pub(crate) fn get_hostname() -> String {
    std::env::var("ATUIN_HOST_NAME")
        .unwrap_or_else(|_| whoami::hostname().unwrap_or_else(|_| "unknown-host".to_string()))
}

pub(crate) fn get_username() -> String {
    std::env::var("ATUIN_HOST_USER")
        .unwrap_or_else(|_| whoami::username().unwrap_or_else(|_| "unknown-user".to_string()))
}

/// Returns a pair of the hostname and username, separated by a colon.
pub(crate) fn get_host_user() -> String {
    format!("{}:{}", get_hostname(), get_username())
}

/// Setup a [`SQLite`] database.
///
/// This takes care of correct locking, so that we avoid a race when setting up the database.
macro_rules! setup_db {
    (
        $db_path:expr,
        $a_timeout:expr,
        $opts:expr,
        $m_name:literal $(,)?
    ) => {{
        async fn migrate(pool: &SqlitePool) -> sqlx::Result<()> {
            { sqlx::sqlx_macros::migrate!($m_name) }.run(pool).await?;
            Ok(())
        }

        crate::atuin_client::utils::setup_db_inner($db_path, $a_timeout, $opts, migrate)
    }};
}
pub(crate) use setup_db;

use std::{os::fd::AsRawFd, path::Path, time::Duration};

use fs_err::OpenOptions;
use sqlx::{
    SqlitePool,
    sqlite::{SqliteConnectOptions, SqlitePoolOptions},
};
use tracing::debug;

/// Helper for `setup_db!`
pub(crate) async fn setup_db_inner(
    db_path: &Path,
    acquire_timeout: f64,
    mk_opts: fn(&str) -> sqlx::Result<SqliteConnectOptions>,
    migrate: impl AsyncFn(&SqlitePool) -> sqlx::Result<()>,
) -> sqlx::Result<SqlitePool> {
    async fn open_db(timeout: f64, opts: SqliteConnectOptions) -> sqlx::Result<SqlitePool> {
        let pool = SqlitePoolOptions::new()
            .acquire_timeout(Duration::from_secs_f64(timeout))
            .connect_with(opts)
            .await?;

        Ok(pool)
    }

    {
        let file = OpenOptions::new()
            .read(true)
            .write(true)
            .create(true)
            .open(db_path)?;

        // Lock the db file while we are running the migrations.
        // Why? Because there is a small chance that we start running migrations (e.g. as the daemon)
        // and then another process is started, which will also try to run migrations.
        // Essentially, one of the processes will receive with a SQLite UNIQUE constraint failure.
        // So let's avoid that possibility from the start.
        file.lock()?;

        let pool = open_db(
            acquire_timeout,
            mk_opts(format!("/proc/self/fd/{}", file.as_raw_fd()).as_str())?,
        )
        .await?;

        debug!("running sqlite database setup");

        migrate(&pool).await?;

        file.unlock()?;
    }

    let real_opts = mk_opts(db_path.to_str().expect("Should be utf-8"))?;
    let pool = open_db(acquire_timeout, real_opts).await?;

    Ok(pool)
}