//	Spludlow Software
//	Copyright © Samuel P. Ludlow 2020 All Rights Reserved
//	Distributed under the terms of the GNU General Public License version 3
//	Distributed WITHOUT ANY WARRANTY; without implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE
//	https://www.spludlow.co.uk/LICENCE.TXT
//	The Spludlow logo is a registered trademark of Samuel P. Ludlow and may not be used without permission
//	v1.14

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

using System.Runtime.InteropServices;

namespace Spludlow.Io
{
	/// <summary>
	/// Wrapper for "InpOut32 and InpOutx64" so you can access the Parallel Port
	/// 
	/// http://www.highrez.co.uk/Downloads/InpOut32/default.htm
	/// InpOutBinaries_1501.zip
	/// Make sure you Run Win32\InstallDriver.exe as admininstrator (even on x64)
	/// "inpoutx64.dll" needs to be in the bin directory (set to copy to output directory) it is not a .net DLL so you can't reference it normally
	/// Look up the Parallel Port (LPT) address in device manager. My PCI card is 0xD050
	/// 
	/// Not tested Inp32() yet. Not sure about char ? Just cast to byte?
	/// </summary>
	public class ParallelPort
	{
		[DllImport("inpoutx64.dll", EntryPoint = "IsInpOutDriverOpen")]
		private static extern UInt32 IsInpOutDriverOpen();

		[DllImport("inpoutx64.dll", EntryPoint = "Out32")]
		private static extern void Out32(int PortAddress, byte Data);

		[DllImport("inpoutx64.dll", EntryPoint = "Inp32")]
		private static extern char Inp32(int PortAddress);

		private int[] _GrayCodes = { 0x00, 0x01, 0x03, 0x02, 0x06, 0x07, 0x05, 0x04 };

		/// <summary>
		/// Write 12 bits (8 data & 4 control) 
		/// </summary>
		public static void Write(int address, int data)
		{
			int dataPart = data & 0x0FF;
			int controlPart = (data & 0xF00) >> 8;

			controlPart ^= 0xFB;

			Out32(address, (byte)dataPart);
			Out32(address + 2, (byte)controlPart);
		}

		/// <summary>
		/// Write 12 bits as 3 nibbles
		/// Makes sense when you have a 3 X 7 Segment Hex displays hooked up 
		/// </summary>
		public static void Write(int address, int nib0, int nib1, int nib2)
		{
			int data = (nib0 & 0xF) | ((nib1 & 0xF) << 4) | ((nib2 & 0xF) << 8);
			Write(address, data);
		}

		/// <summary>
		/// Write 8 bits to the data lines
		/// </summary>
		public static void WriteData(int address, int data)
		{
			int dataPart = data & 0x0FF;
			Out32(address, (byte)dataPart);
		}

		/// <summary>
		/// Write 4 bits to the control lines
		/// bits are inverted except "nInitialize" so the 4 bits behave just like the data bits
		/// </summary>
		public static void WriteControl(int address, int data)
		{
			int controlPart = data;
			controlPart ^= 0xFB;
			Out32(address + 2, (byte)controlPart);
		}


		/// <summary>
		/// Simple test Method
		/// 
		/// Add DLL to "Applications.txt" with:
		/// Spludlow.Io.ParallelPort	C:\Program Files\SpludlowV1\Spludlow.Io.ParallelPort		Lib
		/// 
		/// configure "Spludlow-Service.txt" with:
		/// Method	ShowTime		Spludlow.Io.ParallelPort		Spludlow.Io.ParallelPort	ShowTime	D050	500
		/// </summary>
		public static void ShowTime(string hexAddress, int miliseconds)
		{
			AskStop = false;

			int address = Int32.Parse(hexAddress, System.Globalization.NumberStyles.AllowHexSpecifier);

			int[] nibs = new int[3];

			while (AskStop == false)
			{
				string message = DateTime.Now.ToString("0000yyyyMMdd0000HHmmss");

				for (int index = 0; index < message.Length; ++index)
				{
					for (int n = 0; n < 3; ++n)
					{
						int offset = index + n;
						if (offset >= message.Length)
							offset = n;

						nibs[n] = Int32.Parse(message.Substring(offset, 1));
					}

					Spludlow.Io.ParallelPort.Write(address, nibs[0], nibs[1], nibs[2]);

					System.Threading.Thread.Sleep(miliseconds);
				}
			}
		}

		private static bool AskStop;
		public static void Stop()
		{
			AskStop = true;
		}

	}
}