ioquatix/relaxo-query-server

# Copyright (c) 2012 Samuel G. D. Williams. <http://www.oriontransfer.co.nz>
# 
# 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.

module Relaxo
    module QueryServer
        class Library
            def self.for(root, path)
                parent = root

                path = path.split('/') unless Array === path

                library = path.inject(parent) do |current, name|
                    return nil if current == nil

                    parent = current

                    current[name]
                end

                return nil if library == nil

                unless Library === library
                    library = parent[path.last] = Library.new(root, path, library)
                end

                return library.instance
            end

            def initialize(root, path, code)
                @root = root
                @path = path
                @code = code

                @klass = nil
                @instance = nil
            end

            def instance
                unless @klass
                    @klass = Class.new
                    @klass.const_set(:ROOT, @root)

                    # Not sure if this is the best way to implement the `load` function
                    @klass.class_eval do
                        def self.root
                            self.const_get(:ROOT)
                        end
                        
                        def self.load(path)
                            Library.for(root, path)
                        end

                        def load(path)
                            self.class.load(path)
                        end
                    end

                    @klass.class_eval @code, @path.join('/')
                end

                @instance ||= @klass.new
            end
        end
        
        class Loader
            # The default library name
            DEFAULT = ['_default']
            
            def initialize
                @libraries = {}
            end
            
            def load(path)
                Library.for(@libraries, path)
            end
            
            def add_libraries(libraries)
                @libraries.merge!(libraries)
            end
            
            def load_default
                load(DEFAULT)
            end
        end
    end
end