BEGIN;

-- Replicas start together during a rollout, so serialize schema creation.
SELECT pg_advisory_xact_lock(hashtext('nereus_schema_migration'));

CREATE TABLE IF NOT EXISTS buoys (
    id          UUID PRIMARY KEY,
    name        TEXT NOT NULL,
    latitude    DOUBLE PRECISION NOT NULL,
    longitude   DOUBLE PRECISION NOT NULL,
    created_at  TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE TABLE IF NOT EXISTS readings (
    id           UUID PRIMARY KEY,
    buoy_id      UUID NOT NULL REFERENCES buoys(id) ON DELETE CASCADE,
    water_temp   DOUBLE PRECISION NOT NULL,
    wave_height  DOUBLE PRECISION NOT NULL,
    salinity     DOUBLE PRECISION,
    recorded_at  TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE INDEX IF NOT EXISTS idx_readings_buoy_time ON readings (buoy_id, recorded_at DESC);

COMMIT;