module Textrepo

  ##
  # Following errors might occur in repository operations:
  #   +---------------------------------+-----------------------+
  #   | operation (args)                | error type            |
  #   +---------------------------------+-----------------------+
  #   | create (timestamp, text)        | Duplicate timestamp   |
  #   |                                 | Empty text            |
  #   +---------------------------------+-----------------------+
  #   | read   (timestamp)              | Missing timestamp     |
  #   +---------------------------------+-----------------------+
  #   | update (timestamp, text)        | Mssing timestamp      |
  #   |                                 | Empty text            |
  #   +---------------------------------+-----------------------+
  #   | delete (timestamp)              | Missing timestamp     |
  #   +---------------------------------+-----------------------+
  #   | search (pattern, stamp_pattern) | Invalid search result |
  #   +---------------------------------+-----------------------+

  class Error < StandardError; end

  # :stopdoc:
  module ErrMsg
    UNKNOWN_REPO_TYPE   = 'unknown type for repository: %s'
    DUPLICATE_TIMESTAMP = 'duplicate timestamp: %s'
    EMPTY_TEXT          = 'empty text'
    MISSING_TIMESTAMP   = 'missing timestamp: %s'
    INVALID_TIMESTAMP_STRING = "invalid string as timestamp: %s"
    INVALID_SEARCH_RESULT = "invalid result by searcher: %s"
  end
  # :startdoc:

  ##
  # An error raised if unknown type was specified as the repository
  # type.

  class UnknownRepoTypeError < Error
    def initialize(type)
      super(ErrMsg::UNKNOWN_REPO_TYPE % type)
    end
  end

  ##
  # An error raised if the specified timestamp has already exist in
  # the repository.

  class DuplicateTimestampError < Error
    def initialize(timestamp)
      super(ErrMsg::DUPLICATE_TIMESTAMP % timestamp)
    end
  end

  ##
  # An error raised if the given text is empty.

  class EmptyTextError < Error
    def initialize
      super(ErrMsg::EMPTY_TEXT)
    end
  end

  ##
  # An error raised if the given timestamp has not exist in the
  # repository.

  class MissingTimestampError < Error
    def initialize(timestamp)
      super(ErrMsg::MISSING_TIMESTAMP % timestamp)
    end
  end

  ##
  # An error raised if an argument is invalid to convert a
  # Textrepo::Timestamp object.

  class InvalidTimestampStringError < Error
    def initialize(str)
      super(ErrMsg::INVALID_TIMESTAMP_STRING % str)
    end
  end

  ##
  # An error raise if the search result is not suitable to use.
  #

  class InvalidSearchResultError < Error
    def initialize(str)
      super(ErrMsg::INVALID_SEARCH_RESULT % str)
    end
  end

end