gcd web p2

gcd-web/src/main.rs

@@ -1,22 +1,45 @@
 use actix_web::{web, App, HttpResponse, HttpServer};
+use serde::Deserialize;
+
+#[derive(Deserialize)]
+struct GcdParams {
+    a: u64,
+    b: u64,
+}
+
+fn gcd(mut a: u64, mut b: u64) -> u64 {
+    while a > 0 {
+        if a < b {
+            let temp = a;
+            a = b;
+            b = temp;
+        }
+
+        a = a % b;
+    }
+
+    b
+}
 
 fn main() {
     let server = HttpServer::new(|| {
         App::new()
             .route("/", web::get().to(get_index))
+            .route("/gcd", web::post().to(post_gcd))
     });
 
     println!("Serving on http://localhost:3300");
 
-    server.bind("127.0.0.1:3300").expect("error binding server to address")
-        .run().expect("error running server")
+    server
+        .bind("127.0.0.1:3300")
+        .expect("error binding server to address")
+        .run()
+        .expect("error running server")
 }
 
 fn get_index() -> HttpResponse {
-    HttpResponse::Ok()
-        .content_type("text/html")
-        .body(
-            r#"
+    HttpResponse::Ok().content_type("text/html").body(
+        r#"
                 <title>GCD Calculator</title>
                 <form action="/gcd" method="post">
                     <input type="text" name="a" />
@@ -24,5 +47,24 @@ fn get_index() -> HttpResponse {
                     <button type="submit">Compute GCD</button>
                 </form>   
             "#,
-        )
-}
+    )
+}
+
+fn post_gcd(form: web::Form<GcdParams>) -> HttpResponse {
+    if form.a == 0 || form.b == 0 {
+        return HttpResponse::BadRequest()
+            .content_type("text/html")
+            .body("Computing the GCD with 0 is boring");
+    }
+
+    let response_text = format!(
+        "The greatest common divisor of {} and {} is {}",
+        form.a,
+        form.b,
+        gcd(form.a, form.b)
+    );
+
+    HttpResponse::Ok()
+        .content_type("text/html")
+        .body(response_text)
+}