From b9381eecf44db7e9fb7486cbabf9c8e0465ff9d1 Mon Sep 17 00:00:00 2001
From: projectmoon <projectmoon@agnos.is>
Date: Sun, 20 Jun 2021 21:45:55 +0000
Subject: [PATCH] Begin creating logic layer in web UI.

---
 Cargo.lock                   |  1 +
 web-ui/crate/Cargo.toml      |  1 +
 web-ui/crate/src/api/auth.rs |  1 -
 web-ui/crate/src/error.rs    |  3 ++
 web-ui/crate/src/lib.rs      |  1 +
 web-ui/crate/src/logic.rs    | 66 ++++++++++++++++++++++++++++++++++++
 6 files changed, 72 insertions(+), 1 deletion(-)
 create mode 100644 web-ui/crate/src/logic.rs

diff --git a/Cargo.lock b/Cargo.lock
index 9a30a1f..f35ea9c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3578,6 +3578,7 @@ dependencies = [
  "graphql_client",
  "graphql_client_web",
  "js-sys",
+ "jsonwebtoken",
  "serde",
  "serde_json",
  "tenebrous-api",
diff --git a/web-ui/crate/Cargo.toml b/web-ui/crate/Cargo.toml
index f9434e5..c65f87d 100644
--- a/web-ui/crate/Cargo.toml
+++ b/web-ui/crate/Cargo.toml
@@ -25,6 +25,7 @@ graphql_client_web = { git = "https://github.com/graphql-rust/graphql-client", b
 serde = { version = "1.0.67", features = ["derive"] }
 serde_json = {version = "1.0" }
 thiserror = "1.0"
+jsonwebtoken = "7.2"
 
 [dependencies.web-sys]
 version = "0.3"
diff --git a/web-ui/crate/src/api/auth.rs b/web-ui/crate/src/api/auth.rs
index 518459a..9751416 100644
--- a/web-ui/crate/src/api/auth.rs
+++ b/web-ui/crate/src/api/auth.rs
@@ -83,7 +83,6 @@ pub async fn refresh_jwt() -> Result<String, UiError> {
     request.headers().set("Content-Type", "application/json")?;
     request.headers().set("Accept", "application/json")?;
 
-    //TODO don't unwrap the response. OR... change it so we have a standard response.
     let response: LoginResponse = make_request(request).await?;
     Ok(response.jwt_token)
 }
diff --git a/web-ui/crate/src/error.rs b/web-ui/crate/src/error.rs
index a4f9d16..dfc2329 100644
--- a/web-ui/crate/src/error.rs
+++ b/web-ui/crate/src/error.rs
@@ -18,6 +18,9 @@ pub enum UiError {
 
     #[error("(de)serialization error: {0}")]
     SerdeError(#[from] serde_json::Error),
+
+    #[error("JWT validation error: {0}")]
+    JwtError(#[from] jsonwebtoken::errors::Error),
 }
 
 impl From<wasm_bindgen::JsValue> for UiError {
diff --git a/web-ui/crate/src/lib.rs b/web-ui/crate/src/lib.rs
index e760859..ed68e69 100644
--- a/web-ui/crate/src/lib.rs
+++ b/web-ui/crate/src/lib.rs
@@ -16,6 +16,7 @@ pub mod api;
 pub mod components;
 pub mod error;
 pub mod grpc;
+pub mod logic;
 pub mod rooms;
 pub mod state;
 
diff --git a/web-ui/crate/src/logic.rs b/web-ui/crate/src/logic.rs
new file mode 100644
index 0000000..4de68c2
--- /dev/null
+++ b/web-ui/crate/src/logic.rs
@@ -0,0 +1,66 @@
+use crate::{
+    api,
+    error::UiError,
+    state::{Action, Room, WebUiDispatcher},
+};
+use jsonwebtoken::{
+    dangerous_insecure_decode_with_validation as decode_without_verify, Validation,
+};
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Serialize, Deserialize)]
+struct Claims {
+    exp: usize,
+    sub: String,
+}
+
+fn map_to_vec(action: Option<Action>) -> Vec<Action> {
+    action.map(|a| vec![a]).unwrap_or_default()
+}
+
+async fn ensure_jwt(dispatch: &WebUiDispatcher) -> Result<(String, Option<Action>), UiError> {
+    //TODO we should add a logout action and return it from here if there's an error when refreshing.
+    //TODO somehow have to handle actions on an error!
+
+    //TODO lots of clones here. can we avoid?
+    use jsonwebtoken::errors::ErrorKind;
+    let token = dispatch.state().jwt_token.as_deref().unwrap_or_default();
+    let validation =
+        decode_without_verify::<Claims>(token, &Validation::default()).map(|data| data.claims);
+
+    //If valid, simply return token. If expired, attempt to refresh.
+    //Otherwise, bubble error.
+    let token_and_action = match validation {
+        Ok(_) => (token.to_owned(), None),
+        Err(e) if matches!(e.kind(), ErrorKind::ExpiredSignature) => {
+            match api::auth::refresh_jwt().await {
+                Ok(new_jwt) => (new_jwt.clone(), Some(Action::UpdateJwt(new_jwt))),
+                Err(e) => return Err(e.into()), //TODO logout action
+            }
+        }
+        Err(e) => return Err(e.into()),
+    };
+
+    Ok(token_and_action)
+}
+
+pub(crate) async fn fetch_rooms(dispatch: &WebUiDispatcher) -> Result<Vec<Action>, UiError> {
+    let (jwt, jwt_update) = ensure_jwt(dispatch)
+        .await
+        .map(|(token, update)| (token, map_to_vec(update)))?;
+
+    //Use new JWT to list rooms from graphql.
+    //TODO get username from state.
+    let rooms: Vec<Action> = api::dicebot::rooms_for_user(&jwt, "@projectmoon:agnos.is")
+        .await?
+        .into_iter()
+        .map(|room| {
+            Action::AddRoom(Room {
+                room_id: room.room_id,
+                display_name: room.display_name,
+            })
+        })
+        .collect();
+
+    Ok(rooms.into_iter().chain(jwt_update).collect())
+}