using UnityEngine;
using System.Collections;

/// <summary>
/// This component is responsible for having paging with a next and prev buttons.
/// It enables/disables the buttons according to whether there are more pages to go through
/// Each page is a GameObject, which is activated when the user is paging.
/// The next/prev buttons need to send a message to this component accordingly (OnNextPageButtonMsg and OnPrevPageButtonMsg).
/// For sending such a message the buttons can easily use UIButtonMessage component.
/// </summary>
public class PagingDialog : MonoBehaviour
{
	public GameObject[] pages;
	public GameObject prevButton, nextButton;
	public bool WinCondomPages;
	public UILabel LabelPages;
	int _currentPageIndex;

	void OnEnable()
	{
		_currentPageIndex = 0;
		if (WinCondomPages)
		{
			LabelPages.text = string.Format("{0}/{1}", _currentPageIndex + 1, pages.Length);
		}
		RefreshPage();
	}

	/// <summary>
	/// Enables the current page, disables the others.
	/// Updates the buttons state according to the current page.
	/// This needs to be called whenever the current page index is changed.
	/// </summary>
	void RefreshPage()
	{
		for (int i = 0; i < pages.Length; i++)
		{
			bool isPageActive = _currentPageIndex == i;
			pages[i].SetActive(isPageActive);
		}
		//prevButton enable/disable
		if (_currentPageIndex == 0)
		{
			UIUtils.EnableWidgets(prevButton, false);
		} else
		{
			UIUtils.EnableWidgets(prevButton, true);
		}
		//nextButton enable/disable
		if (_currentPageIndex == pages.Length - 1)
		{
			UIUtils.EnableWidgets(nextButton, false);
		} else
		{
			UIUtils.EnableWidgets(nextButton, true);
		}
	}

	#region Next/Prev button messages
	void OnNextPageButtonMsg()
	{
		if (_currentPageIndex < pages.Length - 1)
		{
			++_currentPageIndex;
			RefreshPage();
		}
		if (WinCondomPages)
		{
			LabelPages.text = string.Format("{0}/{1}", _currentPageIndex + 1, pages.Length);
		}
	}

	void OnPrevPageButtonMsg()
	{
		if (_currentPageIndex > 0)
		{
			--_currentPageIndex;
			RefreshPage();
		}
		if (WinCondomPages)
		{
			LabelPages.text = string.Format("{0}/{1}", _currentPageIndex + 1, pages.Length);
		}
	}
	#endregion
}