ipgallery_import.rb

module IPGallery

  class LegacyCategory
    include DataMapper::Resource

    storage_names[:default] = "gallery_categories"

    has n, :albums, 'LegacyAlbum', child_key: [:category_id]
    has n, :images, 'LegacyImage'
    has n, :child_categories, self.name, child_key: [:parent]
    belongs_to :parent_category, self.name, child_key: [:parent]

    property :id, Serial
    property :title, String, field: 'name'
    property :description, String
    property :parent, Integer

    def attr_to_be_imported
      attributes = self.attributes.extract!(:title, :description)
      attributes.each {|key, value| attributes[key] = CGI.unescape_html(value)}.merge(legacy_id: self.id)
    end
  end

  class LegacyAlbum
    include DataMapper::Resource

    storage_names[:default] = "gallery_albums"

    has n, :images, 'LegacyImage'
    belongs_to :category, 'LegacyCategory'

    property :id, Serial
    property :title, String, field: 'name'
    property :description, String
    property :category_id, Integer

    def attr_to_be_imported
      attributes = self.attributes.extract!(:title, :description)
      attributes.each {|key, value| attributes[key] = CGI.unescape_html(value)}.merge(legacy_id: self.id)
    end
  end

  class LegacyImage
    include DataMapper::Resource

    storage_names[:default] = "gallery_images"

    belongs_to :category, 'LegacyCategory'
    belongs_to :album, 'LegacyAlbum'

    property :id, Serial
    property :category_id, Integer
    property :album_id, Integer
    property :directory, String
    property :file_name, String, field: 'masked_file_name'

    def file_path(upload_root)
      path = File.join(upload_root, directory, file_name)
      File.file?(path) && %w(.jpg .jpeg .gif .png).include?(File.extname(path)) ? path : nil
    end
  end

  class Import

    def initialize(upload_root)
      config = YAML.load_file(File.join(Rails.root, 'config/legacy_import.yml'))
      DataMapper::Logger.new(STDOUT, :warn)
      DataMapper.setup(:default, config['ipgallery'])
      @upload_root = upload_root
    end

    def start
      import_categories
      import_albums
      import_images
      puts 'Import Successful!'
    rescue Exception => e
      Category.destroy_all(conditions: {:legacy_id.exists => true})
      raise e
    end

    def import_categories
      Category.collection.insert(LegacyCategory.all.collect {|lc| lc.attr_to_be_imported})
      categories = Category.where(:legacy_id.exists => true)
      progress_bar = ProgressBar.new('Category Import', categories.count)
      categories.each do |category|
        category.send(:generate_slug!)
        legacy_category = LegacyCategory.get(category.legacy_id)
        unless legacy_category.parent.eql?(0)
          category.parent_category = Category.where(legacy_id: legacy_category.parent).first
        end
        category.save
        progress_bar.inc
      end
      progress_bar.finish
    end

    def import_albums
      Album.collection.insert(LegacyAlbum.all.collect {|la| la.attr_to_be_imported})
      albums = Album.where(:legacy_id.exists => true)
      progress_bar = ProgressBar.new('Album Import', albums.count)
      albums.each do |album|
        album.send(:generate_slug!)
        legacy_album = LegacyAlbum.get(album.legacy_id)
        unless legacy_album.category_id.eql?(0)
          album.category = Category.where(legacy_id: legacy_album.category_id).first
        end
        album.save
        progress_bar.inc
      end
      progress_bar.finish
    end

    def import_images
      progress_bar = ProgressBar.new('Image Import', LegacyImage.count(:album_id.not => 0))
      LegacyImage.all(:album_id.not => 0).each do |legacy_image|
        if image_file_path = legacy_image.file_path(@upload_root)
          if image_album = Album.where(legacy_id: legacy_image.album_id).first
            begin
              image = Image.new
              image.album = image_album
              image.image = File.open(image_file_path)
              image.save
            rescue Exception => e
              puts e.message
            end
          end
        end
        progress_bar.inc
      end
      progress_bar.finish
    end
  end
end