feat: implement on-chain audit trail module for asset lifecycle tracking

contracts/assetsup/src/audit.rs

@@ -1,7 +1,5 @@
 use soroban_sdk::{contracttype, Address, BytesN, Env, String, Vec};
 
-use crate::types::ActionType;
-
 #[contracttype]
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub enum DataKey {
@@ -11,19 +9,20 @@ pub enum DataKey {
 #[contracttype]
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct AuditEntry {
-    pub actor: Address,
-    pub action: ActionType,
     pub timestamp: u64,
-    pub note: String,
+    pub action: String,
+    pub actor: Address,
+    pub details: String,
 }
 
-#[allow(dead_code)]
-pub fn log_action(
+/// Internal function to append an audit log entry for an asset
+/// This function is used by various modules to record significant events
+pub(crate) fn append_audit_log(
     env: &Env,
     asset_id: &BytesN<32>,
+    action: String,
     actor: Address,
-    action: ActionType,
-    note: String,
+    details: String,
 ) {
     let key = DataKey::AuditLog(asset_id.clone());
     let mut log: Vec<AuditEntry> = env
@@ -33,16 +32,18 @@ pub fn log_action(
         .unwrap_or_else(|| Vec::new(env));
 
     let entry = AuditEntry {
-        actor,
-        action,
         timestamp: env.ledger().timestamp(),
-        note,
+        action,
+        actor,
+        details,
     };
 
     log.push_back(entry);
     env.storage().persistent().set(&key, &log);
 }
 
+/// Public function to retrieve the audit log for an asset
+/// Returns an empty vector if no history exists
 pub fn get_asset_log(env: &Env, asset_id: &BytesN<32>) -> Vec<AuditEntry> {
     let key = DataKey::AuditLog(asset_id.clone());
     env.storage()

contracts/assetsup/src/insurance.rs

@@ -1,7 +1,8 @@
 #![allow(dead_code)]
 
+use crate::audit;
 use crate::Error;
-use soroban_sdk::{contracttype, log, Address, BytesN, Env, Vec};
+use soroban_sdk::{contracttype, log, Address, BytesN, Env, String, Vec};
 
 #[contracttype]
 #[derive(Clone, Debug, Eq, PartialEq)]
@@ -123,6 +124,15 @@ pub fn create_policy(env: Env, policy: InsurancePolicy) -> Result<(), Error> {
     list.push_back(policy.policy_id.clone());
     store.set(&DataKey::AssetPolicies(policy.asset_id.clone()), &list);
 
+    // Append audit log
+    audit::append_audit_log(
+        &env,
+        &policy.asset_id,
+        String::from_str(&env, "INSURANCE_POLICY_CREATED"),
+        policy.insurer.clone(),
+        String::from_str(&env, "Insurance policy created"),
+    );
+
     log!(&env, "PolicyCreated: {:?}", policy.policy_id);
     Ok(())
 }
@@ -147,6 +157,15 @@ pub fn cancel_policy(env: Env, policy_id: BytesN<32>, caller: Address) -> Result
     policy.status = PolicyStatus::Cancelled;
     store.set(&key, &policy);
 
+    // Append audit log
+    audit::append_audit_log(
+        &env,
+        &policy.asset_id,
+        String::from_str(&env, "INSURANCE_POLICY_CANCELLED"),
+        caller,
+        String::from_str(&env, "Insurance policy cancelled"),
+    );
+
     log!(&env, "PolicyCancelled: {:?}", policy_id);
     Ok(())
 }
@@ -244,6 +263,15 @@ pub fn renew_policy(
 
     store.set(&key, &policy);
 
+    // Append audit log
+    audit::append_audit_log(
+        &env,
+        &policy.asset_id,
+        String::from_str(&env, "INSURANCE_POLICY_RENEWED"),
+        insurer,
+        String::from_str(&env, "Insurance policy renewed"),
+    );
+
     log!(&env, "PolicyRenewed: {:?}", policy_id);
     Ok(())
 }

contracts/assetsup/src/lib.rs

@@ -157,6 +157,15 @@ impl AssetUpContract {
             .persistent()
             .set(&DataKey::TotalAssetCount, &total_count);
 
+        // Append audit log
+        audit::append_audit_log(
+            &env,
+            &asset.id,
+            String::from_str(&env, "ASSET_REGISTERED"),
+            caller.clone(),
+            String::from_str(&env, "Asset registered by authorized registrar"),
+        );
+
         // Emit event
         env.events().publish(
             (symbol_short!("asset_reg"),),
@@ -247,6 +256,15 @@ impl AssetUpContract {
 
         store.set(&key, &asset);
 
+        // Append audit log
+        audit::append_audit_log(
+            &env,
+            &asset_id,
+            String::from_str(&env, "METADATA_UPDATED"),
+            caller.clone(),
+            String::from_str(&env, "Asset metadata updated"),
+        );
+
         // Emit event
         env.events().publish(
             (symbol_short!("asset_upd"),),
@@ -313,6 +331,15 @@ impl AssetUpContract {
         asset.status = AssetStatus::Transferred;
         store.set(&key, &asset);
 
+        // Append audit log
+        audit::append_audit_log(
+            &env,
+            &asset_id,
+            String::from_str(&env, "OWNERSHIP_TRANSFERRED"),
+            caller.clone(),
+            String::from_str(&env, "Asset ownership transferred to new owner"),
+        );
+
         // Emit event
         env.events().publish(
             (symbol_short!("asset_tx"),),
@@ -345,6 +372,15 @@ impl AssetUpContract {
         asset.status = AssetStatus::Retired;
         store.set(&key, &asset);
 
+        // Append audit log
+        audit::append_audit_log(
+            &env,
+            &asset_id,
+            String::from_str(&env, "ASSET_RETIRED"),
+            caller.clone(),
+            String::from_str(&env, "Asset retired from active use"),
+        );
+
         // Emit event
         env.events().publish(
             (symbol_short!("asset_ret"),),