using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Sharp7;

namespace LibS7Adv
{
    /// <summary>
    /// Implementación de conexión PLC usando la librería Sharp7 (C#)
    /// </summary>
    public class Sharp7Connection : IPlcConnection
    {
        private S7Client _client;
        private bool _isConnected;
        private string _ipAddress = "";
        private int _rack;
        private int _slot;
        private string _lastError = "";
        private readonly Dictionary<EArea, int> _areaMapping;

        public bool IsConnected => _isConnected && _client != null && _client.Connected;
        public string Status => IsConnected ? "Conectado" : "Desconectado";
        public string LastError => _lastError;
        public ConnectionType ConnectionType => LibS7Adv.ConnectionType.Sharp7;

        public Sharp7Connection()
        {
            _client = new S7Client();
            _isConnected = false;
            _lastError = "";
            
            // Mapeo de áreas de memoria entre nuestro enum y Sharp7
            _areaMapping = new Dictionary<EArea, int>
            {
                { EArea.Input, (int)S7Area.PE },
                { EArea.Output, (int)S7Area.PA },
                { EArea.Marker, (int)S7Area.MK },
                { EArea.DataBlock, (int)S7Area.DB }
            };
        }

        public bool Connect(string ipAddress, string instanceName)
        {
            try
            {
                _ipAddress = ipAddress;
                // Para Sharp7, usamos valores por defecto para rack y slot
                _rack = 0;
                _slot = 2; // Valor típico para S7-300

                int result = _client.ConnectTo(ipAddress, _rack, _slot);
                _isConnected = result == 0;

                if (!_isConnected)
                {
                    _lastError = $"Error conectando: {result}";
                }
                else
                {
                    _lastError = "";
                }

                return _isConnected;
            }
            catch (Exception ex)
            {
                _isConnected = false;
                _lastError = ex.Message;
                return false;
            }
        }

        public void Disconnect()
        {
            try
            {
                _client?.Disconnect();
                _lastError = "";
            }
            catch (Exception ex)
            {
                _lastError = ex.Message;
            }
            finally
            {
                _isConnected = false;
            }
        }

        public bool? ReadBool(string address)
        {
            if (!IsConnected) return null;

            try
            {
                var parsed = ParseAddress(address);
                if (parsed == null) return null;

                // Para bits, necesitamos calcular el offset en bits
                int bitOffset = (parsed.Offset * 8) + parsed.Bit;
                byte[] buffer = new byte[1];

                int result = _client.ReadArea(parsed.Area, parsed.DbNumber, bitOffset, 1, (int)S7WordLength.Bit, buffer);

                if (result == 0)
                {
                    return S7.GetBitAt(buffer, 0, 0);
                }
                
                _lastError = $"Error leyendo bool: {result}";
                return null;
            }
            catch (Exception ex)
            {
                _lastError = ex.Message;
                return null;
            }
        }

        public bool WriteBool(string address, bool value)
        {
            if (!IsConnected) return false;

            try
            {
                var parsed = ParseAddress(address);
                if (parsed == null) return false;

                // Para bits, necesitamos calcular el offset en bits
                int bitOffset = (parsed.Offset * 8) + parsed.Bit;
                byte[] buffer = new byte[1];
                
                S7.SetBitAt(buffer, 0, 0, value);

                int result = _client.WriteArea(parsed.Area, parsed.DbNumber, bitOffset, 1, (int)S7WordLength.Bit, buffer);

                if (result != 0)
                {
                    _lastError = $"Error escribiendo bool: {result}";
                    return false;
                }

                _lastError = "";
                return true;
            }
            catch (Exception ex)
            {
                _lastError = ex.Message;
                return false;
            }
        }

        public bool ReadOutputBool(byte pByte, int pBit)
        {
            if (!IsConnected) return false;

            try
            {
                int bitOffset = (pByte * 8) + pBit;
                byte[] buffer = new byte[1];

                int result = _client.ReadArea((int)S7Area.PA, 0, bitOffset, 1, (int)S7WordLength.Bit, buffer);

                if (result == 0)
                {
                    return S7.GetBitAt(buffer, 0, 0);
                }
                
                _lastError = $"Error leyendo output: {result}";
                return false;
            }
            catch (Exception ex)
            {
                _lastError = ex.Message;
                return false;
            }
        }

        public void WriteInputBool(byte pByte, int pBit, bool value)
        {
            if (!IsConnected) return;

            try
            {
                int bitOffset = (pByte * 8) + pBit;
                byte[] buffer = new byte[1];
                
                S7.SetBitAt(buffer, 0, 0, value);

                int result = _client.WriteArea((int)S7Area.PE, 0, bitOffset, 1, (int)S7WordLength.Bit, buffer);

                if (result != 0)
                {
                    _lastError = $"Error escribiendo input: {result}";
                }
                else
                {
                    _lastError = "";
                }
            }
            catch (Exception ex)
            {
                _lastError = ex.Message;
            }
        }

        public string ReadNumber(string address, bool signed = false)
        {
            if (!IsConnected) return "";

            try
            {
                var parsed = ParseNumberAddress(address);
                if (parsed == null) return "";

                byte[] buffer;
                int wordLen;
                int amount = 1;

                // Determinar el tamaño del buffer y WordLen según el tipo de dato
                switch (parsed.DataType.ToUpper())
                {
                    case "B":
                    case "BYTE":
                        buffer = new byte[1];
                        wordLen = (int)S7WordLength.Byte;
                        break;
                    case "W":
                    case "WORD":
                        buffer = new byte[2];
                        wordLen = (int)S7WordLength.Word;
                        break;
                    case "DW":
                    case "DWORD":
                        buffer = new byte[4];
                        wordLen = (int)S7WordLength.DWord;
                        break;
                    case "R":
                    case "REAL":
                        buffer = new byte[4];
                        wordLen = (int)S7WordLength.Real;
                        break;
                    default:
                        return "";
                }

                int result = _client.ReadArea(parsed.Area, parsed.DbNumber, parsed.Offset, amount, wordLen, buffer);

                if (result == 0)
                {
                    return parsed.DataType.ToUpper() switch
                    {
                        "B" or "BYTE" => S7.GetByteAt(buffer, 0).ToString(),
                        "W" or "WORD" => signed ? S7.GetIntAt(buffer, 0).ToString() : S7.GetWordAt(buffer, 0).ToString(),
                        "DW" or "DWORD" => signed ? S7.GetDIntAt(buffer, 0).ToString() : S7.GetDWordAt(buffer, 0).ToString(),
                        "R" or "REAL" => S7.GetRealAt(buffer, 0).ToString(),
                        _ => ""
                    };
                }

                _lastError = $"Error leyendo número: {result}";
                return "";
            }
            catch (Exception ex)
            {
                _lastError = ex.Message;
                return "";
            }
        }

        public bool WriteNumber(string address, object value)
        {
            if (!IsConnected) return false;

            try
            {
                var parsed = ParseNumberAddress(address);
                if (parsed == null) return false;

                byte[] buffer;
                int wordLen;
                int amount = 1;

                // Convertir el valor
                double numValue = Convert.ToDouble(value);

                // Determinar el tamaño del buffer y WordLen según el tipo de dato
                switch (parsed.DataType.ToUpper())
                {
                    case "B":
                    case "BYTE":
                        buffer = new byte[1];
                        wordLen = (int)S7WordLength.Byte;
                        S7.SetByteAt(buffer, 0, (byte)numValue);
                        break;
                    case "W":
                    case "WORD":
                        buffer = new byte[2];
                        wordLen = (int)S7WordLength.Word;
                        S7.SetWordAt(buffer, 0, (ushort)numValue);
                        break;
                    case "DW":
                    case "DWORD":
                        buffer = new byte[4];
                        wordLen = (int)S7WordLength.DWord;
                        S7.SetDWordAt(buffer, 0, (uint)numValue);
                        break;
                    case "R":
                    case "REAL":
                        buffer = new byte[4];
                        wordLen = (int)S7WordLength.Real;
                        S7.SetRealAt(buffer, 0, (float)numValue);
                        break;
                    default:
                        return false;
                }

                int result = _client.WriteArea(parsed.Area, parsed.DbNumber, parsed.Offset, amount, wordLen, buffer);

                if (result != 0)
                {
                    _lastError = $"Error escribiendo número: {result}";
                    return false;
                }

                _lastError = "";
                return true;
            }
            catch (Exception ex)
            {
                _lastError = ex.Message;
                return false;
            }
        }

        // Tags no son soportados en Sharp7 (solo direccionamiento directo)
        public object? ReadTag(string tagName)
        {
            throw new NotSupportedException("Sharp7 no soporta tags simbólicos. Use direccionamiento directo como 'DB1.DBX0.0'");
        }

        public bool WriteTag(string tagName, object value)
        {
            throw new NotSupportedException("Sharp7 no soporta tags simbólicos. Use direccionamiento directo como 'DB1.DBX0.0'");
        }

        public bool? ReadTagBool(string tagName)
        {
            throw new NotSupportedException("Sharp7 no soporta tags simbólicos. Use direccionamiento directo como 'DB1.DBX0.0'");
        }

        public bool WriteTagBool(string tagName, bool value)
        {
            throw new NotSupportedException("Sharp7 no soporta tags simbólicos. Use direccionamiento directo como 'DB1.DBX0.0'");
        }

        public int? ReadTagInt16(string tagName)
        {
            throw new NotSupportedException("Sharp7 no soporta tags simbólicos. Use direccionamiento directo como 'DB1.DBW0'");
        }

        public bool WriteTagInt16(string tagName, int value)
        {
            throw new NotSupportedException("Sharp7 no soporta tags simbólicos. Use direccionamiento directo como 'DB1.DBW0'");
        }

        public int? ReadTagDInt(string tagName)
        {
            throw new NotSupportedException("Sharp7 no soporta tags simbólicos. Use direccionamiento directo como 'DB1.DBD0'");
        }

        public bool WriteTagDInt(string tagName, int value)
        {
            throw new NotSupportedException("Sharp7 no soporta tags simbólicos. Use direccionamiento directo como 'DB1.DBD0'");
        }

        public byte[]? ReadBytes(EArea area, uint offset, int length)
        {
            if (!IsConnected) return null;

            try
            {
                if (!_areaMapping.TryGetValue(area, out int s7Area))
                    return null;

                byte[] buffer = new byte[length];
                int result = _client.ReadArea(s7Area, 0, (int)offset, length, (int)S7WordLength.Byte, buffer);

                if (result == 0)
                {
                    return buffer;
                }

                _lastError = $"Error leyendo bytes: {result}";
                return null;
            }
            catch (Exception ex)
            {
                _lastError = ex.Message;
                return null;
            }
        }

        public bool WriteBytes(EArea area, uint offset, byte[] data)
        {
            if (!IsConnected) return false;

            try
            {
                if (!_areaMapping.TryGetValue(area, out int s7Area))
                    return false;

                int result = _client.WriteArea(s7Area, 0, (int)offset, data.Length, (int)S7WordLength.Byte, data);

                if (result != 0)
                {
                    _lastError = $"Error escribiendo bytes: {result}";
                    return false;
                }

                _lastError = "";
                return true;
            }
            catch (Exception ex)
            {
                _lastError = ex.Message;
                return false;
            }
        }

        private AddressParsed? ParseAddress(string address)
        {
            try
            {
                // Ejemplos: "DB1.DBX0.0", "I0.0", "Q0.1", "M0.0"
                if (address.StartsWith("DB"))
                {
                    // DB1.DBX0.0
                    var parts = address.Split('.');
                    if (parts.Length >= 3)
                    {
                        int dbNum = int.Parse(parts[0].Substring(2));
                        int offset = int.Parse(parts[1].Substring(3));
                        int bit = int.Parse(parts[2]);
                        return new AddressParsed { Area = (int)S7Area.DB, DbNumber = dbNum, Offset = offset, Bit = bit };
                    }
                }
                else if (address.StartsWith("I"))
                {
                    // I0.0
                    var parts = address.Split('.');
                    if (parts.Length >= 2)
                    {
                        int offset = int.Parse(parts[0].Substring(1));
                        int bit = int.Parse(parts[1]);
                        return new AddressParsed { Area = (int)S7Area.PE, DbNumber = 0, Offset = offset, Bit = bit };
                    }
                }
                else if (address.StartsWith("Q"))
                {
                    // Q0.0
                    var parts = address.Split('.');
                    if (parts.Length >= 2)
                    {
                        int offset = int.Parse(parts[0].Substring(1));
                        int bit = int.Parse(parts[1]);
                        return new AddressParsed { Area = (int)S7Area.PA, DbNumber = 0, Offset = offset, Bit = bit };
                    }
                }
                else if (address.StartsWith("M"))
                {
                    // M0.0
                    var parts = address.Split('.');
                    if (parts.Length >= 2)
                    {
                        int offset = int.Parse(parts[0].Substring(1));
                        int bit = int.Parse(parts[1]);
                        return new AddressParsed { Area = (int)S7Area.MK, DbNumber = 0, Offset = offset, Bit = bit };
                    }
                }

                return null;
            }
            catch
            {
                return null;
            }
        }

        private NumberAddressParsed? ParseNumberAddress(string address)
        {
            try
            {
                // Ejemplos: "DB1.DBW0", "DB1.DBD0", "DB1.DBB0", "IW0", "QW0", "MW0"
                if (address.StartsWith("DB"))
                {
                    // DB1.DBW0
                    var parts = address.Split('.');
                    if (parts.Length >= 2)
                    {
                        int dbNum = int.Parse(parts[0].Substring(2));
                        string dataTypePart = parts[1].Substring(2); // W0, D0, B0, etc.
                        string dataType = dataTypePart.Substring(0, 1); // W, D, B
                        int offset = int.Parse(dataTypePart.Substring(1));
                        return new NumberAddressParsed { Area = (int)S7Area.DB, DbNumber = dbNum, Offset = offset, DataType = dataType };
                    }
                }
                else if (address.StartsWith("IW") || address.StartsWith("IB") || address.StartsWith("ID"))
                {
                    string dataType = address.Substring(1, 1);
                    int offset = int.Parse(address.Substring(2));
                    return new NumberAddressParsed { Area = (int)S7Area.PE, DbNumber = 0, Offset = offset, DataType = dataType };
                }
                else if (address.StartsWith("QW") || address.StartsWith("QB") || address.StartsWith("QD"))
                {
                    string dataType = address.Substring(1, 1);
                    int offset = int.Parse(address.Substring(2));
                    return new NumberAddressParsed { Area = (int)S7Area.PA, DbNumber = 0, Offset = offset, DataType = dataType };
                }
                else if (address.StartsWith("MW") || address.StartsWith("MB") || address.StartsWith("MD"))
                {
                    string dataType = address.Substring(1, 1);
                    int offset = int.Parse(address.Substring(2));
                    return new NumberAddressParsed { Area = (int)S7Area.MK, DbNumber = 0, Offset = offset, DataType = dataType };
                }

                return null;
            }
            catch
            {
                return null;
            }
        }

        public void Dispose()
        {
            Disconnect();
            _client = null!;
        }

        private class AddressParsed
        {
            public int Area { get; set; }
            public int DbNumber { get; set; }
            public int Offset { get; set; }
            public int Bit { get; set; }
        }

        private class NumberAddressParsed
        {
            public int Area { get; set; }
            public int DbNumber { get; set; }
            public int Offset { get; set; }
            public required string DataType { get; set; }
        }
    }
}