Feat(split): fee waiver system, circuit breaker, compute estimation & payment batching (#922, #923, #924, #925)

contracts/split/src/events.rs

@@ -677,6 +677,88 @@ pub fn circuit_breaker_deactivated(env: &Env) {
         .publish((symbol_short!("split"), symbol_short!("cb_dact")), ());
 }
 
+/// Issue #925: Emitted when a payment batch is opened.
+/// Topics: (split, pb_open, payer)
+/// Data: (batch_id, token)
+pub fn payment_batch_opened(env: &Env, batch_id: u64, payer: &Address, token: &Address) {
+    env.events().publish(
+        (symbol_short!("split"), symbol_short!("pb_open"), payer.clone()),
+        (batch_id, token.clone()),
+    );
+}
+
+/// Issue #925: Emitted when a payment batch is executed.
+/// Topics: (split, pb_exec, payer)
+/// Data: (batch_id, item_count, total_amount, savings_bps)
+pub fn payment_batch_executed(
+    env: &Env,
+    batch_id: u64,
+    payer: &Address,
+    item_count: u32,
+    total_amount: i128,
+    savings_bps: u32,
+) {
+    env.events().publish(
+        (symbol_short!("split"), symbol_short!("pb_exec"), payer.clone()),
+        (batch_id, item_count, total_amount, savings_bps),
+    );
+}
+
+/// Issue #925: Emitted when a payment batch is cancelled.
+/// Topics: (split, pb_cncl, payer)
+/// Data: batch_id
+pub fn payment_batch_cancelled(env: &Env, batch_id: u64, payer: &Address) {
+    env.events().publish(
+        (symbol_short!("split"), symbol_short!("pb_cncl"), payer.clone()),
+        batch_id,
+    );
+}
+
+/// Issue #923: Emitted on every circuit breaker state transition.
+/// Topics: (split, cb_state)
+/// Data: (from, to, actor, reason, ledger)
+pub fn circuit_breaker_state_changed(
+    env: &Env,
+    from: CircuitBreakerState,
+    to: CircuitBreakerState,
+    actor: &Address,
+    reason: &String,
+) {
+    env.events().publish(
+        (symbol_short!("split"), symbol_short!("cb_state")),
+        (from, to, actor.clone(), reason.clone(), env.ledger().sequence()),
+    );
+}
+
+/// Issue #923: Emitted when a failure is reported against the circuit breaker.
+/// Topics: (split, cb_fail, reporter)
+/// Data: (failure_count, failure_threshold)
+pub fn circuit_breaker_failure_reported(
+    env: &Env,
+    reporter: &Address,
+    failure_count: u32,
+    failure_threshold: u32,
+) {
+    env.events().publish(
+        (
+            symbol_short!("split"),
+            symbol_short!("cb_fail"),
+            reporter.clone(),
+        ),
+        (failure_count, failure_threshold),
+    );
+}
+
+/// Issue #923: Emitted when an operation is added to or removed from the exemption list.
+/// Topics: (split, cb_exmpt)
+/// Data: (function, exempt)
+pub fn circuit_breaker_exemption_set(env: &Env, function: &Symbol, exempt: bool) {
+    env.events().publish(
+        (symbol_short!("split"), symbol_short!("cb_exmpt")),
+        (function.clone(), exempt),
+    );
+}
+
 /// Issue #296: Emitted when a fee waiver is granted to a creator.
 /// Topics: (split, fw_grant, creator)
 /// Data: ()
@@ -705,6 +787,34 @@ pub fn fee_waiver_revoked(env: &Env, creator: &Address) {
     );
 }
 
+/// Issue #922: Emitted when a fee waiver's expiry is set or extended.
+/// Topics: (split, fw_exp, creator)
+/// Data: expires_at (0 = never)
+pub fn fee_waiver_expiry_set(env: &Env, creator: &Address, expires_at: u64) {
+    env.events().publish(
+        (
+            symbol_short!("split"),
+            symbol_short!("fw_exp"),
+            creator.clone(),
+        ),
+        expires_at,
+    );
+}
+
+/// Issue #922: Emitted when an expired fee waiver is purged from the whitelist.
+/// Topics: (split, fw_purge, creator)
+/// Data: expires_at
+pub fn fee_waiver_expired(env: &Env, creator: &Address, expires_at: u64) {
+    env.events().publish(
+        (
+            symbol_short!("split"),
+            symbol_short!("fw_purge"),
+            creator.clone(),
+        ),
+        expires_at,
+    );
+}
+
 /// Issue #285: Emitted when fee tiers are updated.
 /// Topics: (split, fee_tiers_updated)
 /// Data: count of tiers