"""
<Program Name>
  exceptions.py

<Author>
  Geremy Condra
  Vladimir Diaz <vladimir.v.diaz@gmail.com>

<Started>
  VD: April 4, 2012 Revision.

<Copyright>
  See LICENSE for licensing information.

<Purpose>
  Define exceptions.  The names chosen for exception classes should end in
  'Error' (except where there is a good reason not to).
"""


class Error(Exception):
    """Indicate a generic error."""


class Warning(Warning):  # pylint: disable=redefined-builtin
    """Generic warning.  It is used by the 'warnings' module."""


class FormatError(Error):
    """Indicate an error while validating an object's format."""


class InvalidMetadataJSONError(FormatError):
    """Indicate that a metadata file is not valid JSON."""

    def __init__(self, exception):  # pylint: disable=super-init-not-called
        # Store the original exception.
        self.exception = exception

    def __str__(self):
        # Show the original exception.
        return repr(self.exception)


class UnsupportedAlgorithmError(Error):
    """Indicate an error while trying to identify a user-specified algorithm."""


class BadHashError(Error):
    """Indicate an error while checking the value a hash object."""

    def __init__(
        self, expected_hash, observed_hash
    ):  # pylint: disable=super-init-not-called
        self.expected_hash = expected_hash
        self.observed_hash = observed_hash

    def __str__(self):
        return (
            "Observed hash ("
            + repr(self.observed_hash)
            + ") != expected hash ("
            + repr(self.expected_hash)
            + ")"
        )


class BadPasswordError(Error):
    """Indicate an error after encountering an invalid password."""


class CryptoError(Error):
    """Indicate any cryptography-related errors."""


class BadSignatureError(CryptoError):
    """Indicate that some metadata has a bad signature."""

    def __init__(
        self, metadata_role_name
    ):  # pylint: disable=super-init-not-called
        self.metadata_role_name = metadata_role_name

    def __str__(self):
        return repr(self.metadata_role_name) + " metadata has bad signature."


class UnknownMethodError(CryptoError):
    """Indicate that a user-specified cryptograpthic method is unknown."""


class UnsupportedLibraryError(Error):
    """Indicate that a supported library could not be located or imported."""


class InvalidNameError(Error):
    """Indicate an error while trying to validate any type of named object."""


class NotFoundError(Error):
    """If a required configuration or resource is not found."""


class URLMatchesNoPatternError(Error):
    """If a URL does not match a user-specified regular expression."""


class InvalidConfigurationError(Error):
    """If a configuration object does not match the expected format."""


class StorageError(Error):
    """Indicate an error occured during interaction with an abstracted storage
    backend."""


class UnverifiedSignatureError(Error):
    """Signature could not be verified: either signature was incorrect or
    something failed during process (see VerificationError)"""


class VerificationError(UnverifiedSignatureError):
    """Signature could not be verified because something failed in the process"""