From 8d8cfe33fa4621e448f7fde61f3814170d25325b Mon Sep 17 00:00:00 2001
From: Compositr <compositr@compositr.dev>
Date: Fri, 1 Nov 2024 21:14:47 +1100
Subject: [PATCH] feat: dynmaic request path handling

---
 src/handlers.rs      | 82 +++++++++++++++++++++++++++++++++++++-------
 src/http/requests.rs | 16 +++++++++
 2 files changed, 85 insertions(+), 13 deletions(-)

diff --git a/src/handlers.rs b/src/handlers.rs
index 8b5e103..b2dbbe1 100644
--- a/src/handlers.rs
+++ b/src/handlers.rs
@@ -1,5 +1,5 @@
 use crate::http::{
-    requests::{Request, RequestStatus},
+    requests::{Request, RequestStatus, URL},
     responses::{Response, UnitOrBoxedError},
 };
 use std::{
@@ -7,17 +7,19 @@ use std::{
     net::{Shutdown, TcpListener},
 };
 
+type HandlerFn = fn(Request) -> Response<'static>;
+
 // Collection of handlers for requests
-pub struct Handlers<FnT> {
-    matchers: HashMap<String, FnT>,
+pub struct Handlers {
+    matchers: HashMap<String, HandlerFn>,
 }
 
-impl<FnT> Handlers<FnT>
-where
-    FnT: Fn(Request) -> Response<'static>,
-{
+impl Handlers {
+    /// Create a new Handlers struct to handle requests
+    ///
+    /// !! This struct does nothing until you add handlers to it (add_handler) and then bind it to a TcpListener !!
     pub fn new() -> Self {
-        Handlers::<FnT> {
+        Handlers {
             matchers: HashMap::new(),
         }
     }
@@ -28,7 +30,7 @@ where
     ///
     /// path: Path to match (no trailing /)
     /// handler: Function to handle the request. Must return a Response
-    pub fn add_handler(&mut self, path: &str, handler: FnT) {
+    pub fn add_handler(&mut self, path: &str, handler: HandlerFn) {
         self.matchers.insert(path.to_string(), handler);
     }
 
@@ -63,10 +65,64 @@ where
         }
     }
 
-    fn handle_req(&self, req: Request) -> UnitOrBoxedError {
-        match self.matchers.get(&req.url.path) {
-            Some(handler) => (*handler)(req).send(),
-            None => Response::new(req, 404, "Not Found").send(),
+    fn match_handler(&self, url: &URL) -> Option<HandlerFn> {
+        'matching_loop: for (path, handler) in self.matchers.iter() {
+            // Exact match
+            if path == &url.path {
+                return Some(*handler);
+            };
+
+            // Segment matching
+            let url_segements = url.path.split('/').collect::<Vec<&str>>();
+            let path_segments = path.split('/').collect::<Vec<&str>>();
+
+            // If the URL has more segments than the path, it can't match
+            // or if the path has no segments, it can't match
+            if (url_segements.len() != path_segments.len()) || (path_segments.len() == 0) {
+                continue;
+            }
+
+            // Check each segment of the url
+            for (url_segment, path_segment) in url_segements.iter().zip(path_segments.iter()) {
+                if path_segment.starts_with('[') {
+                    // e.g. /path/[id]
+                    if path_segment.ends_with(']') { 
+                        continue;
+                    }
+                    
+                    // e.g. /path/prefix[id].suffix
+                    let prefix = path_segment.split('[').collect::<Vec<_>>()[0];
+                    let suffix = path_segment.split(']').collect::<Vec<_>>()[1];
+
+                    // begins_with and starts_with always return true on empty strings
+                    if url_segment.starts_with(prefix) && url_segment.ends_with(suffix) {
+                        continue;
+                    }
+
+                    break 'matching_loop;
+                }
+
+                if url_segment == path_segment {
+                    continue;
+                }
+
+                break 'matching_loop;
+            }
+
+            return Some(*handler);
         }
+
+        None
+    }
+
+    fn handle_req(&self, req: Request) -> UnitOrBoxedError {
+        match self.match_handler(&req.url) {
+            Some(handler) => handler(req).send()?,
+            None => {
+                return Response::new(req, 404, "Not Found").send();
+            }
+        };
+
+        Ok(())
     }
 }
diff --git a/src/http/requests.rs b/src/http/requests.rs
index 21e80f1..b085f6c 100644
--- a/src/http/requests.rs
+++ b/src/http/requests.rs
@@ -39,6 +39,22 @@ impl URL {
 
         Some(URL { path, query, raw })
     }
+
+    /// Utility function to get a path segment by index
+    /// 
+    /// This is a very simple function, and its implementation is fairly naïve
+    /// 
+    /// index: Index of the path segment to get
+    /// 
+    /// # Examples
+    /// 
+    /// ```
+    /// let url = URL::new("/path/to/resource").unwrap();
+    /// assert_eq!(url.get_path_segment(1), Some("to"));
+    /// ```
+    pub fn get_path_segment(&self, index: usize) -> Option<&str> {
+        self.path.split('/').nth(index + 1)
+    }
 }
 
 pub struct Request {