Implement visual selection of necessary country on the map(MapBox)

You must implement the following: - Working with maps MapBox. - Searches for the required point on the map ( it is not necessary to implement ) is determined by which country are the coordinates of the point and this country stands out visually . - The entire map is " in the shadows ", and highlighted the country displayed a "normal" - At the same time can be allocated to several countries. - All information ( roads, rivers , towns, etc. ) is displayed in normal mode, without restrictions and changes. - The allocated region to be exactly repeated border countries. Image with an example in the attached file . Requires neat and fully commented code .