require 'flydata/source'
require 'flydata/source/component'
require 'flydata/source/errors'

module Flydata
module Source

class GenerateSourceDump < Component
  def self.inherited(child_class)
    Source.register(child_class, self)
  end

  def initialize(source, dp, options)
    super(source, options)
    @dp = dp
  end
  attr_reader :dp

  # Public Interface: Run compatibility check
  #
  # Run whatever check (compatibility, connectivity, privilege, etc) to ensure
  # that initial sync can run without an issue.
  #
  # dump_dir: A directory path string to the dump directory
  # backup_dir: A directory path string to the backup directory
  #
  # Raises exception when check fails
  def run_compatibility_check(dump_dir, backup_dir)
    raise UnsupportedSourceError,  "subclass must implement"
  end

  # Public Interface: Confirmation items
  #
  # Returns a hash of items to be shown as the final confirmation before
  # initial sync.
  #  Example: Return value {"host" => "ubertas","port" => 3306}
  #           will be displayed as
  #               host: ubertas
  #               port: 3306
  def confirmation_items
    raise UnsupportedSourceError,  "subclass must implement"
  end

  # Public Interface: Dump size
  #
  # tables: An array of table names to be dumped.
  #
  # Returns an approximate size of dump in bytes.  The value may be a
  # best-effort estimate.  It doesn't have to be accurate.
  def dump_size(tables)
    raise UnsupportedSourceError,  "subclass must implement"
  end

  # Public Interface: Dump data
  #
  # tables: An array of tables to be dumped.
  # file_path: A file path string of the dump file to which data is written.
  #         This value may be nil, in which case contents are written to a
  #         pipe.
  # src_pos_callback: A callback called when the source position of the dump
  #         becomes available. The callback takes the following arguments.
  #           io: Input IO to the dump.
  #           src_pos: Source position of the dump
  #
  # Returns none
  def dump(tables, file_path = nil, &src_pos_callback)
    raise UnsupportedSourceError,  "subclass must implement"
  end
end

end
end