-- Adds job groups: every job belongs to a job_group (defaults to its own
-- job_name when not given explicitly, set by broker_add_job). A dependency
-- can now target a whole group instead of a single job id -- the dependent
-- job is claimable once every job tagged with that group has completed
-- (complete_status = 2); already-completed group members simply drop out of
-- the gating check, they don't need to have existed at any particular time.
-- The existing id-based dependency (broker_job_dependency.depends_on_job_id)
-- is kept as-is; each dependency row targets exactly one of an id or a group.

ALTER TABLE broker.broker_jobs ADD COLUMN IF NOT EXISTS job_group TEXT;
UPDATE broker.broker_jobs SET job_group = job_name WHERE job_group IS NULL;
ALTER TABLE broker.broker_jobs ALTER COLUMN job_group SET NOT NULL;

CREATE INDEX IF NOT EXISTS idx_broker_jobs_group
    ON broker.broker_jobs (tenant_id, job_group, complete_status);

ALTER TABLE broker.broker_job_dependency DROP CONSTRAINT IF EXISTS broker_job_dependency_pkey;
ALTER TABLE broker.broker_job_dependency ALTER COLUMN depends_on_job_id DROP NOT NULL;
ALTER TABLE broker.broker_job_dependency ADD COLUMN IF NOT EXISTS depends_on_group TEXT;
ALTER TABLE broker.broker_job_dependency ADD COLUMN IF NOT EXISTS id_broker_job_dependency BIGSERIAL;
ALTER TABLE broker.broker_job_dependency ADD PRIMARY KEY (id_broker_job_dependency);

ALTER TABLE broker.broker_job_dependency DROP CONSTRAINT IF EXISTS broker_job_dependency_one_target;
ALTER TABLE broker.broker_job_dependency ADD CONSTRAINT broker_job_dependency_one_target CHECK (
    (depends_on_job_id IS NOT NULL AND depends_on_group IS NULL) OR
    (depends_on_job_id IS NULL AND depends_on_group IS NOT NULL)
);

-- Plain (non-partial) unique constraint, matching the old PK's guarantee --
-- NULLs in depends_on_job_id (the group-dependency rows) are never
-- considered equal by a standard unique constraint, so this only constrains
-- id-based rows, and keeps "ON CONFLICT (job_id, depends_on_job_id)" (no
-- predicate needed) working for existing callers.
ALTER TABLE broker.broker_job_dependency DROP CONSTRAINT IF EXISTS broker_job_dependency_unique_id;
ALTER TABLE broker.broker_job_dependency ADD CONSTRAINT broker_job_dependency_unique_id
    UNIQUE (job_id, depends_on_job_id);
CREATE UNIQUE INDEX IF NOT EXISTS idx_broker_job_dependency_unique_group
    ON broker.broker_job_dependency (job_id, depends_on_group) WHERE depends_on_group IS NOT NULL;

COMMENT ON COLUMN broker.broker_jobs.job_group IS 'Group tag for this job; defaults to job_name. Other jobs can depend on the whole group.';
COMMENT ON COLUMN broker.broker_job_dependency.depends_on_group IS 'Alternative to depends_on_job_id: job_id is not claimable until every job with job_group = depends_on_group has completed';