package com.moiseum.wolnelektury.components;

import android.content.Context;
import android.graphics.Point;
import android.graphics.Rect;
import android.graphics.RectF;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.Display;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;

import it.sephiroth.android.library.imagezoom.ImageViewTouch;

/**
 * Created by Piotr Ostrowski on 29.06.2017.
 */

public class ZoomableViewPager extends ViewPager {

	public interface OnItemClickListener {
		void onItemClick(int position);
	}

	private class TapGestureListener extends GestureDetector.SimpleOnGestureListener {

		@Override
		public boolean onSingleTapConfirmed(MotionEvent e) {
			if (mOnItemClickListener != null) {
				mOnItemClickListener.onItemClick(getCurrentItem());
			}
			return true;
		}
	}

	private OnItemClickListener mOnItemClickListener;
	private GestureDetector tapGestureDetector;

	public ZoomableViewPager(Context context) {
		super(context);
		setup();
	}

	public ZoomableViewPager(Context context, AttributeSet attrs) {
		super(context, attrs);
		setup();
	}

	@Override
	protected boolean canScroll(View v, boolean checkV, int dx, int x, int y) {
		if (v instanceof ImageViewTouch) {
			ImageViewTouch imageViewTouch = (ImageViewTouch) v;
			return imageViewTouchCanScroll(imageViewTouch, dx);
		} else {
			return super.canScroll(v, checkV, dx, x, y);
		}
	}

	/**
	 * Determines whether the ImageViewTouch can be scrolled.
	 *
	 * @param direction - positive direction value means scroll from right to left,
	 * negative value means scroll from left to right
	 * @return true if there is some more place to scroll, false - otherwise.
	 */
	private boolean imageViewTouchCanScroll(ImageViewTouch imageViewTouch, int direction) {
		int widthScreen = getWidthScreen();

		RectF bitmapRect = imageViewTouch.getBitmapRect();
		Rect imageViewRect = new Rect();
		getGlobalVisibleRect(imageViewRect);

		int widthBitmapViewTouch = (int) bitmapRect.width();

		if (widthBitmapViewTouch < widthScreen) {
			return false;
		}

		if (direction < 0) {
			return Math.abs(bitmapRect.right - imageViewRect.right) > 1.0f;
		} else {
			return Math.abs(bitmapRect.left - imageViewRect.left) > 1.0f;
		}

	}

	private int getWidthScreen() {
		WindowManager wm = (WindowManager) getContext().getSystemService(Context.WINDOW_SERVICE);
		Display display = wm.getDefaultDisplay();

		Point size = new Point();
		display.getSize(size);
		return size.x;
	}

	private void setup() {
		tapGestureDetector = new GestureDetector(getContext(), new TapGestureListener());
	}


	@Override
	public boolean onInterceptTouchEvent(MotionEvent ev) {
		tapGestureDetector.onTouchEvent(ev);
		return super.onInterceptTouchEvent(ev);
	}

	public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
		mOnItemClickListener = onItemClickListener;
	}

}