Room levels 2 and 3, researched in the library: a quarter better each, brighter, with gold trim

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/research.rs

@@ -46,6 +46,26 @@ pub const RESEARCH: &[(usize, f32)] = &[
     (51, 1000.0), // catapult
 ];
 
+// room levels, researched once everything else is known: (index in ROOM_KINDS, level, points)
+pub const UPGRADES: &[(usize, u8, f32)] = &[
+    (1, 2, 500.0),   // lair
+    (2, 2, 500.0),   // mushroom garden
+    (0, 2, 550.0),   // treasury
+    (4, 2, 600.0),   // library
+    (3, 2, 600.0),   // training hall
+    (8, 2, 650.0),   // forge
+    (6, 2, 650.0),   // temple
+    (7, 2, 650.0),   // aerie
+    (1, 3, 1000.0),  // lair
+    (2, 3, 1000.0),  // mushroom garden
+    (0, 3, 1100.0),  // treasury
+    (4, 3, 1200.0),  // library
+    (3, 3, 1200.0),  // training hall
+    (8, 3, 1300.0),  // forge
+    (6, 3, 1300.0),  // temple
+    (7, 3, 1300.0),  // aerie
+];
+
 // known from the start in free play
 pub const BASE_TOOLS: &[usize] = &[0, 1, 2, 3, 4, 6, 7, 8, 9, 14, 17, 20, 45, 46, 49];
 
@@ -92,13 +112,45 @@ impl Game {
         !self.known(tool) && self.researchable.get(tool).copied().unwrap_or(false) && RESEARCH.iter().any(|&(t, _)| t == tool)
     }
 
+    // the room level being researched once no tool is left: index in UPGRADES
+    pub fn upgrade_target(&self) -> Option<usize> {
+        if self.research_target().is_some() || self.known.is_empty() {
+            return None;
+        }
+        UPGRADES.iter().position(|&(r, lv, _)| self.room_level.get(r).copied().unwrap_or(1).max(1) < lv)
+    }
+
     pub(crate) fn add_research(&mut self, points: f32) {
-        if self.research_target().is_some() {
+        if self.research_target().is_some() || self.upgrade_target().is_some() {
             self.research += points;
         }
     }
 
+    // a room kind reached level `lv` (the map keeps it for the look of the rooms)
+    pub fn set_room_level(&mut self, r: usize, lv: u8) {
+        if self.room_level.len() < crate::game::N_ROOMS {
+            self.room_level.resize(crate::game::N_ROOMS, 1);
+        }
+        self.room_level[r] = lv;
+        let side = self.me_side;
+        self.map.upgrades.retain(|u| !(u.0 == side && u.1 as usize == r));
+        if lv > 1 {
+            self.map.upgrades.push((side, r as u8, lv));
+        }
+    }
+
     pub(crate) fn update_research(&mut self) {
+        if let Some(u) = self.upgrade_target() {
+            let (r, lv, cost) = UPGRADES[u];
+            if self.research >= cost {
+                self.research -= cost;
+                self.set_room_level(r, lv);
+                let roman = if lv == 2 { "II" } else { "III" };
+                self.msg("msg.room_upgraded", vec![format!("@{}", crate::game::ROOM_NAMES[r]), roman.to_string()]);
+                self.sfx_ui(Sfx::LevelUp);
+            }
+            return;
+        }
         let Some(k) = self.research_target() else { return };
         let (tool, cost) = RESEARCH[k];
         if self.research >= cost {
@@ -154,4 +206,23 @@ mod tests {
         assert!(g.can_research(10), "heal comes soon and can be researched");
         assert!(!g.can_research(31), "magic doors are far away");
     }
+
+    #[test]
+    fn once_everything_is_known_the_library_raises_room_levels() {
+        let mut g = Game::new(9, 64, 64);
+        assert!(g.upgrade_target().is_none(), "tools first");
+        for v in g.known.iter_mut() {
+            *v = true;
+        }
+        let u = g.upgrade_target().expect("a room level to research");
+        let (r, lv, cost) = UPGRADES[u];
+        assert_eq!(lv, 2);
+        let before = g.room_bonus(ROOM_KINDS[r]);
+        g.research = cost + 1.0;
+        g.update_research();
+        assert_eq!(g.room_level_of(ROOM_KINDS[r]), 2);
+        assert!(g.room_bonus(ROOM_KINDS[r]) > before);
+        assert!(g.map.upgrades.iter().any(|x| x.1 as usize == r && x.2 == 2), "the map shows it");
+        assert_ne!(g.upgrade_target(), Some(u), "the next one");
+    }
 }