# hx/listing/recursiveindex - Recursive index generator
#
# 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 'hx'
require 'hx/listing/limit'
require 'hx/listing/paginate'
require 'set'

module Hx
module Listing

class RecursiveIndex
  include Hx::Filter

  def self.new(input, options)
    listing = super(input, options)
    if options.has_key? :limit
      listing = Limit.new(listing, :limit => options[:limit])
    end
    if options.has_key? :page_size
      listing = Paginate.new(listing, :page_size => options[:page_size])
    end
    listing
  end

  def initialize(input, options)
    @input = input
  end

  def merge_updated(index, entry)
    updated = [entry, index].map { |e| e['updated'] }.compact.max
    index['updated'] = updated if updated
  end
  private :merge_updated

  def each_entry_path(selector)
    emitted = Set.new
    @input.each_entry_path(Path::ALL) do |path, entry|
      components = path.split("/")
      until components.empty?
        components.pop
        index_path = (components + ["index"]).join("/")
        break if emitted.include? index_path
        yield index_path if selector.accept_path? index_path
        emitted.add index_path
      end
    end
    self
  end

  def get_entry(path)
    raise NoSuchEntryError, path unless path =~ %r!^((?:.*/)?)index$!
    prefix = $1
    selector = Path.parse_pattern("#{prefix}**")
    index = {'items' => []}
    @input.each_entry(selector) do |child_path, entry|
      if child_path == path
        index = entry.merge(index)
      else
        index['items'] << {'path' => child_path, 'entry' => entry}
      end
      merge_updated(index, entry)
    end
    raise NoSuchEntryError, path if index['items'].empty?
    index
  end
end

end
end