using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text.RegularExpressions;

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);
            }
        }


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

        [KeywordMethod(Token.PrintL)]
        private void PrintL()
        {
            console.PrintSingleLine(Expr().ToString());
        }


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


        [KeywordMethod(Token.PrintButton)]
        private void PrintButton()
        {
            console.PrintButton(Expr().ToString(), 0);
        }

        private static readonly Regex FormRegex = new Regex("{(.*?)}");

        [KeywordMethod(Token.PrintFormL)]
        private void PrintFormL()
        {
            string rawString = Expr().ToString();

            var evaluator = new MatchEvaluator(match => Variables[match.Groups[1].Value].ToString());

            console.PrintSingleLine(FormRegex.Replace(rawString, evaluator));
        }

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

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

        [KeywordMethod(Token.If)]
        private void If()
        {
            bool result = Expr().Real == 1;

            AssertToken(Token.Then, false);
            GetNextToken();

            if (result)
            {
                int i = ifcounter;
                while (true)
                {
                    if (lastToken == Token.If)
                    {
                        i++;
                    }
                    else if (lastToken == Token.Else)
                    {
                        if (i == ifcounter)
                        {
                            GetNextToken();
                            return;
                        }
                    }
                    else if (lastToken == Token.EndIf)
                    {
                        if (i == ifcounter)
                        {
                            GetNextToken();
                            return;
                        }
                        i--;
                    }
                    GetNextToken();
                }
            }
        }

        [KeywordMethod(Token.Else)]
        private void Else()
        {
            int i = ifcounter;
            while (true)
            {
                if (lastToken == Token.If)
                {
                    i++;
                }
                else if (lastToken == Token.EndIf)
                {
                    if (i == ifcounter)
                    {
                        GetNextToken();
                        return;
                    }
                    i--;
                }
                GetNextToken();
            }
        }

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

        }

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

        [KeywordMethod(Token.Let)]
        private void Let()
        {
            if (lastToken != Token.Equal)
            {
                AssertToken(Token.Identifer, false);
                AssertToken(Token.Equal);
            }

            string id = lex.Identifer;

            GetNextToken();

            Variables[id] = Expr();
        }

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

            AssertToken(Token.Equal);

            GetNextToken();
            Value v = Expr();

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

            AssertToken(Token.To, false);

            GetNextToken();
            v = Expr();

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

                    if (lex.Identifer == var)
                    {
                        loops.Remove(var);
                        AssertToken(Token.NewLine);
                        break;
                    }
                }
            }
        }

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

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

            string var = lex.Identifer;

            AssertToken(Token.Comma);

            GetNextToken();
            var arg2 = Expr();

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

            AssertToken(Token.NewLine, false);
        }
    }
}