# Copyright, 2018, by Samuel G. D. Williams. <http://www.codeotaku.com>
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

require 'nio'

module Async
	class DebugSelector
		class MonitorProxy
			def initialize(monitor, selector)
				@monitor = monitor
				@selector = selector
			end
			
			def close
				@selector.deregister(@monitor.io)
				@monitor.close
			end
			
			def method_missing(*args, &block)
				@monitor.send(*args)
			end
			
			def respond_to?(*args)
				@monitor.respond_to?(*args)
			end
		end
		
		def initialize(selector)
			@selector = selector
			@monitors = {}
		end
		
		def register(io, interests)
			$stderr.puts "Registering #{io.inspect} for #{interests}."
			
			if monitor = @monitors[io.fileno]
				raise RuntimeError, "Trying to register monitor for #{io.inspect} but it was already registered as #{monitor.io.inspect}!"
			end
			
			@monitors[io.fileno] = io
			
			MonitorProxy.new(@selector.register(io, interests), self)
		end
		
		def deregister(io)
			$stderr.puts "Deregistering #{io.inspect}."
			
			unless @monitors.delete(io.fileno)
				raise RuntimeError, "Trying to remove monitor for #{io.inspect} but it was not registered!"
			end
		end
		
		def wakeup
			@selector.wakeup
		end
		
		def close
			if @monitors.any?
				$stderr.puts "Trying to close selector with active monitors: #{@monitors.values.inspect}!"
			end
			
			@selector.close
		end
		
		def select(*args)
			@selector.select(*args)
		end
	end
end