[wip, feat] Action dispatcher state machine

Signed-off-by: dd di cesare <[email protected]>

src/action_dispatcher.rs

@@ -0,0 +1,124 @@
+#[derive(PartialEq, Debug)]
+enum State {
+    Pending,
+    Waiting,
+    Done,
+}
+
+impl State {
+    fn next(&mut self) {
+        match self {
+            State::Pending => *self = State::Waiting,
+            State::Waiting => *self = State::Done,
+            _ => {}
+        }
+    }
+}
+#[derive(PartialEq)]
+enum Action {
+    Auth { state: State },
+    RateLimit { state: State },
+}
+
+impl Action {
+    pub fn trigger(&mut self) {
+        match self {
+            Action::Auth { .. } => self.auth(),
+            Action::RateLimit { .. } => self.rate_limit(),
+        }
+    }
+
+    fn get_state(&self) -> &State {
+        match self {
+            Action::Auth { state } => state,
+            Action::RateLimit { state } => state,
+        }
+    }
+
+    fn rate_limit(&mut self) {
+        // Specifics for RL, returning State
+        if let Action::RateLimit { state } = self {
+            match state {
+                State::Pending => {
+                    println!("Trigger the request and return State::Waiting");
+                    state.next();
+                }
+                State::Waiting => {
+                    println!(
+                        "When got on_grpc_response, process RL response and return State::Done"
+                    );
+                    state.next();
+                }
+                State::Done => {
+                    println!("Done for RL... calling next action (?)");
+                }
+            }
+        }
+    }
+
+    fn auth(&mut self) {
+        // Specifics for Auth, returning State
+        if let Action::Auth { state } = self {
+            match state {
+                State::Pending => {
+                    println!("Trigger the request and return State::Waiting");
+                    state.next();
+                }
+                State::Waiting => {
+                    println!(
+                        "When got on_grpc_response, process Auth response and return State::Done"
+                    );
+                    state.next();
+                }
+                State::Done => {
+                    println!("Done for Auth... calling next action (?)");
+                }
+            }
+        }
+    }
+}
+
+pub struct ActionDispatcher {
+    actions: Vec<Action>,
+}
+
+impl ActionDispatcher {
+    pub fn default() -> ActionDispatcher {
+        ActionDispatcher { actions: vec![] }
+    }
+
+    pub fn new(/*vec of PluginConfig actions*/) -> ActionDispatcher {
+        ActionDispatcher::default()
+    }
+
+    pub fn next(&mut self) -> bool {
+        if let Some((i, action)) = self.actions.iter_mut().enumerate().next() {
+            if let State::Done = action.get_state() {
+                self.actions.remove(i);
+                true
+            } else {
+                action.trigger();
+                true
+            }
+        } else {
+            false
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn action_transition() {
+        let mut action = Action::Auth {
+            state: State::Pending,
+        };
+        assert_eq!(*action.get_state(), State::Pending);
+        action.trigger();
+        assert_eq!(*action.get_state(), State::Waiting);
+        action.trigger();
+        assert_eq!(*action.get_state(), State::Done);
+    }
+}

src/lib.rs

@@ -1,3 +1,4 @@
+mod action_dispatcher;
 mod attribute;
 mod configuration;
 mod envoy;