//! Database connection setup for the native API server.
//!
//! Provides [`open`] which opens a `tokio-rusqlite` connection, configures
//! SQLite pragmas for WAL mode and foreign key enforcement, and wraps the
//! result in a [`NativeRepository`].

use super::{DbError, NativeRepository};
use tokio_rusqlite::Connection;

/// Open a SQLite database at `path` and return a configured [`NativeRepository`].
///
/// This function:
/// 1. Opens the file-backed SQLite connection via `tokio_rusqlite::Connection::open`.
/// 2. Enables Write-Ahead Logging (`PRAGMA journal_mode=WAL`) for better
///    concurrent read performance.
/// 3. Enables foreign key enforcement (`PRAGMA foreign_keys=ON`) so that
///    `ON DELETE CASCADE` works on the `quote_tags` table.
///
/// Returns `Err(DbError::Internal(...))` if the file cannot be opened or if
/// the pragma commands fail.
///
/// # Examples
///
/// ```no_run
/// # async fn example() -> Result<(), Box<dyn std::error::Error>> {
/// let repo = quotesdb::db::connection::open("quotesdb.sqlite").await?;
/// repo.run_migrations().await?;
/// # Ok(())
/// # }
/// ```
pub async fn open(path: &str) -> Result<NativeRepository, DbError> {
    let conn = Connection::open(path)
        .await
        .map_err(|e| DbError::Internal(format!("failed to open database: {e}")))?;

    // Configure SQLite pragmas on the connection thread
    conn.call(|c| {
        // WAL mode improves concurrent reader throughput
        c.execute_batch("PRAGMA journal_mode=WAL; PRAGMA foreign_keys=ON;")?;
        Ok(())
    })
    .await
    .map_err(|e| DbError::Internal(format!("pragma configuration failed: {e}")))?;

    Ok(NativeRepository::new(conn))
}