namespace System.Windows.Forms
{
    public class TextBox : Control
    {
        private System.Windows.Controls.TextBox textBox;
        private System.Windows.Controls.PasswordBox passwordBox;
        protected new System.Windows.Controls.ContentControl control { get; }

        private bool IsPassword => control.Content == passwordBox;

        private System.Windows.Controls.Control InnerControl => control.Content as System.Windows.Controls.Control;

        internal bool IsFocused => InnerControl.IsFocused;

        internal bool IsMouseOver => InnerControl.IsMouseOver;

        public override string Text
        {
            get
            {
                if (IsPassword)
                    return passwordBox.Password;
                else
                {
                    if (Multiline)
                        return textBox.Text;
                    return textBox.Text.Replace(((char)1).ToString(), "\r\n");
                }
            }
            set
            {
                if (IsPassword)
                    passwordBox.Password = value;
                else
                {
                    if (Multiline)
                        textBox.Text = value;
                    else
                        textBox.Text = string.IsNullOrEmpty(value) ? value : value.Replace("\r\n", ((char)1).ToString());
                }
            }
        }

        public int MaxLength
        {
            get => textBox.MaxLength;
            set => textBox.MaxLength = value;
        }

        private bool multiline;
        public bool Multiline 
        {
            get => multiline;
            set
            {
                multiline = value;
                WordWrap = value ? WordWrap : false;
                textBox.AcceptsReturn = value || AcceptsReturn;
            }
        }

        public bool AcceptsReturn
        {
            get => textBox.AcceptsReturn; 
            set => textBox.AcceptsReturn = value;
        }

        public bool AcceptsTab
        {
            get => textBox.AcceptsTab;
            set => textBox.AcceptsTab = value;
        }

        public bool ReadOnly
        {
            get => textBox.IsReadOnly;
            set => textBox.IsReadOnly = value;
        }

        public bool Modified { get; set; }

        public int SelectionStart
        {
            get => textBox.SelectionStart;
            set => textBox.SelectionStart = value;
        }

        public int SelectionLength
        {
            get => textBox.SelectionLength;
            set => textBox.SelectionLength = value;
        }

        public string SelectedText
        {
            get => textBox.SelectedText;
            set => textBox.SelectedText = value;
        }

        private bool wordWrap;
        public bool WordWrap
        {
            get => wordWrap;
            set
            {
                wordWrap = value;
                if (Multiline)
                    textBox.TextWrapping = value ? TextWrapping.Wrap : TextWrapping.NoWrap;
            }
        }

        private ScrollBars scrollBars;
        public ScrollBars ScrollBars
        {
            get => scrollBars;
            set
            {
                scrollBars = value;
                if (value == ScrollBars.None)
                {
                    textBox.HorizontalScrollBarVisibility = Windows.Controls.ScrollBarVisibility.Hidden;
                    textBox.VerticalScrollBarVisibility = Windows.Controls.ScrollBarVisibility.Hidden;
                }
                else if (value == ScrollBars.Horizontal)
                {
                    textBox.HorizontalScrollBarVisibility = Windows.Controls.ScrollBarVisibility.Visible;
                    textBox.VerticalScrollBarVisibility = Windows.Controls.ScrollBarVisibility.Hidden;
                }
                else if (value == ScrollBars.Vertical)
                {
                    textBox.HorizontalScrollBarVisibility = Windows.Controls.ScrollBarVisibility.Hidden;
                    textBox.VerticalScrollBarVisibility = Windows.Controls.ScrollBarVisibility.Visible;
                }
                else if (value == ScrollBars.Both)
                {
                    textBox.HorizontalScrollBarVisibility = Windows.Controls.ScrollBarVisibility.Visible;
                    textBox.VerticalScrollBarVisibility = Windows.Controls.ScrollBarVisibility.Visible;
                }
            }
        }

        private char passwordChar;
        public char PasswordChar
        {
            get => passwordChar;
            set
            {
                passwordChar = value;
                control.Content = value != 0 ? passwordBox : textBox;
            }
        }

        public bool UseSystemPasswordChar
        {
            get => PasswordChar == '*';
            set => PasswordChar = value ? '*' : '\0';
        }

        private HorizontalAlignment textAlign;
        public HorizontalAlignment TextAlign
        {
            get => textAlign;
            set
            {
                textAlign = value;
                textBox.HorizontalContentAlignment = value switch
                {
                    HorizontalAlignment.Center => Windows.HorizontalAlignment.Center,
                    HorizontalAlignment.Right => Windows.HorizontalAlignment.Right,
                    _ => Windows.HorizontalAlignment.Left
                };
            }
        }

        public override BorderStyle BorderStyle 
        {
            get => textBox.BorderThickness.Left == 0 ? BorderStyle.None : BorderStyle.FixedSingle;
            set
            {
                textBox.BorderThickness = passwordBox.BorderThickness = new Thickness(value == BorderStyle.None ? 0 : 1);
                if (value == BorderStyle.None)
                {
                    textBox.Padding = passwordBox.Padding = new Thickness(0);
                }
            }
        }

        public bool HideSelection
        {
            get => !textBox.IsInactiveSelectionHighlightEnabled;
            set => textBox.IsInactiveSelectionHighlightEnabled = !value;
        }

        private CharacterCasing characterCasing;
        public CharacterCasing CharacterCasing
        {
            get => characterCasing;
            set
            {
                characterCasing = value;
                textBox.CharacterCasing = value switch
                {
                    CharacterCasing.Upper => Windows.Controls.CharacterCasing.Upper,
                    CharacterCasing.Lower => Windows.Controls.CharacterCasing.Lower,
                    _ => Windows.Controls.CharacterCasing.Normal
                };
            }
        }

        public bool CanUndo => textBox.CanUndo;

        public string[] Lines
        {
            get => Text.Split(new string[] { Environment.NewLine }, StringSplitOptions.None);
            set => Text = String.Join(Environment.NewLine, value);
        }

        public override Padding Padding 
        {
            get => Helper.ThicknessToPadding(textBox.Padding);
            set => textBox.Padding = passwordBox.Padding = Helper.PaddingToThickness(value);
        }

        public override Drawing.Size PreferredSize => new Drawing.Size(Width, (int)((BorderStyle == BorderStyle.None ? 16 : 20) * DpiScale));

        protected override void SetControlHeight(int value)
        {
            if (multiline)
                base.SetControlHeight(value);
        }

        public int GetCharIndexFromPosition(System.Drawing.Point pos) =>
            textBox.GetCharacterIndexFromPoint(new System.Windows.Point(pos.X / DpiScale, pos.Y / DpiScale), true);

        public void Select(int start, int length) => textBox.Select(start, length);

        public void SelectAll() => textBox.SelectAll();

        public void Copy() => textBox.Copy();

        public void Cut() => textBox.Cut();

        public void Paste() => textBox.Paste();

        public void Undo() => textBox.Undo();

        public new void Focus()
        {
            if (control.IsLoaded)
                InnerControl.Focus();
            else
                control.Dispatcher.InvokeAsync(() => InnerControl.Focus(), Threading.DispatcherPriority.Loaded);
        }

        public TextBox()
        {
            textBox = new() { Tag = this };
            passwordBox = new() { Tag = this };
            textBox.Padding = passwordBox.Padding = new Thickness(0, 1, 0, 2);

            control = new();
            SetControl(control);
            control.Content = textBox;
            Width = 100;
            Height = 22;
            WordWrap = true;

            textBox.TextChanged += (sender, e) =>
            {
                Modified = true;
                OnTextChanged(e);
            };
            // WPF TextBox has issues with regular DragOver & Drop events
            control.PreviewDragOver += (sender, e) =>
            {
                OnDragOver(Helper.GetDragEventArgs(control, e));
                e.Handled = true;
            };
            control.PreviewDrop += (sender, e) =>
            {
                OnDragDrop(Helper.GetDragEventArgs(control, e));
                e.Handled = true;
            };
            // this control needs its own logic of DoubleClick (see Control.cs for explanation)
            control.MouseDoubleClick += (sender, e) => OnDoubleClick(e);
            // SWF consistency: some text boxes handle Enter&Esc in their KeyPress handler
            control.PreviewKeyDown += (sender, e) =>
            {
                if (e.Key == Input.Key.Enter || e.Key == Input.Key.Escape)
                {
                    var args = new KeyPressEventArgs(e.Key == Input.Key.Enter ? (char)13 : (char)27);
                    OnKeyPress(args);
                    e.Handled = args.Handled;
                }
            };
        }
    }
}