92 lines
3.3 KiB
Python

"""Message_instance."""
import enum
from dataclasses import dataclass
from typing import Any
from typing import Optional
from typing import TYPE_CHECKING
from flask_bpmn.models.db import db
from flask_bpmn.models.db import SpiffworkflowBaseDBModel
from sqlalchemy import ForeignKey
from sqlalchemy.event import listens_for
from sqlalchemy.orm import relationship
from sqlalchemy.orm import Session
from sqlalchemy.orm import validates
from spiffworkflow_backend.models.message_model import MessageModel
from spiffworkflow_backend.models.process_instance import ProcessInstanceModel
if TYPE_CHECKING:
from spiffworkflow_backend.models.message_correlation_message_instance import ( # noqa: F401
MessageCorrelationMessageInstanceModel,
)
class MessageTypes(enum.Enum):
"""MessageTypes."""
send = "send"
receive = "receive"
class MessageStatuses(enum.Enum):
"""MessageStatuses."""
ready = "ready"
running = "running"
completed = "completed"
failed = "failed"
@dataclass
class MessageInstanceModel(SpiffworkflowBaseDBModel):
"""Messages from a process instance that are ready to send to a receiving task."""
__tablename__ = "message_instance"
id: int = db.Column(db.Integer, primary_key=True)
process_instance_id: int = db.Column(ForeignKey(ProcessInstanceModel.id), nullable=False) # type: ignore
message_model_id: int = db.Column(ForeignKey(MessageModel.id), nullable=False)
message_model = relationship("MessageModel")
message_correlations_message_instances = relationship(
"MessageCorrelationMessageInstanceModel", cascade="delete"
)
message_type: str = db.Column(db.String(20), nullable=False)
payload: str = db.Column(db.JSON)
status: str = db.Column(db.String(20), nullable=False, default="ready")
failure_cause: str = db.Column(db.Text())
updated_at_in_seconds: int = db.Column(db.Integer)
created_at_in_seconds: int = db.Column(db.Integer)
message_correlations: Optional[dict] = None
@validates("message_type")
def validate_message_type(self, key: str, value: Any) -> Any:
"""Validate_message_type."""
return self.validate_enum_field(key, value, MessageTypes)
@validates("status")
def validate_status(self, key: str, value: Any) -> Any:
"""Validate_status."""
return self.validate_enum_field(key, value, MessageStatuses)
# This runs for ALL db flushes for ANY model, not just this one even if it's in the MessageInstanceModel class
# so this may not be worth it or there may be a better way to do it
#
# https://stackoverflow.com/questions/32555829/flask-validates-decorator-multiple-fields-simultaneously/33025472#33025472
# https://docs.sqlalchemy.org/en/14/orm/session_events.html#before-flush
@listens_for(Session, "before_flush") # type: ignore
def ensure_failure_cause_is_set_if_message_instance_failed(
session: Any, _flush_context: Optional[Any], _instances: Optional[Any]
) -> None:
"""Ensure_failure_cause_is_set_if_message_instance_failed."""
for instance in session.new:
if isinstance(instance, MessageInstanceModel):
if instance.status == "failed" and instance.failure_cause is None:
raise ValueError(
f"{instance.__class__.__name__}: failure_cause must be set if"
" status is failed"
)