From c813356eaa51106774c0adaebf1aa8f270723208 Mon Sep 17 00:00:00 2001
From: Lyle Mantooth <lyle@menteeth.us>
Date: Sun, 14 May 2023 14:56:40 -0400
Subject: [PATCH] Use server state to reuse HTTP client.

---
 src/main.rs | 56 ++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 38 insertions(+), 18 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index bdb6840..5adb3e0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,7 +2,8 @@ use std::str::FromStr;
 
 use axum::{
     body::BoxBody,
-    http::header,
+    extract::State,
+    http::header::{self, HeaderMap},
     response::{IntoResponse, Response},
     routing::get,
     Router,
@@ -12,6 +13,11 @@ use serde::Deserialize;
 use tracing::{info, Level};
 use tracing_subscriber::{filter::Targets, layer::SubscriberExt, util::SubscriberInitExt};
 
+#[derive(Clone)]
+struct ServerState {
+    client: reqwest::Client,
+}
+
 #[tokio::main]
 async fn main() {
     let filter = Targets::from_str(std::env::var("RUST_LOG").as_deref().unwrap_or("info"))
@@ -23,7 +29,11 @@ async fn main() {
         .with(filter)
         .init();
 
-    let app = Router::new().route("/", get(root_get));
+    let state = ServerState {
+        client: Default::default(),
+    };
+
+    let app = Router::new().route("/", get(root_get)).with_state(state);
 
     let addr = "0.0.0.0:8080".parse().unwrap();
     info!("Listening on {addr}");
@@ -33,8 +43,8 @@ async fn main() {
         .unwrap();
 }
 
-async fn root_get() -> Response<BoxBody> {
-    match get_cat_ascii_art().await {
+async fn root_get(_headers: HeaderMap, State(state): State<ServerState>) -> Response<BoxBody> {
+    match get_cat_ascii_art(&state.client).await {
         Ok(art) => (
             StatusCode::OK,
             [(header::CONTENT_TYPE, "text/html; charset=utf-8")],
@@ -48,14 +58,30 @@ async fn root_get() -> Response<BoxBody> {
     }
 }
 
-async fn get_cat_ascii_art() -> color_eyre::Result<String> {
+async fn get_cat_ascii_art(client: &reqwest::Client) -> color_eyre::Result<String> {
+    let image_url = get_cat_image_url(client).await?;
+
+    let image_bytes = download_file(client, &image_url).await?;
+
+    let image = image::load_from_memory(&image_bytes)?;
+
+    let ascii_art = artem::convert(
+        image,
+        artem::options::OptionBuilder::new()
+            .target(artem::options::TargetType::HtmlFile(true, true))
+            .build(),
+    );
+
+    Ok(ascii_art)
+}
+
+async fn get_cat_image_url(client: &reqwest::Client) -> color_eyre::Result<String> {
     #[derive(Deserialize)]
     struct CatImage {
         url: String,
     }
 
     let api_url = "https://api.thecatapi.com/v1/images/search";
-    let client = reqwest::Client::default();
 
     let image = client
         .get(api_url)
@@ -66,22 +92,16 @@ async fn get_cat_ascii_art() -> color_eyre::Result<String> {
         .await?
         .pop()
         .ok_or_else(|| color_eyre::eyre::eyre!("The Cat API returned no images"))?;
+    Ok(image.url)
+}
 
-    let image_bytes = client
-        .get(image.url)
+async fn download_file(client: &reqwest::Client, url: &str) -> color_eyre::Result<Vec<u8>> {
+    let bytes = client
+        .get(url)
         .send()
         .await?
         .error_for_status()?
         .bytes()
         .await?;
-
-    let image = image::load_from_memory(&image_bytes)?;
-    let ascii_art = artem::convert(
-        image,
-        artem::options::OptionBuilder::new()
-            .target(artem::options::TargetType::HtmlFile(true, true))
-            .build(),
-    );
-
-    Ok(ascii_art)
+    Ok(bytes.to_vec())
 }