<?php declare(strict_types=1);
require __DIR__ . '/../vendor/autoload.php';
use Dotenv\Dotenv;
$dotenv = Dotenv::createImmutable(__DIR__ . '/..'); $dotenv->safeLoad();
const JSON_OPTS = JSON_UNESCAPED_SLASHES|JSON_UNESCAPED_UNICODE;
function json($data, int $code=200): void {
  http_response_code($code);
  header('Content-Type: application/json; charset=utf-8');
  echo json_encode($data, JSON_OPTS); exit;
}
function db(): PDO {
  static $pdo; if ($pdo) return $pdo;
  $path = $_ENV['SQLITE_PATH'] ?? (__DIR__.'/iot.sqlite');
  $pdo = new PDO('sqlite:'.$path, null, null, [
    PDO::ATTR_ERRMODE=>PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE=>PDO::FETCH_ASSOC,
  ]);
  $pdo->exec("
    CREATE TABLE IF NOT EXISTS device (id TEXT PRIMARY KEY, token TEXT NOT NULL, created_at TEXT NOT NULL);
    CREATE TABLE IF NOT EXISTS reading (id INTEGER PRIMARY KEY AUTOINCREMENT, device_id TEXT NOT NULL, ts INTEGER NOT NULL, data TEXT NOT NULL);
    CREATE INDEX IF NOT EXISTS idx_reading_dev_ts ON reading(device_id, ts);
  ");
  return $pdo;
}
function require_token(PDO $pdo): string {
  $hdr=$_SERVER['HTTP_AUTHORIZATION']??''; $api=$_SERVER['HTTP_X_API_KEY']??''; $t='';
  if (preg_match('/Bearer\s+(.+)/i',$hdr,$m)) $t=trim($m[1]); elseif ($api) $t=$api;
  if ($t==='') json(['error'=>'missing token'],401);
  $st=$pdo->prepare("SELECT id FROM device WHERE token=:t LIMIT 1"); $st->execute([':t'=>$t]); $r=$st->fetch();
  if(!$r) json(['error'=>'invalid token'],401); return $r['id'];
}