From dcd117393a88dae37c1b2f01a6941c39e7337970 Mon Sep 17 00:00:00 2001
From: Erik Hollensbe <linux@hollensbe.org>
Date: Sat, 15 Jan 2022 23:23:25 -0800
Subject: [PATCH] Path management for the router

Signed-off-by: Erik Hollensbe <linux@hollensbe.org>
---
 src/handler.rs |  17 +++++-
 src/lib.rs     |  13 +----
 src/path.rs    | 155 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 172 insertions(+), 13 deletions(-)
 create mode 100644 src/path.rs

diff --git a/src/handler.rs b/src/handler.rs
index 337a65b..b83e37a 100644
--- a/src/handler.rs
+++ b/src/handler.rs
@@ -1,10 +1,19 @@
-use std::sync::Arc;
+use std::{collections::BTreeMap, sync::Arc};
 
-use crate::{HTTPResult, Params};
+use crate::HTTPResult;
 
 use async_trait::async_trait;
 use http::{Request, Response};
 
+#[derive(Debug, Clone)]
+pub struct Params(BTreeMap<String, String>);
+
+impl Default for Params {
+    fn default() -> Self {
+        Self(BTreeMap::default())
+    }
+}
+
 pub type HandlerFunc =
     dyn Fn(Request<hyper::Body>, Params, Option<Response<hyper::Body>>) -> HTTPResult + Sync;
 
@@ -63,10 +72,12 @@ where
 }
 
 mod tests {
-    use crate::{Error, HTTPResult, Params};
+    use crate::{Error, HTTPResult};
     use http::{HeaderValue, Request, Response, StatusCode};
     use hyper::Body;
 
+    use super::Params;
+
     // this method adds a header:
     // wakka: wakka wakka
     // to the request. that's it!
diff --git a/src/lib.rs b/src/lib.rs
index 77c85be..55c84b7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,6 @@
 pub mod handler;
+pub mod path;
+//pub mod router;
 
 use http::{Request, Response};
 
@@ -6,15 +8,6 @@ use crate::handler::BasicHandler;
 
 use std::collections::BTreeMap;
 
-#[derive(Debug, Clone)]
-pub struct Params(BTreeMap<String, String>);
-
-impl Default for Params {
-    fn default() -> Self {
-        Self(BTreeMap::default())
-    }
-}
-
 #[derive(Clone, Debug)]
 pub struct Error(String);
 
@@ -43,5 +36,5 @@ pub type HTTPResult = Result<(Request<hyper::Body>, Option<Response<hyper::Body>
 
 pub struct App {
     #[allow(dead_code)] // FIXME remove
-    routes: Vec<&'static BasicHandler>,
+    routes: BTreeMap<String, &'static BasicHandler>,
 }
diff --git a/src/path.rs b/src/path.rs
new file mode 100644
index 0000000..f6f190c
--- /dev/null
+++ b/src/path.rs
@@ -0,0 +1,155 @@
+use std::collections::BTreeMap;
+
+use crate::Error;
+
+#[derive(Debug, Clone)]
+pub enum RoutePart {
+    PathComponent(&'static str),
+    Param(&'static str),
+}
+
+#[derive(Debug, Clone)]
+pub struct Path(Vec<RoutePart>);
+
+impl Path {
+    pub(crate) fn new(path: &'static str) -> Self {
+        let mut parts = Self::default();
+
+        for arg in path.split("/") {
+            if arg.starts_with(":") {
+                // is param
+                parts.push(RoutePart::Param(arg.trim_start_matches(":")));
+            } else {
+                // is not param
+                parts.push(RoutePart::PathComponent(arg));
+            }
+        }
+
+        parts
+    }
+
+    fn push(&mut self, arg: RoutePart) -> Self {
+        self.0.push(arg);
+        self.clone()
+    }
+
+    fn params(&self) -> Vec<&str> {
+        let mut params = Vec::new();
+        for arg in self.0.clone() {
+            match arg {
+                RoutePart::Param(p) => params.push(p),
+                _ => {}
+            }
+        }
+
+        params
+    }
+
+    fn extract(&self, provided: &'static str) -> Result<BTreeMap<&'static str, &str>, Error> {
+        let parts: Vec<&str> = provided.split("/").collect();
+        let mut params = BTreeMap::new();
+
+        if parts.len() != self.0.len() {
+            return Err(Error::new("invalid parameters"));
+        }
+
+        let mut i = 0;
+
+        for part in self.0.clone() {
+            match part {
+                RoutePart::Param(p) => params.insert(p, parts[i]),
+                RoutePart::PathComponent(part) => {
+                    if part != parts[i] {
+                        return Err(Error::new("invalid path for parameter extraction"));
+                    }
+
+                    None
+                }
+            };
+
+            i += 1
+        }
+
+        Ok(params)
+    }
+
+    fn matches(&self, path: &'static str) -> bool {
+        let parts = path.split("/");
+
+        if parts.clone().count() != self.0.len() {
+            return false;
+        }
+
+        let mut i = 0;
+        for arg in parts {
+            let res = match self.0[i] {
+                RoutePart::PathComponent(pc) => pc == arg,
+                RoutePart::Param(_param) => {
+                    // FIXME advanced parameter shit here later
+                    true
+                }
+            };
+
+            if !res {
+                return res;
+            }
+
+            i += 1;
+        }
+
+        true
+    }
+}
+
+impl Default for Path {
+    fn default() -> Self {
+        Self(Vec::new())
+    }
+}
+
+impl ToString for Path {
+    fn to_string(&self) -> String {
+        let mut s = Vec::new();
+
+        for part in self.0.clone() {
+            s.push(match part {
+                RoutePart::PathComponent(pc) => pc.to_string(),
+                RoutePart::Param(param) => {
+                    format!(":{}", param)
+                }
+            });
+        }
+
+        s.join("/")
+    }
+}
+
+mod tests {
+    #[test]
+    fn test_path() {
+        use super::Path;
+        use std::collections::BTreeMap;
+
+        let path = Path::new("/abc/def/ghi");
+        assert!(path.matches("/abc/def/ghi"));
+        assert!(!path.matches("//abc/def/ghi"));
+        assert!(!path.matches("//def/ghi"));
+        assert!(path.params().is_empty());
+
+        let path = Path::new("/abc/:def/:ghi/jkl");
+        assert!(!path.matches("/abc/def/ghi"));
+        assert!(path.matches("/abc/def/ghi/jkl"));
+        assert!(path.matches("/abc/ghi/def/jkl"));
+        assert!(path.matches("/abc/wooble/wakka/jkl"));
+        assert!(!path.matches("/nope/ghi/def/jkl"));
+        assert!(!path.matches("/abc/ghi/def/nope"));
+
+        let mut bt = BTreeMap::new();
+        bt.insert("def", "wooble");
+        bt.insert("ghi", "wakka");
+
+        assert_eq!(path.extract("/abc/wooble/wakka/jkl").unwrap(), bt);
+        assert!(path.extract("/wooble/wakka/jkl").is_err());
+        assert!(path.extract("/def/wooble/wakka/jkl").is_err());
+    }
+}