feat: implement Real Estate Oracle Integration System #36

contracts/lib/src/lib.rs

@@ -84,6 +84,8 @@ mod propchain_contracts {
         pause_info: PauseInfo,
         /// Accounts authorized to pause the contract
         pause_guardians: Mapping<AccountId, bool>,
+        /// Oracle contract address (optional)
+        oracle: Option<AccountId>,
     }
 
     /// Escrow information
@@ -765,6 +767,7 @@ mod propchain_contracts {
                     required_approvals: 2, // Default requirement
                 },
                 pause_guardians: Mapping::default(),
+                oracle: None,
             };
 
             // Emit contract initialization event
@@ -790,6 +793,46 @@ mod propchain_contracts {
             self.admin
         }
 
+        /// Set the oracle contract address
+        #[ink(message)]
+        pub fn set_oracle(&mut self, oracle: AccountId) -> Result<(), Error> {
+            let caller = self.env().caller();
+            if caller != self.admin {
+                return Err(Error::Unauthorized);
+            }
+            self.oracle = Some(oracle);
+            Ok(())
+        }
+
+        /// Returns the oracle contract address
+        #[ink(message)]
+        pub fn oracle(&self) -> Option<AccountId> {
+            self.oracle
+        }
+
+        /// Update property valuation using the oracle
+        #[ink(message)]
+        pub fn update_valuation_from_oracle(&mut self, property_id: u64) -> Result<(), Error> {
+            let oracle_addr = self.oracle.ok_or(Error::OracleError)?;
+
+            // Use the Oracle trait to perform the cross-contract call
+            use ink::env::call::FromAccountId;
+            let oracle: ink::contract_ref!(Oracle) = FromAccountId::from_account_id(oracle_addr);
+
+            // Fetch valuation from oracle
+            let valuation = oracle.get_valuation(property_id).map_err(|_| Error::OracleError)?;
+
+            // Update the property's recorded valuation in its metadata
+            if let Some(mut property) = self.properties.get(&property_id) {
+                property.metadata.valuation = valuation.valuation;
+                self.properties.insert(&property_id, &property);
+            } else {
+                return Err(Error::PropertyNotFound);
+            }
+
+            Ok(())
+        }
+
         /// Changes the admin account (only callable by current admin)
         #[ink(message)]
         pub fn change_admin(&mut self, new_admin: AccountId) -> Result<(), Error> {

contracts/oracle/README.md

@@ -11,6 +11,10 @@ The Property Valuation Oracle provides real-time property valuations for the Pro
 - **Location-Based Adjustments**: Geographic market adjustments
 - **Price Alert System**: Notifications for significant valuation changes
 - **Fallback Mechanisms**: Redundant oracle sources for reliability
+- **Oracle Reputation System**: Performance tracking and automated source management
+- **Slashing System**: Stake-based penalties for malicious or inaccurate data
+- **Gas-Efficient Batching**: Support for multiple property valuation requests in a single transaction
+- **Anomaly Detection**: Advanced validation logic to detect market outliers
 
 ## Architecture
 
@@ -48,6 +52,12 @@ Returns historical valuations (most recent first).
 #### `set_price_alert(property_id: u64, threshold_percentage: u32, alert_address: AccountId)`
 Sets up alerts for price changes exceeding the threshold.
 
+#### `request_property_valuation(property_id: u64) -> Result<u64, OracleError>`
+Initiates a new valuation request for a property.
+
+#### `batch_request_valuations(property_ids: Vec<u64>) -> Result<Vec<u64>, OracleError>`
+Batch requests valuations for multiple properties efficiently.
+
 ### Administrative Functions
 
 #### `add_oracle_source(source: OracleSource) -> Result<(), OracleError>`
@@ -59,6 +69,12 @@ Configures location-based valuation adjustments (admin only).
 #### `update_market_trend(trend: MarketTrend) -> Result<(), OracleError>`
 Updates market trend data for volatility calculations (admin only).
 
+#### `update_source_reputation(source_id: String, success: bool) -> Result<(), OracleError>`
+Manages oracle source reputation scores (admin only).
+
+#### `slash_source(source_id: String, penalty: u128) -> Result<(), OracleError>`
+Slashes staked funds for underperforming or malicious sources (admin only).
+
 ## Data Structures
 
 ### PropertyValuation