From 452d1cbb4709b190226eb4b08e1e74cffd1d9beb Mon Sep 17 00:00:00 2001
From: ascandone <alescandone@gmail.com>
Date: Tue, 21 Jan 2025 00:53:49 +0100
Subject: [PATCH] implemented oneof in destination

---
 internal/interpreter/interpreter.go      | 21 +++++++
 internal/interpreter/interpreter_test.go | 77 ++++++++++++++++++++++++
 2 files changed, 98 insertions(+)

diff --git a/internal/interpreter/interpreter.go b/internal/interpreter/interpreter.go
index 5ef54d2..d2afd2e 100644
--- a/internal/interpreter/interpreter.go
+++ b/internal/interpreter/interpreter.go
@@ -715,6 +715,27 @@ func (s *programState) receiveFrom(destination parser.Destination, amount *big.I
 		// passing "remainingAmount" directly breaks the code
 		return handler(destination.Remaining, remainingAmountCopy)
 
+	case *parser.DestinationOneof:
+		err := s.checkFeatureFlag(ExperimentalOneofFeatureFlag)
+		if err != nil {
+			return err
+		}
+		for _, destinationClause := range destination.Clauses {
+			cap, err := evaluateExprAs(s, destinationClause.Cap, expectMonetaryOfAsset(s.CurrentAsset))
+			if err != nil {
+				return err
+			}
+
+			// if the clause cap is >= the amount we're trying to receive, only go through this branch
+			switch cap.Cmp(amount) {
+			case 0, 1:
+				return s.receiveFromKeptOrDest(destinationClause.To, amount)
+			}
+
+			// otherwise try next clause (keep looping)
+		}
+		return s.receiveFromKeptOrDest(destination.Remaining, amount)
+
 	default:
 		utils.NonExhaustiveMatchPanic[any](destination)
 		return nil
diff --git a/internal/interpreter/interpreter_test.go b/internal/interpreter/interpreter_test.go
index a3a88ed..4988b22 100644
--- a/internal/interpreter/interpreter_test.go
+++ b/internal/interpreter/interpreter_test.go
@@ -3666,3 +3666,80 @@ func TestOneofSingleton(t *testing.T) {
 	}
 	testWithFeatureFlag(t, tc, machine.ExperimentalOneofFeatureFlag)
 }
+
+func TestOneofDestinationFirstClause(t *testing.T) {
+	tc := NewTestCase()
+	tc.compile(t, `
+	send [GEM 10] (
+		source = @world
+		destination = oneof {
+			max [GEM 99999] to @a
+			remaining to @b
+		}
+	)
+	`)
+	tc.expected = CaseResult{
+		Postings: []Posting{
+			{
+				Asset:       "GEM",
+				Amount:      big.NewInt(10),
+				Source:      "world",
+				Destination: "a",
+			},
+		},
+		Error: nil,
+	}
+	testWithFeatureFlag(t, tc, machine.ExperimentalOneofFeatureFlag)
+}
+
+func TestOneofDestinationSecondClause(t *testing.T) {
+	tc := NewTestCase()
+	tc.compile(t, `
+	send [GEM 10] (
+		source = @world
+		destination = oneof {
+			max [GEM 9] to @a
+			max [GEM 10] to @b
+			remaining to @rem
+		}
+	)
+	`)
+	tc.expected = CaseResult{
+		Postings: []Posting{
+			{
+				Asset:       "GEM",
+				Amount:      big.NewInt(10),
+				Source:      "world",
+				Destination: "b",
+			},
+		},
+		Error: nil,
+	}
+	testWithFeatureFlag(t, tc, machine.ExperimentalOneofFeatureFlag)
+}
+
+func TestOneofDestinationRemainingClause(t *testing.T) {
+	tc := NewTestCase()
+	tc.compile(t, `
+	send [GEM 100] (
+		source = @world
+		destination = oneof {
+			max [GEM 9] to @a
+			max [GEM 10] to @b
+			remaining to @rem
+		}
+	)
+	`)
+	tc.expected = CaseResult{
+		Postings: []Posting{
+			{
+				Asset:       "GEM",
+				Amount:      big.NewInt(100),
+				Source:      "world",
+				Destination: "rem",
+			},
+		},
+		Error: nil,
+	}
+	testWithFeatureFlag(t, tc, machine.ExperimentalOneofFeatureFlag)
+}