generate_share_image_with_text.rb

class SharePhoto

  attr_reader :image

  SRC_PATH = Rails.root.join("app/assets/images/private_share/")

  def self.update_all
    source_files = SRC_PATH.join("src/backgrounds")

    Dir.foreach(source_files).each do |image_name|
      next if image_name == "." or image_name == ".." or image_name == ".DS_Store"
      share_photo = SharePhoto.new(image_name)
      share_photo.render
      share_photo.image.format "png"

      FileUtils.mv share_photo.image.path, SRC_PATH.join("v3").join(File.basename(image_name, ".*") + ".png")
    end
  end

  def self.update_vk_all
    source_files = SRC_PATH.join("vk/src/backgrounds")

    Dir.foreach(source_files).each do |image_name|
      next if image_name == "." or image_name == ".." or image_name == ".DS_Store"

      share_photo = SharePhoto.new(image_name, "vk/")
      share_photo.render_vk
      # share_photo.image.format "png"

      FileUtils.mv share_photo.image.path, SRC_PATH.join("vk2").join(image_name)
    end
  end

  def initialize(source_background, project_prefix = "")
    @project_prefix = project_prefix
    @background_path = private_share_path("backgrounds/#{source_background}")
  end

  def render
    @image = background

    @image = add_text(@image, " Путешествие\n на двоих\n от Hotellook") do |t|
      t.pointsize '80'
      t.interline_spacing "20"
    end

    hl_logo = MiniMagick::Image.open private_share_path('hl_logo.png')
    @image = add_logo(@image, hl_logo)

    cta = MiniMagick::Image.open private_share_path('cta_win.png')
    @image = add_button(@image, cta)

    label = MiniMagick::Image.open private_share_path('label.png')
    @image = add_label(@image, label)

    # @image.format "png"

    @image
  rescue MiniMagick::Error => error
    Rails.logger.error "Error generate image"
    Rollbar.report_exception(error)

    nil
  end

  def render_vk
    @image = background

    @image = add_text(@image, " Путешествие\n на двоих\n от Hotellook", x: 14, y: 50) do |t|
    t.pointsize '34'
    t.interline_spacing "8"
    end

    # hl_logo = MiniMagick::Image.open private_share_path('hl_logo.png')
    # @image = add_logo(@image, hl_logo)

    cta = MiniMagick::Image.open private_share_path('cta_win.png')
    @image = add_button(@image, cta)

    @image.format "jpg"

    @image
  rescue MiniMagick::Error => error
    Rails.logger.error "Error generate image"
    Rollbar.report_exception(error)

    nil
  end

  def add_text(image, message, x: 110, y: 170)
    text_color =  "#ffffffff"
    escape = ->(str) { str.gsub("'", "\\\\'") }

    image.combine_options do |c|
      # NorthWest, North, NorthEast, West, Center, East, SouthWest, South, or SouthEast
      #c.gravity 'Center'

      # for more info see(http://www.imagemagick.org/Usage/fonts/#advanced)
      c.font font_path("Intro")
      c.family "Intro"

      c.weight "600"
      c.style "Normal"
      c.quality "100"

      c.undercolor "none"
      yield(c) if block_given?
      c.fill text_color
      c.draw("text #{x},#{y} '#{escape[message]}'")
    end
  end

  def background
    MiniMagick::Image.open @background_path
  end

  def add_logo(background, logo)
    background.composite(logo) do |c|
      c.compose "src-over"
    end
  end

  def add_button(background, logo)
    background.composite(logo) do |c|
      c.compose "src-over"
    end
  end

  def add_label(background, label)
    background.composite(label) do |c|
      c.compose "src-over"
    end
  end

  private

  def private_share_path(path)
    SRC_PATH.join(@project_prefix).join("src").join(path)
  end

  def font_path(file_name)
    "#{Rails.root}/app/assets/fonts/#{file_name}.ttf".tap do |path|
      raise "Error font not found: #{path}" unless File.exist?(path)
    end
  end

end