implement conditions on choices

src/chat.rs

@@ -117,13 +117,29 @@ pub enum ChatEvent {
     DespawnAllChoices,
     DespawnAllChats,
     SpawnMessage(String, hud::LogLevel, String),
-    SpawnChoice(String, usize, ChatPos, bool),
+    SpawnChoice(String, usize, ChatPos, bool, Option<String>),
     RunScript(String),
     SleepSeconds(f64),
     SetVariable(String),
     GotoIf(String, ChatPos),
 }
 
+pub struct Extracted {
+    choice_text: Option<String>,
+    nowait: bool,
+    condition: Option<String>,
+}
+impl Default for Extracted {
+    fn default() -> Self {
+        Self {
+            choice_text: None,
+            nowait: false,
+            condition: None,
+        }
+    }
+}
+
+
 // This is the only place where any YAML interaction should be happening.
 #[derive(Resource)]
 pub struct ChatDB(Vec<Value>);
@@ -229,28 +245,38 @@ impl ChatDB {
     // Not acceptable:
     // - `"What's up?"`
     // - `{"goto": "foo"}`
-    // Returns (choice text, sub-conversation branch, nowait flag)
-    fn search_choice(&self, yaml: Option<&Value>) -> Option<(String, Value, bool)> {
+    fn is_choice(&self, yaml: Option<&Value>) -> bool {
+        if let Some(data) = self.extract(yaml) {
+            return data.choice_text.is_some();
+        }
+        return false;
+    }
+
+    fn extract(&self, yaml: Option<&Value>) -> Option<Extracted> {
         let non_choice_tokens = NON_CHOICE_TOKENS.to_vec();
-        let mut result: Option<(String, Value, bool)> = None;
-        let mut nowait = false;
         if let Some(Value::Mapping(map)) = yaml {
+            let mut result: Extracted = Extracted::default();
             for (key, value) in map {
                 if let Value::String(key) = key {
                     if key == TOKEN_NOWAIT && value.as_bool() == Some(true) {
-                        nowait = true;
+                        result.nowait = true;
                     }
-                    if non_choice_tokens.contains(&key.as_str()) {
-                        continue;
+                    else if key == TOKEN_IF {
+                        if let Some(condition) = value.as_str() {
+                            result.condition = Some(condition.to_string());
+                        }
                     }
-                    if key.as_str().starts_with(TOKEN_IF_INLINE) {
-                        continue;
+                    else if non_choice_tokens.contains(&key.as_str()) {
+                        // skip over the other non-choice tokens
+                    }
+                    else {
+                        result.choice_text = Some(key.to_string());
                     }
-                    result = Some((key.into(), map[key].clone(), nowait));
                 }
             }
+            return Some(result);
         }
-        return result;
+        return None;
     }
 
     fn search_label_recursively(&self, sequence: &Value, label: &String, mut pos: ChatPos) -> Option<ChatPos> {
@@ -317,7 +343,7 @@ impl ChatDB {
                     }
                 },
                 Some(Value::Mapping(map)) => {
-                    if seek_past_dialog_choices && self.search_choice(Some(&Value::Mapping(map))).is_some() {
+                    if seek_past_dialog_choices && self.is_choice(Some(&Value::Mapping(map))) {
                         // we just dropped out of a branch and ended up in a dialog
                         // choice. let's seek past all the choices until we find
                         // the next non-dialog-choice item.
@@ -426,7 +452,7 @@ impl ChatDB {
                 let mut sound = DEFAULT_SOUND.to_string();
 
                 // Is this a dialog choice?
-                if let Some(_) = self.search_choice(Some(&Value::Mapping(map.clone()))) {
+                if self.is_choice(Some(&Value::Mapping(map.clone()))) {
                     processed_a_choice = true;
                 }
 
@@ -542,16 +568,21 @@ impl ChatDB {
             // Spawn choices until we reach a non-choice item or the end of the branch
             let mut key: usize = 0;
             let mut reached_end_of_branch = false;
-            while let Some((choice, _, nowait)) =
-                    self.search_choice(self.at(chat.internal_id, &chat.position).as_ref()) {
-                if reached_end_of_branch {
+            while let Some(data) = self.extract(self.at(chat.internal_id, &chat.position).as_ref()) {
+                if let Some(choice_text) = data.choice_text {
+                    if reached_end_of_branch {
+                        break;
+                    }
+                    let mut goto: Vec<usize> = chat.position.clone();
+                    goto.push(0);
+                    event.send(ChatEvent::SpawnChoice(choice_text,
+                        key, goto, data.nowait, data.condition));
+                    key += 1;
+                    reached_end_of_branch = self.advance_pointer(chat);
+                }
+                else {
                     break;
                 }
-                let mut goto: Vec<usize> = chat.position.clone();
-                goto.push(0);
-                event.send(ChatEvent::SpawnChoice(choice, key, goto, nowait));
-                key += 1;
-                reached_end_of_branch = self.advance_pointer(chat);
             }
         }
     }
@@ -661,17 +692,25 @@ pub fn handle_chat_events(
                 let sfx = audio::str2sfx(sound);
                 ew_sfx.send(audio::PlaySfxEvent(sfx));
             }
-            ChatEvent::SpawnChoice(replytext, key, goto, nowait) => {
-                commands.spawn((
-                    world::DespawnOnPlayerDeath,
-                    Choice {
-                        text: replytext.into(),
-                        key: *key,
-                        goto: goto.clone(),
+            ChatEvent::SpawnChoice(replytext, key, goto, nowait, condition) => {
+                'out: {
+                    dbg!(condition);
+                    if let Some(condition) = condition {
+                        if !vars.evaluate_condition(condition, &chat.talker.actor_id) {
+                            break 'out;
+                        }
+                    }
+                    commands.spawn((
+                        world::DespawnOnPlayerDeath,
+                        Choice {
+                            text: replytext.into(),
+                            key: *key,
+                            goto: goto.clone(),
+                        }
+                    ));
+                    if !nowait {
+                        chat.timer = now + CHOICE_TIMER / settings.chat_speed as f64;
                     }
-                ));
-                if !nowait {
-                    chat.timer = now + CHOICE_TIMER / settings.chat_speed as f64;
                 }
             }
             ChatEvent::RunScript(script) => {