using System;
using System.Text.RegularExpressions;
using IoTClient.Clients.PLC;
using IoTClient.Common.Enums;

namespace StandardScene.Signal.Plc
{
    /// <summary>西门子 S7 长连接。地址兼容 Hsl 的 DB1.0 与 IoTClient 的 DB1.DBB0。</summary>
    public sealed class SiemensPlcSession : IDisposable
    {
        private static readonly Regex BareDbByte = new Regex(@"^DB(\d+)\.(\d+)$", RegexOptions.IgnoreCase | RegexOptions.Compiled);

        private readonly SiemensVersion _version;
        private readonly string _ip;
        private readonly int _port;
        private readonly byte _slot;
        private SiemensClient _client;
        private readonly object _sync = new object();

        public SiemensPlcSession(string version, string ip, int port, int slot)
        {
            _version = ParseVersion(version);
            _ip = ip ?? "";
            _port = port > 0 ? port : 102;
            _slot = (byte)Math.Max(0, slot);
        }

        public bool Connected
        {
            get
            {
                lock (_sync) return _client?.Connected == true;
            }
        }

        public bool EnsureOpen()
        {
            lock (_sync)
            {
                try
                {
                    if (_client == null)
                        _client = new SiemensClient(_version, _ip, _port, _slot);
                    if (_client.Connected)
                        return true;
                    var r = _client.Open();
                    return r != null && r.IsSucceed;
                }
                catch
                {
                    return false;
                }
            }
        }

        public bool TryReadByte(string address, out byte value)
        {
            value = 0;
            if (string.IsNullOrWhiteSpace(address) || !EnsureOpen())
                return false;
            try
            {
                var r = _client.ReadByte(NormalizeByteAddress(address));
                if (r == null || !r.IsSucceed)
                    return false;
                value = r.Value;
                return true;
            }
            catch
            {
                return false;
            }
        }

        public bool TryWriteByte(string address, byte value)
        {
            if (string.IsNullOrWhiteSpace(address) || !EnsureOpen())
                return false;
            try
            {
                var r = _client.Write(NormalizeByteAddress(address), value);
                return r != null && r.IsSucceed;
            }
            catch
            {
                return false;
            }
        }

        public bool TryReadBool(string address, out bool value)
        {
            value = false;
            if (string.IsNullOrWhiteSpace(address) || !EnsureOpen())
                return false;
            try
            {
                var r = _client.ReadBoolean(address.Trim());
                if (r == null || !r.IsSucceed)
                    return false;
                value = r.Value;
                return true;
            }
            catch
            {
                return false;
            }
        }

        public bool TryWriteBool(string address, bool value)
        {
            if (string.IsNullOrWhiteSpace(address) || !EnsureOpen())
                return false;
            try
            {
                var r = _client.Write(address.Trim(), value);
                return r != null && r.IsSucceed;
            }
            catch
            {
                return false;
            }
        }

        public void Close()
        {
            lock (_sync)
            {
                try { _client?.Close(); }
                catch { }
                _client = null;
            }
        }

        public void Dispose() => Close();

        internal static string NormalizeByteAddress(string address)
        {
            var addr = address.Trim();
            var m = BareDbByte.Match(addr);
            return m.Success ? $"DB{m.Groups[1].Value}.DBB{m.Groups[2].Value}" : addr;
        }

        internal static SiemensVersion ParseVersion(string version)
        {
            if (string.IsNullOrWhiteSpace(version))
                return SiemensVersion.S7_1500;
            return Enum.TryParse(version.Replace("-", "_"), true, out SiemensVersion parsed)
                ? parsed
                : SiemensVersion.S7_1500;
        }
    }
}