using System;
using System.Collections.Generic;

using BizHawk.Emulation.Common;

namespace BizHawk.Emulation.Cores.Atari.Atari2600
{
	public partial class Atari2600 : IDebuggable
	{
		public IDictionary<string, RegisterValue> GetCpuFlagsAndRegisters()
		{
			return new Dictionary<string, RegisterValue>
			{
				["A"] = Cpu.A,
				["X"] = Cpu.X,
				["Y"] = Cpu.Y,
				["S"] = Cpu.S,
				["PC"] = Cpu.PC,

				["Flag C"] = Cpu.FlagC,
				["Flag Z"] = Cpu.FlagZ,
				["Flag I"] = Cpu.FlagI,
				["Flag D"] = Cpu.FlagD,

				["Flag B"] = Cpu.FlagB,
				["Flag V"] = Cpu.FlagV,
				["Flag N"] = Cpu.FlagN,
				["Flag T"] = Cpu.FlagT
			};
		}

		public void SetCpuRegister(string register, int value)
		{
			switch (register)
			{
				default:
					throw new InvalidOperationException();
				case "A":
					Cpu.A = (byte)value;
					break;
				case "X":
					Cpu.X = (byte)value;
					break;
				case "Y":
					Cpu.Y = (byte)value;
					break;
				case "S":
					Cpu.S = (byte)value;
					break;
				case "PC":
					Cpu.PC = (ushort)value;
					break;
				case "Flag I":
					Cpu.FlagI = value > 0;
					break;
			}
		}

		public IMemoryCallbackSystem MemoryCallbacks { get; } = new MemoryCallbackSystem(new[] { "System Bus" });

		public bool CanStep(StepType type)
		{
			return false;
		}

		[FeatureNotImplemented]
		public void Step(StepType type)
		{
			throw new NotImplementedException();
		}


		public int TotalExecutedCycles => Cpu.TotalExecutedCycles;

		private int JSRCount = 0;

		private const byte JSR = 0x20;
		private const byte RTS = 0x60;

		// the opsize table is used to quickly grab the instruction sizes (in bytes)
		private readonly byte[] opsize =
		{
		/*0x00*/	1,2,0,0,0,2,2,0,1,2,1,0,0,3,3,0,
		/*0x10*/	2,2,0,0,0,2,2,0,1,3,0,0,0,3,3,0,
		/*0x20*/	3,2,0,0,2,2,2,0,1,2,1,0,3,3,3,0,
		/*0x30*/	2,2,0,0,0,2,2,0,1,3,0,0,0,3,3,0,
		/*0x40*/	1,2,0,0,0,2,2,0,1,2,1,0,3,3,3,0,
		/*0x50*/	2,2,0,0,0,2,2,0,1,3,0,0,0,3,3,0,
		/*0x60*/	1,2,0,0,0,2,2,0,1,2,1,0,3,3,3,0,
		/*0x70*/	2,2,0,0,0,2,2,0,1,3,0,0,0,3,3,0,
		/*0x80*/	0,2,0,0,2,2,2,0,1,0,1,0,3,3,3,0,
		/*0x90*/	2,2,0,0,2,2,2,0,1,3,1,0,0,3,0,0,
		/*0xA0*/	2,2,2,0,2,2,2,0,1,2,1,0,3,3,3,0,
		/*0xB0*/	2,2,0,0,2,2,2,0,1,3,1,0,3,3,3,0,
		/*0xC0*/	2,2,0,0,2,2,2,0,1,2,1,0,3,3,3,0,
		/*0xD0*/	2,2,0,0,0,2,2,0,1,3,0,0,0,3,3,0,
		/*0xE0*/	2,2,0,0,2,2,2,0,1,2,1,0,3,3,3,0,
		/*0xF0*/	2,2,0,0,0,2,2,0,1,3,0,0,0,3,3,0
		};


		/*the optype table is a quick way to grab the addressing mode for any 6502 opcode
		//
		//  0 = Implied\Accumulator\Immediate\Branch\NULL
		//  1 = (Indirect,X)
		//  2 = Zero Page
		//  3 = Absolute
		//  4 = (Indirect),Y
		//  5 = Zero Page,X
		//  6 = Absolute,Y
		//  7 = Absolute,X
		//  8 = Zero Page,Y
		*/
		private readonly byte[] optype =
		{
		/*0x00*/	0,1,0,0,0,2,2,0,0,0,0,0,0,3,3,0,
		/*0x10*/	0,4,0,0,0,5,5,0,0,6,0,0,0,7,7,0,
		/*0x20*/	0,1,0,0,2,2,2,0,0,0,0,0,3,3,3,0,
		/*0x30*/	0,4,0,0,0,5,5,0,0,6,0,0,0,7,7,0,
		/*0x40*/	0,1,0,0,0,2,2,0,0,0,0,0,0,3,3,0,
		/*0x50*/	0,4,0,0,0,5,5,0,0,6,0,0,0,7,7,0,
		/*0x60*/	0,1,0,0,0,2,2,0,0,0,0,0,3,3,3,0,
		/*0x70*/	0,4,0,0,0,5,5,0,0,6,0,0,0,7,7,0,
		/*0x80*/	0,1,0,0,2,2,2,0,0,0,0,0,3,3,3,0,
		/*0x90*/	0,4,0,0,5,5,8,0,0,6,0,0,0,7,0,0,
		/*0xA0*/	0,1,0,0,2,2,2,0,0,0,0,0,3,3,3,0,
		/*0xB0*/	0,4,0,0,5,5,8,0,0,6,0,0,7,7,6,0,
		/*0xC0*/	0,1,0,0,2,2,2,0,0,0,0,0,3,3,3,0,
		/*0xD0*/	0,4,0,0,0,5,5,0,0,6,0,0,0,7,7,0,
		/*0xE0*/	0,1,0,0,2,2,2,0,0,0,0,0,3,3,3,0,
		/*0xF0*/	0,4,0,0,0,5,5,0,0,6,0,0,0,7,7,0
		};

		#region Currently Unused Debug hooks

		private int CurrentScanLine
		{
			get { return _tia.LineCount; }
		}

		private bool IsVsync
		{
			get { return _tia.IsVSync; }
		}

		private bool IsVBlank
		{
			get { return _tia.IsVBlank; }
		}

		#endregion
	}
}