feat(oracle): bond escrow, bounty settlement and provider slashing (SC-023)

packages/contracts/oracle_marketplace/src/errors.rs

@@ -17,4 +17,22 @@ pub enum OracleMarketplaceError {
     OracleNotSelectedForCall = 11,
     AlreadyRated = 12,
     InvalidRating = 13,
+    /// Escrow for this call id already exists — call ids must be unique.
+    EscrowAlreadyExists = 14,
+    /// The call has already been resolved; it cannot be resolved twice.
+    EscrowAlreadyResolved = 15,
+    /// The call has been resolved but the bounty has not been settled yet.
+    EscrowNotSettled = 16,
+    /// Escrow amount is zero or negative — nothing to lock.
+    InvalidEscrowAmount = 17,
+    /// The address that called `resolve_call` is not the provider selected
+    /// for this call.
+    NotSelectedOracle = 18,
+    /// Slashing would push the provider below their own `min_stake`, which
+    /// would let a provider avoid being slashed by posting a tiny bond.
+    SlashBelowMinStake = 19,
+    /// Bond amount is not positive.
+    InvalidBond = 20,
+    /// Settlement amount exceeds what was escrowed.
+    SettlementOverflow = 21,
 }

packages/contracts/oracle_marketplace/src/events.rs

@@ -29,3 +29,55 @@ pub fn emit_oracle_rated(env: &Env, provider: &BytesN<32>, user: &Address, satis
         (provider.clone(), user.clone(), satisfied),
     );
 }
+
+/// A caller locked a bounty for a call.
+pub fn emit_escrow_created(env: &Env, call_id: u64, caller: &Address, oracle: &BytesN<32>, amount: i128) {
+    env.events().publish(
+        ("oracle_marketplace", "EscrowCreated"),
+        (call_id, caller.clone(), oracle.clone(), amount),
+    );
+}
+
+/// An escrowed bounty was paid out to the provider that answered correctly.
+pub fn emit_escrow_settled(
+    env: &Env,
+    call_id: u64,
+    oracle: &BytesN<32>,
+    provider_amount: i128,
+    fee_amount: i128,
+) {
+    env.events().publish(
+        ("oracle_marketplace", "EscrowSettled"),
+        (call_id, oracle.clone(), provider_amount, fee_amount),
+    );
+}
+
+/// A provider answered inaccurately; part of their bond was slashed.
+pub fn emit_bond_slashed(
+    env: &Env,
+    oracle: &BytesN<32>,
+    caller: &Address,
+    slashed: i128,
+    remaining_stake: i128,
+) {
+    env.events().publish(
+        ("oracle_marketplace", "BondSlashed"),
+        (oracle.clone(), caller.clone(), slashed, remaining_stake),
+    );
+}
+
+/// A provider topped their bond back up.
+pub fn emit_bond_increased(env: &Env, oracle: &BytesN<32>, amount: i128, total_stake: i128) {
+    env.events().publish(
+        ("oracle_marketplace", "BondIncreased"),
+        (oracle.clone(), amount, total_stake),
+    );
+}
+
+/// A provider withdrew bond after deregistering (subject to the cooldown).
+pub fn emit_bond_withdrawn(env: &Env, oracle: &BytesN<32>, provider: &Address, amount: i128) {
+    env.events().publish(
+        ("oracle_marketplace", "BondWithdrawn"),
+        (oracle.clone(), provider.clone(), amount),
+    );
+}