feat(backend): add initial backend

Backend as is can query GitHub for the information that will be
necessary later on in the frontend's pages. It does not cache this
information yet though.

Signed-off-by: Lucien Cartier-Tilet <lucien@phundrak.com>

src/main.rs

@@ -0,0 +1,112 @@
+use actix_web::{error, get, web, Responder, Result};
+use derive_more::{Display, Error};
+use dotenvy::dotenv;
+use gql_client::Client;
+use std::collections::HashMap;
+
+mod data;
+
+#[derive(Debug, Display, Error)]
+#[display(fmt = "my error: {}", name)]
+struct MyError {
+    name: String,
+}
+
+struct AppState {
+    github_token: String,
+}
+
+impl Default for AppState {
+    fn default() -> Self {
+        Self {
+            github_token: github_token(),
+        }
+    }
+}
+
+impl error::ResponseError for MyError {}
+
+fn github_token() -> String {
+    std::env::var("GH_TOKEN")
+        .expect("Environment variable GH_TOKEN **MUST** be set!")
+}
+
+#[get("/phundrak-com/{user}")]
+async fn user_info_github(
+    user: web::Path<String>,
+    state: web::Data<AppState>,
+) -> Result<impl Responder> {
+    let gh_token = &state.github_token;
+    let body = format!(
+        r#"query {{
+  user(login: "{}") {{
+    newest: repositories(first: 10, orderBy: {{field: UPDATED_AT, direction: DESC}}) {{
+      nodes {{
+        name
+        stargazerCount
+        forkCount
+      }}
+    }}
+    mostStarred: repositories(first: 10, orderBy: {{field: STARGAZERS, direction: DESC}}) {{
+      nodes {{
+        name
+        stargazerCount
+        forkCount
+      }}
+    }}
+    pinned: pinnedItems(first: 10) {{
+      nodes {{
+        ... on Repository {{
+          name
+          stargazerCount
+          forkCount
+        }}
+      }}
+    }}
+  }}
+}}"#,
+        user
+    );
+    let mut headers: HashMap<String, String> = HashMap::new();
+    headers.insert("Authorization".to_string(), format!("Bearer {}", gh_token));
+    headers.insert("User-Agent".to_string(), "PhunCache-App".to_string());
+    let client =
+        Client::new_with_headers("https://api.github.com/graphql", headers);
+    client
+        .query::<data::Data>(&body)
+        .await
+        .map(web::Json)
+        .map_err(|e| {
+            MyError {
+                name: format!("Failed to retrieve data from GitHub: {e:?}"),
+            }
+            .into()
+        })
+}
+
+#[actix_web::main]
+async fn main() -> std::io::Result<()> {
+    use actix_web::{App, HttpServer};
+    use std::env::var;
+
+    std::env::set_var("RUST_LOG", "debug");
+    env_logger::init();
+    dotenv().ok();
+    human_panic::setup_panic!();
+
+    HttpServer::new(|| {
+        App::new()
+            .app_data(web::Data::new(AppState::default()))
+            .service(user_info_github)
+    })
+    .bind((
+        var("ACTIX_ADDRESS")
+            .expect("Environment variable ACTIX_ADDRESS must be set!"),
+        var("ACTIX_PORT")
+            .expect("Environment variable ACTIX_PORT must be set!")
+            .parse()
+            .expect("Failed to parse value of ACTIX_PORT into a u16"),
+    ))?
+    .run()
+    .await
+}