[BE][Class] Get session cookie and store it for ~20m

backend/src/online_classroom/json_result.rs

@@ -0,0 +1,23 @@
+use rocket::serde::json::Json;
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Serialize, Deserialize)]
+pub enum JsonResult<A> {
+    Ok(A),
+    Error(JsonError),
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct JsonError {
+    reason: String,
+}
+
+impl<A> JsonResult<A> {
+    pub fn error(reason: String) -> Json<JsonResult<A>> {
+        Json(JsonResult::Error(JsonError { reason }))
+    }
+
+    pub fn ok(data: A) -> Json<JsonResult<A>> {
+        Json(JsonResult::Ok(data))
+    }
+}

backend/src/online_classroom/mod.rs

@@ -4,7 +4,13 @@ use reqwest::Client;
 use rocket::{http::Status, serde::json::Json};
 use serde::{Deserialize, Serialize};
 
-static SESSION_COOKIE: OnceCell<String> = OnceCell::new();
+use self::session::ensure_session;
+
+pub mod json_result;
+mod session;
+pub mod users;
+
+
 
 #[derive(Debug, Serialize, Deserialize)]
 pub enum ConnectionResult {
@@ -22,64 +28,10 @@ fn new_error(reason: String) -> ConnectionResult {
 /// Tries to connect to the online classroom, and get a session cookie
 #[get("/classroom/connect")]
 pub async fn connection() -> (Status, Json<ConnectionResult>) {
-    // Get session cookie
-    let _cookie = match get_cookie().await {
-        Ok(cookie) => cookie,
-        Err(reason) => return (Status::InternalServerError, Json(new_error(reason))),
-    };
-
-    (Status::Ok, Json(ConnectionResult::Ok()))
-}
-
-async fn get_cookie<'a>() -> Result<&'a String, String> {
-    match SESSION_COOKIE.get() {
-        Some(cookie) => Ok(cookie),
-        None => {
-            // Try to create cookie
-            let _ = create_cookie().await?;
-
-            // Try to get cookie again
-            match SESSION_COOKIE.get() {
-                Some(cookie) => Ok(cookie),
-                None => Err("Error getting session cookie".into()),
-            }
-        }
+    match ensure_session().await {
+        Ok(_) => (Status::Ok, Json(ConnectionResult::Ok())),
+        Err(err) => (Status::Ok, Json(new_error(err))),
     }
 }
 
-/// Tries to connect to the online classroom, and get a session cookie.
-/// Stores the session coookie in a global static variable.
-pub async fn create_cookie() -> Result<(), String> {
-    let clasroom_url = std::env::var("CLASSROOM_URL").expect("CLASSROOM_URL env var is not set!");
-    let clasroom_user =
-        std::env::var("CLASSROOM_USER").expect("CLASSROOM_USER env var is not set!");
-    let clasroom_password =
-        std::env::var("CLASSROOM_PASSWORD").expect("CLASSROOM_PASSWORD env var is not set!");
 
-    let params = [
-        ("login", clasroom_user),
-        ("password", clasroom_password),
-        ("submitAuth", "".into()),
-        ("_qf__formLogin", "".into()),
-    ];
-    let client = Client::new();
-    let result = client
-        .post(format!("{}/index.php", clasroom_url))
-        .form(&params)
-        .send()
-        .await;
-
-    match result {
-        Ok(response) => {
-            let Some(session_cookie) = response.cookies().find(|c| c.name() == "ch_sid") else {
-                return Err("Response succeeded, but no session cookie was foun".into());
-            };
-
-            match SESSION_COOKIE.set(session_cookie.value().into()) {
-                Ok(_) => Ok(()),
-                Err(error) => Err(format!("Error setting session cookie: {:?}", error)),
-            }
-        }
-        Err(error) => Err(format!("Error connecting to online classroom: {:?}", error)),
-    }
-}

backend/src/online_classroom/session.rs

@@ -0,0 +1,75 @@
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use once_cell::sync::OnceCell;
+use reqwest::Client;
+
+static SESSION_COOKIE: OnceCell<String> = OnceCell::new();
+static SESSION_TIME: OnceCell<u64> = OnceCell::new();
+
+/// Makes a request to the online classroom, and returns the html string
+pub async fn request(url: String) -> Result<String, String> {
+    todo!()
+}
+
+
+/// Makes sure that the session cookie is set, and that it is valid
+pub async fn ensure_session() -> Result<(), String> {
+    let last_usage_time = match SESSION_TIME.get() {
+        Some(time) => *time,
+        None => 0,
+    };
+
+    // Get current time in seconds
+    let current_time = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .expect("Time went backwards")
+        .as_secs();
+
+    let time_passed = current_time - last_usage_time;
+
+    // Default PHP session timeout is 1440 seconds. Use a 1400 seconds timeout to be safe
+    if time_passed > 1400 {
+        login().await?;
+        if let Err(err) = SESSION_TIME.set(current_time) {
+            return Err(format!("Error setting session time: {:?}", err));
+        }
+    }
+
+    Ok(())
+}
+
+/// Logins to the online classroom, and sets the session cookie
+async fn login() -> Result<(), String> {
+    let clasroom_url = std::env::var("CLASSROOM_URL").expect("CLASSROOM_URL env var is not set!");
+    let clasroom_user =
+        std::env::var("CLASSROOM_USER").expect("CLASSROOM_USER env var is not set!");
+    let clasroom_password =
+        std::env::var("CLASSROOM_PASSWORD").expect("CLASSROOM_PASSWORD env var is not set!");
+
+    let params = [
+        ("login", clasroom_user),
+        ("password", clasroom_password),
+        ("submitAuth", "".into()),
+        ("_qf__formLogin", "".into()),
+    ];
+    let client = Client::new();
+    let result = client
+        .post(format!("{}/index.php", clasroom_url))
+        .form(&params)
+        .send()
+        .await;
+
+    match result {
+        Ok(response) => {
+            let Some(session_cookie) = response.cookies().find(|c| c.name() == "ch_sid") else {
+                return Err("Response succeeded, but no session cookie was foun".into());
+            };
+
+            match SESSION_COOKIE.set(session_cookie.value().into()) {
+                Ok(_) => Ok(()),
+                Err(error) => Err(format!("Error setting session cookie: {:?}", error)),
+            }
+        }
+        Err(error) => Err(format!("Error connecting to online classroom: {:?}", error)),
+    }
+}

backend/src/online_classroom/users.rs

@@ -0,0 +1,15 @@
+use rocket::{http::Status, serde::json::Json};
+
+use super::{ json_result::JsonResult};
+
+// Instead of requesting pages and managing session & cookies manually,
+// create a wrapper that:
+// - Checks if the session cookie is valid
+//   - If not, tries to login
+// - Makes the request
+// - Returns the html string, or an error
+
+#[get("/classroom/users/<full_name>")]
+pub async fn get_users(full_name: String) -> (Status, Json<JsonResult<()>>) {
+    (Status::Ok, JsonResult::ok(()))
+}