require "final_destination" require "mini_mime" require "open-uri" class FileHelper def self.is_image?(filename) filename =~ images_regexp end def self.download(url, max_file_size:, tmp_file_name:, follow_redirect: false, read_timeout: 5, skip_rate_limit: false) url = "https:" + url if url.start_with?("//") raise Discourse::InvalidParameters.new(:url) unless url =~ /^https?:\/\// uri = FinalDestination.new( url, max_redirects: follow_redirect ? 5 : 1, skip_rate_limit: skip_rate_limit ).resolve return unless uri.present? downloaded = uri.open("rb", read_timeout: read_timeout) extension = File.extname(uri.path) if extension.blank? && downloaded.content_type.present? ext = MiniMime.lookup_by_content_type(downloaded.content_type)&.extension ext = "jpg" if ext == "jpe" extension = "." + ext if ext.present? end tmp = Tempfile.new([tmp_file_name, extension]) File.open(tmp.path, "wb") do |f| while f.size <= max_file_size && data = downloaded.read(512.kilobytes) f.write(data) end end tmp ensure downloaded&.close! rescue nil end private def self.images @@images ||= Set.new %w{jpg jpeg png gif tif tiff bmp svg webp ico} end def self.images_regexp @@images_regexp ||= /\.(#{images.to_a.join("|")})$/i end end