using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO.Ports;
using System.IO;
using System.Threading;

namespace RadioBroadcaster.Server
{
    static class SerialManager
    {
        static bool _continue;
        static SerialPort _serialPort;
        /// <summary>
        /// Data is sent at a predetermined rate. As the arduino can only process one piece of data at a time,
        /// we add each command to the buffer; which will be sent as soon as possible
        /// </summary>
        static string[] SendBuffer = new string[0];
        static int SendBufferSize = 64;
        static int currentBufferPos = 0; // The current line to send
        static int lastBufferAddition = -1; // The last position added to within the buffer
        private static System.Timers.Timer CarouselTimer;
        private static System.Timers.Timer SendBufferTimer;

        const string FileName = "PortSelection.txt";
        public static void Init()
        {
            Thread readThread = new Thread(Read);
            SendBuffer = new string[SendBufferSize]; 
            _serialPort = new SerialPort();
            _serialPort.BaudRate = 9600;
            SendBufferTimer = new System.Timers.Timer(610); // We tick at the same rate as the arduino. There may be clashing 
            // Due to timing differences, but so long as we always take longer than it takes to process data, we
            // we will ensure data arrives correctly. Make sure this is delayed while serial gets set-up.
            // Currently, as the carousel works on a 2 second timer, we can send at least 3 packets of data before 
            // a new one is routinely added.
            SendBufferTimer.Elapsed += SendBufferTimer_Elapsed;
            CarouselTimer = new System.Timers.Timer(2000);
            CarouselTimer.Elapsed += CarouselTimer_Elapsed;
            string[] AvailablePorts;
            string s = System.Reflection.Assembly.GetExecutingAssembly().Location;
            try
            {
                AvailablePorts = File.ReadAllText(s.Remove(s.LastIndexOf("\\")) + "\\" + FileName).Replace(Environment.NewLine, "\n").Split('\n');
            }
            catch
            {
                AvailablePorts = SerialPort.GetPortNames();
                File.WriteAllLines(s.Remove(s.LastIndexOf("\\")) + "\\" + FileName, AvailablePorts);
            }
            bool[] removedPorts = new bool[AvailablePorts.Length];
            for (int i = 0; i < AvailablePorts.Length; i++)
            {
                if (AvailablePorts[i].StartsWith("//"))
                {
                    removedPorts[i] = true;
                }
                else
                {
                    removedPorts[i] = false;
                }
            }
            _serialPort.PortName = AvailablePorts[Array.IndexOf(removedPorts,false)];
            try
            {
                _serialPort.Open();
                LogManager.Write("Serial port opened successfully");
            }
            catch
            {
                LogManager.Write("Couldn't access " + _serialPort.PortName + ", loading first port as a default");
                _serialPort.PortName = SerialPort.GetPortNames()[0];
                _serialPort.Open();
            }
            _continue = true;
            readThread.Start();
            SendBufferTimer.Start();
            Console.Write("Ready to write data to the port");
        }
        static bool SendBufferLock = false;
        static int waitTicks = 0;
        /// <summary>
        /// Sends data, if there is any, at every timer tick. Allows a queue of commands
        /// to be executed without clashing. 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private static void SendBufferTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            if(waitTicks > 5)
            {
                if (!SendBufferLock)
                {
                    SendBufferLock = true;
                    if (SendBuffer[currentBufferPos] != null)
                    {
                        string s = SendBuffer[currentBufferPos].Trim();
                        if (s == "" || s == null)
                        {

                        }
                        else
                        {
                            LogManager.WriteSerial("\tOut: " + s);
                            _serialPort.WriteLine(s);
                            SendBuffer[currentBufferPos] = "";
                            if (currentBufferPos >= SendBufferSize - 1)
                            {
                                currentBufferPos = 0;
                            }
                            else
                            {
                                currentBufferPos++;
                            }
                        }
                    }
                    SendBufferLock = false;
                }
            }
            else
            {
                waitTicks++;
            }
            
        }

        static string currentIteration = "";
        public static void SetRDSStationName(string setStationName, bool useCarousel = false, bool stopCarousel = false)
        {
            if (useCarousel)
            {
                LogManager.Write("Starting carousel...");
                CarouselTimer.Stop();
                if(setStationName.Last() != ' ') // Make sure there is a space between the first and last char
                {
                    setStationName = setStationName + " ";
                }
                currentIteration = setStationName;
                
                CarouselTimer.Start();
            }
            else
            {
                if (setStationName.Length < 9)
                {
                    Write("RDSName" + setStationName);
                }
                else
                {
                    Write("RDSName" + setStationName.Remove(8));
                }
            }
            if (stopCarousel)
            {

            }

        }
        public static void SetRDSStationData(string data)
        {
            Write("RDSData" + data);
        }
        public static void SetFrequency(string Frequency)
        {
            string temp = Frequency.ToLower();
            if (temp.Contains("mhz"))
            {
                temp = temp.Remove(temp.IndexOf("mhz"));
            }
            temp = temp.Replace(".", "");
            temp = temp.Trim();
            Write("StatFreq" + temp);
        }
        public static void SetTXPower(string power)
        {
            string s = power.Trim();
            Write("TXpower" + s);
        }

        private static void CarouselTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            char one = currentIteration[0];
            currentIteration = currentIteration.Remove(0, 1) + one;
            SetRDSStationName(currentIteration);
        }
        /// <summary>
        /// Adds the data to the write queue
        /// </summary>
        /// <param name="message"></param>
        static void Write(string message)
        {
            if(message.Trim() != "")
            {
                lastBufferAddition = lastBufferAddition + 1;
                if (lastBufferAddition > SendBufferSize -1)
                {
                    lastBufferAddition = 0;
                }
                SendBuffer[lastBufferAddition] = message;
            }
        }
        static void Read()
        {
            while (_continue)
            {
                try
                {
                    string message = _serialPort.ReadLine();
                    LogManager.WriteSerial(message);
                    if (message == "beat")
                    {
                        // We recieved a heartbeat
                        
                    }
                    else if (message.Trim() != "")
                    {
                        Console.WriteLine(message);
                        switch (message.Remove(message.IndexOf(":")))
                        {
                            case "Freq":
                                break;
                            case "TXPower":
                                break;
                            case "InLevel":
                                break;
                            case "ASQ":
                                break;
                            default:
                                break;
                        }
                    }
                }
                catch (TimeoutException) { }
            }
        }
        public static bool carouselContinue = false;
        public static void RDSStationNameCarousel(string StationName, SerialPort serialPort)
        {
            string originalName = StationName;
            string currentIteration = originalName;
            carouselContinue = true;
            while (carouselContinue)
            {
                char one = currentIteration[0];
                currentIteration = currentIteration.Remove(0, 1) + one;
                if (currentIteration.Length < 9)
                {
                    serialPort.WriteLine("RDSName" + currentIteration);
                }
                else
                {
                    serialPort.WriteLine("RDSName" + currentIteration.Remove(8));
                }
                Thread.Sleep(1000);
            }
        }
    }
}