# frozen_string_literal: true

# This file is part of Alexandria.
#
# See the file README.md for authorship and licensing information.

class GdkPixbuf::Pixbuf
  def tag(tag_pixbuf)
    # Computes some tweaks.
    tweak_x = tag_pixbuf.width / 3
    tweak_y = tag_pixbuf.height / 3

    # Creates the destination pixbuf.
    new_pixbuf = GdkPixbuf::Pixbuf.new(colorspace: :rgb,
                                       has_alpha: true,
                                       bits_per_sample: 8,
                                       width: width + tweak_x,
                                       height: height + tweak_y)

    # Fills with blank.
    new_pixbuf.fill!(0)

    # Copies the current pixbuf there (south-west).
    copy_area(0, 0,
              width, height,
              new_pixbuf,
              0, tweak_y)

    # Copies the tag pixbuf there (north-est).
    tag_pixbuf_x = width - (tweak_x * 2)
    new_pixbuf.composite!(tag_pixbuf,
                          dest_x: 0, dest_y: 0,
                          dest_width: tag_pixbuf.width + tag_pixbuf_x,
                          dest_height: tag_pixbuf.height,
                          offset_x: tag_pixbuf_x, offset_y: 0,
                          scale_x: 1, scale_y: 1,
                          interpolation_type: :hyper, overall_alpha: 255)
    new_pixbuf
  end
end

module Alexandria
  module UI
    module Icons
      include Logging

      ICONS_DIR = File.join(Alexandria::Config::DATA_DIR, "icons")
      def self.init
        load_icon_images
      end

      # loads icons from icons_dir location and gives them as uppercase constants to
      # Alexandria::UI::Icons namespace, e.g., Icons::STAR_SET
      def self.load_icon_images
        Dir.entries(ICONS_DIR).each do |file|
          next unless /\.png$/.match?(file) # skip non '.png' files

          # Don't use upcase and use tr instead
          # For example in Turkish the upper case of 'i' is still 'i'.
          name = File.basename(file, ".png").tr("a-z", "A-Z")
          const_set(name, GdkPixbuf::Pixbuf.new(file: File.join(ICONS_DIR, file)))
        end
      end

      def self.cover(library, book)
        begin
          return BOOK_ICON if library.nil?

          filename = library.cover(book)
          return GdkPixbuf::Pixbuf.new(file: filename) if File.exist?(filename)
        rescue GdkPixbuf::PixbufError
          log.error do
            "Failed to load GdkPixbuf::Pixbuf," \
              " please ensure that #{filename} is a valid image file"
          end
        end
        BOOK_ICON
      end

      def self.blank?(filename)
        pixbuf = GdkPixbuf::Pixbuf.new(file: filename)
        (pixbuf.width == 1) && (pixbuf.height == 1)
      rescue StandardError => ex
        puts ex.message
        puts ex.backtrace.join("\n> ")
        true
      end
    end
  end
end