module ActionController
    
  module MuckApplication
    
    module ClassMethods

    end

    module InstanceMethods
      private

      # I18n methods from:
      # http://guides.rubyonrails.org/i18n.html
      # http://zargony.com/2009/01/09/selecting-the-locale-for-a-request
      def discover_locale
        I18n.locale = extract_locale_from_user_selection || extract_locale_from_tld || extract_locale_from_subdomain || extract_locale_from_headers || I18n.default_locale
      end
      
      def extract_locale_from_browser
        if http_lang = request.env["HTTP_ACCEPT_LANGUAGE"] and ! http_lang.blank?
          browser_locale = http_lang[/^[a-z]{2}/i].downcase + '-' + http_lang[3,2].upcase
          browser_locale.sub!(/-US/, '')
        end
        nil
      end

      def extract_locale_from_user_selection
        if params[:locale] && I18n.available_locales.include?(params[:locale].to_sym)
          cookies['locale'] = { :value => params[:locale], :expires => 1.year.from_now }
          params[:locale].to_sym
        elsif cookies['locale'] && I18n.available_locales.include?(cookies['locale'].to_sym)
          cookies['locale'].to_sym
        end
      end
      
      def extract_locale_from_headers
        preferred_locales = request.headers['HTTP_ACCEPT_LANGUAGE'].split(',').map { |l| l.split(';').first }
        accepted_locales = preferred_locales.select { |l| I18n.available_locales.include?(l.to_sym) }
        accepted_locales.empty? ? nil : accepted_locales.first
      end
      
      # Get locale from top-level domain or return nil if such locale is not available 
      # You have to put something like: # 127.0.0.1 application.com 
      # 127.0.0.1 application.it # 127.0.0.1 application.pl 
      # in your /etc/hosts file to try this out locally 
      def extract_locale_from_tld 
        parsed_locale = request.host.split('.').last 
        (I18n.available_locales.include? parsed_locale) ? parsed_locale.to_sym : nil 
      end 

      # Get locale code from request subdomain (like http://it.application.local:3000) 
      # You have to put something like: 
      # 127.0.0.1 gr.application.local 
      # in your /etc/hosts file to try this out locally 
      def extract_locale_from_subdomain 
        parsed_locale = request.subdomains.first
        if !parsed_locale.blank?
          I18n.available_locales.include?(parsed_locale.to_sym) ? parsed_locale.to_sym : nil 
        else
          nil
        end
      end 
      
      def setup_paging
        @page = (params[:page] || 1).to_i
        @page = 1 if @page < 1
        @per_page = (params[:per_page] || (RAILS_ENV=='test' ? 1 : 40)).to_i
      end

      def set_will_paginate_string
        # Because I18n.locale are dynamically determined in ApplicationController, 
        # it should not put in config/initializers/will_paginate.rb
        WillPaginate::ViewHelpers.pagination_options[:previous_label] = t('common.previous_page')
        WillPaginate::ViewHelpers.pagination_options[:next_label] = t('common.next_page')
      end

      def get_redirect_to
        if params[:redirect_to]
          redirect_to params[:redirect_to]
        else
          yield
        end
      end

    end

    def self.included(receiver)
      receiver.extend ClassMethods
      receiver.class_eval do
        include InstanceMethods
      end
    end

  end

end