# * George Moschovitis  <gm@navel.gr>
# (c) 2004-2005 Navel, all rights reserved.
# $Id: l10n.rb 185 2004-12-10 13:29:09Z gmosx $

require 'yaml'

require 'nitro/filters'
require 'nitro/shaders'

module N

# Represents a locale.
#--
# TODO: initialize translation map from a yaml file.
#++

class Locale

	# The localization map.

	attr_accessor :map
	
	def initialize(map)
		parse_hash(map)
	end

	# Transalte the given key.
	#
	# [+args+]
	#		An array of arguments. The first argument
	#		is the translation key. If additional arguments
	#		are provided they are used for sprintf 
	#		interpolation.
	#--
	# THINK: Possibly avoid the creation of the 
	#	array by making the api less elegant.
	#++

	def translate(*args)
		if xlated = @map[args.shift]
			if xlated.is_a?(String)
				args.empty? ? xlated : sprintf(xlated, *args)
			else
				xlated.call(*args)
			end
		end
	end
	alias_method :[], :translate

	private

	def parse_hash(map)
		@map = map
	end

	def parse_yaml(yaml)
		raise 'Not implemented'
	end
	
end

# Localization support.
#
# === Example 
#
#	locale_en = {
#		'See you' => 'See you',
#		:long_paragraph => 'The best new books, up to 30% reduced price',
#		:price => 'Price: %d %s',
#		:proc_price => proc { |value, cur| "Price: #{value} #{cur}" }
#	}
#
#	locale_de = {
#		'See you' => 'Auf wieder sehen',
#		:long_paragraph => 'Die besten neuer buecher, bis zu 30% reduziert',
#		...
#	}
#
#	Localization.add(:en => locale_en, :de => locale_de)
#
# lc = Localization.get
# lc['See you'] -> See you
# lc[:price, 100, 'euro'] -> Price: 100 euro
# lc = Localization.get[:de]
# lc['See you'] -> Auf wiedersehen
#
# To make localization even more easier, a LocalizationFilter
# and a LocalizationShader are provided.

class Localization

	class << self
		
		# A hash of the available locales.

		attr_accessor :locales

		def add(map = {})
			for key, locale in map
				if locale.is_a?(String)
					# this is the name of the localization file.
					locale = YAML.load(File.read(locale))
				end
				@locales[key.to_s] = Locale.new(locale)
			end
		end
				
		# Return the localization hash for the given
		# locale.

		def get(locale = :en)
			locale ||= 'en'
			@locales[locale.to_s]
		end
		alias_method :locale, :get
		alias_method :[], :get

	end

	@locales = {}
	
end

# Localization filter.

module LocalizationFilter
	def localize
		#		@lc = @context.conf.localization[@session[:LOCALE]]
		@lc = Localization[@context.session[:LOCALE]]
	end
end

# Localization shader.
#
# === Examples
#
# <h1>[[Welcome]]</h1>
# <h1>[[:welcome]]</h1>

class LocalizationShader < Shader
	
	def process(hash, text)
		# handle symbols
		text.gsub!(/\[\[\:(.*?)\]\]/, '#{@lc[\1]}')

		# handle strings 
		text.gsub!(/\[\[(.*?)\]\]/, '#{@lc["\1"]}')

		process_next(hash, text)
	end

end

end