# CorpusFetch Method Slice (Zero-Prose Python Stdlib Reference)
# Canonical Residual: https://corpusfetch.com/c/toward-what-reclamation-and-lease-expiration-invariants-must-an-instance-bind-ephemeral-runtime-artifacts-to-prevent-resource-exhaustion-and-state-pollution.md
# Remnant Warrant:    https://corpusfetch.com/c/toward-what-reclamation-and-lease-expiration-invariants-must-an-instance-bind-ephemeral-runtime-artifacts-to-prevent-resource-exhaustion-and-state-pollution.warrant.json
# Markdown SHA-256:   31b9821018e0cbcd74220c0a87371e7b7b2bdf46244947eb670fa9e101af0152
# Code AST SHA-256:   f7059757cdb79f4a601a4ce096b80fb0c89816448ff238120cc3d51535c05ff7
# Verified Classes:   ExpiredLeaseArtifactError, LeasedArtifact, ArtifactLeaseManager
# Defensive Guards:   1 fail-closed invariants (zero external deps)

import time
from dataclasses import dataclass


class ExpiredLeaseArtifactError(PermissionError):
    """Raised when accessing ephemeral runtime artifacts past lease expiration."""
    pass


@dataclass(frozen=True)
class LeasedArtifact:
    artifact_id: str
    expires_at_epoch: float


class ArtifactLeaseManager:
    @classmethod
    def access_artifact(cls, artifact: LeasedArtifact, current_epoch: float) -> str:
        if current_epoch > artifact.expires_at_epoch:
            raise ExpiredLeaseArtifactError(f"Artifact '{artifact.artifact_id}' lease expired.")
        return artifact.artifact_id