-- Metrics captured from the Prometheus an alert came from (its generatorURL),
-- once when the incident opens and once when it closes, so the graph outlives
-- Prometheus' own retention. One row per incident, alert and kind.
--
-- A row exists whether or not the capture worked: a failure is recorded in
-- error with the attempt count, which is what stops the worker from retrying a
-- host that is not on the allowlist (or is gone) forever.

CREATE TABLE incident_metric_snapshots (
    id bigint GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
    incident_id bigint NOT NULL REFERENCES incidents(id) ON DELETE CASCADE,
    alert_id bigint NOT NULL REFERENCES alerts(id) ON DELETE CASCADE,
    kind text NOT NULL CHECK (kind IN ('opened', 'closed')),
    expr text NOT NULL DEFAULT '',
    window_start bigint NOT NULL,
    window_end bigint NOT NULL,
    step_seconds integer NOT NULL DEFAULT 0,
    series jsonb NOT NULL DEFAULT '[]'::jsonb,
    error text,
    attempts integer NOT NULL DEFAULT 1,
    captured_at bigint NOT NULL,
    UNIQUE (incident_id, alert_id, kind)
);

CREATE INDEX incident_metric_snapshots_alert_id_idx ON incident_metric_snapshots (alert_id);