refactor EscrowCreate

include/xrpl/ledger/helpers/MPToken.h

@@ -28,6 +28,32 @@ public:
         return issuance_;
     }
 
+    MPTIssue
+    getMptIssue() const
+    {
+        return issuance_.getMptIssue();
+    }
+
+    [[nodiscard]] TER
+    checkSpendable(
+        STAmount const& amount,
+        FreezeHandling zeroIfFrozen,
+        AuthHandling zeroIfUnauthorized,
+        beast::Journal j) const override
+    {
+        STAmount const spendableAmount = accountHolds(zeroIfFrozen, zeroIfUnauthorized, j);
+
+        // If the balance is less than or equal to 0, return tecINSUFFICIENT_FUNDS
+        if (spendableAmount <= beast::zero)
+            return tecINSUFFICIENT_FUNDS;
+
+        // If the spendable amount is less than the amount, return tecINSUFFICIENT_FUNDS
+        if (!canSubtract(spendableAmount, amount))
+            return tecINSUFFICIENT_FUNDS;
+
+        return tesSUCCESS;
+    }
+
 protected:
     MPTokenIssuance const& issuance_;
 };

include/xrpl/ledger/helpers/MPTokenHelpers.h

@@ -46,7 +46,7 @@ public:
     }
 
     AccountID const&
-    getIssuer() const
+    getIssuer() const override
     {
         return mptIssue_.getIssuer();
     }
@@ -127,6 +127,12 @@ public:
     [[nodiscard]] bool
     canClawback() const override;
 
+    [[nodiscard]] bool
+    canEscrow() const override
+    {
+        return sle_->isFlag(lsfMPTCanEscrow);
+    }
+
     [[nodiscard]] bool
     requiresAuth() const override;
 
@@ -135,6 +141,8 @@ public:
     {
         if (!exists())
             return tecOBJECT_NOT_FOUND;
+        if (sle_->getAccountID(sfIssuer) != mptIssue_.getIssuer())
+            return tecINTERNAL;
         return tesSUCCESS;
     }
 
@@ -144,6 +152,17 @@ public:
         return readView_.exists(keylet::mptoken(mptID_, holder));
     }
 
+    [[nodiscard]] TER
+    checkHolder(AccountID const& holder) const override
+    {
+        if (!hasHolder(holder))
+            return tecOBJECT_NOT_FOUND;
+        return tesSUCCESS;
+    }
+
+    [[nodiscard]] std::unique_ptr<TokenHolderBase>
+    getHolder(AccountID const& holder) const override;
+
     STAmount
     accountHolds(
         AccountID const& account,

include/xrpl/ledger/helpers/RippleState.h

@@ -38,6 +38,42 @@ public:
         return iouToken_;
     }
 
+    [[nodiscard]] TER
+    checkSpendable(
+        STAmount const& amount,
+        FreezeHandling zeroIfFrozen,
+        AuthHandling zeroIfUnauthorized,
+        beast::Journal j) const override
+    {
+        STAmount const balance = (*sle_)[sfBalance];
+        AccountID const& issuer = iouToken_.getIssuer();
+
+        // If balance is positive, issuer must have higher address than account
+        if (balance > beast::zero && issuer < holder_)
+            return tecNO_PERMISSION;  // LCOV_EXCL_LINE
+
+        // If balance is negative, issuer must have lower address than account
+        if (balance < beast::zero && issuer > holder_)
+            return tecNO_PERMISSION;  // LCOV_EXCL_LINE
+
+        STAmount const spendableAmount = accountHolds(zeroIfFrozen, zeroIfUnauthorized, j);
+
+        // If the balance is less than or equal to 0, return tecINSUFFICIENT_FUNDS
+        if (spendableAmount <= beast::zero)
+            return tecINSUFFICIENT_FUNDS;
+
+        // If the spendable amount is less than the amount, return
+        // tecINSUFFICIENT_FUNDS
+        if (spendableAmount < amount)
+            return tecINSUFFICIENT_FUNDS;
+
+        // If the amount is not addable to the balance, return tecPRECISION_LOSS
+        if (!canAdd(spendableAmount, amount))
+            return tecPRECISION_LOSS;
+
+        return tesSUCCESS;
+    }
+
 protected:
     IOUToken const& iouToken_;
 };

include/xrpl/ledger/helpers/RippleStateHelpers.h

@@ -38,7 +38,7 @@ public:
     }
 
     [[nodiscard]] AccountID const&
-    getIssuer() const
+    getIssuer() const override
     {
         return issuer_;
     }
@@ -129,6 +129,12 @@ public:
     [[nodiscard]] bool
     canClawback() const override;
 
+    [[nodiscard]] bool
+    canEscrow() const override
+    {
+        return issuerAccount_->isFlag(lsfAllowTrustLineLocking);
+    }
+
     [[nodiscard]] bool
     requiresAuth() const override;
 
@@ -146,6 +152,17 @@ public:
         return readView_.exists(keylet::line(issuer_, holder, currency_));
     }
 
+    [[nodiscard]] TER
+    checkHolder(AccountID const& holder) const override
+    {
+        if (!hasHolder(holder))
+            return tecNO_LINE;
+        return tesSUCCESS;
+    }
+
+    [[nodiscard]] std::unique_ptr<TokenHolderBase>
+    getHolder(AccountID const& holder) const override;
+
 protected:
     Issue const issue_;
     AccountID const issuer_;

include/xrpl/ledger/helpers/TokenHelpers.h

@@ -44,15 +44,14 @@ enum class WaiveTransferFee : bool { No = false, Yes };
  */
 enum class AuthType { StrongAuth, WeakAuth, Legacy };
 
-//------------------------------------------------------------------------------
-//
-// Freeze checking (Asset-based dispatchers)
-//
-//------------------------------------------------------------------------------
+class TokenHolderBase;
 
 class TokenBase : public virtual ReadOnlySLE
 {
 public:
+    [[nodiscard]] virtual AccountID const&
+    getIssuer() const = 0;
+
     [[nodiscard]] virtual bool
     isGlobalFrozen() const = 0;
 
@@ -153,6 +152,9 @@ public:
     [[nodiscard]] virtual bool
     canClawback() const = 0;
 
+    [[nodiscard]] virtual bool
+    canEscrow() const = 0;
+
     /** Check if the token requires authorization for holders.
      * For IOUs, checks lsfRequireAuth on issuer's AccountRoot.
      * For MPTs, checks lsfMPTRequireAuth on the issuance.
@@ -166,6 +168,12 @@ public:
     [[nodiscard]] virtual bool
     hasHolder(AccountID const& holder) const = 0;
 
+    [[nodiscard]] virtual TER
+    checkHolder(AccountID const& holder) const = 0;
+
+    [[nodiscard]] virtual std::unique_ptr<TokenHolderBase>
+    getHolder(AccountID const& holder) const = 0;
+
 protected:
     TokenBase(ReadView const& view, std::shared_ptr<SLE const> sle) : ReadOnlySLE(sle, view)
     {

include/xrpl/ledger/helpers/TokenHolderBase.h

@@ -88,6 +88,13 @@ public:
             holder_, zeroIfFrozen, zeroIfUnauthorized, j, includeFullBalance);
     }
 
+    [[nodiscard]] virtual TER
+    checkSpendable(
+        STAmount const& amount,
+        FreezeHandling zeroIfFrozen,
+        AuthHandling zeroIfUnauthorized,
+        beast::Journal j) const = 0;
+
     [[nodiscard]] TER
     requireAuth(AuthType authType = AuthType::Legacy, int depth = 0) const
     {

include/xrpl/protocol/STAmount.h

@@ -11,6 +11,7 @@
 #include <xrpl/protocol/SField.h>
 #include <xrpl/protocol/STBase.h>
 #include <xrpl/protocol/Serializer.h>
+#include <xrpl/protocol/TER.h>
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/protocol/json_get_or_throw.h>
 
@@ -739,6 +740,9 @@ canAdd(STAmount const& amt1, STAmount const& amt2);
 bool
 canSubtract(STAmount const& amt1, STAmount const& amt2);
 
+NotTEC
+checkAmount(STAmount const& amount);
+
 }  // namespace xrpl
 
 //------------------------------------------------------------------------------