feat: implement contract rollback, governance, insurance, and oracle contracts

backend/src/services/mod.rs

@@ -26,3 +26,4 @@ pub mod compilation;
 pub mod dependency_analyzer;
 pub mod contract_call_logger;
 pub mod compliance;
+pub mod rollback;

backend/src/services/rollback.rs

@@ -0,0 +1,154 @@
+/// Contract Rollback Service
+/// 
+/// Handles contract state rollback and transaction reversal capability
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ContractState {
+    pub contract_id: String,
+    pub storage: HashMap<String, Vec<u8>>,
+    pub ledger_seq: u64,
+    pub timestamp: i64,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct RollbackCheckpoint {
+    pub checkpoint_id: String,
+    pub states: HashMap<String, ContractState>,
+    pub created_at: i64,
+}
+
+#[derive(Debug, Clone)]
+pub struct RollbackManager {
+    checkpoints: HashMap<String, RollbackCheckpoint>,
+    active_transactions: HashMap<String, Vec<String>>,
+}
+
+impl RollbackManager {
+    pub fn new() -> Self {
+        Self {
+            checkpoints: HashMap::new(),
+            active_transactions: HashMap::new(),
+        }
+    }
+
+    /// Create a checkpoint of current contract states
+    pub fn create_checkpoint(
+        &mut self,
+        contract_ids: Vec<String>,
+        states: HashMap<String, ContractState>,
+    ) -> Result<String, String> {
+        let checkpoint_id = format!("cp_{}", chrono::Utc::now().timestamp_millis());
+
+        let checkpoint = RollbackCheckpoint {
+            checkpoint_id: checkpoint_id.clone(),
+            states,
+            created_at: chrono::Utc::now().timestamp(),
+        };
+
+        self.checkpoints.insert(checkpoint_id.clone(), checkpoint);
+        Ok(checkpoint_id)
+    }
+
+    /// Rollback contract to a specific checkpoint
+    pub fn rollback_to_checkpoint(&self, checkpoint_id: &str) -> Result<RollbackCheckpoint, String> {
+        self.checkpoints
+            .get(checkpoint_id)
+            .cloned()
+            .ok_or_else(|| format!("Checkpoint {} not found", checkpoint_id))
+    }
+
+    /// Start transaction tracking for rollback capability
+    pub fn begin_transaction(&mut self, tx_id: String) -> Result<(), String> {
+        self.active_transactions.insert(tx_id, vec![]);
+        Ok(())
+    }
+
+    /// Record a state change in the transaction
+    pub fn record_state_change(&mut self, tx_id: &str, contract_id: String) -> Result<(), String> {
+        if let Some(tx) = self.active_transactions.get_mut(tx_id) {
+            tx.push(contract_id);
+            Ok(())
+        } else {
+            Err(format!("Transaction {} not found", tx_id))
+        }
+    }
+
+    /// Commit transaction
+    pub fn commit_transaction(&mut self, tx_id: &str) -> Result<(), String> {
+        self.active_transactions.remove(tx_id);
+        Ok(())
+    }
+
+    /// Rollback transaction
+    pub fn rollback_transaction(&mut self, tx_id: &str) -> Result<Vec<String>, String> {
+        self.active_transactions
+            .remove(tx_id)
+            .ok_or_else(|| format!("Transaction {} not found", tx_id))
+    }
+
+    /// Get list of all checkpoints
+    pub fn list_checkpoints(&self) -> Vec<String> {
+        self.checkpoints.keys().cloned().collect()
+    }
+
+    /// Validate rollback safety
+    pub fn validate_rollback(&self, checkpoint_id: &str) -> Result<bool, String> {
+        if !self.checkpoints.contains_key(checkpoint_id) {
+            return Err(format!("Checkpoint {} not found", checkpoint_id));
+        }
+
+        // Validate checkpoint integrity
+        if let Some(checkpoint) = self.checkpoints.get(checkpoint_id) {
+            Ok(!checkpoint.states.is_empty())
+        } else {
+            Ok(false)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_create_checkpoint() {
+        let mut manager = RollbackManager::new();
+        let states = HashMap::new();
+        let result = manager.create_checkpoint(vec!["contract1".to_string()], states);
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn test_begin_transaction() {
+        let mut manager = RollbackManager::new();
+        let result = manager.begin_transaction("tx1".to_string());
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn test_record_state_change() {
+        let mut manager = RollbackManager::new();
+        manager.begin_transaction("tx1".to_string()).unwrap();
+        let result = manager.record_state_change("tx1", "contract1".to_string());
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn test_commit_transaction() {
+        let mut manager = RollbackManager::new();
+        manager.begin_transaction("tx1".to_string()).unwrap();
+        let result = manager.commit_transaction("tx1");
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn test_rollback_transaction() {
+        let mut manager = RollbackManager::new();
+        manager.begin_transaction("tx1".to_string()).unwrap();
+        manager.record_state_change("tx1", "contract1".to_string()).unwrap();
+        let result = manager.rollback_transaction("tx1");
+        assert!(result.is_ok());
+    }
+}

contracts/governance/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "governance"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+soroban-sdk = { version = "21.0.0", features = ["alloc"] }
+
+[profile.release]
+opt-level = "z"
+overflow-checks = false
+lto = true
+codegen-units = 1
+strip = true