//	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.Data;

namespace Spludlow
{
	public class ConsoleMenu
	{
		public static void Run(DataTable menuTable)
		{
			int group = 0;

			ShowMenu(menuTable, group);

			string line;
			while ((line = Console.In.ReadLine()) != null)
			{
				int option;
				if (Int32.TryParse(line, out option) == true)
				{
					if (option == 0)
					{
						if (group == 0)
							break;

						group = (int)ParentRow(menuTable, group)["Group"];
					}
					else
					{
						DataRow row = menuTable.Rows.Find(new object[] { group, option });
						if (row != null)
						{
							int target = (int)row["Target"];
							if (target == -1)
							{
								DateTime startTime = DateTime.Now;

								try
								{
									object[] parameters = new object[0];
									if (row.IsNull("Parameter") == false)
									{
										string argText = (string)row["Parameter"];

										if (argText.StartsWith("@") == true)
										{
											Console.Write(argText.Substring(1) + " >");
											argText = Console.ReadLine();

											if (argText == "")
											{
												Console.WriteLine("----------------");
												Console.WriteLine("! Bad Parameter !");
												continue;
											}
										}

										Type type = Spludlow.SimpleEncoding.Guess(argText);
										parameters = new object[] { Spludlow.SimpleEncoding.Decode(argText, type.Name) };
									}

									object result = Spludlow.Reflections.Invoke((string)row["Assembly"], (string)row["Type"], (string)row["Method"], parameters);

									Console.WriteLine("----------------");
									Console.WriteLine("! COMPLETED ! " + Spludlow.Text.TimeTook(startTime));

									if (result != null)
									{
										Console.WriteLine("----------------");
										Console.WriteLine(Convert.ToString(result));
									}
								}
								catch (Exception ee)
								{
									Console.WriteLine("----------------");
									Console.WriteLine("! ERROR ! " + Spludlow.Text.TimeTook(startTime));
									Console.WriteLine("----------------");
									Console.WriteLine(ee.ToString());
								}
							}
							else
							{
								group = target;
							}
						}
						else
						{
							option = -1;
						}
					}
				}

				if (option == -1)
				{
					Console.WriteLine("----------------");
					Console.WriteLine("! Bad command !");
				}

				ShowMenu(menuTable, group);
			}

			Console.WriteLine("----------------");
			Console.WriteLine("! EXIT !");
		}

		private static void ShowMenu(DataTable menuTable, int group)
		{
			string title = "Root Menu";
			if (group > 0)
				title = (string)ParentRow(menuTable, group)["Text"] + " Menu";

			Console.WriteLine("----------------");
			Console.WriteLine(title);
			Console.WriteLine("----------------");
			Console.WriteLine();

			DataView view = new DataView(menuTable);
			view.RowFilter = "Group = " + group;
			foreach (DataRowView rowView in view)
			{
				DataRow row = rowView.Row;
				Console.Write("  ");
				Console.Write((int)row["Option"]);
				Console.Write("  :  ");
				Console.Write((string)row["Text"]);
				if (row.IsNull("Parameter") == false && ((string)row["Parameter"]).StartsWith("@") == true)
				{
					Console.Write(" [");
					Console.Write(((string)row["Parameter"]).Substring(1));
					Console.Write("]");
				}
				Console.WriteLine();
				Console.WriteLine();
			}
			Console.WriteLine("  0  :  Exit");
			Console.WriteLine("----------------");
			Console.Write(">");
		}

		private static DataRow ParentRow(DataTable menuTable, int group)
		{
			DataRow[] rows = menuTable.Select("Target = " + group);
			if (rows.Length != 1)
				throw new ApplicationException("Menu Inconsisteancy");
			return rows[0];
		}
	}
}