using System;
using Xamarin.Forms;

namespace Tizen.Xamarin.Forms.Extension
{
    /// <summary>
    /// The dialog widget displays its content with buttons and title.
    /// </summary>
    /// <example>
    /// <code>
    /// var dialog = new Dialog();
    /// dialog.Title = "Dialog"
    ///
    /// var positive = new Button()
    /// {
    ///     Text = "OK"
    /// }
    /// var negative = new Button()
    /// {
    ///     Text = "Cancel"
    /// }
    /// negative.Clicked += (s,e)=>
    /// {
    ///     dialog.Hide();
    /// }
    ///
    /// dialog.Positive = positive;
    /// dialog.Negative = negative;
    ///
    /// var label = new Label()
    /// {
    ///     Text = "New Dialog"
    /// }
    ///
    /// dialog.Content = label;
    ///
    /// dialog.Show();
    ///
    /// </code>
    /// </example>
    public class Dialog : BindableObject
    {
        /// <summary>
        /// BindableProperty. Identifies the content bindable property.
        /// </summary>
        public static readonly BindableProperty ContentProperty = BindableProperty.Create(nameof(Content), typeof(View), typeof(Dialog), null);

        /// <summary>
        /// BindableProperty. Identifies the positive bindable property.
        /// </summary>
        public static readonly BindableProperty PositiveProperty = BindableProperty.Create(nameof(Positive), typeof(Button), typeof(Dialog), null);

        /// <summary>
        /// BindableProperty. Identifies the neutral bindable property.
        /// </summary>
        public static readonly BindableProperty NeutralProperty = BindableProperty.Create(nameof(Neutral), typeof(Button), typeof(Dialog), null);

        /// <summary>
        /// BindableProperty. Identifies the negative bindable property.
        /// </summary>
        public static readonly BindableProperty NegativeProperty = BindableProperty.Create(nameof(Negative), typeof(Button), typeof(Dialog), null);

        /// <summary>
        /// BindableProperty. Identifies the title bindable property.
        /// </summary>
        public static readonly BindableProperty TitleProperty = BindableProperty.Create(nameof(Title), typeof(string), typeof(Dialog), null);

        /// <summary>
        /// BindableProperty. Identifies the subtitle bindable property.
        /// </summary>
        public static readonly BindableProperty SubtitleProperty = BindableProperty.Create(nameof(Subtitle), typeof(string), typeof(Dialog), null);

        /// <summary>
        /// BindableProperty. Identifies the HorizontalOption bindable property.
        /// </summary>
        public static readonly BindableProperty HorizontalOptionProperty = BindableProperty.Create(nameof(HorizontalOption), typeof(LayoutOptions), typeof(Dialog), LayoutOptions.Center);

        /// <summary>
        /// BindableProperty. Identifies the VerticalOption bindable property.
        /// </summary>
        public static readonly BindableProperty VerticalOptionProperty = BindableProperty.Create(nameof(VerticalOption), typeof(LayoutOptions), typeof(Dialog), LayoutOptions.End);

        IDialog _dialog = null;

        /// <summary>
        /// Occurs when the dialog is hidden.
        /// </summary>
        public event EventHandler Hidden;

        /// <summary>
        /// Occurs when outside of the dialog is clicked.
        /// </summary>
        public event EventHandler OutsideClicked;

        /// <summary>
        /// Occurs when the dialog is shown on the display.
        /// </summary>
        public event EventHandler Shown;

        /// <summary>
        /// Occurs when the device's back button is pressed.
        /// </summary>
        public event EventHandler BackButtonPressed;

        public Dialog()
        {
            _dialog = DependencyService.Get<IDialog>(DependencyFetchTarget.NewInstance);
            if (_dialog == null)
            {
                throw new Exception("Object reference not set to an instance of a Dialog.");
            }

            _dialog.Hidden += (s, e) =>
            {
                Hidden?.Invoke(this, EventArgs.Empty);
            };

            _dialog.OutsideClicked += (s, e) =>
            {
                OutsideClicked?.Invoke(this, EventArgs.Empty);
            };

            _dialog.Shown += (s, e) =>
            {
                Shown?.Invoke(this, EventArgs.Empty);
            };

            _dialog.BackButtonPressed += (s, e) =>
            {
                BackButtonPressed?.Invoke(this, EventArgs.Empty);
            };

            SetBinding(ContentProperty, new Binding(nameof(Content), mode: BindingMode.OneWayToSource, source: _dialog));
            SetBinding(PositiveProperty, new Binding(nameof(Positive), mode: BindingMode.OneWayToSource, source: _dialog));
            SetBinding(NeutralProperty, new Binding(nameof(Neutral), mode: BindingMode.OneWayToSource, source: _dialog));
            SetBinding(NegativeProperty, new Binding(nameof(Negative), mode: BindingMode.OneWayToSource, source: _dialog));
            SetBinding(TitleProperty, new Binding(nameof(Title), mode: BindingMode.OneWayToSource, source: _dialog));
            SetBinding(SubtitleProperty, new Binding(nameof(Subtitle), mode: BindingMode.OneWayToSource, source: _dialog));
            SetBinding(HorizontalOptionProperty, new Binding(nameof(HorizontalOption), mode: BindingMode.OneWayToSource, source: _dialog));
            SetBinding(VerticalOptionProperty, new Binding(nameof(VerticalOption), mode: BindingMode.OneWayToSource, source: _dialog));
        }

        /// <summary>
        /// Gets or sets content view of the dialog.
        /// </summary>
        public View Content
        {
            get { return (View)GetValue(ContentProperty); }
            set { SetValue(ContentProperty, value); }
        }

        /// <summary>
        /// Gets or sets positive button of the dialog.
        /// This button is on the left.
        /// When used alone, it is variable in size (can increase to the size of dialog).
        /// Dialog's all buttons style is bottom
        /// </summary>
        public Button Positive
        {
            get { return (Button)GetValue(PositiveProperty); }
            set { SetValue(PositiveProperty, value); }
        }

        /// <summary>
        /// Gets or sets neutral button of the dialog.
        /// This button is at the center.
        /// When used alone or used with positive, its size is half the size of the dialog and is on the right.
        /// </summary>
        public Button Neutral
        {
            get { return (Button)GetValue(NeutralProperty); }
            set { SetValue(NeutralProperty, value); }
        }

        /// <summary>
        /// Gets or sets negative button of the dialog.
        /// This button is always on the right and is displayed at a fixed size.
        /// </summary>
        public Button Negative
        {
            get { return (Button)GetValue(NegativeProperty); }
            set { SetValue(NegativeProperty, value); }
        }

        /// <summary>
        /// Gets or sets title of the dialog.
        /// </summary>
        public string Title
        {
            get { return (string)GetValue(TitleProperty); }
            set { SetValue(TitleProperty, value); }
        }

        /// <summary>
        /// Gets or sets subtitle of the dialog.
        /// When title property value is null, subtitle is not displayed.
        /// </summary>
        public string Subtitle
        {
            get { return (string)GetValue(SubtitleProperty); }
            set { SetValue(SubtitleProperty, value); }
        }

        /// <summary>
        /// Gets or sets the LayoutOptions that define how the dialog gets laid in a layout cycle.
        /// The default is center.
        /// </summary>
        public LayoutOptions HorizontalOption
        {
            get { return (LayoutOptions)GetValue(HorizontalOptionProperty); }
            set { SetValue(HorizontalOptionProperty, value); }
        }

        /// <summary>
        /// Gets or sets the LayoutOptions that define how the dialog gets laid in a layout cycle.
        /// The default is end.
        /// </summary>
        public LayoutOptions VerticalOption
        {
            get { return (LayoutOptions)GetValue(VerticalOptionProperty); }
            set { SetValue(VerticalOptionProperty, value); }
        }

        /// <summary>
        /// Shows the dialog.
        /// </summary>
        public void Show()
        {
            _dialog.Show();
        }

        /// <summary>
        /// Hides the dialog.
        /// </summary>
        public void Hide()
        {
            _dialog.Hide();
        }
    }
}