From 497345f2e9ec8839075ff0bcb633876a77079364 Mon Sep 17 00:00:00 2001
From: Sebastian Pravda <sebastian.pravda@gmail.com>
Date: Tue, 25 Oct 2022 19:34:30 +0200
Subject: [PATCH] feat: improve error handling

---
 api/src/lib.rs                         | 18 +++++++++++++----
 core/src/error.rs                      | 16 ++++++++++-----
 core/src/services/candidate_service.rs | 27 +++++++++++++++++---------
 3 files changed, 43 insertions(+), 18 deletions(-)

diff --git a/api/src/lib.rs b/api/src/lib.rs
index 26e2210..004f83a 100644
--- a/api/src/lib.rs
+++ b/api/src/lib.rs
@@ -2,10 +2,11 @@
 extern crate rocket;
 
 use guard::candidate_jwt::TokenRequest;
+use portfolio_core::error::ServiceError;
 use portfolio_core::services::candidate_service::CandidateService;
 use requests::LoginRequest;
 use rocket::http::Status;
-use rocket::{Rocket, Build};
+use rocket::{Rocket, Build, custom};
 use rocket::serde::json::Json;
 use rocket::fairing::{self, AdHoc};
 use rocket::response::status::Custom;
@@ -27,6 +28,10 @@ pub use entity::candidate::Entity as Candidate;
 use portfolio_core::crypto::random_8_char_string;
 
 
+fn custom_err_from_service_err(err: ServiceError) -> Custom<String> {
+    Custom(Status::InternalServerError, err.1.to_string())
+}
+
 #[post("/", data = "<post_form>")]
 async fn create(conn: Connection<'_, Db>, post_form: Json<candidate::Model>) -> Result<String, Custom<String>> {   
     let db = conn.into_inner();
@@ -50,10 +55,15 @@ async fn login(conn: Connection<'_, Db>, login_form: Json<LoginRequest>) -> Resu
         login_form.application_id, 
         login_form.password.to_owned()).await;
 
-    if jwt.is_some() {
-        return Ok(jwt.unwrap())
+    if jwt.is_ok() {
+        return Ok(
+            jwt.ok().unwrap()
+        );
+    } else {
+        return Err(
+            custom_err_from_service_err(jwt.err().unwrap())
+        )
     }
-    Err(Custom(Status::Unauthorized, "Invalid credentials".to_string()))
 }
 
 #[get("/whoami")]
diff --git a/core/src/error.rs b/core/src/error.rs
index a76d2ec..36cb105 100644
--- a/core/src/error.rs
+++ b/core/src/error.rs
@@ -2,8 +2,14 @@ pub struct Status {
     pub code: u16,
 }
 
-pub const InvalidCredentialsError: ServiceError<String> = ServiceError(Status { code: 401 }, 
-    "Invalid credentials".to_string());
-pub const JwtError: ServiceError<String> = ServiceError(Status { code: 500 }, 
-    "Error while encoding JWT".to_string());
-pub struct ServiceError<R>(pub Status, pub R);
\ No newline at end of file
+pub const INVALID_CREDENTIALS_ERROR: ServiceError = ServiceError(Status { code: 401 }, 
+    "Invalid credentials");
+pub const JWT_ERROR: ServiceError = ServiceError(Status { code: 500 }, 
+    "Error while encoding JWT");
+
+pub const USER_NOT_FOUND_ERROR: ServiceError = ServiceError(Status { code: 404 }, 
+    "User not found");
+
+pub const DB_ERROR: ServiceError = ServiceError(Status { code: 500 }, 
+    "Database error");
+pub struct ServiceError<'a>(pub Status, pub &'a str);
\ No newline at end of file
diff --git a/core/src/services/candidate_service.rs b/core/src/services/candidate_service.rs
index 4ccd003..fb7eda4 100644
--- a/core/src/services/candidate_service.rs
+++ b/core/src/services/candidate_service.rs
@@ -1,23 +1,28 @@
 use jsonwebtoken::{Header, EncodingKey};
 use sea_orm::DatabaseConnection;
 
-use crate::{crypto, Query, token::candidate_token::CandidateToken};
+use crate::{crypto, Query, token::candidate_token::CandidateToken, error::{ServiceError, USER_NOT_FOUND_ERROR, INVALID_CREDENTIALS_ERROR, JWT_ERROR, DB_ERROR}};
 
 pub struct CandidateService;
 
 impl CandidateService {
-    pub async fn login(db: &DatabaseConnection, id: i32, password: String) -> Option<String> {
-        let candidate = Query::find_candidate_by_id(db, id).await
-            .unwrap()
-            .unwrap();
+    pub async fn login(db: &DatabaseConnection, id: i32, password: String) -> Result<String, ServiceError> {
+        let candidate = match Query::find_candidate_by_id(db, id).await {
+            Ok(candidate) => match candidate {
+                Some(candidate) => candidate,
+                None => return Err(USER_NOT_FOUND_ERROR)
+            },
+            Err(_) => {return Err(DB_ERROR)}
+        };
     
         
         let valid = crypto::verify_password(&password,&candidate.code )
             .expect("Invalid password");
         
         if !valid {
-            return None;
+            return Err(INVALID_CREDENTIALS_ERROR)
         }
+
         let payload = CandidateToken::generate("candidate.name.unwrap()".to_owned(),
             "candidate.surname.unwrap()".to_owned());
     
@@ -26,7 +31,11 @@ impl CandidateService {
         &payload,
             &EncodingKey::from_secret(&[0])
         ).ok();
-        jwt
+        
+        match jwt {
+            Some(jwt) => Ok(jwt),
+            None => Err(JWT_ERROR)
+        }
+            
+        }
     }
-
-}