mg_villages/protection.lua

-- get the id of the village pos lies in (or nil if outside of villages)
mg_villages.get_town_id_at_pos = function( pos )
	for id, v in pairs( mg_villages.all_villages ) do
		local size = v.vs * 3;
		if(   ( math.abs( pos.x - v.vx ) < size )
		  and ( math.abs( pos.z - v.vz ) < size )
		  and ( pos.y - v.vh < 40 and v.vh - pos.y < 10 )) then
			local village_noise = minetest.get_perlin(7635, 3, 0.5, 16);
			if( mg_villages.inside_village_area( pos.x,  pos.z, v, village_noise)) then

				local node = minetest.get_node( pos );
				if( node
				   and node.name
				   and minetest.registered_nodes[ node.name ]
				   and minetest.registered_nodes[ node.name ].groups
				   and minetest.registered_nodes[ node.name ].groups.leaves ) then
					return nil;
				else
					return id;
				end
			end
		end
	end
	return nil;
end

local old_is_protected = minetest.is_protected
minetest.is_protected = function(pos, name)

	if( mg_villages.get_town_id_at_pos( pos )) then
		return true;
	end
	return old_is_protected(pos, name);
end             

minetest.register_on_protection_violation( function(pos, name)
	local found = mg_villages.get_town_id_at_pos( pos );
	if( not( found ) or not( mg_villages.all_villages[ found ]))  then
		minetest.chat_send_player( name, 'Error: This area does not belong to a village.');
		return;
	end
	minetest.chat_send_player( name, "You are inside of the area of the village "..tostring( mg_villages.all_villages[ found ].name )..". The inhabitants do not allow you any modifications.");
end );

-- TODO: add a limited griefing liscence/buying of houses or plots for players