using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Reflection;
using NTERA.Core;
using NTERA.Core.Interop;
using NTERA.Engine.Compiler;

namespace NTERA.Engine.Runtime.Base
{
	public static class Keywords
	{
		private static Random random = new Random();

		[AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]
		private class KeywordAttribute : Attribute
		{
			public string Name { get; }

			public bool ImplicitString { get; }
			public bool ImplicitFormatted { get; }

			public KeywordAttribute(string name, bool implicitString = false, bool implicitFormatted = false)
			{
				if (implicitFormatted && !implicitString)
					throw new ArgumentException("Keyword cannot support formatting if it does not use implicit strings");

				Name = name;

				ImplicitString = implicitString;
				ImplicitFormatted = implicitFormatted;
			}
		}

		public static Dictionary<string, Action<EraRuntime, StackFrame, ExecutionNode>> StaticKeywords { get; } = _getKeywords();

		private static Dictionary<string, Action<EraRuntime, StackFrame, ExecutionNode>> _getKeywords()
		{
			var output = new Dictionary<string, Action<EraRuntime, StackFrame, ExecutionNode>>();

			foreach (MethodInfo method in typeof(Keywords).GetMethods(BindingFlags.Public | BindingFlags.Static))
			{
				var keywords = method.GetCustomAttributes<KeywordAttribute>();

				foreach (KeywordAttribute keyword in keywords)
					output[keyword.Name] = (Action<EraRuntime, StackFrame, ExecutionNode>)Delegate.CreateDelegate(typeof(Action<EraRuntime, StackFrame, ExecutionNode>), method);
			}

			return output;
		}

		[Keyword("RESTART")]
		public static void Restart(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			runtime.Initialize(runtime.Console);

			runtime.Call(runtime.ExecutionProvider.DefinedProcedures.First(x => x.Name == "SYSTEM_TITLE"));
		}

		[Keyword("INPUT")]
		public static void Input(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			runtime.InputResetEvent.WaitOne();

			context.Variables["RESULT"][0] = runtime.LastInputValue;
		}

		[Keyword("INPUTS")]
		public static void InputString(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			runtime.InputResetEvent.WaitOne();

			context.Variables["RESULTS"][0] = runtime.LastInputValue;
		}

		[Keyword("LOADGLOBAL")]
		public static void LoadGlobal(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{

		}

		[Keyword("SAVEGLOBAL")]
		public static void SaveGlobal(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{

		}

		[Keyword("TIMES")]
		public static void Times(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			Variable variable = runtime.ComputeVariable(context, node[0], out var index);

			variable[index] *= runtime.ComputeExpression(context, node[1]);
		}

		[Keyword("VARSIZE")]
		public static void Varsize(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			Variable variable = runtime.ComputeVariable(context, node[0], out var index);

			int maxArrayDimensions = variable.Max(x => x.Key.Length);
			var resultVariable = runtime.GlobalVariables["RESULT"];

			for (int i = 0; i < maxArrayDimensions; i++)
			{
				resultVariable[i] = variable.Where(x => x.Key.Length > i).Max(x => x.Key[i]) + 1;
			}
		}

		[Keyword("ALIGNMENT")]
		public static void Alignment(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			string alignmentType = runtime.ComputeExpression(context, node[0]).String;

			if (!Enum.TryParse(alignmentType, true, out DisplayLineAlignment alignmentValue))
				throw new EraRuntimeException($"Unable to parse alignment type: '{alignmentType}'");

			runtime.Console.Alignment = alignmentValue;
		}

		private static Color ParseColorArguments(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			if (node.SubNodes.Length == 1)
			{
				uint argb = (uint)runtime.ComputeExpression(context, node[0]).Real;
				argb |= 0xFF000000U;

				return Color.FromArgb((int)argb);
			}
			else if (node.SubNodes.Length == 3)
			{
				int r = (int)runtime.ComputeExpression(context, node[0]).Real;
				int g = (int)runtime.ComputeExpression(context, node[1]).Real;
				int b = (int)runtime.ComputeExpression(context, node[2]).Real;

				return Color.FromArgb(r, g, b);
			}
			else
				throw new EraRuntimeException("Unable to parse color");
		}

		[Keyword("SETCOLOR")]
		public static void SetColor(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			runtime.Console.SetStringStyle(ParseColorArguments(runtime, context, node));
		}

		[Keyword("RESETCOLOR")]
		public static void ResetColor(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			runtime.Console.ResetStyle();
		}

		[Keyword("SETBGCOLOR")]
		public static void SetBgColor(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{

			runtime.Console.SetBgColor(ParseColorArguments(runtime, context, node));
		}

		[Keyword("RESETBGCOLOR")]
		public static void ResetBgColor(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			runtime.Console.SetBgColor(Color.Black);
		}

		[Keyword("CLEARLINE")]
		public static void ClearLine(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			runtime.Console.ClearLine((int)runtime.ComputeExpression(context, node.Single()).Real);
		}

		[Keyword("REDRAW")]
		public static void Redraw(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			runtime.Console.SetRedraw((long)runtime.ComputeExpression(context, node.Single()).Real);
		}

		[Keyword("DRAWLINE")]
		public static void DrawLine(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			runtime.Console.PrintBar();
		}

		[Keyword("CUSTOMDRAWLINE", true)]
		public static void CustomDrawLine(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			if (node.SubNodes.Length == 1)
			{
				var value = runtime.ComputeExpression(context, node.Single());
				runtime.Console.printCustomBar(value.ToString());
			}
			else {
				throw new ArgumentException("Missing argument to CUSTOMDRAWLINE");
			}

		}

		[Keyword("DRAWLINEFORM", true, true)]
		public static void DrawLineForm(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			var value = runtime.ComputeExpression(context, node.Single());

			runtime.Console.printCustomBar(value.ToString());
		}

		[Keyword("PRINT_IMG")]
		public static void PrintImg(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			var value = runtime.ComputeExpression(context, node.Single());

			runtime.Console.PrintImg(value.ToString());
		}

		[Keyword("PRINTBUTTON")]
		public static void PrintButton(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			var textValue = runtime.ComputeExpression(context, node[0]);
			var intValue = runtime.ComputeExpression(context, node[1]);

			runtime.Console.PrintButton(textValue.String, (long)intValue.Real);
		}

		[Keyword("HTML_PRINT")]
		public static void PrintHtml(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			var htmlValue = runtime.ComputeExpression(context, node.Single());

			runtime.Console.PrintHtml(htmlValue.String, false);
		}

		private static PrintFlags ParsePrintFlags(string opts)
		{
			return new PrintFlags {
				NewLine = opts.Contains("L") || opts.Contains("W"),
				Wait = opts.Contains("W"),
				ForceKana = opts.Contains("K"),
				NoColor = opts.Contains("D")
			};
		}

		[Keyword("PRINTFORM", true, true)]
		[Keyword("PRINTFORMK", true, true)]
		[Keyword("PRINTFORMD", true, true)]
		[Keyword("PRINTFORML", true, true)]
		[Keyword("PRINTFORMW", true, true)]
		[Keyword("PRINTFORMK", true, true)]
		[Keyword("PRINTFORMKL", true, true)]
		[Keyword("PRINTFORMKW", true, true)]
		[Keyword("PRINTFORMD", true, true)]
		[Keyword("PRINTFORMDL", true, true)]
		[Keyword("PRINTFORMDW", true, true)]
		public static void PrintForm(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			var flags = ParsePrintFlags(node["name"].Substring(9));
			var value = runtime.ComputeExpression(context, node.Single());
			runtime.Console.Write(value.ToString(), flags);
			if (flags.Wait) {
				runtime.InputResetEvent.WaitOne();
			}
		}

		[Keyword("PRINT", true, false)]
		[Keyword("PRINTL", true, false)]
		[Keyword("PRINTW", true, false)]
		[Keyword("PRINTK", true, false)]
		[Keyword("PRINTKL", true, false)]
		[Keyword("PRINTKW", true, false)]
		[Keyword("PRINTD", true, false)]
		[Keyword("PRINTDL", true, false)]
		[Keyword("PRINTDW", true, false)]
		public static void Print(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			var flags = ParsePrintFlags(node["name"].Substring(5));
			var value = runtime.ComputeExpression(context, node.Single());
			runtime.Console.Write(value.ToString(), flags);
			if (flags.Wait) {
				runtime.InputResetEvent.WaitOne();
			}
		}

		private class PrintDataOptions
		{
			public PrintFlags Flags = new PrintFlags();
			public int Count = 0;
			public ExecutionNode ChosenNode;
		}
		static private PrintDataOptions CurrentPrintDataOptions;

		[Keyword("PRINTDATA")]
		[Keyword("PRINTDATAL")]
		[Keyword("PRINTDATAW")]
		[Keyword("PRINTDATAK")]
		[Keyword("PRINTDATAKL")]
		[Keyword("PRINTDATAKW")]
		[Keyword("PRINTDATAD")]
		[Keyword("PRINTDATADL")]
		[Keyword("PRINTDATADW")]
		public static void PrintData(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			/* This function doesn't do anything itself, but lets you specify a bunch of
			   DATAFORMs followed by a ENDDATA and it picks one at random and prints that.
			 */
			CurrentPrintDataOptions = new PrintDataOptions();
			CurrentPrintDataOptions.Flags = ParsePrintFlags(node["name"].Substring(9));
		}

		[Keyword("DATA", true, true)]
		[Keyword("DATAFORM", true, true)]
		public static void DataForm(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			CurrentPrintDataOptions.Count++;
			if (random.Next(0, CurrentPrintDataOptions.Count) == 0)
				CurrentPrintDataOptions.ChosenNode = node.Single();
		}

		[Keyword("ENDDATA")]
		public static void EndData(EraRuntime runtime, StackFrame context, ExecutionNode node)
		{
			if (CurrentPrintDataOptions.ChosenNode == null) {
				throw new ArgumentException("No DATAFORM found before ENDDATA");
			}
			var value = runtime.ComputeExpression(context, CurrentPrintDataOptions.ChosenNode);
			var flags = CurrentPrintDataOptions.Flags;
			runtime.Console.Write(value.ToString(), flags);
			if (flags.Wait) {
				runtime.InputResetEvent.WaitOne();
			}
		}
	}
}