New rule engine architecture

contracts/CMTAT_STANDALONE.sol

@@ -28,7 +28,7 @@ contract CMTAT_STANDALONE is CMTAT_BASE {
         uint8 decimalsIrrevocable,
         string memory tokenId_,
         string memory terms_,
-        IERC1404Wrapper ruleEngine_,
+        IRuleEngineCMTAT ruleEngine_,
         string memory information_,
         uint256 flag_
     ) MetaTxModule(forwarderIrrevocable) {

contracts/interfaces/draft-IERC1404/IRuleEngineCMTAT.sol

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: MPL-2.0
+
+pragma solidity ^0.8.0;
+
+import "./draft-IERC1404Wrapper.sol";
+
+interface IRuleEngineCMTAT is IERC1404Wrapper {
+    /**
+     * @dev Returns true if the operation is a success, and false otherwise.
+     */
+    function operateOnTransfer(
+        address _from,
+        address _to,
+        uint256 _amount
+    ) external returns (bool isValid);
+
+}

contracts/mocks/RuleEngine/RuleEngineMock.sol

@@ -67,6 +67,16 @@ contract RuleEngineMock is IRuleEngine {
         return detectTransferRestriction(_from, _to, _amount) == 0;
     }
 
+    /*
+    @dev 
+    Warning: if you want to use this mock, you have to restrict the access to this function through an an access control
+    */
+    function operateOnTransfer(  address _from,
+        address _to,
+        uint256 _amount) public override returns (bool){
+        return validateTransfer(_from, _to, _amount);
+    }
+
     /**
     @dev
     For all the rules, each restriction code has to be unique.

contracts/mocks/RuleEngine/interfaces/IRuleEngine.sol

@@ -3,9 +3,9 @@
 pragma solidity ^0.8.0;
 
 import "./IRule.sol";
-import "../../../interfaces/draft-IERC1404/draft-IERC1404Wrapper.sol";
+import "../../../interfaces/draft-IERC1404/IRuleEngineCMTAT.sol";
 
-interface IRuleEngine is IERC1404Wrapper {
+interface IRuleEngine is IRuleEngineCMTAT {
     /**
      * @dev define the rules, the precedent rules will be overwritten
      */

contracts/modules/CMTAT_BASE.sol

@@ -62,8 +62,8 @@ abstract contract CMTAT_BASE is
         uint8 decimalsIrrevocable,
         string memory tokenId_,
         string memory terms_,
-        IERC1404Wrapper ruleEngine_,
-        string memory information_,
+        IRuleEngineCMTAT ruleEngine_,
+        string memory information_, 
         uint256 flag_
     ) public initializer {
         __CMTAT_init(
@@ -91,7 +91,7 @@ abstract contract CMTAT_BASE is
         uint8 decimalsIrrevocable,
         string memory tokenId_,
         string memory terms_,
-        IERC1404Wrapper ruleEngine_,
+        IRuleEngineCMTAT ruleEngine_,
         string memory information_,
         uint256 flag_
     ) internal onlyInitializing {
@@ -110,9 +110,11 @@ abstract contract CMTAT_BASE is
         __Enforcement_init_unchained();
         /*
         SnapshotModule:
-        Add this call in case you add the SnapshotModule
+        Add these two calls in case you add the SnapshotModule
+
+        __SnapshotModuleBase_init_unchained();
         __ERC20Snapshot_init_unchained();
-        */
+         */
         __Validation_init_unchained(ruleEngine_);
 
         /* Wrapper */
@@ -174,26 +176,23 @@ abstract contract CMTAT_BASE is
 
     /**
      * @dev
-     * SnapshotModule:
-     * - override SnapshotModuleInternal if you add the SnapshotModule
-     * e.g. override(ERC20SnapshotModuleInternal, ERC20Upgradeable)
-     * - remove the keyword view
+     *
      */
     function _update(
         address from,
         address to,
         uint256 amount
     ) internal override(ERC20Upgradeable) {
-        if (!ValidationModule.validateTransfer(from, to, amount)) {
+        if (!ValidationModule._operateOnTransfer(from, to, amount)) {
             revert Errors.CMTAT_InvalidTransfer(from, to, amount);
         }
-        ERC20Upgradeable._update(from, to, amount);
-        // We call the SnapshotModule only if the transfer is valid
         /*
         SnapshotModule:
-        Add this call in case you add the SnapshotModule
-        ERC20SnapshotModuleInternal._update(from, to, amount);
+        Add this in case you add the SnapshotModule
+        We call the SnapshotModule only if the transfer is valid
         */
+        // ERC20SnapshotModuleInternal._snapshotUpdate(from, to);
+        ERC20Upgradeable._update(from, to, amount);
     }
 
     /**