-- migrate:up

CREATE TABLE slo.targets (
    metric          text PRIMARY KEY,
    threshold       numeric NOT NULL,
    window_seconds  int NOT NULL,
    description     text,
    updated_at      timestamptz NOT NULL DEFAULT now()
);

INSERT INTO slo.targets (metric, threshold, window_seconds, description) VALUES
    ('fix_freshness_pct_60s', 95,  300, 'Pct of active devices with a fix within 90s, window 5 min'),
    ('parser_lag_p95_sec',    30,  300, 'P95 of received_at -> events.parsed insertion lag, window 5 min'),
    ('contract_drift_days',    1, 86400, 'Days since last successful sandbox contract validation');

CREATE TABLE slo.measurements (
    measurement_id  bigserial,
    metric          text NOT NULL REFERENCES slo.targets(metric),
    value           numeric NOT NULL,
    measured_at     timestamptz NOT NULL DEFAULT now(),
    PRIMARY KEY (measurement_id, measured_at)
);

SELECT create_hypertable('slo.measurements', 'measured_at', chunk_time_interval => INTERVAL '7 days');

CREATE INDEX slo_measurements_metric_time_idx
    ON slo.measurements (metric, measured_at DESC);

CREATE OR REPLACE VIEW slo.v_current_status AS
SELECT
    t.metric,
    t.threshold,
    t.window_seconds,
    latest.value             AS current_value,
    latest.measured_at       AS measured_at,
    CASE
        WHEN latest.value IS NULL THEN 'unknown'
        WHEN t.metric LIKE '%pct%'
             AND latest.value >= t.threshold THEN 'green'
        WHEN t.metric LIKE '%pct%'
             AND latest.value <  t.threshold THEN 'red'
        WHEN latest.value <= t.threshold THEN 'green'
        ELSE 'red'
    END AS status
FROM slo.targets t
LEFT JOIN LATERAL (
    SELECT value, measured_at
      FROM slo.measurements m
     WHERE m.metric = t.metric
     ORDER BY measured_at DESC
     LIMIT 1
) latest ON true;

-- migrate:down

DROP VIEW IF EXISTS slo.v_current_status;
DROP TABLE IF EXISTS slo.measurements;
DROP TABLE IF EXISTS slo.targets;