# * George Moschovitis  <gm@navel.gr>
# (c) 2004-2005 Navel, all rights reserved.
# $Id$

module N

require 'nitro/controller'
require 'nitro/routing'
require 'nitro/simple'

# The Dispatcher manages a set of controllers.

class Dispatcher 
	include Router
	
	# The public root directory. The files in this
	# directory are published by the web server.

	attr_accessor :public_root
	
	# The template root directory. By default this
	# points to the public root directory to allow
	# for PHP/JSP/ASP style programming. But you should
	# probably change this to another directory for
	# extra security.

	attr_accessor :template_root

	# The controllers map.

	attr_accessor :controllers

	# APIs map.

	attr_accessor :apis

	# Create a new Dispatcher.
	#
	# Input:
	#
	# [+controllers+]
	#		Either a hash of controller mappings or a single
	#		controller that gets mapped to :root.
	#
	# [+apis+]
	# 	A hash of apis supported by the Dispatcher.
	
	def initialize(controllers = nil, apis = nil, routes = nil)
		@public_root = 'public'
		@template_root = @public_root
		
		if controllers and controllers.is_a?(Class) and controllers.ancestors.include?(Controller)
			controllers = { :root => controllers }
		else
			controllers ||= { :root => SimpleController }
		end

		mount(controllers)

		@apis = apis || {}
	end

	# Process the given hash and mount the 
	# defined controllers.
	#
	# Input:
	#
	# [+controllers+]
	#		A hash representing the mapping of
	#		mount points to controllers.
	#
	# === Examples
	#
	# dispatcher.mount {
	#		:root => MainController # mounts /
	#		'users' => UsersController # mounts /users
	#	}
	
	def add_controller(controllers)
		(@controllers ||= {}).update(controllers)
		update_routes
	end
	alias_method :mount, :add_controller

	# Add a new api to the dispatcher
	#
	# [+api+]
	#		API symbol
	# [+data+]
	#		Data for this API [content_type, ..]
	#
	# === Example
	#
	# dispatcher.add_api(:xml, 'text/xml')
	
	def add_api(api, data)
		(@apis ||= {})[api] = data
	end

	# Update the routes. Typically called after a new
	# Controller is mounted.

	def update_routes
		@routes = []
		@controllers.each do |base, c|
			base = (base == :root ? '' : "/#{base}")
			c.action_metadata.each do |action, meta|
				if route = meta[:route]
					@routes << [route, "#{base}/#{action}", *meta.params.keys]
				end
			end
		end
	end
	
	# Processes the path and dispatches to the corresponding
	# controller/action pair.
	# The base returned contains a trailing '/'.
	#
	# [+path+]
	#		The path to dispatch.
	#
	# [:context]
	#		The dispatching context.

	def dispatch(path, context = nil)
		api = :xhtml

		path = route(path, context)

		if @apis
			# OPTIMIZE: check only if lookup fails.
			@apis.each { |k, v| api = k if path.slice!(/#{k}\//) }
		end

		parts = path.split('/')

		case parts.size
			when 0
				# / -> root.index
				#	base = @template_root 
				klass = controller_class_for(:root, context)
				action = 'index'
			
			when 2
				if klass = controller_class_for(parts[1], context)
					# controller/ -> controller.index
					#	base = "#{@template_root}/#{parts[1]}"
					action = 'index'
				else
					# action/ -> root.action
					#	base = @template_root
					klass = controller_class_for(:root, context)
					action = parts[1]
				end
				
			when 3
				# controller/action/ -> controller.action
				# base = "#{@template_root}/#{parts[1]}"
				klass = controller_class_for(parts[1], context)
				action = parts[2]
		end
	
		content_type = @apis[:api] || 'text/html'

		return klass, "__#{api}__#{action}", content_type 
	end
	alias_method :split_path, :dispatch

	# Get the controller for the given key.
	# Also handles reloading of controllers.

	def controller_class_for(key, context)
		klass = @controllers[key]

		if (:full == Rendering.reload) and context and context[:__RELOADED__].nil? and klass
			def_file = klass::DEF_FILE
			Controller.remove_subclasses
			load(def_file)
			klass = @controllers[key] = Object.const_get(klass.name.intern) 
			context[:__RELOADED__] = true
		end

		return klass
	end

end

end