improv: #5 use tokio crate to handle incoming conn async

src/main.rs

@@ -1,45 +1,38 @@
 mod handlers;
 
 use std::io::prelude::*;
-use std::net::TcpListener;
-use std::net::TcpStream;
+
+use tokio::{
+    io::{AsyncReadExt, AsyncWriteExt},
+    net::{TcpListener, TcpStream},
+};
 
 use handlers::handle_request;
 
-// TODO: must be set in a conf file
 const SERVER_URL: &str = "127.0.0.1:9000";
 
-// switch to an asynchronous main function
-#[async_std::main]
+#[tokio::main]
 async fn main() {
-    let listener = TcpListener::bind(SERVER_URL).unwrap();
-    println!("server is listening at {}", SERVER_URL);
-    for stream in listener.incoming() {
-        let stream = stream.unwrap();
+    let listener = TcpListener::bind(SERVER_URL).await.unwrap();
+
+    loop {
+        let (stream, _) = listener.accept().await.unwrap();
         handle_connection(stream).await;
     }
 }
 
 async fn handle_connection(mut stream: TcpStream) {
-    let mut buffer = [0; 1024];
-    stream.read(&mut buffer).unwrap();
+    let mut buffer: [u8; 1024] = [0; 1024];
+    let n = stream.read(&mut buffer).await.unwrap();
 
-    // transform buffer bytes array into `String`
-    let buffer_string = String::from_utf8_lossy(&buffer);
-    let request = handle_request(&buffer_string);
+    println!("buffer : {:?}", std::str::from_utf8(&buffer[0..n]));
 
-    // TODO: `Response` struct must be implemented
-    let status_line = if request.start_line.target == "/".to_string() {
-        "HTTP/1.1 200 OK\r\n"
-    } else {
-        "HTTP/1.1 404 NOT FOUND\r\n"
-    };
-
-    let content_type = "Content-Type: application/json\r\n\r\n";
-    let json = r#"{"access_token":"AAAAAAAAAAAA.BBBBBBBBBB.CCCCCCCCCC","refresh_token": "DDDDDDDDDDD.EEEEEEEEEEE.FFFFF"}"#;
-    let response = format!("{status_line}{content_type}{json}\n");
-
-    println!("return status code : {}", status_line);
-    stream.write(response.as_bytes()).unwrap();
-    stream.flush().unwrap();
+    let contents = "{\"balance\": 0.00}";
+    let response = format!(
+        "HTTP/1.1 200 OK\r\nContent-Type: application/json\r\nContent-Length: {}\r\n\r\n{}",
+        contents.len(),
+        contents
+    );
+    stream.write(response.as_bytes()).await.unwrap();
+    stream.flush().await.unwrap();
 }