From 9fe27d8465142ddba9a8a87d9f7e903614bfec6d Mon Sep 17 00:00:00 2001
From: ZelionD <k.kotliar@inc4.net>
Date: Wed, 17 Apr 2024 08:26:46 +0300
Subject: [PATCH] add check-email

---
 gov-portal-db/src/server.rs            | 27 ++++++++++++++++++++++++++
 gov-portal-db/src/users_manager/mod.rs | 24 +++++++++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/gov-portal-db/src/server.rs b/gov-portal-db/src/server.rs
index 50aa519..d9113aa 100644
--- a/gov-portal-db/src/server.rs
+++ b/gov-portal-db/src/server.rs
@@ -91,6 +91,14 @@ pub struct UpdateUserRequest {
     pub session: SessionToken,
 }
 
+/// JSON-serialized request passed as POST-data to `/check-email` endpoint
+#[derive(Debug, Deserialize)]
+pub struct CheckEmailRequest {
+    email: serde_email::Email,
+    #[serde(flatten)]
+    pub session: SessionToken,
+}
+
 /// JSON-serialized request passed as POST-data to `/verify-email` endpoint to send email verification link to user's email
 #[derive(Debug, Deserialize)]
 pub struct VerifyEmailRequest {
@@ -140,6 +148,7 @@ pub async fn start(config: AppConfig, users_manager: Arc<UsersManager>) -> Resul
         .route("/token", post(token_route))
         .route("/user", post(user_route))
         .route("/update-user", post(update_user_route))
+        .route("/check-email", post(check_email_route))
         .route("/verify-email", post(verify_email_route))
         .route("/quiz", post(quiz_route))
         .route("/verify-quiz", post(verify_quiz_route))
@@ -302,6 +311,24 @@ async fn update_user_route(
     res.map(Json)
 }
 
+/// Route handler to check if an email is already in database
+async fn check_email_route(
+    State(state): State<AppState>,
+    Json(req): Json<CheckEmailRequest>,
+) -> Result<Json<bool>, String> {
+    tracing::debug!("[/check-email] Request {req:?}");
+
+    let res = match state.session_manager.verify_token(&req.session) {
+        Ok(_) => state.users_manager.is_email_being_used(&req.email).await,
+        Err(e) => Err(e),
+    }
+    .map_err(|e| format!("Check email request failure. Error: {e}"));
+
+    tracing::debug!("[/check-email] Response {res:?}");
+
+    res.map(Json)
+}
+
 /// Route handler to generate email verification JWT token and send it to user's email address
 async fn verify_email_route(
     State(state): State<AppState>,
diff --git a/gov-portal-db/src/users_manager/mod.rs b/gov-portal-db/src/users_manager/mod.rs
index 0252fe0..ed4bf1a 100644
--- a/gov-portal-db/src/users_manager/mod.rs
+++ b/gov-portal-db/src/users_manager/mod.rs
@@ -419,6 +419,30 @@ impl UsersManager {
             )),
         }
     }
+
+    /// Checks if email already being used by some user
+    pub async fn is_email_being_used(
+        &self,
+        email: &serde_email::Email,
+    ) -> Result<bool, anyhow::Error> {
+        let filter = doc! {
+            "email": bson::to_bson(&email)?,
+        };
+
+        let find_options = FindOptions::builder()
+            .max_time(self.mongo_client.req_timeout)
+            .build();
+
+        Ok(tokio::time::timeout(self.mongo_client.req_timeout, async {
+            self.mongo_client
+                .find(filter, find_options)
+                .await?
+                .try_next()
+                .await
+        })
+        .await??
+        .is_some())
+    }
 }
 
 /// Returns true if an input error kind [`MongoErrorKind`] is representing duplication error or false otherwise.