-- Migration 009: Workflow State Persistence
-- Replaces DashMap (in-memory, lost on restart) with durable SurrealDB storage.
-- WorkflowInstance is stored as a JSON document; status is a tagged serde enum.

DEFINE TABLE workflow_instances SCHEMAFULL;

DEFINE FIELD id           ON TABLE workflow_instances TYPE record<workflow_instances>;
DEFINE FIELD template_name ON TABLE workflow_instances TYPE string  ASSERT $value != NONE;
DEFINE FIELD status       ON TABLE workflow_instances FLEXIBLE TYPE any ASSERT $value != NONE;
DEFINE FIELD stages       ON TABLE workflow_instances FLEXIBLE TYPE array;
DEFINE FIELD current_stage_idx ON TABLE workflow_instances TYPE int DEFAULT 0;
DEFINE FIELD initial_context   ON TABLE workflow_instances FLEXIBLE TYPE object;
DEFINE FIELD accumulated_artifacts ON TABLE workflow_instances FLEXIBLE TYPE object DEFAULT {};
DEFINE FIELD created_at   ON TABLE workflow_instances TYPE datetime DEFAULT time::now();
DEFINE FIELD updated_at   ON TABLE workflow_instances TYPE datetime DEFAULT time::now() VALUE time::now();

DEFINE INDEX idx_workflow_instances_template
    ON TABLE workflow_instances COLUMNS template_name;

DEFINE INDEX idx_workflow_instances_created_at
    ON TABLE workflow_instances COLUMNS created_at;