From 0943ed42dd4feb88943f2d8583e009f27820c938 Mon Sep 17 00:00:00 2001
From: Buddy Sandidge <git@buddy.wtf>
Date: Sun, 3 Nov 2019 15:27:19 -0800
Subject: [PATCH] Add methods for Bucket structs

---
 lib/bucket/bucket.go      | 22 ++++++++++++++++++++++
 lib/bucket/bucket_test.go | 28 ++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)
 create mode 100644 lib/bucket/bucket_test.go

diff --git a/lib/bucket/bucket.go b/lib/bucket/bucket.go
index 97e8975..2077fca 100644
--- a/lib/bucket/bucket.go
+++ b/lib/bucket/bucket.go
@@ -7,3 +7,25 @@ type Bucket struct {
 	// Volume is the current volume of the bucket
 	Volume uint64
 }
+
+// Fill sets the volume to the capacity to fill bucket
+func (b *Bucket) Fill() {
+	b.Volume = b.Capacity
+}
+
+// Empty sets the volume to 0
+func (b *Bucket) Empty() {
+	b.Volume = 0
+}
+
+// Pour fills the target bucket to the top
+func (b *Bucket) Pour(target *Bucket) {
+	availableVolume := target.Capacity - target.Volume
+	if availableVolume > b.Volume {
+		target.Volume += b.Volume
+		b.Volume = 0
+	} else {
+		b.Volume -= availableVolume
+		target.Volume += availableVolume
+	}
+}
diff --git a/lib/bucket/bucket_test.go b/lib/bucket/bucket_test.go
new file mode 100644
index 0000000..476ab63
--- /dev/null
+++ b/lib/bucket/bucket_test.go
@@ -0,0 +1,28 @@
+package bucket
+
+import "testing"
+
+func TestPour(t *testing.T) {
+	var testcases = []struct {
+		source            *Bucket
+		target            *Bucket
+		expectedSrcVol    uint64
+		expectedTargetVol uint64
+	}{
+		{&Bucket{Capacity: 5, Volume: 2}, &Bucket{Capacity: 3, Volume: 2}, 1, 3},
+		{&Bucket{Capacity: 5, Volume: 1}, &Bucket{Capacity: 3, Volume: 1}, 0, 2},
+		{&Bucket{Capacity: 5, Volume: 0}, &Bucket{Capacity: 3, Volume: 0}, 0, 0},
+		{&Bucket{Capacity: 5, Volume: 5}, &Bucket{Capacity: 3, Volume: 3}, 5, 3},
+		{&Bucket{Capacity: 5, Volume: 4}, &Bucket{Capacity: 3, Volume: 2}, 3, 3},
+	}
+
+	for _, tc := range testcases {
+		tc.source.Pour(tc.target)
+		if tc.source.Volume != tc.expectedSrcVol {
+			t.Errorf("expected source volume %d, got = %d", tc.expectedSrcVol, tc.source.Volume)
+		}
+		if tc.target.Volume != tc.expectedTargetVol {
+			t.Errorf("expected target volume %d, got = %d", tc.expectedTargetVol, tc.target.Volume)
+		}
+	}
+}