// Copyright (C) 2019-2020 Zilliz. All rights reserved.
//
// 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 datanode

import (
	"encoding/binary"
	"math"
	"math/rand"
	"testing"

	"github.com/bits-and-blooms/bloom/v3"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"github.com/milvus-io/milvus/internal/proto/internalpb"
	"github.com/milvus-io/milvus/internal/types"
)

func newSegmentReplica(rc types.RootCoord, collID UniqueID) *SegmentReplica {
	metaService := newMetaService(rc, collID)

	var replica = &SegmentReplica{
		collectionID: collID,

		newSegments:     make(map[UniqueID]*Segment),
		normalSegments:  make(map[UniqueID]*Segment),
		flushedSegments: make(map[UniqueID]*Segment),

		metaService: metaService,
	}
	return replica
}

func TestSegmentReplica(t *testing.T) {
	rc := &RootCoordFactory{}
	collID := UniqueID(1)

	t.Run("Test coll mot match", func(t *testing.T) {
		replica := newSegmentReplica(rc, collID)

		err := replica.addNewSegment(1, collID+1, 0, "", nil, nil)
		assert.NotNil(t, err)
	})

	t.Run("Test segmentFlushed", func(t *testing.T) {
		testReplica := &SegmentReplica{
			newSegments:     make(map[UniqueID]*Segment),
			normalSegments:  make(map[UniqueID]*Segment),
			flushedSegments: make(map[UniqueID]*Segment),
		}

		type Test struct {
			inisNew     bool
			inisFlushed bool
			inSegID     UniqueID

			expectedisNew     bool
			expectedisFlushed bool
			expectedSegID     UniqueID
		}

		tests := []Test{
			// new segment
			{true, false, 1, false, true, 1},
			{true, false, 2, false, true, 2},
			{true, false, 3, false, true, 3},
			// normal segment
			{false, false, 10, false, true, 10},
			{false, false, 20, false, true, 20},
			{false, false, 30, false, true, 30},
			// flushed segment
			{false, true, 100, false, true, 100},
			{false, true, 200, false, true, 200},
			{false, true, 300, false, true, 300},
		}

		newSeg := func(sr *SegmentReplica, isNew, isFlushed bool, id UniqueID) {
			ns := &Segment{segmentID: id}
			ns.isNew.Store(isNew)
			ns.isFlushed.Store(isFlushed)

			if isNew && !isFlushed {
				sr.newSegments[id] = ns
				return
			}

			if !isNew && !isFlushed {
				sr.normalSegments[id] = ns
				return
			}

			if !isNew && isFlushed {
				sr.flushedSegments[id] = ns
				return
			}
		}

		for _, te := range tests {
			// prepare case
			newSeg(testReplica, te.inisNew, te.inisFlushed, te.inSegID)

			testReplica.segmentFlushed(te.inSegID)

			flushedSeg := testReplica.flushedSegments[te.inSegID]
			assert.Equal(t, te.expectedSegID, flushedSeg.segmentID)
			assert.Equal(t, te.expectedisNew, flushedSeg.isNew.Load().(bool))
			assert.Equal(t, te.expectedisFlushed, flushedSeg.isFlushed.Load().(bool))
		}

	})

	t.Run("Test inner function segment", func(t *testing.T) {
		replica := newSegmentReplica(rc, collID)
		assert.False(t, replica.hasSegment(0, true))
		assert.False(t, replica.hasSegment(0, false))

		startPos := &internalpb.MsgPosition{ChannelName: "insert-01", Timestamp: Timestamp(100)}
		endPos := &internalpb.MsgPosition{ChannelName: "insert-01", Timestamp: Timestamp(200)}
		err := replica.addNewSegment(0, 1, 2, "insert-01", startPos, endPos)
		assert.NoError(t, err)
		assert.True(t, replica.hasSegment(0, true))
		assert.Equal(t, 1, len(replica.newSegments))

		seg, ok := replica.newSegments[UniqueID(0)]
		assert.True(t, ok)
		require.NotNil(t, seg)
		assert.Equal(t, UniqueID(0), seg.segmentID)
		assert.Equal(t, UniqueID(1), seg.collectionID)
		assert.Equal(t, UniqueID(2), seg.partitionID)
		assert.Equal(t, "insert-01", seg.channelName)
		assert.Equal(t, Timestamp(100), seg.startPos.Timestamp)
		assert.Equal(t, Timestamp(200), seg.endPos.Timestamp)
		assert.Equal(t, startPos.ChannelName, seg.checkPoint.pos.ChannelName)
		assert.Equal(t, startPos.Timestamp, seg.checkPoint.pos.Timestamp)
		assert.Equal(t, int64(0), seg.numRows)
		assert.True(t, seg.isNew.Load().(bool))
		assert.False(t, seg.isFlushed.Load().(bool))

		err = replica.updateStatistics(0, 10)
		assert.NoError(t, err)
		assert.Equal(t, int64(10), seg.numRows)

		cpPos := &internalpb.MsgPosition{ChannelName: "insert-01", Timestamp: Timestamp(10)}
		cp := &segmentCheckPoint{int64(10), *cpPos}
		err = replica.addNormalSegment(1, 1, 2, "insert-01", int64(10), cp)
		assert.NoError(t, err)
		assert.True(t, replica.hasSegment(1, true))
		assert.Equal(t, 1, len(replica.normalSegments))
		seg, ok = replica.normalSegments[UniqueID(1)]
		assert.True(t, ok)
		require.NotNil(t, seg)
		assert.Equal(t, UniqueID(1), seg.segmentID)
		assert.Equal(t, UniqueID(1), seg.collectionID)
		assert.Equal(t, UniqueID(2), seg.partitionID)
		assert.Equal(t, "insert-01", seg.channelName)
		assert.Equal(t, cpPos.ChannelName, seg.checkPoint.pos.ChannelName)
		assert.Equal(t, cpPos.Timestamp, seg.checkPoint.pos.Timestamp)
		assert.Equal(t, int64(10), seg.numRows)
		assert.False(t, seg.isNew.Load().(bool))
		assert.False(t, seg.isFlushed.Load().(bool))

		err = replica.updateStatistics(1, 10)
		assert.NoError(t, err)
		assert.Equal(t, int64(20), seg.numRows)

		segPos := replica.listNewSegmentsStartPositions()
		assert.Equal(t, 1, len(segPos))
		assert.Equal(t, UniqueID(0), segPos[0].SegmentID)
		assert.Equal(t, "insert-01", segPos[0].StartPosition.ChannelName)
		assert.Equal(t, Timestamp(100), segPos[0].StartPosition.Timestamp)

		assert.Equal(t, 0, len(replica.newSegments))
		assert.Equal(t, 2, len(replica.normalSegments))

		cps := replica.listSegmentsCheckPoints()
		assert.Equal(t, 2, len(cps))
		assert.Equal(t, startPos.Timestamp, cps[UniqueID(0)].pos.Timestamp)
		assert.Equal(t, int64(0), cps[UniqueID(0)].numRows)
		assert.Equal(t, cp.pos.Timestamp, cps[UniqueID(1)].pos.Timestamp)
		assert.Equal(t, int64(10), cps[UniqueID(1)].numRows)

		updates, err := replica.getSegmentStatisticsUpdates(0)
		assert.NoError(t, err)
		assert.Equal(t, int64(10), updates.NumRows)

		updates, err = replica.getSegmentStatisticsUpdates(1)
		assert.NoError(t, err)
		assert.Equal(t, int64(20), updates.NumRows)

		replica.updateSegmentCheckPoint(0)
		assert.Equal(t, int64(10), replica.normalSegments[UniqueID(0)].checkPoint.numRows)
		replica.updateSegmentCheckPoint(1)
		assert.Equal(t, int64(20), replica.normalSegments[UniqueID(1)].checkPoint.numRows)
	})
}

func TestSegmentUpdatePKRange(t *testing.T) {
	seg := &Segment{
		pkFilter: bloom.NewWithEstimates(100000, 0.005),
		maxPK:    math.MinInt64,
		minPK:    math.MaxInt64,
	}

	cases := make([]int64, 0, 100)
	for i := 0; i < 100; i++ {
		cases = append(cases, rand.Int63())
	}
	buf := make([]byte, 8)
	for _, c := range cases {
		seg.updatePKRange([]int64{c})

		assert.LessOrEqual(t, seg.minPK, c)
		assert.GreaterOrEqual(t, seg.maxPK, c)

		binary.BigEndian.PutUint64(buf, uint64(c))
		assert.True(t, seg.pkFilter.Test(buf))
	}
}

func TestReplicaUpdatePKRange(t *testing.T) {
	rc := &RootCoordFactory{}
	collID := UniqueID(1)
	partID := UniqueID(2)
	chanName := "insert-02"
	startPos := &internalpb.MsgPosition{ChannelName: chanName, Timestamp: Timestamp(100)}
	endPos := &internalpb.MsgPosition{ChannelName: chanName, Timestamp: Timestamp(200)}
	cpPos := &internalpb.MsgPosition{ChannelName: chanName, Timestamp: Timestamp(10)}
	cp := &segmentCheckPoint{int64(10), *cpPos}

	replica := newSegmentReplica(rc, collID)

	err := replica.addNewSegment(1, collID, partID, chanName, startPos, endPos)
	assert.Nil(t, err)
	err = replica.addNormalSegment(2, collID, partID, chanName, 100, cp)
	assert.Nil(t, err)

	segNew := replica.newSegments[1]
	segNormal := replica.normalSegments[2]

	cases := make([]int64, 0, 100)
	for i := 0; i < 100; i++ {
		cases = append(cases, rand.Int63())
	}
	buf := make([]byte, 8)
	for _, c := range cases {
		replica.updateSegmentPKRange(1, []int64{c}) // new segment
		replica.updateSegmentPKRange(2, []int64{c}) // normal segment
		replica.updateSegmentPKRange(3, []int64{c}) // non-exist segment

		assert.LessOrEqual(t, segNew.minPK, c)
		assert.GreaterOrEqual(t, segNew.maxPK, c)
		assert.LessOrEqual(t, segNormal.minPK, c)
		assert.GreaterOrEqual(t, segNormal.maxPK, c)

		binary.BigEndian.PutUint64(buf, uint64(c))
		assert.True(t, segNew.pkFilter.Test(buf))
		assert.True(t, segNormal.pkFilter.Test(buf))

	}

}