class AgentError(Exception):
    """Base error with a stable public code."""

    code = "AGENT_ERROR"
    status_code = 500

    def __init__(self, message: str) -> None:
        super().__init__(message)
        self.message = message


class ValidationAgentError(AgentError):
    code = "VALIDATION_ERROR"
    status_code = 400


class UnauthorizedAgentError(AgentError):
    code = "UNAUTHORIZED"
    status_code = 401


class AgentTypeNotFoundError(ValidationAgentError):
    code = "AGENT_TYPE_NOT_FOUND"
    status_code = 404


class ForbiddenAgentError(AgentError):
    code = "FORBIDDEN"
    status_code = 403


class ConflictAgentError(AgentError):
    code = "CONFLICT"
    status_code = 409


class IdempotencyConflictError(ConflictAgentError):
    code = "IDEMPOTENCY_CONFLICT"


class RecoverableAgentError(AgentError):
    code = "RECOVERABLE_ERROR"
    status_code = 503


class RunLeaseLostError(ConflictAgentError):
    code = "RUN_LEASE_LOST"


class ResourceNotFoundError(AgentError):
    code = "RESOURCE_NOT_FOUND"
    status_code = 404