gatewayd: serve, posting approvals, marking them, and the listener

Implemented-By: OpenCode session (model recorded in docs/implementer-log.md)

crates/gatewayd/tests/support/fake_mm.rs

@@ -30,6 +30,10 @@ struct Inner {
     posts: Vec<(String, String, String)>,
     /// Every REST call: method and path.
     calls: Vec<(String, String)>,
+    /// Every edit: the post and its new text.
+    edits: Vec<(String, String)>,
+    /// When set, `POST /posts` is refused with 400.
+    refuse_posts: bool,
 }
 
 pub struct FakeMm {
@@ -223,6 +227,28 @@ impl FakeMm {
     pub fn calls(&self) -> Vec<(String, String)> {
         self.inner.lock().unwrap().calls.clone()
     }
+
+    /// The id of the n-th post made (from 0).
+    pub fn post_id(n: usize) -> String {
+        id('x', u32::try_from(n).unwrap())
+    }
+
+    pub fn edits(&self) -> Vec<(String, String)> {
+        self.inner.lock().unwrap().edits.clone()
+    }
+
+    /// Wait until at least `n` edits were made, for at most `wait`.
+    pub fn wait_edits(&self, n: usize, wait: Duration) -> Vec<(String, String)> {
+        let until = Instant::now() + wait;
+        while self.edits().len() < n && Instant::now() < until {
+            std::thread::sleep(Duration::from_millis(10));
+        }
+        self.edits()
+    }
+
+    pub fn refuse_posts(&self, refuse: bool) {
+        self.inner.lock().unwrap().refuse_posts = refuse;
+    }
 }
 
 fn connection(mut stream: TcpStream, inner: &Mutex<Inner>, ws_tx: &mpsc::Sender<WsPeer>) {
@@ -298,6 +324,9 @@ fn rest(inner: &Mutex<Inner>, method: &str, path: &str, body: &[u8]) -> (u16, Va
             };
             (201, json!({"id": channel, "type": "D"}))
         }
+        ("POST", "/api/v4/posts") if inner.refuse_posts => {
+            (400, json!({"id": "api.post.create_post.refused"}))
+        }
         ("POST", "/api/v4/posts") => {
             let p: Value = serde_json::from_slice(body).unwrap();
             let n = u32::try_from(inner.posts.len()).unwrap();
@@ -326,6 +355,27 @@ fn rest(inner: &Mutex<Inner>, method: &str, path: &str, body: &[u8]) -> (u16, Va
                     .unwrap_or(json!({"order": [], "posts": {}})),
             )
         }
+        ("PUT", p) if p.starts_with("/api/v4/posts/") && p.ends_with("/patch") => {
+            let post_id = p
+                .trim_start_matches("/api/v4/posts/")
+                .trim_end_matches("/patch")
+                .to_string();
+            let message = serde_json::from_slice::<Value>(body).unwrap()["message"]
+                .as_str()
+                .unwrap()
+                .to_string();
+            inner.edits.push((post_id.clone(), message.clone()));
+            (200, post(&post_id, BOT, DM, "", &message, 1))
+        }
+        ("GET", p) if p.starts_with("/api/v4/users/") => {
+            let user = p.trim_start_matches("/api/v4/users/");
+            let name = if user == KYLE {
+                "kyle".to_string()
+            } else {
+                format!("user-{}", &user[..4])
+            };
+            (200, json!({"id": user, "username": name}))
+        }
         _ => (404, json!({"message": "not found"})),
     }
 }