# Redmine - project management software

# Copyright (C) 2006-2017  Jean-Philippe Lang

#

# This program is free software; you can redistribute it and/or

# modify it under the terms of the GNU General Public License

# as published by the Free Software Foundation; either version 2

# of the License, or (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.



require 'zlib'



class WikiContentVersion < ActiveRecord::Base

  belongs_to :page, :class_name => 'WikiPage'

  belongs_to :author, :class_name => 'User'



  acts_as_event :title => Proc.new {|o| "#{l(:label_wiki_edit)}: #{o.page.title} (##{o.version})"},

                :description => :comments,

                :datetime => :updated_on,

                :type => 'wiki-page',

                :group => :page,

                :url => Proc.new {|o| {:controller => 'wiki', :action => 'show', :project_id => o.page.wiki.project, :id => o.page.title, :version => o.version}}



  acts_as_activity_provider :type => 'wiki_edits',

                            :timestamp => "#{table_name}.updated_on",

                            :author_key => "#{table_name}.author_id",

                            :permission => :view_wiki_edits,

                            :scope => select("#{table_name}.updated_on, #{table_name}.comments, " +

                                             "#{table_name}.version, #{WikiPage.table_name}.title, " +

                                             "#{table_name}.page_id, #{table_name}.author_id, " +

                                             "#{table_name}.id").

                                      joins("LEFT JOIN #{WikiPage.table_name} ON #{WikiPage.table_name}.id = #{table_name}.page_id " +

                                            "LEFT JOIN #{Wiki.table_name} ON #{Wiki.table_name}.id = #{WikiPage.table_name}.wiki_id " +

                                            "LEFT JOIN #{Project.table_name} ON #{Project.table_name}.id = #{Wiki.table_name}.project_id")



  after_destroy :page_update_after_destroy



  def text=(plain)

    case Setting.wiki_compression

    when 'gzip'

    begin

      self.data = Zlib::Deflate.deflate(plain, Zlib::BEST_COMPRESSION)

      self.compression = 'gzip'

    rescue

      self.data = plain

      self.compression = ''

    end

    else

      self.data = plain

      self.compression = ''

    end

    plain

  end



  def text

    @text ||= begin

      str = case compression

            when 'gzip'

              Zlib::Inflate.inflate(data)

            else

              # uncompressed data

              data

            end

      str.force_encoding("UTF-8")

      str

    end

  end



  def project

    page.project

  end



  def attachments

    page.nil? ? [] : page.attachments

  end



  # Return true if the content is the current page content

  def current_version?

    page.content.version == self.version

  end



  # Returns the previous version or nil

  def previous

    @previous ||= WikiContentVersion.

      reorder(version: :desc).

      includes(:author).

      where("wiki_content_id = ? AND version < ?", wiki_content_id, version).first

  end



  # Returns the next version or nil

  def next

    @next ||= WikiContentVersion.

      reorder(version: :asc).

      includes(:author).

      where("wiki_content_id = ? AND version > ?", wiki_content_id, version).first

  end



  private



  # Updates page's content if the latest version is removed

  # or destroys the page if it was the only version

  def page_update_after_destroy

    latest = page.content.versions.reorder(version: :desc).first

    if latest && page.content.version != latest.version

      raise ActiveRecord::Rollback unless page.content.revert_to!(latest)

    elsif latest.nil?

      raise ActiveRecord::Rollback unless page.destroy

    end

  end

end