"""Exception hierarchy for the PMP reference node.

Every error raised intentionally by this package derives from
:class:`PMPError`, so callers (the CLI, tests, embedding applications)
can catch one base class.  Subclasses indicate *where* in the stack the
failure happened, which matters for a system whose whole point is
auditable integrity: a :class:`SignatureError` is a very different event
from an :class:`AdapterError`.
"""
from __future__ import annotations


class PMPError(Exception):
    """Base class for all errors raised by the PMP reference node."""


class CanonicalizationError(PMPError):
    """A value cannot be represented in canonical JSON form.

    Raised when a document contains non-finite floats, non-string object
    keys, or unsupported Python types.  Canonical bytes are the basis of
    every hash and signature, so this is always a programming error in
    the producer of the document, never recoverable data.
    """


class KeyStoreError(PMPError):
    """Key material could not be created, loaded, or parsed."""


class SignatureError(PMPError):
    """A cryptographic signature is missing, malformed, or invalid."""


class OperationError(PMPError):
    """An operation is structurally invalid (bad fields, bad body, bad op_id)."""


class LogIntegrityError(PMPError):
    """The append-only log is broken: bad hash chain, bad sequence, or
    on-disk bytes that do not match their canonical form."""


class AdapterError(PMPError):
    """An import adapter could not read or parse its source material."""


class NodeError(PMPError):
    """Node-level configuration or lifecycle failure (init/open/import)."""