# frozen_string_literal: true

module Decidim
  # This class deals with uploading attachments to a participatory space.
  class AttachmentUploader < ApplicationUploader
    include CarrierWave::MiniMagick

    process :set_content_type_and_size_in_model
    process :validate_dimensions
    process :strip

    version :thumbnail, if: :image? do
      process resize_to_fit: [nil, 237]
    end

    version :big, if: :image? do
      process resize_to_limit: [nil, 1000]
    end

    def extension_whitelist
      case upload_context
      when :admin
        Decidim.organization_settings(model).upload_allowed_file_extensions_admin
      else
        Decidim.organization_settings(model).upload_allowed_file_extensions
      end
    end

    # CarrierWave automatically calls this method and validates the content
    # type fo the temp file to match against any of these options.
    def content_type_whitelist
      case upload_context
      when :admin
        Decidim.organization_settings(model).upload_allowed_content_types_admin
      else
        Decidim.organization_settings(model).upload_allowed_content_types
      end
    end

    protected

    # Strips out all embedded information from the image
    def strip
      return unless image?(self)

      manipulate! do |img|
        img.strip
        img
      end
    end

    def upload_context
      return :participant unless model.respond_to?(:context)

      model.context
    end

    # Checks if the file is an image based on the content type. We need this so
    # we only create different versions of the file when it's an image.
    #
    # new_file - The uploaded file.
    #
    # Returns a Boolean.
    def image?(new_file)
      content_type = model.content_type || new_file.content_type
      content_type.to_s.start_with? "image"
    end

    # Copies the content type and file size to the model where this is mounted.
    #
    # Returns nothing.
    def set_content_type_and_size_in_model
      model.content_type = file.content_type if file.content_type
      model.file_size = file.size
    end

    # A simple check to avoid DoS with maliciously crafted images, or just to
    # avoid reckless users that upload gigapixels images.
    #
    # See https://hackerone.com/reports/390
    def validate_dimensions
      return unless image?(self)

      manipulate! do |image|
        raise CarrierWave::IntegrityError, I18n.t("carrierwave.errors.image_too_big") if image.dimensions.any? { |dimension| dimension > max_image_height_or_width }

        image
      end
    end

    def max_image_height_or_width
      8000
    end
  end
end