Refresh access token when needed, automatically auth when page opens

src/geo_t/azure/b2c.gleam

@@ -38,6 +38,11 @@ pub type Tokens {
   )
 }
 
+pub type Credentials {
+  WithToken(String)
+  WithUsernamePassword(username: String, password: String)
+}
+
 pub type B2CError {
   HashError(inner: crypto.HashingError)
   RequestError(inner: fetch.FetchError)
@@ -59,6 +64,42 @@ type Confirmed {
   Confirmed(code: String)
 }
 
+/// Authenticate to API and get new tokens with a username/password combination,
+/// or by using the refresh token.
+pub fn authenticate_or_refresh(
+  config: Config,
+  credentials: Credentials,
+) -> Promise(Result(Tokens, B2CError)) {
+  case credentials {
+    WithUsernamePassword(username, password) ->
+      authenticate(config, username, password)
+    WithToken(refresh_token) -> refresh(config, refresh_token)
+  }
+}
+
+pub fn refresh(
+  config: Config,
+  token: String,
+) -> Promise(Result(Tokens, B2CError)) {
+  let request_data = [
+    #("refresh_token", token),
+    #("grant_type", "refresh_token"),
+    ..base_request_data(config)
+  ]
+
+  let req =
+    build_req(get_token_url(config), http.Post)
+    |> request.set_body(uri_helpers.form_urlencoded_serialize(request_data))
+
+  use resp <- promise.try_await(run_req(req))
+  use data <- promise.map_try(promise.resolve(
+    json.decode(resp.body, using: dynamic.dynamic)
+    |> b2c_error("Get tokens JSON parsing error: " <> string.inspect(resp.body)),
+  ))
+
+  parse_tokens(data)
+}
+
 /// Authenticate to API with B2C authentication, returning the tokens needed
 /// for using the API.
 pub fn authenticate(
@@ -241,38 +282,34 @@ fn get_tokens(
 
   use resp <- promise.try_await(run_req(req))
 
-  use data <- promise.try_await(promise.resolve(
+  use data <- promise.map_try(promise.resolve(
     json.decode(resp.body, using: dynamic.dynamic)
     |> b2c_error("Get tokens JSON parsing error: " <> string.inspect(resp.body)),
   ))
 
-  use token <- promise.try_await(promise.resolve(data_get(
-    data,
-    "access_token",
-    dynamic.string,
-  )))
-  use expires_in <- promise.try_await(promise.resolve(data_get(
-    data,
-    "expires_in",
-    dynamic.int,
-  )))
-  use refresh_token <- promise.try_await(promise.resolve(data_get(
+  parse_tokens(data)
+}
+
+fn parse_tokens(data: dynamic.Dynamic) {
+  use token <- result.try(data_get(data, "access_token", dynamic.string))
+  use expires_in <- result.try(data_get(data, "expires_in", dynamic.int))
+  use refresh_token <- result.try(data_get(
     data,
     "refresh_token",
     dynamic.string,
-  )))
-  use refresh_token_expires_in <- promise.try_await(promise.resolve(data_get(
+  ))
+  use refresh_token_expires_in <- result.try(data_get(
     data,
     "refresh_token_expires_in",
     dynamic.int,
-  )))
+  ))
 
-  promise.resolve(Ok(Tokens(
+  Ok(Tokens(
     access_token: token,
     access_token_expires_in: expires_in,
     refresh_token: refresh_token,
     refresh_token_expires_in: refresh_token_expires_in,
-  )))
+  ))
 }
 
 fn hash_challenge(

src/geo_t/pump_api/auth/api.gleam

@@ -10,7 +10,7 @@ import geo_t/pump_api/auth/installation_info.{InstallationInfo}
 import geo_t/pump_api/http
 import geo_t/helpers/date
 import geo_t/helpers/parsing
-import geo_t/azure/b2c
+import geo_t/azure/b2c.{Credentials}
 import geo_t/helpers/promise as promise_helpers
 import geo_t/helpers/fetch as fetch_helpers
 import geo_t/config.{Config}
@@ -18,13 +18,12 @@ import geo_t/pump_api/api.{
   ApiError, ApiRequestFailed, AuthError, InvalidData, NotOkResponse,
 }
 
-pub fn auth(
+pub fn auth_or_refresh(
   config: Config,
-  username: String,
-  password: String,
+  credentials: Credentials,
 ) -> Promise(Result(User, ApiError)) {
   use tokens <- promise.try_await(
-    b2c.authenticate(config, username, password)
+    b2c.authenticate_or_refresh(config, credentials)
     |> promise_helpers.map_error(AuthError),
   )
 

src/geo_t/pump_api/auth/tokens.gleam

@@ -1,3 +1,4 @@
+import gleam/order
 import geo_t/helpers/date.{Date}
 
 pub type Tokens {
@@ -8,3 +9,12 @@ pub type Tokens {
     refresh_token_expiry: Date,
   )
 }
+
+pub fn is_access_expired(tokens: Tokens, diff: Int) -> Bool {
+  let assert Ok(target) =
+    date.from_unix(date.to_unix(tokens.access_token_expiry) - diff)
+  case date.compare(date.now(), target) {
+    order.Gt -> True
+    _ -> False
+  }
+}

src/geo_t/web.gleam

@@ -8,6 +8,7 @@ import lustre/element/html
 import lustre/effect.{Effect}
 import lustre/element
 import plinth/javascript/storage.{Storage}
+import geo_t/azure/b2c.{Credentials, WithToken, WithUsernamePassword}
 import geo_t/helpers/timers
 import geo_t/helpers/date
 import geo_t/config.{Config}
@@ -15,6 +16,7 @@ import geo_t/web/login_view
 import geo_t/web/installations_view
 import geo_t/web/pump_view
 import geo_t/pump_api/auth/user.{User}
+import geo_t/pump_api/auth/tokens
 import geo_t/pump_api/api.{ApiError}
 import geo_t/pump_api/auth/api as auth_api
 import geo_t/web/auth.{AuthInfo, AuthInfoStorage}
@@ -63,16 +65,21 @@ fn init(_) {
   let auth_refresh_effect =
     effect.from(fn(dispatch) { auth_refresh_check_timer(dispatch) })
 
-  let #(inst_model, inst_effect) = case auth_info {
+  let #(inst_model, init_effect) = case auth_info {
     Some(info) ->
-      update_installations(
-        installations_view.init(),
-        installations_view.LoadInstallations(config, info.user),
-      )
+      case tokens.is_access_expired(info.user.tokens, 0) {
+        True -> #(installations_view.init(), effect.none())
+
+        False ->
+          update_installations(
+            installations_view.init(),
+            installations_view.LoadInstallations(config, info.user),
+          )
+      }
     None -> #(installations_view.init(), effect.none())
   }
 
-  #(
+  let model =
     Model(
       config: config,
       login: login_view.init(),
@@ -83,8 +90,11 @@ fn init(_) {
       auth: auth_info,
       logging_in: False,
       logged_in: option.is_some(auth_info),
-    ),
-    effect.batch([auth_refresh_effect, inst_effect]),
+    )
+
+  #(
+    model,
+    effect.batch([auth_refresh_effect, auth_refresh_check(model), init_effect]),
   )
 }
 
@@ -93,14 +103,35 @@ fn update(model: Model, msg: Msg) {
     AuthRefreshCheck -> #(model, auth_refresh_check(model))
 
     RefreshLogin | LoginView(login_view.AttemptLogin) -> {
-      #(
-        Model(
-          ..model,
-          logging_in: True,
-          login: login_view.update(model.login, login_view.AttemptLogin),
-        ),
-        login(model),
-      )
+      let model = Model(..model, logging_in: True)
+
+      case model.auth {
+        Some(auth) -> #(
+          model,
+          login(model.config, WithToken(auth.user.tokens.refresh_token)),
+        )
+
+        None -> {
+          // We don't have a refresh token, we don't have a username and password -> reset view
+          case model.login.username {
+            "" -> #(
+              Model(..model, logging_in: False, logged_in: False, auth: None),
+              effect.none(),
+            )
+            _ -> #(
+              Model(
+                ..model,
+                logging_in: True,
+                login: login_view.update(model.login, login_view.AttemptLogin),
+              ),
+              login(
+                model.config,
+                WithUsernamePassword(model.login.username, model.login.password),
+              ),
+            )
+          }
+        }
+      }
     }
 
     LoginView(other) -> #(
@@ -212,20 +243,19 @@ fn auth_refresh_check(model: Model) {
 
   case model.auth {
     Some(auth) -> {
-      let now = date.now()
-      let assert Ok(last_valid_time) =
-        date.from_unix(
-          date.to_unix(auth.user.tokens.access_token_expiry) - model.config.api_auth_token_refresh_diff,
+      case
+        tokens.is_access_expired(
+          auth.user.tokens,
+          model.config.api_auth_token_refresh_diff,
         )
-
-      case date.compare(now, last_valid_time) {
-        order.Gt -> {
+      {
+        True -> {
           io.println("[AuthCheck] Auth expiring soon, refreshing...")
           dispatch(RefreshLogin)
           Nil
         }
 
-        order.Lt | order.Eq -> {
+        False -> {
           io.println("[AuthCheck] Auth not expiring yet, no need to refresh.")
         }
       }
@@ -236,10 +266,10 @@ fn auth_refresh_check(model: Model) {
   }
 }
 
-fn login(model: Model) -> Effect(Msg) {
+fn login(config: Config, credentials: Credentials) -> Effect(Msg) {
   use dispatch <- effect.from()
 
-  auth_api.auth(model.config, model.login.username, model.login.password)
+  auth_api.auth_or_refresh(config, credentials)
   |> promise.map(LoginResult)
   |> promise.tap(dispatch)
 

src/geo_t/web/auth.gleam

@@ -37,7 +37,7 @@ pub fn load(storage: AuthInfoStorage) {
     |> result.map_error(LoadError),
   )
 
-  case date.compare(date.now(), info.user.tokens.access_token_expiry) {
+  case date.compare(date.now(), info.user.tokens.refresh_token_expiry) {
     order.Lt -> Ok(info)
     _ -> Error(ExpiredError)
   }