module EY
  module Backup
    module CLI #rename to option parser and config loader
      extend self

      def run(argv)
        options = default_options.merge(opt_parse(argv))

        config_path = options[:config] || "/etc/.#{options[:engine]}.backups.yml"

        config_for(config_path).merge(options)
      end

      def default_options
        {
          :command => :new_backup,
          :format => "gzip",
          :engine => 'mysql',
        }
      end

      def opt_parse(argv)
        # Build a parser for the command line arguments
        options = {}

        opts = OptionParser.new do |opts|
          opts.version = EY::CloudServer::VERSION

          opts.banner = "Usage: eybackup [-flag] [argument]"
          opts.define_head "eybackup: manage dump (mysqldump/pg_dump) style backups of your database."
          opts.separator '*'*80

          opts.on("-l", "--list-backup DATABASE", "List mysql backups for DATABASE") do |db|
            if db == "all"
              db = nil
            end
            options[:db] = db
            options[:command] = :list
          end

          opts.on("-n", "--new-backup", "Create new mysql backup") do
            options[:command] = :new_backup
          end

          opts.on("-c", "--config CONFIG", "Use config file.") do |config|
            options[:config] = config
          end

          opts.on("-b", "--bucket BUCKET", "Override default S3 bucket name. (Be Careful!)") do |bucket|
            options[:backup_bucket] = bucket
          end

          opts.on("-t", "--tmp_dir TMPDIR", "Use the given directory for temporary storage.") do |tmp_dir|
            options[:tmp_dir] = tmp_dir
          end

          opts.on("-d", "--download BACKUP_INDEX", "download the backup specified by index. Run eybackup -l to get the index.") do |index_and_db|
            options[:command] = :download
            db, index = split_index(index_and_db)
            options[:index] = index
            options[:db] = db
          end

          opts.on("-e", "--engine DATABASE_ENGINE", "The database engine. ex: mysql, postgres.") do |engine|
            options[:engine] = engine
          end

          opts.on("-r", "--restore BACKUP_INDEX", "Download and apply the backup specified by index WARNING! will overwrite the current db with the backup. Run eybackup -l to get the index.") do |index_and_db|
            options[:command] = :restore
            db, index = split_index(index_and_db)
            options[:index] = index
            options[:db] = db
          end

          opts.on("-k", "--key KEYID", "Public key ID to use for the backup operation") do |key_id|
            options[:key_id] = key_id
          end

          opts.on("-q", "--quiet", "Supress output to STDOUT") do
            options[:quiet] = true
          end

          opts.on("-s", "--split_size INTEGER", "Maximum size of a single backup file before splitting.") do |split_size|
            options[:split_size] = split_size.to_i
          end
        end

        opts.parse!(argv)

        options
      end

      def split_index(index)
        index.split(':').reverse
      end

      def config_for(filename)
        if File.exist?(filename)
          # Make the loaded config have symbols rather than strings
          config_orig = YAML::load(File.read(filename))
          config = {}
          config_orig.each do |key, val|
            config[key.to_sym] = val
          end
          config[:environment] ||= config[:env]
          config
        else
          abort "You need to have a backup file at #{filename}"
        end
      end
    end
  end
end