feat: add Campaign work orchestration contract

src/govoplan_core/core/campaigns.py

@@ -3,7 +3,7 @@ from __future__ import annotations
 from collections.abc import Callable, Iterable, Mapping
 from dataclasses import dataclass, field
 from datetime import datetime
-from typing import Protocol, runtime_checkable
+from typing import Literal, Protocol, runtime_checkable
 
 
 CAPABILITY_CAMPAIGNS_MAIL_POLICY_CONTEXT = "campaigns.mailPolicyContext"
@@ -12,6 +12,20 @@ CAPABILITY_CAMPAIGNS_POLICY_CONTEXT = "campaigns.policyContext"
 CAPABILITY_CAMPAIGNS_DELIVERY_TASKS = "campaigns.deliveryTasks"
 CAPABILITY_CAMPAIGNS_SCHEDULES = "campaigns.schedules"
 CAPABILITY_CAMPAIGNS_RETENTION = "campaigns.retention"
+CAPABILITY_CAMPAIGNS_WORK_ORCHESTRATION = "campaigns.workOrchestration"
+
+CampaignWorkAssigneeKind = Literal[
+    "account",
+    "group",
+    "organization_function",
+]
+CampaignWorkHandoffStatus = Literal[
+    "open",
+    "in_progress",
+    "completed",
+    "rejected",
+    "cancelled",
+]
 
 
 @dataclass(frozen=True, slots=True)
@@ -32,6 +46,88 @@ class CampaignPolicyContext:
     settings: Mapping[str, object] = field(default_factory=dict)
 
 
+@dataclass(frozen=True, slots=True)
+class CampaignWorkHandoffRequest:
+    """Typed request used by Workflow to open accountable Campaign work."""
+
+    tenant_id: str
+    idempotency_key: str
+    purpose: str
+    assignee_kind: CampaignWorkAssigneeKind
+    assignee_id: str
+    campaign_id: str | None = None
+    create_external_id: str | None = None
+    create_name: str | None = None
+    create_description: str | None = None
+    expected_campaign_revision: int | None = None
+    due_at: datetime | None = None
+    mirror_to_tasks: bool = True
+    correlation_id: str | None = None
+    workflow_instance_id: str | None = None
+    workflow_step_id: str | None = None
+
+    def __post_init__(self) -> None:
+        for value, label in (
+            (self.tenant_id, "Campaign hand-off tenant"),
+            (self.idempotency_key, "Campaign hand-off idempotency key"),
+            (self.purpose, "Campaign hand-off purpose"),
+            (self.assignee_id, "Campaign hand-off assignee"),
+        ):
+            if not value.strip():
+                raise ValueError(f"{label} is required")
+        references_existing = bool(self.campaign_id and self.campaign_id.strip())
+        creates_new = bool(
+            self.create_external_id
+            and self.create_external_id.strip()
+            and self.create_name
+            and self.create_name.strip()
+        )
+        if references_existing == creates_new:
+            raise ValueError(
+                "Campaign hand-offs must either reference one campaign or "
+                "declare one new campaign."
+            )
+        if self.expected_campaign_revision is not None and (
+            self.expected_campaign_revision < 1
+        ):
+            raise ValueError("Expected Campaign revisions start at one")
+        if self.due_at is not None and self.due_at.tzinfo is None:
+            raise ValueError("Campaign hand-off due dates require a timezone")
+
+
+@dataclass(frozen=True, slots=True)
+class CampaignWorkHandoffRef:
+    """Stable, revision-bearing reference returned to the Workflow instance."""
+
+    tenant_id: str
+    campaign_id: str
+    campaign_version_id: str
+    campaign_revision: int
+    assignment_id: str
+    assignment_revision: int
+    status: CampaignWorkHandoffStatus
+    action_url: str
+    campaign_ref: str
+    assignment_ref: str
+    event_type: str = "campaign.work.changed"
+    replayed: bool = False
+    optional_capabilities: Mapping[str, bool] = field(default_factory=dict)
+    provenance: Mapping[str, object] = field(default_factory=dict)
+
+
+@dataclass(frozen=True, slots=True)
+class CampaignWorkHandoffInspection:
+    """Current authorization and revision check before Workflow continuation."""
+
+    allowed: bool
+    status: CampaignWorkHandoffStatus | None = None
+    assignment_revision: int | None = None
+    action_url: str | None = None
+    assignment_ref: str | None = None
+    reason: str | None = None
+    provenance: Mapping[str, object] = field(default_factory=dict)
+
+
 @runtime_checkable
 class CampaignMailPolicyContextProvider(Protocol):
     def get_campaign_mail_policy_context(
@@ -132,3 +228,45 @@ class CampaignRetentionProvider(Protocol):
         policy_for_campaign_id: Callable[[str | None], object],
     ) -> Mapping[str, Mapping[str, int]]:
         ...
+
+
+@runtime_checkable
+class CampaignWorkOrchestrationProvider(Protocol):
+    """Optional Campaign boundary for durable Workflow-owned hand-offs."""
+
+    def prepare_handoff(
+        self,
+        session: object,
+        principal: object,
+        *,
+        request: CampaignWorkHandoffRequest,
+    ) -> CampaignWorkHandoffRef:
+        ...
+
+    def inspect_handoff(
+        self,
+        session: object,
+        principal: object,
+        *,
+        tenant_id: str,
+        assignment_id: str,
+        expected_revision: int | None = None,
+    ) -> CampaignWorkHandoffInspection:
+        ...
+
+
+def campaign_work_orchestration_provider(
+    registry: object | None,
+) -> CampaignWorkOrchestrationProvider | None:
+    if (
+        registry is None
+        or not hasattr(registry, "has_capability")
+        or not registry.has_capability(CAPABILITY_CAMPAIGNS_WORK_ORCHESTRATION)
+    ):
+        return None
+    capability = registry.capability(CAPABILITY_CAMPAIGNS_WORK_ORCHESTRATION)
+    return (
+        capability
+        if isinstance(capability, CampaignWorkOrchestrationProvider)
+        else None
+    )