WIP stack-based conversation position

src/chat.rs

@@ -54,7 +54,7 @@ impl Plugin for ChatPlugin {
 #[derive(Component)]
 pub struct Chat {
     pub id: usize,
-    pub position: usize,
+    pub position: Vec<usize>,
     pub timer: f64,
     pub talker: Talker,
 }
@@ -110,6 +110,21 @@ impl ChatDB {
         return None;
     }
 
+    // returns false if the advanced pointer is out of bounds
+    fn advance_pointer(&self, chat: &mut Chat) -> bool {
+        chat.position[0] += 1;
+        return true;
+    }
+
+    fn pointer_lookahead(&self, position: &mut Vec<usize>) {
+        let index = position.len() - 1;
+        position[index] += 1;
+    }
+
+    fn at(&self, id: usize, position: Vec<usize>) -> Option<Yaml> {
+        return None;
+    }
+
     pub fn advance_chat(&self, chat: &mut Chat, event: &mut EventWriter<ChatEvent>) {
         event.send(ChatEvent::DespawnAllChoices);
         let conv = &self.0[chat.id].as_vec();
@@ -120,34 +135,34 @@ impl ChatDB {
 
         // Handle next entry in the chat list
         let mut is_skipping_through = false;
-        chat.position += 1;
-        if chat.position >= conv.len() {
+        if !self.advance_pointer(chat) {
             event.send(ChatEvent::SpawnMessage("Disconnected.".to_string()));
             event.send(ChatEvent::DespawnAllChats);
             return;
         }
-        else if let Some(_) = self.search_choice(&conv[chat.position]) {
+        else if let Some(_) = self.search_choice(&conv[chat.position[0]]) {
             is_skipping_through = true;
         }
-        else if let Some(message) = conv[chat.position].as_str() {
+        else if let Some(message) = conv[chat.position[0]].as_str() {
             event.send(ChatEvent::SpawnMessage(message.to_string()));
         }
 
         // Check if the immediately following entries are choices
-        let mut pos = chat.position + 1;
+        let mut pos = chat.position.clone();
+        self.pointer_lookahead(&mut pos);
         let mut key: usize = 0;
         loop {
-            if is_skipping_through || pos >= conv.len() {
+            if is_skipping_through || pos[0] >= conv.len() {
                 break;
             }
-            if let Some(choice) = self.search_choice(&conv[pos]) {
+            if let Some(choice) = self.search_choice(&conv[pos[0]]) {
                 event.send(ChatEvent::SpawnChoice(choice, key));
                 key += 1;
             }
             else {
                 break;
             }
-            pos += 1;
+            self.pointer_lookahead(&mut pos);
         }
     }
 }
@@ -202,7 +217,7 @@ pub fn handle_new_conversations(
                 ew_sfx.send(audio::PlaySfxEvent(audio::Sfx::Ping));
                 let mut chat = Chat {
                     id: chat_id,
-                    position: 0,
+                    position: vec![0],
                     timer: time.elapsed_seconds_f64(),
                     talker: event.talker.clone(),
                 };