Dev/refacto oracle charac

README.md

@@ -42,7 +42,7 @@ docker compose up -d mosquitto        # Broker only (for MQTT Explorer)
 ```bash
 rustup default stable       # Rust 1.89+
 cargo build                 # Build workspace
-cargo test                  # 158 tests (api + game-logic + screen-hub + mqtt-bridge + shared)
+cargo test                  # 173 tests (api + game-logic + screen-hub + mqtt-bridge + shared)
 ```
 Documentation of the codebase:
 ```bash
@@ -120,7 +120,7 @@ HTML report + Tab of the coverage
 ```
 cargo llvm-cov --html
 ```
-(Last tested 18/06/2026: ~68.55% code coverage)
+(Last tested 26/06/2026: ~69.19% code coverage)
 
 
 ## Tech stack

crates/game-logic/src/engine/config.rs

@@ -56,6 +56,7 @@ pub struct GameConfigPatch {
     pub oracle_ulti_duration_ms: Option<u64>,
     pub oracle_slow_factor: Option<f32>,
     pub oracle_time_rate: Option<f32>,
+    pub oracle_activation_min_ratio: Option<f32>,
     pub streak_window_ms: Option<u64>,
     pub streak_tier_1_count: Option<u32>,
     pub streak_tier_2_count: Option<u32>,
@@ -150,6 +151,8 @@ pub struct GameConfig {
     pub oracle_ulti_duration_ms: u64,
     pub oracle_slow_factor: f32,
     pub oracle_time_rate: f32,
+    /// Fraction of charge_max below which time_slow cannot be activated (default 5%).
+    pub oracle_activation_min_ratio: f32,
 
     // Streak multiplier
     pub streak_window_ms: u64,
@@ -230,6 +233,7 @@ impl Default for GameConfig {
             oracle_ulti_duration_ms: 5_000,
             oracle_slow_factor: 0.25,
             oracle_time_rate: 1.0,
+            oracle_activation_min_ratio: 0.05,
             streak_window_ms: 2_000,
             streak_tier_1_count: 2,
             streak_tier_2_count: 5,
@@ -322,6 +326,7 @@ pub fn apply_patch(patch: GameConfigPatch) {
     apply!(oracle_ulti_duration_ms);
     apply!(oracle_slow_factor);
     apply!(oracle_time_rate);
+    apply!(oracle_activation_min_ratio);
     apply!(streak_window_ms);
     apply!(streak_tier_1_count);
     apply!(streak_tier_2_count);

crates/game-logic/src/engine/core/charge.rs

@@ -1,6 +1,7 @@
 use std::time::Instant;
 
 use crate::engine::config;
+use crate::engine::services::charge::{score_to_charge, time_to_charge};
 use crate::engine::states::GamePhase;
 
 use super::{ChargeSource, GameEngine};
@@ -17,15 +18,14 @@ impl GameEngine {
             return;
         }
         let delta_s = config::get().pve_tick_interval_ms as f32 / 1000.0;
-        self.state.time_charge_buffer += time_rate * delta_s;
-        let to_add = self.state.time_charge_buffer.floor() as u32;
-        if to_add > 0 {
-            self.state.time_charge_buffer -= to_add as f32;
+        let (gain, new_buffer) = time_to_charge(time_rate, delta_s, self.state.time_charge_buffer);
+        self.state.time_charge_buffer = new_buffer;
+        if gain > 0 {
             let charge_max = stats.charge_profile.charge_max;
             self.state.ultimate_charge = self
                 .state
                 .ultimate_charge
-                .saturating_add(to_add)
+                .saturating_add(gain)
                 .min(charge_max);
         }
     }
@@ -37,24 +37,22 @@ impl GameEngine {
         if self.state.is_ulti_active(now) {
             return;
         }
-        let stats = self.character.stats();
-        let profile = stats.charge_profile;
+        let profile = self.character.stats().charge_profile;
         let weight = match source {
             ChargeSource::Bumper => profile.weight_bumper,
             ChargeSource::Rail => profile.weight_rail,
             ChargeSource::Combo => profile.weight_combo,
             ChargeSource::Other => profile.weight_other,
         };
-        let charge_ratio = config::get().ultime_charge_ratio;
-        let weighted = (base_pts as f32 * weight).round() as u32;
-        self.state.point_buffer = self.state.point_buffer.saturating_add(weighted);
-        let gain = self.state.point_buffer / charge_ratio;
-        self.state.point_buffer %= charge_ratio;
-        let charge_max = profile.charge_max;
-        self.state.ultimate_charge = self
-            .state
-            .ultimate_charge
-            .saturating_add(gain)
-            .min(charge_max);
+        let (new_charge, new_buffer) = score_to_charge(
+            base_pts,
+            weight,
+            self.state.point_buffer,
+            config::get().ultime_charge_ratio,
+            self.state.ultimate_charge,
+            profile.charge_max,
+        );
+        self.state.ultimate_charge = new_charge;
+        self.state.point_buffer = new_buffer;
     }
 }

crates/game-logic/src/engine/core/emit.rs

@@ -14,12 +14,12 @@ impl GameEngine {
         let charge_max = self.character.stats().charge_profile.charge_max;
 
         let displayed_charge = if self.state.is_ulti_active(now) {
-            self.state.residual_charge_with_max(now, charge_max)
+            self.state.residual_charge(now)
         } else {
             self.state.ultimate_charge
         };
-        let ulti_ready =
-            !self.state.is_ulti_active(now) && self.state.ultimate_charge >= charge_max;
+        let ulti_ready = !self.state.is_ulti_active(now)
+            && self.state.ultimate_charge >= self.activation_min_charge();
 
         let mut payload = serde_json::json!({
             "score": self.state.score,