import pg from "pg";

const pool = new pg.Pool({
  connectionString: "postgresql://nate@localhost:5432/gtfs"
});

async function dbQuery(sql, params = []) {
  const client = await pool.connect();
  try {
    const res = await client.query(sql, params);
    return res.rows;
  } finally {
    client.release();
  }
}

function toNumber(v) {
  const n = Number(v);
  return Number.isFinite(n) ? n : undefined;
}


export async function getVehicles() {
  const rows = await dbQuery(
    `SELECT vehicle_id, route_num, route_name, destination,
            bearing, speed, latitude, longitude
     FROM vehicles`
  );

  return rows.map((v) => ({
    vehicleId: v.vehicle_id,
    routeNum: v.route_num,
    routeName: v.route_name,
    destination: v.destination,
    bearing: v.bearing == null ? undefined : toNumber(v.bearing),
    speed: v.speed == null ? undefined : toNumber(v.speed),
    location: {
      latitude: toNumber(v.latitude),
      longitude: toNumber(v.longitude),
    },
  }));
}

export async function getVehicleById(id) {
  if (id == null) return null;

  const rows = await dbQuery(
    `SELECT vehicle_id, route_num, route_name, destination,
            bearing, speed, latitude, longitude
     FROM vehicles
     WHERE vehicle_id = $1`,
    [String(id)]
  );

  if (!rows.length) return null;
  const v = rows[0];

  return {
    vehicleId: v.vehicle_id,
    routeNum: v.route_num,
    routeName: v.route_name,
    destination: v.destination,
    bearing: v.bearing == null ? undefined : toNumber(v.bearing),
    speed: v.speed == null ? undefined : toNumber(v.speed),
    location: {
      latitude: toNumber(v.latitude),
      longitude: toNumber(v.longitude),
    },
  };
}


export async function getRoutes() {
  const rows = await dbQuery(`SELECT data FROM routes ORDER BY route_id`);
  return rows.map((r) => r.data);
}

export async function getRouteById(routeId) {
  if (routeId == null) return null;

  const rows = await dbQuery(
    `SELECT data FROM routes WHERE route_id = $1`,
    [String(routeId)]
  );

  return rows[0]?.data || null;
}


export async function getRoutePathsMap() {
  const rows = await dbQuery(`SELECT route_id, path FROM route_paths`);
  const map = {};
  for (const row of rows) {
    map[String(row.route_id)] = row.path;
  }
  return map;
}

export async function getRoutePath(routeId) {
  if (routeId == null) return null;

  const rows = await dbQuery(
    `SELECT path FROM route_paths WHERE route_id = $1`,
    [String(routeId)]
  );

  return rows[0]?.path || null;
}


function transformationStationRow(row) {
  return {
    stop_id: row.stop_id,
    stop_code: row.stop_code,
    stop_name: row.stop_name,
    stop_desc: row.stop_desc,
    location: {
      latitude: toNumber(row.latitude),
      longitude: toNumber(row.longitude),
    },
    stop_url: row.stop_url,
    location_type: row.location_type,
    parent_station: row.parent_station,
    lines: row.lines, // text[]
  };
}

export async function getStationsRaw() {
  const rows = await dbQuery(`SELECT * FROM stations`);
  return rows;
}

export async function getStations() {
  const rows = await dbQuery(`SELECT * FROM stations`);
  return rows.map(transformationStationRow);
}

export async function getStopsByRoute(routeId) {
  if (routeId == null) return [];
  const rows = await dbQuery(
    `SELECT * FROM stations WHERE lines @> ARRAY[$1]::text[]`,
    [String(routeId)]
  );
  return rows.map(transformationStationRow);
}

export async function getStationById(id) {
  if (id == null) return null;

  const rows = await dbQuery(
    `SELECT * FROM stations WHERE stop_id = $1`,
    [String(id)]
  );

  if (!rows.length) return null;
  return transformationStationRow(rows[0]);
}