feat: swap fee should update

src/fly/src/app/erc20_bridge/swap_fee.rs

@@ -7,6 +7,7 @@ use ic_stable_structures::{DefaultMemoryImpl, StableCell};
 use crate::app::memory::{
     ERC20_SWAP_FEE_LAST_UPDATE_MEMORY_ID, ERC20_SWAP_FEE_MEMORY_ID, MEMORY_MANAGER,
 };
+use crate::constants::{ERC20_SWAP_FEE_MULTIPLIER, ONE_WEEK};
 use crate::utils::time;
 
 thread_local! {
@@ -49,6 +50,24 @@ impl SwapFee {
 
         Ok(())
     }
+
+    /// Returns whether the swap fee should be updated.
+    pub fn should_update_swap_fee(paid_gas: u64) -> bool {
+        let current_real_swap_fee = Self::get_real_swap_fee();
+        let paid_gas = paid_gas as f64;
+
+        let has_elapsed_one_week = LAST_SWAP_FEE_UPDATE
+            .with(|lsfu| time() - *lsfu.borrow().get() > ONE_WEEK.as_nanos() as u64);
+
+        (current_real_swap_fee * 1.75 <= paid_gas)
+            || (current_real_swap_fee * 1.25 <= paid_gas && has_elapsed_one_week)
+            || (current_real_swap_fee * 0.75 >= paid_gas && has_elapsed_one_week)
+    }
+
+    /// Get the swap fee without the multiplier.
+    fn get_real_swap_fee() -> f64 {
+        SWAP_FEE.with(|sf| *sf.borrow().get()) as f64 / ERC20_SWAP_FEE_MULTIPLIER
+    }
 }
 
 #[cfg(test)]
@@ -71,4 +90,36 @@ mod test {
 
         assert_ne!(LAST_SWAP_FEE_UPDATE.with(|lsfu| *lsfu.borrow().get()), 0);
     }
+
+    #[test]
+    fn test_should_tell_whether_to_update_swap_fee() {
+        // init swap fee to 120 (real fee is 100)
+        SwapFee::set_swap_fee(130).unwrap();
+        assert_eq!(SwapFee::get_real_swap_fee(), 100.0);
+
+        // 75%
+        assert!(SwapFee::should_update_swap_fee(175));
+
+        // 25 % and one week has elapsed
+        SwapFee::set_swap_fee(130).unwrap();
+        LAST_SWAP_FEE_UPDATE
+            .with_borrow_mut(|lsfu| lsfu.set(time() - ONE_WEEK.as_nanos() as u64))
+            .unwrap();
+        assert!(SwapFee::should_update_swap_fee(125));
+
+        // 25% and one week has not elapsed
+        SwapFee::set_swap_fee(130).unwrap();
+        assert!(!SwapFee::should_update_swap_fee(125));
+
+        // 0.75 and one week has elapsed
+        SwapFee::set_swap_fee(130).unwrap();
+        LAST_SWAP_FEE_UPDATE
+            .with_borrow_mut(|lsfu| lsfu.set(time() - ONE_WEEK.as_nanos() as u64))
+            .unwrap();
+        assert!(SwapFee::should_update_swap_fee(75));
+
+        // 0.75 and one week has not elapsed
+        SwapFee::set_swap_fee(130).unwrap();
+        assert!(!SwapFee::should_update_swap_fee(75));
+    }
 }

src/fly/src/constants.rs

@@ -18,9 +18,13 @@ pub const INITIAL_RMC: f64 = 0.0000042;
 /// Minimum reward
 pub const MIN_REWARD: u64 = ICRC1_FEE * 2;
 
+/// Factor to multiply the swap fee by
+pub const ERC20_SWAP_FEE_MULTIPLIER: f64 = 1.3;
+
+pub const ONE_WEEK: Duration = Duration::from_secs(60 * 60 * 24 * 7);
+
 #[cfg(target_family = "wasm")]
-pub const SPEND_ALLOWANCE_EXPIRED_ALLOWANCE_TIMER_INTERVAL: Duration =
-    Duration::from_secs(60 * 60 * 24 * 7); // 7 days
+pub const SPEND_ALLOWANCE_EXPIRED_ALLOWANCE_TIMER_INTERVAL: Duration = ONE_WEEK;
 
 #[cfg(target_family = "wasm")]
 pub const LIQUIDITY_POOL_SWAP_INTERVAL: Duration = Duration::from_secs(60 * 60 * 24); // 1 day