-- AP-A1-PM-2: Progression graph — join_gate, strand binding, recurring strand

ALTER TABLE roadmap_items
    DROP CONSTRAINT IF EXISTS roadmap_items_item_type_check;

ALTER TABLE roadmap_items
    ADD CONSTRAINT roadmap_items_item_type_check
    CHECK (item_type IN (
        'milestone', 'review_gate', 'maturity_stage', 'work_cycle', 'join_gate'
    ));

ALTER TABLE roadmap_items
    ADD COLUMN IF NOT EXISTS strand_project_id UUID NULL
        REFERENCES projects(id) ON DELETE SET NULL;

CREATE INDEX IF NOT EXISTS idx_roadmap_items_strand
    ON roadmap_items(tenant_id, strand_project_id)
    WHERE strand_project_id IS NOT NULL;

ALTER TABLE recurring_elements
    ADD COLUMN IF NOT EXISTS project_id UUID NULL
        REFERENCES projects(id) ON DELETE SET NULL;

CREATE INDEX IF NOT EXISTS idx_recurring_elements_project
    ON recurring_elements(tenant_id, project_id)
    WHERE project_id IS NOT NULL;