require 'dbus'
require 'singleton'

module Compiz
    class Node
        include Enumerable

        def initialize(service, dbus_node)
            @service = service
            @node = dbus_node
            @node.introspect
            @subnodes = {}
        end

        def leaf?
            @node.has_iface?('org.freedesktop.compiz') && @node["org.freedesktop.compiz"].methods.key?('get')
        end

        def each
            @node.subnodes.each do |n|
                nnode = __subnode(n)
                yield nnode unless nnode.leaf?
                
            end
        end

        def __subnode(name)
            @subnodes[name] ||= Node.new(@service, @service.object("#{@node.path}/#{name}"))
        end

        def __get
            iface = @node["org.freedesktop.compiz"]
            iface.get
        end

        def __set(*args)
            iface = @node["org.freedesktop.compiz"]
            iface.set(*args)
        end

        def to_s
            if leaf?
                @node.__get.to_s
            else
                @node.subnodes.join(", ")
            end
        end

        def method_missing(sym, *args)
            if sym =~ /^.+=$/ && @node.subnodes.include?(sym.to_s.chop)
                nnode = __subnode(sym.to_s.chop)
                if nnode.leaf?
                    nnode.__set(*args)
                else
                    super
                end
            elsif @node.subnodes.include? sym.to_s
                nnode = __subnode(sym.to_s)
                if nnode && nnode.leaf?
                    nnode.__get
                else
                    nnode
                end
            else
                super
            end
        end
    end

    class Root < Node
        include Singleton

        def initialize
            session = DBus::SessionBus.instance
            @service = session.service("org.freedesktop.compiz")
            @node = @service.object("/org/freedesktop/compiz")
            @node.introspect
            @subnodes = {}
        end
    end
end