using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Reflection;
using System.Text.RegularExpressions;
using NTERA.Core.Interop;

namespace NTERA.Interpreter
{
    public partial class Interpreter
    {
        private void GenerateKeywordDictionary()
        {
            KeywordMethods = new Dictionary<Token, Action>();

            foreach (var method in typeof(Interpreter).GetMethods(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance))
            {
                var attribute = method.GetCustomAttributes(typeof(KeywordMethodAttribute), true).FirstOrDefault() as KeywordMethodAttribute;

                if (attribute == null)
                    continue;

                KeywordMethods[attribute.Token] = () => method.Invoke(this, null);
            }
        }

        #region Printing

        [KeywordMethod(Token.Print)]
        private void Print()
        {
            console.Write(RealExpression().ToString());
        }

        [KeywordMethod(Token.PrintL)]
        private void PrintL()
        {
            console.PrintSingleLine(ParseFormat(Expression(new Lexer(Lexer.Value, LexerType.String), type: LexerType.String)));

            GetNextToken();
        }


        [KeywordMethod(Token.PrintHtml)]
        private void PrintHtml()
        {
            AssertToken(Token.Value, false);

            console.PrintHtml(ParseFormat(Expression(new Lexer(Lexer.Value, LexerType.String), type: LexerType.String)), true);

            GetNextToken();
        }


        [KeywordMethod(Token.PrintImg)]
        private void PrintImg()
        {
            console.PrintImg(RealExpression().ToString().Trim().Trim('"'));
        }


        [KeywordMethod(Token.PrintButton)]
        private void PrintButton()
        {
            string text = Lexer.Value;
            
            AssertToken(Token.Comma);
            GetNextToken();

            var value = RealExpression();

            console.PrintButton(text, (long)value.Real);
        }

        private static readonly Regex RealFormatRegex = new Regex("{(.*?)}");
        private static readonly Regex StringFormatRegex = new Regex("%(.*?)%");

        private string ParseFormat(string rawInput)
        {
            var realEvaluator = new MatchEvaluator(match => Expression(new Lexer(match.Groups[1].Value)).ToString());

            string reals = RealFormatRegex.Replace(rawInput, realEvaluator);

            return StringFormatRegex.Replace(reals, realEvaluator);
        }

        [KeywordMethod(Token.PrintForm)]
        private void PrintForm()
        {
            AssertToken(Token.Value, false);

            console.Write(ParseFormat(Lexer.Value));

            GetNextToken();
        }

        [KeywordMethod(Token.PrintFormL)]
        private void PrintFormL()
        {
            AssertToken(Token.Value, false);

            console.PrintSingleLine(ParseFormat(Lexer.Value));

            GetNextToken();
        }

        [KeywordMethod(Token.DrawLine)]
        private void DrawLine()
        {
            console.PrintBar();
        }

        [KeywordMethod(Token.DrawLineForm)]
        private void DrawLineForm()
        {
            console.printCustomBar(RealExpression().ToString().Trim());
        }

        [KeywordMethod(Token.CustomDrawLine)]
        private void CustomDrawLine()
        {
            console.printCustomBar(RealExpression().ToString().Trim());
        }

        [KeywordMethod(Token.Alignment)]
        private void Alignment()
        {
            AssertToken(Token.Value, false);

            console.Alignment = (DisplayLineAlignment)Enum.Parse(typeof(DisplayLineAlignment), Lexer.Value);

            GetNextToken();
        }

        [KeywordMethod(Token.SetColor)]
        private void SetColor()
        {
            if (TryAssertToken(Token.Identifer, false))
            {
                int argb = (int)((int)RealExpression().Real | 0xFF000000);
                Color c = Color.FromArgb(argb);

                console.SetStringStyle(c);
                return;
            }

            AssertToken(Token.Value, false);

            if (TryAssertToken(Token.Comma))
            {
                int r = (int)Lexer.Value.Real;

                AssertToken(Token.Value);

                int g = (int)Lexer.Value;

                AssertToken(Token.Comma);
                AssertToken(Token.Value);

                int b = (int)Lexer.Value;

                console.SetStringStyle(Color.FromArgb(r, g, b));

                GetNextToken();
            }
            else
            {
                int argb = (int)((int)Lexer.Value.Real | 0xFF000000);
                Color c = Color.FromArgb(argb);

                console.SetStringStyle(c);
            }
        }

        [KeywordMethod(Token.ResetColor)]
        private void ResetColor()
        {
            console.ResetStyle();

            GetNextToken();
        }

        #endregion

        #region Control

        [KeywordMethod(Token.If)]
        private void If()
        {
            bool result = RealExpression();

            //needs to be redone
        }

        [KeywordMethod(Token.Else)]
        private void Else()
        {
            //needs to be redone
        }

        [KeywordMethod(Token.EndIf)]
        private void EndIf()
        {

        }

        [KeywordMethod(Token.End)]
        private void End()
        {
            exit = true;
        }

        [KeywordMethod(Token.Let)]
        private void Let()
        {
            int arrayIndex = 0;
            bool appending = false;

            if (CurrentToken == Token.Colon)
            {
                GetNextToken();
                if (CurrentToken == Token.Value)
                    arrayIndex = (int)Lexer.Value.Real;
                else
                {
                    arrayIndex = (int)RealExpression(Lexer.Identifer).Real;
                }

                GetNextToken();
            }

            if (CurrentToken == Token.Append)
            {
                appending = true;
            }
            else
            {
                AssertToken(Token.Equal, false);
            }

            string id = Lexer.Identifer;


            var typeHint = Variables[id].Type;
            Value value;


            if (typeHint == ValueType.Real)
            {
                GetNextToken();
                value = RealExpression();
            }
            else
                value = StringExpression();


            if (appending)
                Variables[id, arrayIndex] += value;
            else
                Variables[id, arrayIndex] = value;
        }

        [KeywordMethod(Token.For)]
        private void For()
        {
            AssertToken(Token.Identifer, false);
            string var = Lexer.Identifer;

            AssertToken(Token.Equal);

            GetNextToken();
            Value v = RealExpression();

            if (Loops.ContainsKey(var))
            {
                Loops[var] = lineMarker;
            }
            else
            {
                Variables[var] = v;
                Loops.Add(var, lineMarker);
            }

            AssertToken(Token.To, false);

            GetNextToken();
            v = RealExpression();

            if (Variables[var].Operate(v, Token.More).Real == 1)
            {
                while (true)
                {
                    while (!(GetNextToken() == Token.Identifer && prevToken == Token.Next)) { }

                    if (Lexer.Identifer == var)
                    {
                        Loops.Remove(var);
                        AssertToken(Token.NewLine);
                        break;
                    }
                }
            }
        }

        [KeywordMethod(Token.Next)]
        private void Next()
        {
            AssertToken(Token.Identifer, false);
            string var = Lexer.Identifer;
            Variables[var] = Variables[var].Operate(new Value(1), Token.Plus);
            Lexer.GoTo(new Marker(Loops[var].Pointer - 1, Loops[var].Line, Loops[var].Column - 1));
        }

        [KeywordMethod(Token.Times)]
        private void Times()
        {
            AssertToken(Token.Identifer, false);

            string var = Lexer.Identifer;

            AssertToken(Token.Comma);

            GetNextToken();
            var arg2 = RealExpression();

            Variables[var] = Variables[var].Operate(arg2, Token.Asterisk);
        }

        #endregion

        #region Global

        [KeywordMethod(Token.Global)]
        void Global()
        {
            if (TryAssertToken(Token.Dim, false))
            {
                if (TryAssertToken(Token.Const))
                {
                    GetNextToken();
                }

                AssertToken(Token.Identifer, false);

                string identifier = Lexer.Identifer;

                AssertToken(Token.Equal);
                GetNextToken();

                Variables[identifier] = Lexer.Value;

                GetNextToken();
                return;
            }

            throw new Exception("Unknown global evalution");
        }

        #endregion
    }
}