-- Dead man's switches become a team's own configuration.
--
-- They were three environment variables — TERDUT_DEADMAN_MATCHERS, _TIMEOUT and
-- _SEVERITY — which made them one setting for the whole install. That was the
-- last piece of the alerting path a team could not control: a team could take
-- its own alerts on its own key and still not say which of them were
-- heartbeats, or how long a silence had to last before somebody was paged.
--
-- One row per team rather than one row per switch. The unit of monitoring is
-- still the fingerprint, as it always was — two clusters sending the same
-- heartbeat alertname are two independent switches — and the matcher string
-- keeps the format the environment variable used, so a value can be moved from
-- one to the other unchanged.
--
-- No rows are seeded here: a migration cannot read the environment. The server
-- inserts a row per team at startup from its own configuration, and the same
-- values therefore carry forward into the first team's row without anybody
-- retyping them. See seedDeadmanConfigs.
CREATE TABLE deadman_configs (
    team_id BIGINT PRIMARY KEY REFERENCES teams(id) ON DELETE CASCADE,

    -- ";" separates matchers, "," the label conditions within one, "=" is exact
    -- equality: `alertname=Watchdog,cluster=prod; alertname=EdgeHeartbeat`.
    -- Every matcher must name an alertname. Empty watches nothing.
    matchers TEXT NOT NULL DEFAULT '',

    -- Seconds rather than a Go duration string: the column is compared and
    -- arithmetic is done on it, and a value that has to be parsed before it can
    -- be believed is a value that can be stored unparseable. Zero disables the
    -- team's switches entirely.
    timeout_seconds BIGINT NOT NULL DEFAULT 0,

    -- The severity these incidents open at. They have no member alerts to
    -- derive one from, and a heartbeat's own severity label is meaningless —
    -- Watchdog ships as "none".
    severity TEXT NOT NULL DEFAULT 'critical',

    updated_at BIGINT NOT NULL DEFAULT FLOOR(EXTRACT(EPOCH FROM now()))::bigint
);