#!/usr/local/bin/ruby

# Copyright 2007 Jay McGavren, jay@mcgavren.com.
# 
# This file is part of Zyps.
# 
# Zyps is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU Lesser General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.


gems_loaded = false
begin
	require 'optparse'
	require 'zyps'
	require 'zyps/actions'
	require 'zyps/conditions'
	require 'zyps/environmental_factors'
	require 'zyps/remote'
	require 'zyps/views/trails'
	require 'drb'
rescue LoadError
	if gems_loaded == false
		require 'rubygems'
		gems_loaded = true
		retry
	else
		raise
	end
end


include Zyps


DEFAULT_VIEW_WIDTH = 800
DEFAULT_VIEW_HEIGHT = 600
DEFAULT_MAX_SPEED = 500
DEFAULT_MAX_POPULATION = 100
DEFAULT_FPS = 60


#A server for a Zyps Environment.
class ZypsServer

	#Port to open service on.
	attr_accessor :uri
	#Maximum allowed number of objects.
	attr_accessor :max_population
	#View dimensions.
	attr_accessor :view_width, :view_height
	
	#Set up default values.
	def initialize(
		uri = nil,
		view_width = DEFAULT_VIEW_WIDTH,
		view_height = DEFAULT_VIEW_HEIGHT,
		fps = DEFAULT_FPS,
		max_population = DEFAULT_MAX_POPULATION,
		max_speed = DEFAULT_MAX_SPEED,
		enclosure = true
	)
		@uri, @view_width, @view_height, @fps, @max_population, @max_speed, @enclosure =
		uri, view_width, view_height, fps, max_population, max_speed, enclosure
	end

	#Create app window, game environment, view, and network service.
	def main
	
		#A clock to track frames to draw this second.
		clock = Clock.new
		time_per_frame = 1.0 / @fps
	
		#Create a window, and set GTK up to quit when it is closed.
		window = Gtk::Window.new
		window.signal_connect("delete_event") {false}
		window.signal_connect("destroy") {Gtk.main_quit}
		
		#Add view to window.
		view = TrailsView.new(@view_width, @view_height)
		window.add(view.canvas)
		window.show_all
		
		#Create environment.
		environment = Environment.new
		
		#Point view at environment.
		environment.add_observer(view)
		
		#Limit population.
		environment.environmental_factors << PopulationLimit.new(environment, @max_population) if @max_population
		
		#Limit speed of objects.
		environment.environmental_factors << SpeedLimit.new(@max_speed) if @max_speed
		
		#Keep objects on screen.
		if @enclosure
			enclosure = Enclosure.new()
			enclosure.left = 0
			enclosure.bottom = 0
			enclosure.top = @view_height
			enclosure.right = @view_width
			environment.environmental_factors << enclosure
		end
		
		#Create thread to update environment.
		update_thread = Thread.new do
		
			begin
			
				loop do
				
					begin
						environment.interact
					rescue Exception => exception
						puts exception, exception.backtrace
						puts environment.inspect
					end
					
					#Control population.
					environment.objects.shift while environment.objects.length > @max_population

					#Determine how much time is left in this frame.
					time_left_in_frame = time_per_frame - clock.elapsed_time
					#Sleep for the remaining time.
					if time_left_in_frame > 0
						sleep time_left_in_frame
					#Skip a frame if things are going too slow.
					else
						sleep time_per_frame
					end
					
				end
				
			rescue Exception => exception
				puts exception, exception.backtrace
			end
			
		end
		
		#Start a network service.
		server = EnvironmentServer.new(environment, @uri)
		server.start
		#Display our URI.
		puts "Zyps server active at #{server.uri}"
		
		#Disable file system access.
		$SAFE = 2

		#Activate the GUI.
		Gtk.main
		
	end
	
	
	#Set attributes according to command-line arguments.
	def process_options(arguments)
	
		#Set up option parser.
		options = OptionParser.new
		
		#Define valid options.
		options.on("-h", "--help", TrueClass, "Display program help.") {
			puts options.help
			exit
		}
		options.on(
			"-m",
			"--max-population [number]",
			Integer,
			"The maximum number of allowed game objects.  #{DEFAULT_MAX_POPULATION} by default."
		) {|value| @max_population = value}
		options.on(
			"-s",
			"--max-speed [number]",
			Integer,
			"The fastest an object can go.  #{DEFAULT_MAX_SPEED ? DEFAULT_MAX_SPEED : 'No limit'} by default."
		) {|value| @max_speed = value}
		options.on(
			"-n",
			"--no-enclosure",
			"Disables the barrier that normally keeps objects on the screen."
		) {|value| @enclosure = false}
		options.on(
			"-u",
			"--uri [uri]",
			String,
			"dRuby URI to run the server on.  If not defined, one will be selected and printed to STDOUT."
		) {|value| @uri = value}
		options.on(
			"-f",
			"--fps [frames]",
			Integer,
			"Number of frames to draw per second.  #{DEFAULT_FPS} by default."
		) {|value| @fps = value}
		options.on(
			"--view-width [pixels]",
			Integer,
			"Window width.  #{DEFAULT_VIEW_WIDTH} by default."
		) {|value| @view_width = value}
		options.on(
			"--view-height [pixels]",
			Integer,
			"Window height.  #{DEFAULT_VIEW_HEIGHT} by default."
		) {|value| @view_height = value}
		
		#Parse the options, printing usage if parsing fails.
		options.parse(arguments) rescue puts "#{$!}\nType '#{$0} --help' for valid options."
		
	end


end


begin
	#Create a server.
	server = ZypsServer.new
	#Parse the command line.
	server.process_options(ARGV)
	#Start the server.
	server.main
rescue => exception
	#Print error to STDERR and exit with an abnormal status.
	abort "Error: " + exception.message + exception.backtrace.join("\n")
end