feat: add reward pool balance validation before hunt activation

contracts/hunty-core/src/lib.rs

@@ -607,15 +607,37 @@ impl HuntyCore {
         if let Some(reward_manager_addr) = Storage::get_reward_manager(&env) {
             let mut balance_args: Vec<Val> = Vec::new(&env);
             balance_args.push_back(hunt_id.into_val(&env));
+
+            // Query the pool balance from the reward manager
             let pool_balance = match env.try_invoke_contract::<i128, RewardErrorCode>(
                 &reward_manager_addr,
                 &Symbol::new(&env, "get_pool_balance"),
-                balance_args,
+                balance_args.clone(),
             ) {
                 Ok(Ok(balance)) => balance,
                 _ => return Err(HuntErrorCode::InsufficientRewardPool),
             };
             hunt.reward_config.xlm_pool = pool_balance;
+
+            // Query the minimum distribution amount for this pool
+            let min_distribution_amount = match env.try_invoke_contract::<i128, RewardErrorCode>(
+                &reward_manager_addr,
+                &Symbol::new(&env, "get_min_distribution_amount"),
+                balance_args,
+            ) {
+                Ok(Ok(amount)) => amount,
+                _ => 0,
+            };
+
+            // Validate pool balance >= min_distribution_amount * max_winners
+            if min_distribution_amount > 0 && hunt.reward_config.max_winners > 0 {
+                let required =
+                    min_distribution_amount.saturating_mul(hunt.reward_config.max_winners as i128);
+                if pool_balance < required {
+                    return Err(HuntErrorCode::InsufficientRewardPool);
+                }
+            }
+
             if !hunt.has_rewards_available() {
                 return Err(HuntErrorCode::InsufficientRewardPool);
             }

contracts/reward-manager/src/lib.rs

@@ -10,8 +10,8 @@
     DistributionRecord, DistributionStatus, RewardConfig, RewardPoolConfig, RewardPoolStatus,
     SemVer, ValidationResult,
 };
 use crate::xlm_handler::XlmHandler;
 
 // Funding validation constants
 // 1 XLM = 10_000_000 stroops (Stellar's base unit)
 /// Minimum funding amount: 1 XLM (prevents dust attacks)
@@ -436,7 +436,7 @@
         let balance = Storage::get_pool_balance(&env, hunt_id);
         let total_deposited = Storage::get_pool_total_deposited(&env, hunt_id);
         let total_distributed = Storage::get_pool_total_distributed(&env, hunt_id);
 
         Some(RewardPoolStatus {
             balance,
             total_deposited,
@@ -699,6 +699,14 @@
         Storage::get_pool_balance(&env, hunt_id)
     }
 
+    /// Returns the minimum distribution amount configured for a hunt's reward pool.
+    /// Returns 0 if no pool has been created for the hunt.
+    pub fn get_min_distribution_amount(env: Env, hunt_id: u64) -> i128 {
+        Storage::get_pool_config(&env, hunt_id)
+            .map(|config| config.min_distribution_amount)
+            .unwrap_or(0)
+    }
+
     /// Returns whether a reward has been distributed to a player for a hunt.
     pub fn is_reward_distributed(env: Env, hunt_id: u64, player: Address) -> bool {
         Storage::is_distributed(&env, hunt_id, &player)