PRAGMA journal_mode=WAL;
PRAGMA synchronous=NORMAL;
PRAGMA foreign_keys=ON;

CREATE TABLE IF NOT EXISTS sessions (
  session_id TEXT PRIMARY KEY,
  start_ts   REAL NOT NULL,
  end_ts     REAL,
  device_id  TEXT,
  note       TEXT
);

CREATE TABLE IF NOT EXISTS gnss_pvt (
  id         INTEGER PRIMARY KEY AUTOINCREMENT,
  session_id TEXT NOT NULL,
  ts_utc     TEXT,
  unix_ts    REAL NOT NULL,
  iTOW_ms    INTEGER,
  lat        REAL,
  lon        REAL,
  height_m   REAL,
  hmsl_m     REAL,
  hacc_m     REAL,
  vacc_m     REAL,
  fix_type   INTEGER,
  carr_soln  INTEGER,
  diff_soln  INTEGER,
  gnss_ok    INTEGER,
  num_sats   INTEGER,
  source     TEXT,
  synced     INTEGER DEFAULT 0,
  FOREIGN KEY(session_id) REFERENCES sessions(session_id)
);

CREATE INDEX IF NOT EXISTS idx_gnss_session_time 
  ON gnss_pvt(session_id, unix_ts);

CREATE INDEX IF NOT EXISTS idx_gnss_unsynced 
  ON gnss_pvt(synced) WHERE synced=0;