collection.rb

require 'mime/types'
require 'RMagick'
require 'yaml'

module NerdNode
  module Photo
    class Collection

      # A list of valid MIME types.
      TYPES = %w{
        image/bmp
        image/gif
        image/jpeg
        image/png
      }

      # Reads in a hash of photo collections in the format of:
      #   {
      #     'Collection Name' => {
      #       'photos' => '/path/to/photos',
      #       'thumbs' => '/path/to/thumbs',
      #     }
      #   }
      def self.from_config(config)
        collections = []
        config.each do |name, options|
          collections << new(name, options['photos'], options['thumbs'])
        end
        collections
      end

      attr_reader :name, :path, :thumb_path

      def initialize(name, path, thumb_path = nil)
        raise "Directory not found: #{path}" unless File.exists?(path)
        @name = name
        @path = path
        @photos = {}
        @thumb_path = thumb_path || File.expand_path("#{File.join(@path, 'thumbs')}")
        read_photos
      end

      def photos
        @photos.keys
      end

      def thumbnails
        @photos.values
      end
      alias_method :thumbs, :thumbnails

      # Returns an array with the base photo path.
      def photo_paths
        photos.map { |photo| remove_from_path(photo, /#{@path}\//) }
      end

      # Returns an array with the base thumbnail photo paths.
      def thumbnail_paths
        thumbnails.map { |thumb| remove_from_path(thumb, /#{@thumb_path}\//) if thumb }
      end
      alias_method :thumb_paths, :thumbnail_paths

      def generate_thumbnails!(*args)
        unless File.exists?(@thumb_path)
          raise "Output directory not found: #{@thumb_path}"
        end

        @photos.each do |photo, thumb|
          thumb = thumbnail_path(photo) unless thumb

          image = Magick::Image.read(photo).first
          image.thumbnail!(*args)
          image.write(thumb)

          @photos[photo] = thumb
        end
      end

      # Returns a URL (semi) safe string of the +name+.
      def url
        url = name.dup
        url.gsub!(/\s/, '_')
        url.downcase!
        url
      end

      # Returns <tt>@photos</tt>, but with relative paths.
      def photo_urls
        urls = {}
        @photos.each do |photo_full, thumb_full|
          photo = remove_from_path(photo_full, /#{@path}\//)
          thumb = thumb_full ? remove_from_path(thumb_full, /#{@thumb_path}\//) : nil
          urls[photo] = thumb
        end
        urls
      end

      private

      def read_photos
        files = Dir["#{@path}/**/*"].select do |file|
          TYPES.include?(MIME::Types.type_for(file).to_s)
        end

        files.reject! { |file| File.directory?(file) }
        files.flatten!

        files.each do |file|
          @photos[file] = File.exists?(thumbnail_path(file)) ? thumbnail_path(file) : nil
        end
      end

      def remove_from_path(path_string, matcher)
        path_string.gsub(matcher, '')
      end

      # Returns the string path of the given <tt>photo</tt>'s thumbnail.
      def thumbnail_path(photo)
        File.expand_path(File.join(@thumb_path, File.basename(photo)))
      end

    end # Collection
  end # Photo
end # NerdNode