/*
 * Author: Pawel Walczak (pewusoft)
 * Date: 2015-01-12 20:50
 *
 */
using System;
using System.IO.Ports;
using System.IO;
using System.Windows.Forms;

namespace SDRSharp.SerialController
{
	/// <summary>
	/// Description of SerialPort.
	/// </summary>
	public class SerialPortCtrl
	{
		bool _enableLogging = true;
		public bool EnableLogging {
			set { this._enableLogging = value; }
			get { return this._enableLogging; }
		}
		public bool IsOpen {
			get { return _port != null && _port.IsOpen; }
		}
		
		StreamWriter logger;
		SerialPort _port;
		
		public delegate void FrequencyChangeHandler(object sender, long freq);
    	public event FrequencyChangeHandler OnFrequencyChange;
    	
    	public delegate long GetFrequencyHandler();
    	public event GetFrequencyHandler OnGetFrequency;
    	
				
    	public static string[] GetAllPorts()
		{
			try {
				return SerialPort.GetPortNames();
    		} catch (Exception e) {
    			MessageBox.Show("Cannot read port list:\n"+e.ToString(), "SerialController", MessageBoxButtons.OK, MessageBoxIcon.Error);
				return new string[0];
			}
		}
		
		public bool openPort(string portName) {
			try {
	    		if (_port != null && _port.IsOpen)
					return false;
    			
    			if (portName == null || (portName.Trim().Equals("")))
    				return false;

				_port = new SerialPort(portName, 9600, Parity.None, 8, StopBits.One);
				_port.DataReceived += new SerialDataReceivedEventHandler( Port_DataReceived );
						
				if (_port != null) {
					_port.Open();
					if (_enableLogging) {
						prepareLogger();
						log("Port " + _port.PortName + " opened");
					}
					return true;
				}
				return false;
			} catch (Exception e) {
    			MessageBox.Show("Couldn't open port "+portName+":\n"+e.ToString(), "SerialController",
    			                MessageBoxButtons.OK, MessageBoxIcon.Error);
				return false;
			}
		}
		
		public bool closePort() {
			if (_port != null) {
				if (_port.IsOpen) {
					try {
						_port.Close();
						if (_enableLogging) {
							log("Port " + _port.PortName + " closed");
							closeLogger();
						}
						return true;
					} catch (IOException) {
						return false;
					}
				} else {
					return false;
				}
			}
			return false;
		}
		
		void Port_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
			string data = "";
			while( data.IndexOf(';') < 0 ) {
				byte[] bytes = new byte[_port.BytesToRead+32];
				try {
					_port.Read(bytes, 0, _port.BytesToRead);
				}
				catch (Exception) {
					log("Error reading COM port");
					return;
				}
				data += System.Text.Encoding.UTF8.GetString(bytes);
			}
			data = data.Substring(0, data.IndexOf(';'));
			
			// TS-50 command parse
			if (data.StartsWith("IF", StringComparison.Ordinal)) {
				long freq = OnGetFrequency();
				string response = "IF";
				response += String.Format("{0:00000000000}", freq);
				response += "000000000000000000000000;";
				_port.Write(response);
			}
			if (data.StartsWith("FA", StringComparison.Ordinal)) {
				long freq;
				if (long.TryParse(data.Substring(2), out freq)) {
					log("Received on COM port: "+data);
					if (OnFrequencyChange == null) return;
					OnFrequencyChange(this, freq);
					log("Changing frequency to: "+freq.ToString("N0"));
				}
			}
        }
		
		void log(String str) {
			if (logger!=null) {
				logger.WriteLine("[" + DateTime.Now + "]: " + str.Trim());
			}
		}
		
		void prepareLogger() {
			try {
				if (logger != null) {
					logger.Close();
				}
				logger = new StreamWriter(new FileStream("serial.log",
				                                         FileMode.Append,
				                                         FileAccess.Write,
				                                         FileShare.ReadWrite,
				                                       	 1024,
				                                         FileOptions.WriteThrough));
				logger.AutoFlush = true;
			} catch (Exception) {
				logger = null;
			}
		}
		void closeLogger() {
			try {
				if (logger != null) {
					logger.Close();
				}
				logger = null;
			} catch (Exception) {
				logger = null;
			}
		}
	}
}