module Backup
  class Manager
    def pack
      # saving additional informations
      s = {}
      s[:db_version]         = "#{ActiveRecord::Migrator.current_version}"
      s[:backup_created_at]  = Time.now
      s[:gitlab_version]     = GitlabCi::VERSION
      s[:tar_version]        = tar_version
      tar_file = "#{s[:backup_created_at].to_i}_gitlab_ci_backup.tar"

      Dir.chdir(GitlabCi.config.backup.path) do
        File.open("#{GitlabCi.config.backup.path}/backup_information.yml",
                  "w+") do |file|
          file << s.to_yaml.gsub(/^---\n/,'')
        end

        FileUtils.chmod(0700, ["db", "builds"])

        # create archive
        $progress.print "Creating backup archive: #{tar_file} ... "
        if Kernel.system('tar', '-cf', tar_file, *backup_contents)
          $progress.puts "done".green
        else
          puts "creating archive #{tar_file} failed".red
          abort 'Backup failed'
        end

        upload(tar_file)
      end
      File.join(GitlabCi.config.backup.path, tar_file)
    end

    def upload(tar_file)
      remote_directory = GitlabCi.config.backup.upload.remote_directory
      $progress.print "Uploading backup archive to remote storage #{remote_directory} ... "

      connection_settings = GitlabCi.config.backup.upload.connection
      if connection_settings.blank?
        $progress.puts "skipped".yellow
        return
      end

      connection = ::Fog::Storage.new(connection_settings)
      directory = connection.directories.get(remote_directory)

      if directory.files.create(key: tar_file, body: File.open(tar_file), public: false,
          multipart_chunk_size: GitlabCi.config.backup.upload.multipart_chunk_size)
        $progress.puts "done".green
      else
        puts "uploading backup to #{remote_directory} failed".red
        abort 'Backup failed'
      end
    end

    def cleanup
      $progress.print "Deleting tmp directories ... "
      
      backup_contents.each do |dir|
        next unless File.exist?(File.join(GitlabCi.config.backup.path, dir))

        if FileUtils.rm_rf(File.join(GitlabCi.config.backup.path, dir))
          $progress.puts "done".green
        else
          puts "deleting tmp directory '#{dir}' failed".red
          abort 'Backup failed'
        end
      end
    end

    def remove_old
      # delete backups
      $progress.print "Deleting old backups ... "
      keep_time = GitlabCi.config.backup.keep_time.to_i

      if keep_time > 0
        removed = 0
        
        Dir.chdir(GitlabCi.config.backup.path) do
          file_list = Dir.glob('*_gitlab_ci_backup.tar')
          file_list.map! { |f| $1.to_i if f =~ /(\d+)_gitlab_ci_backup.tar/ }
          file_list.sort.each do |timestamp|
            if Time.at(timestamp) < (Time.now - keep_time)
              if Kernel.system(*%W(rm #{timestamp}_gitlab_ci_backup.tar))
                removed += 1
              end
            end
          end
        end

        $progress.puts "done. (#{removed} removed)".green
      else
        $progress.puts "skipping".yellow
      end
    end

    def unpack
      Dir.chdir(GitlabCi.config.backup.path)

      # check for existing backups in the backup dir
      file_list = Dir.glob("*_gitlab_ci_backup.tar").each.map { |f| f.split(/_/).first.to_i }
      puts "no backups found" if file_list.count == 0

      if file_list.count > 1 && ENV["BACKUP"].nil?
        puts "Found more than one backup, please specify which one you want to restore:"
        puts "rake gitlab:backup:restore BACKUP=timestamp_of_backup"
        exit 1
      end

      tar_file = ENV["BACKUP"].nil? ? File.join("#{file_list.first}_gitlab_ci_backup.tar") : File.join(ENV["BACKUP"] + "_gitlab_ci_backup.tar")

      unless File.exists?(tar_file)
        puts "The specified backup doesn't exist!"
        exit 1
      end

      $progress.print "Unpacking backup ... "

      unless Kernel.system(*%W(tar -xf #{tar_file}))
        puts "unpacking backup failed".red
        exit 1
      else
        $progress.puts "done".green
      end

      ENV["VERSION"] = "#{settings[:db_version]}" if settings[:db_version].to_i > 0

      # restoring mismatching backups can lead to unexpected problems
      if settings[:gitlab_version] != GitlabCi::VERSION
        puts "GitLab CI version mismatch:".red
        puts "  Your current GitLab CI version (#{GitlabCi::VERSION}) differs from the GitLab CI version in the backup!".red
        puts "  Please switch to the following version and try again:".red
        puts "  version: #{settings[:gitlab_version]}".red
        puts
        puts "Hint: git checkout v#{settings[:gitlab_version]}"
        exit 1
      end
    end

    def tar_version
      tar_version = `tar --version`
      tar_version.force_encoding('locale').split("\n").first
    end

    private

    def backup_contents
      ["db", "builds", "backup_information.yml"]
    end

    def settings
      @settings ||= YAML.load_file("backup_information.yml")
    end
  end
end
