#-- encoding: UTF-8
#-- copyright
# OpenProject is a project management system.
#
# Copyright (C) 2012-2013 the OpenProject Team
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License version 3.
#
# See doc/COPYRIGHT.rdoc for more details.
#++

require 'will_paginate'

module PaginationHelper
  def pagination_links_full(paginator, options = {})
    merged_options = { next_label: I18n.t(:label_next),
                       previous_label: I18n.t(:label_next),
                       container: true }.merge(options)

    html = ''.html_safe

    if paginator.total_entries > 0
      html << will_paginate(paginator, merged_options.merge({ :container => false }) )

      html << content_tag(:span, "(#{paginator.offset + 1} - #{paginator.offset + paginator.length}/#{paginator.total_entries})", :class => 'range')

      if per_page_links && links = per_page_links(paginator.per_page)
        html << links
      end
    end

    merged_options[:container] ?
      content_tag(:p, html, :class => "pagination") :
      html
  end

  def per_page_links(selected=nil)
    links = Setting.per_page_options_array.collect do |n|
      n == selected ?
              content_tag(:span, n, :class => 'current') :
              link_to_content_update(n, params.merge(:per_page => n))
    end
    content_tag :span, :class => 'per_page_options' do
      links.size > 1 ? l(:label_display_per_page, links.join(', ')).html_safe : nil
    end
  end

  # Returns page option used for pagination
  # based on:
  #  * offset
  #  * limit
  #  * page
  #  parameters.
  #  Preferes page over the other two and
  #  calculates page in it's absence based on limit and offset.
  #  Return 1 if all else fails.

  def page_param(options = params)
    page = if options[:page]

             options[:page].to_i

           elsif options[:offset] && options[:limit]

             begin
              # + 1 as page is not 0 but 1 based
              options[:offset].to_i/per_page_param(options) + 1
             rescue ZeroDivisionError
               1
             end

           else

             1

           end

    page > 0 ?
      page :
      1
  end

  # Returns per_page option used for pagination
  # based on:
  #  * per_page session value
  #  * per_page options value
  #  * limit options value
  #  in that order
  #  Return smallest possible setting if all else fails.

  def per_page_param(options = params)
    per_page_candidates = [session[:per_page].to_i, options[:per_page].to_i, options[:limit].to_i]

    unless (union = per_page_candidates & Setting.per_page_options_array).empty?
      session[:per_page] = union.first

      union.first
    else
      Setting.per_page_options_array.sort.first
    end
  end
end