"     => CtrlFrame.Led(V("room"), V("value")),
                    "reset"   => CtrlFrame.Reset(V("value")),
                    "reserve" => CtrlFrame.Reserve(V("value")),   // (꺼짐)예약 0~8시간
                    "vsp"     => CtrlFrame.Vsp(V("group"), V("index"), V("sa"), V("ea")),
                    _ => null,
                };
            }
            catch (Exception ex) { Json(ctx, 400, $"{{\"ok\":false,\"error\":\"bad request: {ex.Message}\"}}"); return; }

            if (frame == null) { Json(ctx, 400, "{\"ok\":false,\"error\":\"unknown action\"}"); return; }
            if (!_sites.Contains(site)) { Json(ctx, 400, "{\"ok\":false,\"error\":\"unknown site\"}"); return; }

            bool ok = _hub.TrySend(site, frame);
            Log?.Invoke($"[{site}] 제어 {action} → {(ok ? "송신" : "실패(연결없음)")} : {HexFormat.Bytes(frame, frame.Length)}");
            Json(ctx, ok ? 200 : 503, $"{{\"ok\":{(ok ? "true" : "false")}}}");
        }

        void HandleHistory(HttpListenerContext ctx)
        {
            var q = ctx.Request.QueryString;
            string site = q["site"] ?? "";
            string dateStr = q["date"] ?? "";
            if (!_sites.Contains(site)) { Json(ctx, 400, "{\"error\":\"unknown site\"}"); return; }
            if (!DateTime.TryParse(dateStr, out var day)) day = DateTime.Now.Date;
            try { Json(ctx, 200, _history.LoadDayJson(site, day)); }
            catch (Exception ex) { Json(ctx, 500, $"{{\"error\":\"{ex.Message}\"}}"); }
        }

        void HandleDates(HttpListenerContext ctx)
        {
            string site = ctx.Request.QueryString["site"] ?? "";
            if (!_sites.Contains(site)) { Json(ctx, 400, "{\"error\":\"unknown site\"}"); return; }
            try { Json(ctx, 200, _history.LoadDatesJson(site)); }
            catch (Exception ex) { Json(ctx, 500, $"{{\"error\":\"{ex.Message}\"}}"); }
        }

        string BuildLatestJson()
        {
            var sb = new StringBuilder("{");
            for (int i = 0; i < _sites.Length; i++)
            {
                var site = _sites[i];
                if (i > 0) sb.Append(',');
                sb.Append('"').Append(site).Append("\":");
                AppendSite(sb, site);
            }
            sb.Append('}');
            return sb.ToString();
        }

        void AppendSite(StringBuilder sb, string site)
        {
            var s = _hub.GetStatus(site);
            bool online = _hub.IsOnline(site);
            if (s == null) { sb.Append($"{{\"online\":{(online ? "true" : "false")},\"g\":null,\"rooms\":[]}}"); return; }
            sb.Append("{\"online\":").Append(online ? "true" : "false").Append(",\"g\":{")
              .Append("\"power\":").Append(s.Power).Append(",\"run_mode\":").Append(s.RunMode)
              .Append(",\"auto_state\":").Append(s.AutoState).Append(",\"fan_mode\":").Append(s.FanMode)
              .Append(",\"sub_mode\":").Append(s.SubMode).Append(",\"hood\":").Append(s.Hood)
              .Append(",\"hyst_preset\":").Append(s.HystPreset).Append(",\"hyst_pm25\":").Append(s.HystPm25)
              .Append(",\"hyst_pm10\":").Append(s.HystPm10).Append(",\"hyst_voc\":").Append(s.HystVoc)
              .Append(",\"hyst_co2\":").Append(s.HystCo2).Append(",\"error_code\":").Append(s.ErrorCode)
              .Append(",\"reset\":").Append(s.Reset)
              .Append(",\"reserve_remain\":").Append(s.ReserveRemainSec).Append("},\"rooms\":[");
            for (int r = 0; r < 4; r++)
            {
                var rm = s.Rooms[r];
                if (r > 0) sb.Append(',');
                sb.Append("{\"damper_sa\":").Append(rm.DamperSa ? 1 : 0).Append(",\"damper_ea\":").Append(rm.DamperEa ? 1 : 0).Append(",\"pm25\":").Append(rm.Pm25)
                  .Append(",\"pm10\":").Append(rm.Pm10).Append(",\"voc\":").Append(rm.Voc)
                  .Append(",\"co2\":").Append(rm.Co2).Append(",\"air_quality\":").Append(rm.AirQuality)
                  .Append(",\"led_dim\":").Append(rm.LedDim).Append(",\"load_score\":").Append(rm.LoadScore)
                  .Append(",\"final_volume\":").Append(rm.FinalVolume)
                  .Append(",\"temp\":").Append(rm.Temp).Append(",\"humi\":").Append(rm.Humi).Append('}');
            }
            sb.Append("],\"vsp\":[");
            for (int i = 0; i < 9; i++)
            {
                var v = s.Vsp[i];
                if (i > 0) sb.Append(',');
                sb.Append("{\"sa\":").Append(v.Sa).Append(",\"ea\":").Append(v.Ea).Append('}');
            }
            sb.Append("],\"hyst\":[");
            for (int i = 0; i < 3; i++)
            {
                var h = s.HystTable[i];
                if (i > 0) sb.Append(',');
                sb.Append("{\"pm25\":").Append(h.Pm25).Append(",\"pm10\":").Append(h.Pm10)
                  .Append(",\"voc\":").Append(h.Voc).Append(",\"co2\":").Append(h.Co2).Append('}');
            }
            // 모드별 오염단계 임계표 (프리셋 ECO/NORMAL/TURBO × 오염원 × L1~L4)
            sb.Append("],\"thr\":[");
            for (int i = 0; i < 3; i++)
            {
                var th = s.ThrTable[i];
                if (i > 0) sb.Append(',');
                sb.Append("{\"co2\":[").Append(string.Join(",", th.Co2))
                  .Append("],\"pm25\":[").Append(string.Join(",", th.Pm25))
                  .Append("],\"pm10\":[").Append(string.Join(",", th.Pm10))
                  .Append("],\"voc\":[").Append(string.Join(",", th.Voc)).Append("]}");
            }
            sb.Append("]}");
        }

        void ServeFile(HttpListenerContext ctx, string rel, string mime)
        {
            var full = Path.GetFullPath(Path.Combine(_webRoot, rel));
            if (!full.StartsWith(_webRoot) || !File.Exists(full)) { Text(ctx, 404, "not found"); return; }
            var bytes = File.ReadAllBytes(full);
            ctx.Response.ContentType = mime;
            ctx.Response.StatusCode = 200;
            ctx.Response.OutputStream.Write(bytes);
            ctx.Response.Close();
        }

        static string GuessMime(string p) =>
            p.EndsWith(".html") ? "text/html; charset=utf-8" :
            p.EndsWith(".js")   ? "application/javascript" :
            p.EndsWith(".css")  ? "text/css" : "application/octet-stream";

        static void Json(HttpListenerContext ctx, int code, string json) => Write(ctx, code, json, "application/json");
        static void Text(HttpListenerContext ctx, int code, string txt) => Write(ctx, code, txt, "text/plain; charset=utf-8");

        static void Write(HttpListenerContext ctx, int code, string body, string mime)
        {
            var bytes = Encoding.UTF8.GetBytes(body);
            ctx.Response.StatusCode = code;
            ctx.Response.ContentType = mime;
            ctx.Response.OutputStream.Write(bytes);
            ctx.Response.Close();
        }
    }

    static class HexFormat
    {
        public static string Bytes(byte[] d, int n)
        {
            var sb = new StringBuilder(n * 3);
            for (int i = 0; i < n; i++) { if (i > 0) sb.Append(' '); sb.Append(d[i].ToString("X2")); }
            return sb.ToString();
        }
    }
}