module Og

# An 'active' collection that reflects a relation.
# A collection stores entitities that participate in
# a relation.

class Collection

	# The owner of this collection.
	
	attr_accessor :owner
	
	# The members of this collection. Keeps the objects
	# that belong to this collection.
	
	attr_accessor :members

	# A method used to add insert objects in the collection.
	 
	attr_accessor :insert_proc

	# A method used to remove objects from the collection.
	
	attr_accessor :remove_proc
	
	# A method used to find the objects that belong to the
	# collection.
	
	attr_accessor :find_proc
	
	# The default find options.
	
	attr_accessor :find_options
	
	# Is the collection in build mode?
	
	attr_accessor :building
	
	# Is the collection loaded?
	
	attr_accessor :loaded

	# Initialize the collection.
		
	def initialize(owner = nil, insert_proc = nil, remove_proc = nil, find_proc = nil, find_options = {})
		@owner = owner
		@insert_proc = insert_proc
		@remove_proc = remove_proc
		@find_proc = find_proc
		@find_options = find_options
		@members = []
		@loaded = false
		@building = false
	end

	# Load the members of the collection.	

	def load_members
		unless @loaded
			@members = @owner.send(@find_proc, @find_options)
			@loaded = true
		end
		@members
	end
	
	# Reload the collection.
	
	def reload(options)
# gmosx, NOOO: this was a bug! it corrupts the default options.
#		@find_options = options
		@members = @owner.send(@find_proc, options)
	end

	# Convert the collection to an array.
		
	def to_ary
		load_members
		@members
	end

	# Defined to avoid the method missing overhead.
	
	def each(&block)
		load_members
		@members.each(&block)
	end
	
	# Defined to avoid the method missing overhead.
	
	def [](idx)
		load_members
		@members[idx]
	end
	
	# Add a new member to the collection.
	
	def push(obj)
		@members.push(obj)
		unless @building or owner.unsaved?
			@owner.send(@insert_proc, obj)
		end
	end
	alias_method :<<, :push
	alias_method :add, :push

	# Remove a member from the collection, the actual object
	# is not deleted.
	
	def remove(*objects)
		objects = objects.flatten

		objects.reject! { |obj| @members.delete(obj) if obj.unsaved? }
		return if objects.empty?

		@owner.transaction do
			objects.each do |obj| 
				@owner.send(@remove_proc, obj)
				@members.delete(obj) 
			end
		end
	end

	# Delete a member from the collection AND the store.
	
	def delete(*objects)
		objects = objects.flatten

		objects.reject! { |obj| @members.delete(obj) if obj.unsaved? }
		return if objects.empty?

		@owner.transaction do
			objects.each do |obj| 
				obj.delete
				@members.delete(obj) 
			end
		end
	end

	# Remove all members from the collection.
	
	def remove_all
		@owner.transaction do
			@members.each { |obj| @owner.send(@remove_proc, obj) }
		end
		@members.clear
	end
	alias_method :clear, :remove_all

	# Delete all members of the collection. Also delete from the
	# store.
	
	def delete_all
		@owner.transaction do
			@members.each { |obj| obj.delete }
		end
		@members.clear
	end

	# Redirect all other methods to the members array.
	
	def method_missing(symbol, *args, &block)
		load_members
		@members.send(symbol, *args, &block)
	end

private

	def check_type(obj)
	end
	
end

end

# * George Moschovitis <gm@navel.gr>
# *	Julien Perrot <jperrot@exosec.fr>