# hx/listing/paginate - Listing paginator
#
# Copyright (c) 2009-2010 MenTaLguY <mental@rydia.net>
# 
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
# 
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

require 'rubygems'
require 'hx'

module Hx
module Listing

class Paginate
  include Hx::Source

  def initialize(source, options)
    @source = source
    @page_size = options[:page_size]
  end

  def each_entry
    @source.each_entry do |index_path, index_entry|
      items = index_entry['items'] || []
      if items.empty?
        index_entry = index_entry.dup
        index_entry['pages'] = [index_entry]
        index_entry['page_index'] = 0
        yield index_path, index_entry
      else
        pages = []
        n_pages = (items.size + @page_size - 1) / @page_size
        for num in 0...n_pages
          page_items = items[@page_size * num, @page_size]
          entry = index_entry.dup
          entry['items'] = page_items
          entry['prev_page'] = "#{num}"
          entry['next_page'] = "#{num+2}"
          entry['pages'] = pages
          entry['page_index'] = num
          pages << {'path' => "#{index_path}/#{num+1}", 'entry' => entry}
        end
        pages[0]['path'] = index_path
        pages[0]['entry'].delete('prev_page')
        if pages.size > 1
          index_name = index_path.split('/').last
          pages[0]['entry']['next_page'] = "#{index_name}/2"
          pages[1]['entry']['prev_page'] = "../#{index_name}"
        end
        pages[-1]['entry'].delete('next_page')
        pages.each do |page|
          yield page['path'], page['entry']
        end
      end
    end
    self
  end
end

end
end