Rework request routing slightly

src/server.rs

@@ -1,6 +1,5 @@
 use std::borrow::Cow;
 use std::io::Cursor;
-use std::ops::Deref;
 
 use tiny_http::Header;
 use tiny_http::Request;
@@ -31,8 +30,7 @@ pub fn go(domains: &[&str]) {
 /// Each route represents a set of logic that should be used to respond to the request,
 /// and the necessary information from the request in order to do so
 pub enum Route<'a> {
-	Next(&'a str),
-	Prev(&'a str),
+	PrevOrNext(&'a str, isize),
 	NotFound,
 }
 
@@ -40,20 +38,17 @@ impl<'a> Route<'a> {
 
 	/// Given a request, parse out the appropriate Route for that request
 	pub fn parse_request(r: &'a Request) -> Self {
-		let segments: Vec<_> = r.url()
-			.split('/')
-			.filter(|s| !s.is_empty())
-			.collect();
+		let (first_segment, referrer_domain) = r.url()
+			.trim_matches('/')
+			.split_once('/')
+			.unwrap_or((r.url(), "missing_referrer_domain"));
 
-		// TODO automatically detect a fallback url from the request's Referer header
-		let referrer_domain = segments.get(1).map(|s| *s).unwrap_or("missing_referrer_domain");
-
-		match segments.get(0).map(Deref::deref) {
-			Some("next") => {
-				Route::Next(referrer_domain)
+		match first_segment {
+			"next" => {
+				Route::PrevOrNext(referrer_domain, 1)
 			},
-			Some("prev") => {
-				Route::Prev(referrer_domain)
+			"prev" => {
+				Route::PrevOrNext(referrer_domain, -1)
 			},
 			_ => Route::NotFound,
 		}
@@ -62,13 +57,7 @@ impl<'a> Route<'a> {
 	/// Generate a Response for this route
 	pub fn render<'b>(&self, domains: &[&'b str]) -> Response<Cursor<Cow<'b, [u8]>>> {
 		match self {
-			Self::Next(this_domain) | Self::Prev(this_domain) => {
-
-				let offset: isize = if let Self::Next(_) = self {
-					1
-				} else {
-					-1
-				};
+			Self::PrevOrNext(this_domain, offset) => {
 
 				let destination = domains.iter()
 					.position(|d| d.starts_with(this_domain))