require "active_support/concern"

module Iqvoc
  module ControllerExtensions
    extend ActiveSupport::Concern

    included do
      prepend_before_filter :set_locale
      before_filter :ensure_extension
      before_filter :require_user

      helper :all
      helper_method :current_user_session, :current_user, :concept_widget_data, :collection_widget_data, :label_widget_data

      rescue_from ActiveRecord::RecordNotFound, :with => :handle_not_found
      rescue_from CanCan::AccessDenied, :with => :handle_access_denied
    end

    protected

    def default_url_options(options = nil)
      { :format => params[:format], :lang => I18n.locale }.
        reject { |key, value| key == :lang and value.to_s.strip.blank? }. # Strip out the lang parameter if it's empty.
        merge(options || {})
    end

    # Force an extension to every url. (LOD)
    def ensure_extension
      unless params[:format] || request.method != "GET"
        flash.keep
        redirect_to url_for(params.merge(:format => (request.format && request.format.symbol) || :html))
      end
    end

    def handle_access_denied(exception)
      @exception = exception
      render :template => 'errors/access_denied', :status => :access_denied
    end

    def handle_multiple_choices(exception)
      @exception = exception
      render :template => 'errors/multiple_choices', :status => :multiple_choices
    end

    def handle_not_found(exception)
      @exception = exception
      SearchResultsController.prepare_basic_variables(self)

      respond_to do |format|
        format.html { render :template => 'errors/not_found', :status => :not_found }
        format.any { head :not_found }
      end
    end

    def set_locale
      if Iqvoc::Concept.pref_labeling_languages.include?(nil)
        I18n.locale = " "
      elsif params[:lang] && Iqvoc::Concept.pref_labeling_languages.include?(params[:lang])
        I18n.locale = params[:lang]
      else
        I18n.locale = Iqvoc::Concept.pref_labeling_languages.first
      end
    end

    def concept_widget_data(concept)
      {
        :id => concept.origin,
        :name => concept.pref_label.value.to_s + (concept.additional_info ? " (#{concept.additional_info })" : "")
      }
    end

    def collection_widget_data(collection)
      {
        :id => collection.origin,
        :name => collection.pref_label.to_s
      }
    end

    def label_widget_data(label)
      {
        :id => label.origin,
        :name => label.value
      }
    end

    # Configurable Ability class
    def current_ability
      @current_ability ||= Iqvoc.ability_class.new(current_user)
    end

    def current_user_session
      return @current_user_session if defined?(@current_user_session)
      @current_user_session = UserSession.find
    end

    def current_user
      return @current_user if defined?(@current_user)
      @current_user = current_user_session && current_user_session.user
    end

    # TODO: Don't require an user (this is skipped in nearly every controller).
    # Use Abilitys instead and handle the AccessDeniedException: (#handle_access_denied)
    # * User logged in: Exception!
    # * User not logged in: Redirect to login path!
    # Don't forget to delete this method and all the /.*before_filter :require_user/
    # statements in the controllers.
    def require_user
      unless current_user
        flash[:error] = I18n.t("txt.controllers.application.login_required")
        redirect_to new_user_session_url(:back_to => request.fullpath)
        return false
      end
    end

  end
end