//! # PTTH Core
//! 
//! Common code used by both `ptth_relay` and `ptth_server`.

#![warn (clippy::pedantic)]

/// Wrapper for graceful and forced shutdowns of `ptth_relay` and `ptth_server`
pub mod graceful_shutdown;

/// An abstraction over HTTP that is easy to (de)serialize
pub mod http_serde;

pub mod prelude;

/// `ptth_server` packs its response headers into this request header
/// 
/// This allows the server's response body to be wrapped verbatim
/// in the request body.
/// The header value is the response's status code and headers,
/// wrapped in a MessagePack structure, and encoded in base64
/// to make it ASCII.

pub const PTTH_MAGIC_HEADER: &str = "X-PTTH-2LJYXWC4";

// The arguments are in order so they are in order overall:
// e.g. prefix_match ("/prefix", "/prefix/middle/suffix") -> "/middle/suffix"

#[must_use]
#[deprecated (
    since = "1.4.0",
    note = "Use `str::strip_prefix instead`"
)]
pub fn prefix_match <'a> (prefix: &str, hay: &'a str) -> Option <&'a str>
{
	hay.strip_prefix (prefix)
}

/// Generates 64 bytes of entropy and returns it as Base64

pub fn gen_key () -> String {
	use rand::RngCore;
	let mut buffer = vec! [0_u8; 64];
	rand::thread_rng ().fill_bytes (&mut buffer);
	
	base64::encode (&buffer)
}

#[cfg (test)]
mod tests {
	use super::*;
	#[test]
	fn prefix () {
		for (p, h, expected) in &[
			("/files/", "/files/a", Some ("a")),
			("/files/", "/files/abc/def", Some ("abc/def")),
			("/files/", "/files", None),
			("/files/", "/not_files", None),
			("/files/", "/files/", Some ("")),
		] {
			assert_eq! (prefix_match (*p, *h), *expected);
		}
	}
}