Multi-Asset Migration Algorithm

lib/core/cardano-wallet-core.cabal

@@ -83,6 +83,7 @@ library
     , persistent
     , persistent-sqlite
     , persistent-template
+    , pretty-simple
     , profunctors
     , quiet
     , random
@@ -175,6 +176,9 @@ library
       Cardano.Wallet.Primitive.AddressDiscovery.SharedState
       Cardano.Wallet.Primitive.SyncProgress
       Cardano.Wallet.Primitive.CoinSelection.MA.RoundRobin
+      Cardano.Wallet.Primitive.Migration
+      Cardano.Wallet.Primitive.Migration.Planning
+      Cardano.Wallet.Primitive.Migration.Selection
       Cardano.Wallet.Primitive.Model
       Cardano.Wallet.Primitive.Types
       Cardano.Wallet.Primitive.Types.Address
@@ -283,6 +287,7 @@ test-suite unit
     , network
     , network-uri
     , persistent
+    , pretty-simple
     , regex-pcre-builtin
     , OddWord
     , ouroboros-consensus
@@ -356,6 +361,9 @@ test-suite unit
       Cardano.Wallet.Primitive.AddressDiscovery.SharedStateSpec
       Cardano.Wallet.Primitive.AddressDiscoverySpec
       Cardano.Wallet.Primitive.CoinSelection.MA.RoundRobinSpec
+      Cardano.Wallet.Primitive.MigrationSpec
+      Cardano.Wallet.Primitive.Migration.PlanningSpec
+      Cardano.Wallet.Primitive.Migration.SelectionSpec
       Cardano.Wallet.Primitive.ModelSpec
       Cardano.Wallet.Primitive.Slotting.Legacy
       Cardano.Wallet.Primitive.SlottingSpec

lib/core/src/Cardano/Wallet/Primitive/CoinSelection/MA/RoundRobin.hs

@@ -223,7 +223,7 @@ data SelectionResult change = SelectionResult
         -- ^ An optional extra source of ada.
     , outputsCovered
         :: ![TxOut]
-        -- ^ A list of ouputs covered.
+        -- ^ A list of outputs covered.
         -- FIXME: Left as a list to allow to work-around the limitation of
         -- 'performSelection' which cannot run for no output targets (e.g. in
         -- the context of a delegation transaction). This allows callers to

lib/core/src/Cardano/Wallet/Primitive/Migration.hs

@@ -0,0 +1,77 @@
+{-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE DuplicateRecordFields #-}
+{-# LANGUAGE OverloadedLabels #-}
+
+-- |
+-- Copyright: © 2021 IOHK
+-- License: Apache-2.0
+--
+-- This module provides a public API for planning wallet migrations.
+--
+-- Use 'createPlan' to create a migration plan.
+--
+module Cardano.Wallet.Primitive.Migration
+    (
+    -- * Creating a migration plan
+      createPlan
+    , MigrationPlan (..)
+    , RewardWithdrawal (..)
+    , Selection (..)
+    , TxSize (..)
+
+    ) where
+
+import Prelude
+
+import Cardano.Wallet.Primitive.Migration.Selection
+    ( RewardWithdrawal (..), Selection (..), TxSize (..) )
+import Cardano.Wallet.Primitive.Types.Coin
+    ( Coin )
+import Cardano.Wallet.Primitive.Types.Tx
+    ( TxConstraints (..), TxIn, TxOut )
+import Cardano.Wallet.Primitive.Types.UTxO
+    ( UTxO )
+import Data.Generics.Internal.VL.Lens
+    ( view )
+import Data.Generics.Labels
+    ()
+import GHC.Generics
+    ( Generic )
+
+import qualified Cardano.Wallet.Primitive.Migration.Planning as Planning
+
+-- | Represents a plan for migrating a 'UTxO' set.
+--
+-- See 'createPlan' to create a migration plan.
+--
+data MigrationPlan size = MigrationPlan
+    { selections :: ![Selection (TxIn, TxOut) size]
+      -- ^ A list of generated selections: each selection is the basis for a
+      -- single transaction.
+    , unselected :: !UTxO
+      -- ^ The portion of the UTxO that was not selected.
+    , totalFee :: !Coin
+      -- ^ The total fee payable: equal to the sum of the fees of the
+      -- individual selections.
+    }
+    deriving (Eq, Generic, Show)
+
+-- | Creates a migration plan for the given UTxO set and reward withdrawal
+--   amount.
+--
+-- See 'MigrationPlan'.
+--
+createPlan
+    :: TxSize size
+    => TxConstraints size
+    -> UTxO
+    -> RewardWithdrawal
+    -> MigrationPlan size
+createPlan constraints utxo reward = MigrationPlan
+    { selections = view #selections plan
+    , unselected = Planning.uncategorizeUTxO (view #unselected plan)
+    , totalFee = view #totalFee plan
+    }
+  where
+    plan = Planning.createPlan
+        constraints (Planning.categorizeUTxO constraints utxo) reward