using System;

namespace Terminal.Gui; 

/// <summary>
/// The Label <see cref="View"/> displays a string at a given position and supports multiple lines separated by newline
/// characters.
/// Multi-line Labels support word wrap.
/// </summary>
/// <remarks>
/// The <see cref="Label"/> view is functionality identical to <see cref="View"/> and is included for API backwards
/// compatibility.
/// </remarks>
public class Label : View {
	/// <inheritdoc/>
	public Label () => SetInitialProperties ();

	/// <inheritdoc/>
	public Label (Rect frame, bool autosize = false) : base (frame) => SetInitialProperties (autosize);

	/// <inheritdoc/>
	public Label (string text, bool autosize = true) : base (text) => SetInitialProperties (autosize);

	/// <inheritdoc/>
	public Label (Rect rect, string text, bool autosize = false) : base (rect, text) => SetInitialProperties (autosize);

	/// <inheritdoc/>
	public Label (int x, int y, string text, bool autosize = true) : base (x, y, text) => SetInitialProperties (autosize);

	/// <inheritdoc/>
	public Label (string text, TextDirection direction, bool autosize = true)
		: base (text, direction) => SetInitialProperties (autosize);

	void SetInitialProperties (bool autosize = true)
	{
		Height   = 1;
		AutoSize = autosize;
		// Things this view knows how to do
		AddCommand (Command.Default, () => {
			// BUGBUG: This is a hack, but it does work.
			var can = CanFocus;
			CanFocus = true;
			SetFocus ();
			SuperView.FocusNext ();
			CanFocus = can;
			return true;
		});
		AddCommand (Command.Accept, () => AcceptKey ());

		// Default key bindings for this view
		KeyBindings.Add (KeyCode.Space, Command.Accept);
	}

	bool AcceptKey ()
	{
		if (!HasFocus) {
			SetFocus ();
		}
		OnClicked ();
		return true;
	}

	/// <summary>
	/// The event fired when the user clicks the primary mouse button within the Bounds of this <see cref="View"/>
	/// or if the user presses the action key while this view is focused. (TODO: IsDefault)
	/// </summary>
	/// <remarks>
	/// Client code can hook up to this event, it is
	/// raised when the button is activated either with
	/// the mouse or the keyboard.
	/// </remarks>
	public event EventHandler Clicked;

	/// <summary>
	/// Method invoked when a mouse event is generated
	/// </summary>
	/// <param name="mouseEvent"></param>
	/// <returns><c>true</c>, if the event was handled, <c>false</c> otherwise.</returns>
	public override bool OnMouseEvent (MouseEvent mouseEvent)
	{
		var args = new MouseEventEventArgs (mouseEvent);
		if (OnMouseClick (args)) {
			return true;
		}
		if (MouseEvent (mouseEvent)) {
			return true;
		}

		if (mouseEvent.Flags == MouseFlags.Button1Clicked) {
			if (!HasFocus && SuperView != null) {
				if (!SuperView.HasFocus) {
					SuperView.SetFocus ();
				}
				SetFocus ();
				SetNeedsDisplay ();
			}

			OnClicked ();
			return true;
		}
		return false;
	}

	///<inheritdoc/>
	public override bool OnEnter (View view)
	{
		Application.Driver.SetCursorVisibility (CursorVisibility.Invisible);

		return base.OnEnter (view);
	}

	/// <summary>
	/// Virtual method to invoke the <see cref="Clicked"/> event.
	/// </summary>
	public virtual void OnClicked () => Clicked?.Invoke (this, EventArgs.Empty);
}