From 9569926e720a374523fee8abe75c267d168f4dae Mon Sep 17 00:00:00 2001
From: Bastian Gruber <foreach@me.com>
Date: Thu, 20 Apr 2023 10:58:47 +0200
Subject: [PATCH] Add first attempt for problem-01

---
 problem_01/.gitignore  |  1 +
 problem_01/Cargo.toml  | 11 ++++--
 problem_01/Dockerfile  | 12 ++++++
 problem_01/fly.toml    | 30 +++++++++++++++
 problem_01/src/main.rs | 87 +++++++++++++++++++++++++++++++++++++++++-
 5 files changed, 136 insertions(+), 5 deletions(-)
 create mode 100644 problem_01/.gitignore
 create mode 100644 problem_01/Dockerfile
 create mode 100644 problem_01/fly.toml

diff --git a/problem_01/.gitignore b/problem_01/.gitignore
new file mode 100644
index 0000000..b83d222
--- /dev/null
+++ b/problem_01/.gitignore
@@ -0,0 +1 @@
+/target/
diff --git a/problem_01/Cargo.toml b/problem_01/Cargo.toml
index 799fe54..ef3ce7b 100644
--- a/problem_01/Cargo.toml
+++ b/problem_01/Cargo.toml
@@ -1,8 +1,13 @@
 [package]
-name = "problem_02"
+name = "problem_01"
 version = "0.1.0"
 edition = "2021"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
 [dependencies]
+bincode = "1.3.3"
+env_logger = "0.9.0"
+log = "0.4.0"
+primes = "0.3.0"
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0.96"
+tokio = { version = "1.27.0", features = ["full"] }
diff --git a/problem_01/Dockerfile b/problem_01/Dockerfile
new file mode 100644
index 0000000..cb1abe3
--- /dev/null
+++ b/problem_01/Dockerfile
@@ -0,0 +1,12 @@
+FROM rust:latest as builder
+RUN apt-get update && apt-get -y install ca-certificates cmake musl-tools libssl-dev && rm -rf /var/lib/apt/lists/*
+COPY . .
+RUN rustup default stable && rustup update
+RUN rustup target add x86_64-unknown-linux-musl
+ENV PKG_CONFIG_ALLOW_CROSS=1
+ENV RUST_LOG=info
+RUN cargo build --target x86_64-unknown-linux-musl --release
+FROM scratch
+COPY --from=builder /target/x86_64-unknown-linux-musl/release/problem_01 .
+EXPOSE 8080
+CMD ["/problem_01"]
diff --git a/problem_01/fly.toml b/problem_01/fly.toml
new file mode 100644
index 0000000..b76808d
--- /dev/null
+++ b/problem_01/fly.toml
@@ -0,0 +1,30 @@
+# fly.toml app configuration file generated for hidden-thunder-1268 on 2023-04-19T21:18:46+02:00
+#
+# See https://fly.io/docs/reference/configuration/ for information about how to use this file.
+#
+
+app = "hidden-thunder-1268"
+primary_region = "ams"
+
+kill_signal = "SIGINT"
+kill_timeout = 5
+processes = []
+
+[experimental]
+  auto_rollback = true
+
+[env]
+  ECHO_PORT = "8080"
+
+[[services]]
+  protocol = "tcp"
+  internal_port = 8080
+
+  [[services.ports]]
+    port = 8080
+
+  [[services.tcp_checks]]
+    grace_period = "5s"
+    interval = "15s"
+    restart_limit = 2
+    timeout = "2s"
diff --git a/problem_01/src/main.rs b/problem_01/src/main.rs
index e7a11a9..0d83556 100644
--- a/problem_01/src/main.rs
+++ b/problem_01/src/main.rs
@@ -1,3 +1,86 @@
-fn main() {
-    println!("Hello, world!");
+use primes::is_prime;
+use serde::{Deserialize, Serialize};
+use tokio::io::AsyncBufReadExt;
+use tokio::io::AsyncWriteExt;
+use tokio::io::BufReader;
+use tokio::net::{TcpListener, TcpStream};
+
+const IS_PRIME: &str = "isPrime";
+const MAL_FORMAT: &str = "}mal";
+
+#[derive(Debug, Deserialize, Serialize)]
+struct Request {
+    method: String,
+    number: u64,
+}
+
+#[derive(Debug, Deserialize, Serialize)]
+struct Response {
+    method: String,
+    prime: bool,
+}
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    env_logger::init();
+    let listener = TcpListener::bind("0.0.0.0:8080").await?;
+    log::info!("Start TCP server");
+
+    loop {
+        let (socket, _) = listener.accept().await?;
+
+        tokio::spawn(async move {
+            log::info!("Handle incoming request");
+            let _ = handle_request(socket).await;
+        });
+    }
+}
+
+async fn handle_request(mut socket: TcpStream) {
+    let (read, mut write) = socket.split();
+
+    let mut buf: Vec<u8> = Vec::new();
+    let mut reader = BufReader::new(read);
+    let bytes = reader.read_until(b'\n', &mut buf).await;
+
+    if let Ok(0) = bytes {
+        return;
+    }
+
+    if let Ok(1) = bytes {
+        return;
+    }
+
+    match serde_json::from_slice::<Request>(&buf) {
+        Ok(m) => {
+            log::error!("Message received: {:?}", m);
+            log::error!("Right method set? {}", m.method == IS_PRIME.to_owned());
+            log::error!("Is {} a prime? {}", m.number, is_prime(m.number));
+
+            let res = Response {
+                method: IS_PRIME.to_owned(),
+                prime: is_prime(m.number),
+            };
+
+            if m.method == IS_PRIME.to_owned() {
+                let _ = write
+                    .write(&bincode::serialize(&serde_json::to_string(&res).unwrap()).unwrap())
+                    .await;
+                let _ = write.write(&[b'\"', b'\n']).await;
+                let _ = write.flush().await;
+            } else {
+                let _ = write.write(&bincode::serialize(&MAL_FORMAT).unwrap()).await;
+                let _ = write.write(&[b'\"', b'\n']).await;
+                let _ = write.flush().await;
+            }
+        }
+        Err(e) => {
+            log::error!("Error parsing the message: {}", e);
+            log::error!("Message: {}", String::from_utf8_lossy(&buf));
+
+            let _ = write.write(&bincode::serialize(&MAL_FORMAT).unwrap()).await;
+            let _ = write.write(&[b'\"', b'\n']).await;
+            let _ = write.flush().await;
+        }
+    }
 }