use crate::api::conn::Command;
use crate::api::method::BoxFuture;
use crate::api::Connection;
use crate::api::Result;
use crate::method::OnceLockExt;
use crate::opt::WaitFor;
use crate::Surreal;
use std::borrow::Cow;
use std::future::IntoFuture;
#[derive(Debug)]
#[must_use = "futures do nothing unless you `.await` or poll them"]
pub struct UseDb<'r, C: Connection> {
	pub(super) client: Cow<'r, Surreal<C>>,
	pub(super) ns: Option<String>,
	pub(super) db: String,
}
impl<C> UseDb<'_, C>
where
	C: Connection,
{
		pub fn into_owned(self) -> UseDb<'static, C> {
		UseDb {
			client: Cow::Owned(self.client.into_owned()),
			..self
		}
	}
}
impl<'r, Client> IntoFuture for UseDb<'r, Client>
where
	Client: Connection,
{
	type Output = Result<()>;
	type IntoFuture = BoxFuture<'r, Self::Output>;
	fn into_future(self) -> Self::IntoFuture {
		Box::pin(async move {
			let router = self.client.router.extract()?;
			router
				.execute_unit(Command::Use {
					namespace: self.ns,
					database: Some(self.db),
				})
				.await?;
			self.client.waiter.0.send(Some(WaitFor::Database)).ok();
			Ok(())
		})
	}
}