using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using SDL2;

namespace Core
{
    public class Operations
    {
        public Operations(int pixBufSize) => WindowSize = pixBufSize;
        public Dictionary<string, int> Variables = new Dictionary<string, int>();
        public static int WindowSize;
        public int Accumulator = 0;
        public int StackX = 0;
        public int StackY = 0;
        public int[] Memory = new int[256];
        public string Filename;
        public int pointer = 0;
        public int[] PixBufferR = new int[WindowSize];
        public int[] PixBufferG = new int[WindowSize];
        public int[] PixBufferB = new int[WindowSize];


        private int ResolveValue(string shite)
        {
            if (shite.Any(char.IsLetter))
            {
                switch (shite)
                {
                    case "ACC":
                        return Accumulator;
                    case "RAX":
                        return StackX;
                    case "RAY":
                        return StackY;
                }
                Variables.TryGetValue(shite, out int a);
                return a;
            }
            else
            {
                int.TryParse(shite, out int a);
                return a;
            }
        }


        public void ExecuteCommand(ComponentType type, string[] args)
        {
            switch (type)
            {
                default: return;
                // Variables
                case ComponentType.NVAR:
                    string name = args[1];
                    int value = ResolveValue(args[2]);
                    Variables.Add(name, value);
                    return;
                case ComponentType.RVAR:
                    string rname = args[1];
                    Variables.Remove(rname);
                    return;
                case ComponentType.SVAR:
                    string sname = args[1];
                    int svalue = ResolveValue(args[2]);
                    Variables[sname] = svalue;
                    return;


                // Memory/stack shite
                case ComponentType.LDA:
                    Accumulator = Memory[ResolveValue(args[1])];
                    return;
                case ComponentType.STA:
                    Memory[ResolveValue(args[1])] = Accumulator;
                    return;
                case ComponentType.LDX:
                    StackX = Accumulator;
                    return;
                case ComponentType.LDY:
                    StackY = Accumulator;
                    return;
                case ComponentType.STX:
                    Accumulator = StackX;
                    return;
                case ComponentType.STY:
                    Accumulator = StackY;
                    return;
                case ComponentType.SEA:
                    Accumulator = ResolveValue(args[1]);
                    return;


                // flow control
                case ComponentType.JMP:
                    pointer = ResolveValue(args[1]) - 1;
                    return;

                // math
                case ComponentType.ADD:
                    Accumulator = StackX + StackY;
                    return;
                case ComponentType.SUB:
                    Accumulator = StackX - StackY;
                    return;
                case ComponentType.MUL:
                    Accumulator = StackX * StackY;
                    return;
                case ComponentType.DIV:
                    Accumulator = StackX / StackY;
                    return;



                // Debug commands
                case ComponentType.PRA:
                    Console.WriteLine(Accumulator);
                    return;
                case ComponentType.PRX:
                    Console.WriteLine(StackX);
                    return;
                case ComponentType.PRY:
                    Console.WriteLine(StackY);
                    return;
                case ComponentType.PRM:
                    int.TryParse(args[1], out int valB);
                    Console.WriteLine(Memory[valB]);
                    return;
                case ComponentType.HLT:
                    while (true) { }
            }
        }
        public void EquParserLoop(string equ)
        {
            string[] lines = equ.Split(new[] { "\r\n", "\r", "\n" }, StringSplitOptions.None);
            while (pointer < lines.Length) 
            {
                string[] tokens = lines[pointer].Split(new char[] { ' ', ',' }, StringSplitOptions.RemoveEmptyEntries);
                string command = tokens[0];
                if (tokens.Length == 0)
                {
                    pointer++;
                    continue;
                }

                switch (command)
                {
                    default: break;
                    case "::":
                        break;
                    // variables
                    case "NVAR":
                        ExecuteCommand(ComponentType.NVAR, tokens);
                        break;
                    case "RVAR":
                        ExecuteCommand(ComponentType.RVAR, tokens);
                        break;
                    case "SVAR":
                        ExecuteCommand(ComponentType.SVAR, tokens);
                        break;

                    // memory
                    case "LDA":
                        ExecuteCommand(ComponentType.LDA, tokens);
                        break;
                    case "STA":
                        ExecuteCommand(ComponentType.STA, tokens);
                        break;
                    case "LDX":
                        ExecuteCommand(ComponentType.LDX, tokens);
                        break;
                    case "LDY":
                        ExecuteCommand(ComponentType.LDY, tokens);
                        break;
                    case "STX":
                        ExecuteCommand(ComponentType.STX, tokens);
                        break;
                    case "STY":
                        ExecuteCommand(ComponentType.STY, tokens);
                        break;
                    case "SEA":
                        ExecuteCommand(ComponentType.SEA, tokens);
                        break;

                    // flow control
                    case "JMP":
                        ExecuteCommand(ComponentType.JMP, tokens);
                        break;

                    // math
                    case "ADD":
                        ExecuteCommand(ComponentType.ADD, tokens);
                        break;

                    // debug
                    case "PRA":
                        ExecuteCommand(ComponentType.PRA, tokens);
                        break;
                    case "PRX":
                        ExecuteCommand(ComponentType.PRX, tokens);
                        break;
                    case "PRY":
                        ExecuteCommand(ComponentType.PRY, tokens);
                        break;
                    case "PRM":
                        ExecuteCommand(ComponentType.PRM, tokens);
                        break;

                    case "HLT":
                        ExecuteCommand(ComponentType.HLT, tokens);
                        break;
                }
                pointer++;
            }

            
        }
    }
}