import Database from 'better-sqlite3';
import path from 'path';

const DB_PATH = path.join(process.cwd(), 'data', 'bodenfeuchte.db');

let db: Database.Database;

export function getDb(): Database.Database {
  if (!db) {
    db = new Database(DB_PATH);
    db.exec(`
      CREATE TABLE IF NOT EXISTS measurements (
        id        INTEGER PRIMARY KEY AUTOINCREMENT,
        timestamp INTEGER NOT NULL,
        soil_moisture REAL NOT NULL
      );
      CREATE INDEX IF NOT EXISTS idx_timestamp ON measurements(timestamp);
    `);
  }
  return db;
}

export function insertMeasurement(soilMoisture: number): void {
  const stmt = getDb().prepare(
    'INSERT INTO measurements (timestamp, soil_moisture) VALUES (?, ?)'
  );
  stmt.run(Date.now(), soilMoisture);
}

export function getLast6Hours(): { timestamp: number; soil_moisture: number }[] {
  const since = Date.now() - 6 * 60 * 60 * 1000;
  return getDb()
    .prepare(
      'SELECT timestamp, soil_moisture FROM measurements WHERE timestamp >= ? ORDER BY timestamp ASC'
    )
    .all(since) as { timestamp: number; soil_moisture: number }[];
}