using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Timers;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;

namespace ProjetTheAlone.ViewModel
{
    public class TextDefilant : BasePropriete
    {
        public Timer aTimer;

        public TextBlock textContainer;
        char[] textAfficherBuffer;
        public string TextAfficher { set { fillBuffer(value); } get { return new string(textAfficherBuffer); } }


        public TextDefilant(TextBlock tb, string text, int timeMs)
        {
            this.textContainer = tb;
            TextAfficher = text;
            SetTimer(timeMs);
            aTimer.Enabled = true;
        }

        private void SetTimer(int timeMs)
        {
            // Create a timer with a two second interval.
            aTimer = new System.Timers.Timer(timeMs);
            // Hook up the Elapsed event for the timer. 
            aTimer.Elapsed += OnTimedEvent;
            aTimer.AutoReset = true;
        }

        private void OnTimedEvent(Object source, ElapsedEventArgs e)
        {
            textAfficherBuffer = RotateChar(textAfficherBuffer);
            OnPropertyChanged("TextAfficher");
        }


        private void fillBuffer(string text)
        {
            char[] charToTrim = { '\r', '\n' };
            text = text.Trim(charToTrim);
            double WTB = textContainer.ActualWidth; //With of textBlock container
            double WT = MeasureString(text).Width; //With of Text
            double WS = MeasureString(" ").Width; //With of whiteSpace
            int nbSp = (int)Math.Ceiling((WTB - WT) / WS); //number of space need to fill textBlock
            char[] spText = new string(' ', nbSp).ToCharArray();
            this.textAfficherBuffer = new char[nbSp + text.ToCharArray().Length];
            Array.Copy(text.ToCharArray(), 0, this.textAfficherBuffer, 0, text.Length);
            Array.Copy(spText, 0, this.textAfficherBuffer, text.Length, spText.Length);
        }
        private char[] RotateChar(char[] txt)
        {
            char[] oldTxt = txt;
            char[] newTxt = new char[oldTxt.Length];
            char fc = txt[0];
            for (int i = oldTxt.Length - 1; i > 0; i--)
                newTxt[((i+1)%oldTxt.Length)] = oldTxt[i];
            newTxt[1] = fc;
            return newTxt;
        }

        //https://stackoverflow.com/questions/9264398/how-to-calculate-wpf-textblock-width-for-its-known-font-size-and-characters
        private Size MeasureString(string candidate)
        {
            var formattedText = new FormattedText(
                candidate,
                CultureInfo.CurrentCulture,
                FlowDirection.LeftToRight,
                new Typeface(this.textContainer.FontFamily, this.textContainer.FontStyle, this.textContainer.FontWeight, this.textContainer.FontStretch),
                this.textContainer.FontSize,
                Brushes.Black,
                new NumberSubstitution(), (TextFormattingMode)1);

            return new Size(formattedText.WidthIncludingTrailingWhitespace, formattedText.Height);
        }
    }
}