using System;
using System.Collections.ObjectModel;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;

namespace Muchinfo.WPF.Controls.CaptchaSpace
{

    public class CaptchaControl : ItemsControl
    {
        static CaptchaControl()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(CaptchaControl), new FrameworkPropertyMetadata(typeof(CaptchaControl)));
        }


        public string QuantityCharacters
        {
            get { return (string)GetValue(QuantityCharactersProperty); }
            set { SetValue(QuantityCharactersProperty, value); }
        }

        // Using a DependencyProperty as the backing store for QuantityCharacters.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty QuantityCharactersProperty =
            DependencyProperty.Register("QuantityCharacters", typeof(string), typeof(CaptchaControl), new PropertyMetadata("", OnQuantityCharactersChanged));



        public Color BackgroundColorStart
        {
            get { return (Color)GetValue(BackgroundColorStartProperty); }
            set { SetValue(BackgroundColorStartProperty, value); }
        }

        // Using a DependencyProperty as the backing store for BackgroundColorStart.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty BackgroundColorStartProperty =
            DependencyProperty.Register("BackgroundColorStart", typeof(Color), typeof(CaptchaControl), new PropertyMetadata(Colors.Coral, OnColorStartChanged));



        public Color BackgroundColorEnd
        {
            get { return (Color)GetValue(BackgroundColorEndProperty); }
            set { SetValue(BackgroundColorEndProperty, value); }
        }

        // Using a DependencyProperty as the backing store for BackgroundColorEnd.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty BackgroundColorEndProperty =
            DependencyProperty.Register("BackgroundColorEnd", typeof(Color), typeof(CaptchaControl), new PropertyMetadata(Colors.YellowGreen, OnColorEndChanged));




        public Color ForegroundColorStart
        {
            get { return (Color)GetValue(ForegroundColorStartProperty); }
            set { SetValue(ForegroundColorStartProperty, value); }
        }

        // Using a DependencyProperty as the backing store for ForegroundColorStart.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty ForegroundColorStartProperty =
            DependencyProperty.Register("ForegroundColorStart", typeof(Color), typeof(CaptchaControl), new PropertyMetadata(Colors.Turquoise, OnForeColorStartChanged));



        public Color ForegroundColorEnd
        {
            get { return (Color)GetValue(ForegroundColorEndProperty); }
            set { SetValue(ForegroundColorEndProperty, value); }
        }

        // Using a DependencyProperty as the backing store for ForegroundColorEnd.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty ForegroundColorEndProperty =
            DependencyProperty.Register("ForegroundColorEnd", typeof(Color), typeof(CaptchaControl), new PropertyMetadata(Colors.Lavender, OnForeColorEndChanged));



        public int SpaceBetweenLetters
        {
            get { return (int)GetValue(SpaceBetweenLettersProperty); }
            set { SetValue(SpaceBetweenLettersProperty, value); }
        }

        // Using a DependencyProperty as the backing store for SpaceBetweenLetters.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty SpaceBetweenLettersProperty =
            DependencyProperty.Register("SpaceBetweenLetters", typeof(int), typeof(CaptchaControl), new PropertyMetadata(10, OnSpaceBetweenLettersChanged));



        public bool IsUniqueForegroundColor
        {
            get { return (bool)GetValue(IsUniqueForegroundColorProperty); }
            set { SetValue(IsUniqueForegroundColorProperty, value); }
        }

        // Using a DependencyProperty as the backing store for IsUniqueForegroundColor.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty IsUniqueForegroundColorProperty =
            DependencyProperty.Register("IsUniqueForegroundColor", typeof(bool), typeof(CaptchaControl), new PropertyMetadata(true, OnIsUniqueForegroundColorChanged));


        public bool IsUniqueBackgroundColor
        {
            get { return (bool)GetValue(IsUniqueBackgroundColorProperty); }
            set { SetValue(IsUniqueBackgroundColorProperty, value); }
        }

        // Using a DependencyProperty as the backing store for IsUniqueBackgroundColor.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty IsUniqueBackgroundColorProperty =
            DependencyProperty.Register("IsUniqueBackgroundColor", typeof(bool), typeof(CaptchaControl), new PropertyMetadata(true, OnIsUniqueBackgroundColorChanged));

        public string CaptchaText
        {
            get { return (string)GetValue(CaptchaTextProperty); }
            set { SetValue(CaptchaTextProperty, value); }
        }

        // Using a DependencyProperty as the backing store for CaptchaText.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty CaptchaTextProperty =
            DependencyProperty.Register("CaptchaText", typeof(string), typeof(CaptchaControl), new PropertyMetadata("", OnCaptchaTextChanged));


        #region Global Variables

        private readonly Random random;
        private readonly Color color = new Color();
        private static readonly char[] CharArray = "ABCDEFGHIJKLMNOPQRSTUVWXYZ123467890".ToCharArray();
        #endregion
        private ObservableCollection<Captcha> captchaLetters = new ObservableCollection<Captcha>();

        public ObservableCollection<Captcha> CaptchaLetters
        {
            get { return captchaLetters; }
            set { captchaLetters = value; }
        }


        public CaptchaControl()
        {
            random = new Random();
        }

        private static void OnCaptchaTextChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            CaptchaControl captchacontrol = d as CaptchaControl;
            captchacontrol.SetBackgroundGradient();
            captchacontrol.SetForegroundGradient();
            captchacontrol.SetBackgroundGradient();
        }



        private static void OnIsUniqueBackgroundColorChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            CaptchaControl captchacontrol = d as CaptchaControl;
            captchacontrol.SetBackgroundGradient();
        }

        private static void OnSpaceBetweenLettersChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {

            CaptchaControl captchacontrol = d as CaptchaControl;


            //foreach (var captcha in captchacontrol.CaptchaLetters)
            //{
            //    captcha.SpaceBetweenLetters = captchacontrol.SpaceBetweenLetters;
            //}
        }

        private static void OnIsUniqueForegroundColorChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {

            CaptchaControl captcha = d as CaptchaControl;

            captcha.SetForegroundGradient();
        }

        private static void OnForeColorEndChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            CaptchaControl captcha = d as CaptchaControl;
            captcha.SetForegroundGradient();
        }

        private static void OnForeColorStartChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            CaptchaControl captcha = d as CaptchaControl;
            captcha.SetForegroundGradient();
        }

        private static void OnQuantityCharactersChanged(DependencyObject d, DependencyPropertyChangedEventArgs args)
        {
            //CaptchaControl captcha = d as CaptchaControl;
            //var quantity = 8;
            //if (int.TryParse(captcha.QuantityCharacters, out quantity))
            //{
            //    captcha.InitializeCaptcha(quantity);
            //}
            //else
            //{
            //    throw new Exception("You have to set QuantityCharacter property");
            //}
        }

        private static void OnColorStartChanged(DependencyObject d, DependencyPropertyChangedEventArgs args)
        {
            CaptchaControl captcha = d as CaptchaControl;
            captcha.SetBackgroundGradient();
        }

        private static void OnColorEndChanged(DependencyObject d, DependencyPropertyChangedEventArgs args)
        {
            CaptchaControl captcha = d as CaptchaControl;
            captcha.SetBackgroundGradient();

        }

        private void InitializeCaptcha(int quantityCharacters)
        {
            CaptchaLetters = new ObservableCollection<Captcha>();
            var captcha = new char[quantityCharacters];

            for (var x = 0; x < captcha.Length; x++)
            {
                captcha[x] = CharArray[random.Next(CharArray.Length)];

                var c = new Captcha
                {
                    Letter = captcha[x].ToString(),
                    FontSize = (int)this.FontSize,
                    SpaceBetweenLetters = this.SpaceBetweenLetters
                };
                SetTransformGroup(c);
                CaptchaLetters.Add(c);
            }

            var builder = new StringBuilder();
            foreach (var letter in CaptchaLetters)
            {
                builder.Append(letter.Letter);
            }
            CaptchaText = builder.ToString();
            this.ItemsSource = CaptchaLetters;
        }

        public override void OnApplyTemplate()
        {
            var quantity = 8;
            if (int.TryParse(QuantityCharacters, out quantity))
            {
                InitializeCaptcha(quantity);
            }
            else
            {
                throw new Exception("You have to set QuantityCharacter property");
            }
            base.OnApplyTemplate();

        }

        protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e)
        {
            ReflushCaptchaText();
            base.OnMouseLeftButtonDown(e);
        }
        /// <summary>
        /// 刷新验证码
        /// </summary>
        public void ReflushCaptchaText()
        {
            var quantity = 8;
            if (int.TryParse(QuantityCharacters, out quantity))
            {
                InitializeCaptcha(quantity);
            }
            else
            {
                throw new Exception("You have to set QuantityCharacter property");
            }
        }

        protected override void OnMouseEnter(MouseEventArgs e)
        {
            // e.MouseDevice.SetCursor(Cursors.Hand);
            Mouse.SetCursor(Cursors.Hand);
            base.OnMouseEnter(e);
        }


        protected override void OnMouseLeave(MouseEventArgs e)
        {
            Mouse.SetCursor(Cursors.Arrow);
            base.OnMouseLeave(e);
        }

        private void SetForegroundGradient()
        {
            if (IsUniqueForegroundColor)
            {
                foreach (var captcha in CaptchaLetters)
                {
                    captcha.ForegroundGradient = this.SetForegroundGradientSameColor();
                }
            }
            else
            {
                foreach (var captcha in CaptchaLetters)
                {
                    captcha.ForegroundGradient = this.SetForegroundGradientRandomColor();
                }
            }
        }

        private LinearGradientBrush SetForegroundGradientRandomColor()
        {
            var gradient = new LinearGradientBrush();
            gradient.StartPoint = new Point(0.5f, 1);
            gradient.EndPoint = new Point(0.8f, 0);
            gradient.GradientStops.Add(new GradientStop()
            {
                Color = Color.FromArgb((byte)random.Next(0, 255),
                    (byte)random.Next(0, 255),
                    (byte)random.Next(0, 255),
                    (byte)random.Next(0, 255)),
                Offset = 3
            });
            gradient.GradientStops.Add(new GradientStop()
            {
                Color = Color.FromArgb((byte)random.Next(0, 255),
                    (byte)random.Next(0, 255),
                    (byte)random.Next(0, 255),
                    (byte)random.Next(0, 255))
            });
            return gradient;
        }

        private LinearGradientBrush SetForegroundGradientSameColor()
        {
            var gradient = new LinearGradientBrush();
            gradient.StartPoint = new Point(0.5f, 1);
            gradient.EndPoint = new Point(0.8f, 0);
            gradient.GradientStops.Add(new GradientStop()
            {
                Color = ForegroundColorStart,
                Offset = 3
            });
            gradient.GradientStops.Add(new GradientStop()
            {
                Color = ForegroundColorEnd
            });
            return gradient;
        }

        private void SetBackgroundGradient()
        {
            var gradient = new LinearGradientBrush();
            gradient.StartPoint = new Point(0.5f, 0);
            gradient.EndPoint = new Point(0.5f, 1);

            if (IsUniqueBackgroundColor)
            {
                gradient.GradientStops.Add(new GradientStop() { Color = BackgroundColorStart, Offset = 3 });
                gradient.GradientStops.Add(new GradientStop() { Color = BackgroundColorStart });
            }
            else
            {
                gradient.GradientStops.Add(new GradientStop() { Color = BackgroundColorStart, Offset = 3 });
                gradient.GradientStops.Add(new GradientStop() { Color = BackgroundColorEnd });
            }

            this.Background = gradient;
        }

        private void SetTransformGroup(Captcha captcha)
        {
            this.SetRotate(ref captcha);
            this.SetScale(ref captcha);
            this.SetSkew(ref captcha);
            this.SetTranslate(ref captcha);
            this.SetFontColor(ref captcha);
        }

        private void SetRotate(ref Captcha captcha)
        {
            captcha.Rotate.Angle = random.Next(-10, 10);
            captcha.Rotate.CenterX = random.Next(1, 3);
            captcha.Rotate.CenterY = random.Next(1, 3);
            captcha.TransformGroup.Children.Add(captcha.Rotate);
        }

        private void SetScale(ref Captcha captcha)
        {
            captcha.Scale.ScaleX = random.Next(2, 3);
            captcha.Scale.ScaleY = random.Next(1, 2);
            //captcha.Scale.CenterX = random.Next(1,5)/10.0;
            //captcha.Scale.CenterY = random.Next(1, 5)/10.0;
            captcha.TransformGroup.Children.Add(captcha.Scale);
        }

        private void SetSkew(ref Captcha captcha)
        {
            captcha.Skew.AngleX = random.Next(-10, 10);
            captcha.Skew.AngleY = random.Next(-10, 10);
            captcha.Skew.CenterX = random.Next(1, 3);
            captcha.Skew.CenterY = random.Next(1, 3);
            captcha.TransformGroup.Children.Add(captcha.Skew);
        }

        private void SetTranslate(ref Captcha captcha)
        {
            captcha.Translate.X = random.Next(2, 4);
            captcha.Translate.Y = random.Next(1, 4);
            captcha.TransformGroup.Children.Add(captcha.Translate);
        }

        private void SetFontColor(ref Captcha captcha)
        {
            captcha.FontColor = Color.FromArgb(255,
                                               0,
                                               0,
                                               (byte)random.Next(0, 20));
        }
    }
}