mod dir;
pub use dir::*;

mod s3;
pub use s3::*;

pub mod misc;

/// A read-only set of [Item]s.
pub trait DataSource {
	/// Get the number of items in this source
	fn len(&self) -> usize;

	/// Get an item from this datasource
	fn get(
		&self,
		key: &str,
	) -> impl Future<Output = Result<Option<crate::value::Item>, std::io::Error>> + Send;

	/// Iterate over all items in this source in sorted key order
	fn iter(&self) -> impl Iterator<Item = &crate::value::Item>;

	/// Iterate over a page of items, sorted by key
	fn iter_page(&self, offset: usize, limit: usize) -> impl Iterator<Item = &crate::value::Item> {
		self.iter().skip(offset).take(limit)
	}

	/// Return the time of the latest change to the data in this source
	fn latest_change(
		&self,
	) -> impl Future<Output = Result<Option<chrono::DateTime<chrono::Utc>>, std::io::Error>> + Send;
}