// Copyright 2015 The etcd Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package mvcc

import (
	"reflect"
	"testing"

	"github.com/coreos/etcd/lease"
	"github.com/coreos/etcd/mvcc/backend"
)

func TestScheduleCompaction(t *testing.T) {
	revs := []revision{{1, 0}, {2, 0}, {3, 0}}

	tests := []struct {
		rev   int64
		keep  map[revision]struct{}
		wrevs []revision
	}{
		// compact at 1 and discard all history
		{
			1,
			nil,
			revs[1:],
		},
		// compact at 3 and discard all history
		{
			3,
			nil,
			nil,
		},
		// compact at 1 and keeps history one step earlier
		{
			1,
			map[revision]struct{}{
				revision{main: 1}: {},
			},
			revs,
		},
		// compact at 1 and keeps history two steps earlier
		{
			3,
			map[revision]struct{}{
				revision{main: 2}: {},
				revision{main: 3}: {},
			},
			revs[1:],
		},
	}
	for i, tt := range tests {
		b, tmpPath := backend.NewDefaultTmpBackend()
		s := NewStore(b, &lease.FakeLessor{}, nil)
		tx := s.b.BatchTx()

		tx.Lock()
		ibytes := newRevBytes()
		for _, rev := range revs {
			revToBytes(rev, ibytes)
			tx.UnsafePut(keyBucketName, ibytes, []byte("bar"))
		}
		tx.Unlock()

		s.scheduleCompaction(tt.rev, tt.keep)

		tx.Lock()
		for _, rev := range tt.wrevs {
			revToBytes(rev, ibytes)
			keys, _ := tx.UnsafeRange(keyBucketName, ibytes, nil, 0)
			if len(keys) != 1 {
				t.Errorf("#%d: range on %v = %d, want 1", i, rev, len(keys))
			}
		}
		_, vals := tx.UnsafeRange(metaBucketName, finishedCompactKeyName, nil, 0)
		revToBytes(revision{main: tt.rev}, ibytes)
		if w := [][]byte{ibytes}; !reflect.DeepEqual(vals, w) {
			t.Errorf("#%d: vals on %v = %+v, want %+v", i, finishedCompactKeyName, vals, w)
		}
		tx.Unlock()

		cleanup(s, b, tmpPath)
	}
}
