module Onebox
  module Engine
    class GithubBlobOnebox
      include Engine
      include LayoutSupport

      MAX_LINES = 20
      MAX_CHARS = 5000

      matches_regexp(/^https?:\/\/(www\.)?github\.com.*\/blob\//)

      private

      def raw
        return @raw if @raw
        m = @url.match(/github\.com\/(?<user>[^\/]+)\/(?<repo>[^\/]+)\/blob\/(?<sha1>[^\/]+)\/(?<file>[^#]+)(#(L(?<from>[^-]*)(-L(?<to>.*))?))?/mi)
        if m
          from = (m[:from] || -1).to_i
          to = (m[:to] || -1).to_i
          @file = m[:file]
          contents = open("https://raw.github.com/#{m[:user]}/#{m[:repo]}/#{m[:sha1]}/#{m[:file]}", read_timeout: timeout).read
          if from > 0
            if to < 0
              from = from - 10
              to = from + 20
            end
            if to > from
              contents = contents.split("\n")[from..to].join("\n")
            end
          end
          if contents.length > MAX_CHARS
            contents = contents[0..MAX_CHARS]
            @truncated = true
          end

          split = contents.split("\n")
          if split.length > MAX_LINES
            contents = split[0..MAX_LINES].join("\n")
            @truncated = true
          end
          @raw = contents
        end
      end

      def data
        @data ||= {title: link.sub(/^https?\:\/\//, ''),
                   link: link,
                   content: raw,
                   truncated: @truncated}
      end
    end
  end
end