SqlDelightDao.kt

class SqlDelightDao() {
  /**
  * Create a SqlDriver instance, which will maintain connections to an underlying SQL database and provide APIs 
  * for managing transactions and executing SQL statements.
  * Params are a Schema of the generated database, an application context and a name of db
  */
  private val driver: SqlDriver = AndroidSqliteDriver(Database.Schema, context, "caching.db")
  // Instance of the generated database instance with adapter. Movie is a generated entoty
  private val database = Database(driver, Movie.Adapter(DateAdapter()))
  // Instance of generated MoviesQueries interface
  private val queries = database.moviesQueries
  
  override suspend fun save(movies: List<Movie>) {
    movies.forEach { movie ->
      queries.insert(movie) // insert is the label that was set to INSERT query in movies.sq file
    }
  }

  override fun getMovies(): Flow<List<Movie>> = 
      queries.selectAll() // selectAll is the label that was set to SELECT query in movies.sq file
      .asFlow() // convert to Coroutines Flow
      .map { query ->
        query.executeAsList().map { movie ->
          Movie(
              id = movie.id,
              backdropPath = movie.backdropPath.orEmpty(),
              posterPath = movie.posterPath.orEmpty(),
              title = movie.title.orEmpty(),
              overview = movie.overview.orEmpty(),
              releaseDate = movie.releaseDate ?: Date(),
          )
        }
      }
}