Multisig: Generalized for any multisig

Author: MrStahlfelge

lib-api/src/main/java/org/ergoplatform/appkit/MultisigTransaction.java

@@ -5,77 +5,55 @@
 /**
  * EIP-41/EIP-11 compliant multi sig transaction
  */
-public class MultisigTransaction {
+public abstract class MultisigTransaction {
 
     /**
      * @return transaction that is going to be signed
      */
-    public Transaction getTransaction() {
-        throw new UnsupportedOperationException();
-    }
-
-    /**
-     * @return multisig address this transaction was created for
-     */
-    public MultisigAddress getMultisigAddress() {
-        throw new UnsupportedOperationException();
-    }
+    abstract public ReducedTransaction getTransaction();
 
     /**
-     * adds a new commitment to this multisig transaction
+     * adds a new hint to this multisig transaction
      * @param prover to add commitment for
      */
-    public void addCommitment(ErgoProver prover) {
-        throw new UnsupportedOperationException();
-    }
+    abstract public void addHint(ErgoProver prover);
 
     /**
-     * adds the commitments not present on this instance from another multisig transaction instance
+     * adds the hints not present on this instance from another multisig transaction instance
      * for the same transaction.
      */
-    public void addCommitments(MultisigTransaction other) {
-        throw new UnsupportedOperationException();
-    }
+    abstract public void mergeHints(MultisigTransaction other);
 
     /**
-     * @return list of participants that added a commitment for the transaction
+     * adds the hints not present on this instance from the EIP-11 json
      */
-    public List<Address> getCommitingParticipants() {
-        throw new UnsupportedOperationException();
-    }
-
-    public boolean hasEnoughCommitments() {
-        throw new UnsupportedOperationException();
-    }
+    abstract public void mergeHints(String json);
 
     /**
-     * @return the signed transaction if enough commitments are available
-     * @throws IllegalStateException if {@link #hasEnoughCommitments()} is false
+     * @return list of participants that added a hint for the transaction
      */
-    public SignedTransaction toSignedTransaction() {
-        throw new UnsupportedOperationException();
-    }
+    abstract public List<Address> getCommitingParticipants();
+    /**
+     * @return true if SignedTransaction can be built
+     */
+    abstract public boolean isHintBagComplete();
 
     /**
-     * @return EIP-11 compliant json string to transfer the partially signed transaction to the
-     * next particpant
+     * @return the signed transaction if enough commitments are available
+     * @throws IllegalStateException if {@link #isHintBagComplete()} is false
      */
-    public String toJson() {
-        throw new UnsupportedOperationException();
-    }
+    abstract public SignedTransaction toSignedTransaction();
 
     /**
-     * constructs a multi sig transaction from an unsigned transaction. The first multi sig address
-     * in input boxes is used.
+     * @return EIP-11 compliant json string to transfer the partially signed transaction to the
+     * next participant
      */
-    public static MultisigTransaction fromTransaction(UnsignedTransaction transaction) {
-        throw new UnsupportedOperationException();
-    }
+    abstract public String hintsToJson();
 
     /**
      * constructs a multi sig transaction from a reduced transaction
      */
-    public static MultisigTransaction fromTransaction(ReducedTransaction transaction, MultisigAddress address) {
+    public static MultisigTransaction fromTransaction(ReducedTransaction transaction) {
         throw new UnsupportedOperationException();
     }
 

lib-api/src/main/java/org/ergoplatform/appkit/ReducedTransaction.java

@@ -21,4 +21,9 @@ public interface ReducedTransaction extends Transaction {
      * Returns the serialized bytes of this transaction.
      */
     byte[] toBytes();
+
+    /**
+     * @return tree of participants required or able to sign for the transaction
+     */
+    SigningParticipants getSignersRequired();
 }

lib-api/src/main/java/org/ergoplatform/appkit/SigningParticipants.java

@@ -0,0 +1,45 @@
+package org.ergoplatform.appkit;
+
+import java.util.List;
+
+/**
+ * Participants able to sign for a {@link ReducedTransaction}
+ */
+abstract public class SigningParticipants {
+
+    /**
+     * @return true if multiple signers are needed
+     */
+    abstract public boolean isMultisig();
+
+    /**
+     * Multisig requirement, k-out-of-n
+     */
+    public static class MultisigRequirement extends SigningParticipants {
+        public final int hintsNeeded;
+        public final List<SigningParticipants> hintbag;
+
+        public MultisigRequirement(int hintsNeeded, List<SigningParticipants> hintbag) {
+            this.hintsNeeded = hintsNeeded;
+            this.hintbag = hintbag;
+        }
+
+        @Override
+        public boolean isMultisig() {
+            return hintsNeeded > 1;
+        }
+    }
+
+    public static class SingleSigner extends SigningParticipants {
+        public final Address address;
+
+        public SingleSigner(Address address) {
+            this.address = address;
+        }
+
+        @Override
+        public boolean isMultisig() {
+            return false;
+        }
+    }
+}

lib-impl/src/main/java/org/ergoplatform/appkit/impl/ReducedTransactionImpl.java

@@ -68,6 +68,11 @@ public byte[] toBytes() {
         return w.toBytes();
     }
 
+    @Override
+    public SigningParticipants getSignersRequired() {
+        throw new UnsupportedOperationException();
+    }
+
     @Override
     public int hashCode() {
         return _tx.hashCode();