// Licensed to the LF AI & Data foundation under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you 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 flusherimpl

import (
	"context"
	"testing"

	"github.com/cockroachdb/errors"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/mock"

	"github.com/milvus-io/milvus/internal/flushcommon/writebuffer"
	"github.com/milvus-io/milvus/pkg/v3/mocks/streaming/util/mock_message"
	"github.com/milvus-io/milvus/pkg/v3/proto/datapb"
	"github.com/milvus-io/milvus/pkg/v3/streaming/util/message"
)

func TestFlushMsgHandler_HandleFlush(t *testing.T) {
	vchannel := "ch-0"

	// test failed
	wbMgr := writebuffer.NewMockBufferManager(t)
	wbMgr.EXPECT().SealSegments(mock.Anything, mock.Anything, mock.Anything).Return(errors.New("mock err"))

	msg := message.NewFlushMessageBuilderV2().
		WithBroadcast([]string{vchannel}).
		WithHeader(&message.FlushMessageHeader{
			CollectionId: 0,
			SegmentId:    1,
		}).
		WithBody(&message.FlushMessageBody{}).
		MustBuildBroadcast().
		WithBroadcastID(1).
		SplitIntoMutableMessage()[0]

	handler := newMsgHandler(wbMgr)
	msgID := mock_message.NewMockMessageID(t)
	im, err := message.AsImmutableFlushMessageV2(msg.IntoImmutableMessage(msgID))
	assert.NoError(t, err)
	err = handler.HandleFlush(im)
	assert.Error(t, err)

	// test normal
	wbMgr = writebuffer.NewMockBufferManager(t)
	wbMgr.EXPECT().SealSegments(mock.Anything, mock.Anything, mock.Anything).Return(nil)

	handler = newMsgHandler(wbMgr)
	err = handler.HandleFlush(im)
	assert.NoError(t, err)
}

func TestFlushMsgHandler_HandleManualFlush(t *testing.T) {
	vchannel := "ch-0"

	// test failed
	wbMgr := writebuffer.NewMockBufferManager(t)
	wbMgr.EXPECT().SealSegments(mock.Anything, mock.Anything, mock.Anything).Return(errors.New("mock err"))
	wbMgr.EXPECT().FlushChannel(mock.Anything, mock.Anything, mock.Anything).Return(errors.New("mock err"))

	msg := message.NewManualFlushMessageBuilderV2().
		WithBroadcast([]string{vchannel}).
		WithHeader(&message.ManualFlushMessageHeader{
			CollectionId: 0,
			FlushTs:      1000,
		}).
		WithBody(&message.ManualFlushMessageBody{}).
		MustBuildBroadcast().
		WithBroadcastID(1).
		SplitIntoMutableMessage()[0]

	handler := newMsgHandler(wbMgr)
	msgID := mock_message.NewMockMessageID(t)
	im, err := message.AsImmutableManualFlushMessageV2(msg.WithTimeTick(1000).IntoImmutableMessage(msgID))
	assert.NoError(t, err)
	err = handler.HandleManualFlush(im)
	assert.Error(t, err)

	wbMgr.EXPECT().SealSegments(mock.Anything, mock.Anything, mock.Anything).Unset()
	wbMgr.EXPECT().SealSegments(mock.Anything, mock.Anything, mock.Anything).Return(nil)
	err = handler.HandleManualFlush(im)
	assert.Error(t, err)

	// test normal
	wbMgr.EXPECT().FlushChannel(mock.Anything, mock.Anything, mock.Anything).Unset()
	wbMgr.EXPECT().FlushChannel(mock.Anything, mock.Anything, mock.Anything).Return(nil)

	err = handler.HandleManualFlush(im)
	assert.NoError(t, err)
}

func TestFlushMsgHandler_HandleCreateSegment(t *testing.T) {
	vchannel := "ch-0"

	// Build a CreateSegment message with L0 level so that createNewGrowingSegment
	// returns nil immediately (L0 skips MixCoordClient allocation).
	// This lets us test the growing-source skip logic in HandleCreateSegment without
	// requiring the full resource.Resource() server context.
	msg, err := message.NewCreateSegmentMessageBuilderV2().
		WithHeader(&message.CreateSegmentMessageHeader{
			CollectionId: 1,
			PartitionId:  10,
			SegmentId:    1001,
			Level:        datapb.SegmentLevel_L0,
		}).
		WithBody(&message.CreateSegmentMessageBody{}).
		WithVChannel(vchannel).
		BuildMutable()
	assert.NoError(t, err)

	msgID := mock_message.NewMockMessageID(t)
	msgID.EXPECT().String().Return("mock-msg-id").Maybe()
	msgID.EXPECT().Marshal().Return("mock-msg-id").Maybe()
	im, err := message.AsImmutableCreateSegmentMessageV2(
		msg.WithTimeTick(1000).WithLastConfirmedUseMessageID().IntoImmutableMessage(msgID),
	)
	assert.NoError(t, err)

	t.Run("growing-source collection creates WriteBuffer shell", func(t *testing.T) {
		wbMgr := writebuffer.NewMockBufferManager(t)
		wbMgr.EXPECT().CreateNewGrowingSegment(mock.Anything, vchannel, mock.MatchedBy(func(info writebuffer.CreateGrowingSegmentInfo) bool {
			return info.PartitionID == 10 && info.SegmentID == 1001 && info.StorageVersion == 0
		})).Return(nil)

		handler := newMsgHandler(wbMgr)
		err := handler.HandleCreateSegment(context.Background(), im)
		assert.NoError(t, err)
	})

	t.Run("non-growing-source collection calls CreateNewGrowingSegment", func(t *testing.T) {
		wbMgr := writebuffer.NewMockBufferManager(t)
		wbMgr.EXPECT().CreateNewGrowingSegment(mock.Anything, vchannel, mock.MatchedBy(func(info writebuffer.CreateGrowingSegmentInfo) bool {
			return info.PartitionID == 10 && info.SegmentID == 1001 && info.StorageVersion == 0
		})).Return(nil)

		handler := newMsgHandler(wbMgr)
		err := handler.HandleCreateSegment(context.Background(), im)
		assert.NoError(t, err)
	})
}

func TestFlushMsgHandler_HandleFlushAll(t *testing.T) {
	vchannel := "ch-0"

	// test failed
	wbMgr := writebuffer.NewMockBufferManager(t)
	wbMgr.EXPECT().SealAllSegments(mock.Anything, mock.Anything).Return(errors.New("mock err"))
	wbMgr.EXPECT().FlushChannel(mock.Anything, mock.Anything, mock.Anything).Return(errors.New("mock err"))

	msg := message.NewFlushAllMessageBuilderV2().
		WithBroadcast([]string{vchannel}).
		WithHeader(&message.FlushAllMessageHeader{}).
		WithBody(&message.FlushAllMessageBody{}).
		WithProperties(map[string]string{
			"_tt": "1",
		}).
		MustBuildBroadcast().
		WithBroadcastID(1).
		SplitIntoMutableMessage()[0]

	handler := newMsgHandler(wbMgr)
	msgID := mock_message.NewMockMessageID(t)
	im, err := message.AsImmutableFlushAllMessageV2(msg.IntoImmutableMessage(msgID))
	assert.NoError(t, err)
	err = handler.HandleFlushAll(vchannel, im)
	assert.Error(t, err)

	wbMgr.EXPECT().SealAllSegments(mock.Anything, mock.Anything).Unset()
	wbMgr.EXPECT().SealAllSegments(mock.Anything, mock.Anything).Return(nil)
	err = handler.HandleFlushAll(vchannel, im)
	assert.Error(t, err)

	// test normal
	wbMgr.EXPECT().FlushChannel(mock.Anything, mock.Anything, mock.Anything).Unset()
	wbMgr.EXPECT().FlushChannel(mock.Anything, mock.Anything, mock.Anything).Return(nil)

	err = handler.HandleFlushAll(vchannel, im)
	assert.NoError(t, err)
}

func TestFlushMsgHandler_HandlSchemaChange(t *testing.T) {
	vchannel := "ch-0"

	// test failed
	wbMgr := writebuffer.NewMockBufferManager(t)
	wbMgr.EXPECT().SealSegments(mock.Anything, mock.Anything, mock.Anything).Return(errors.New("mock err"))

	msg := message.NewSchemaChangeMessageBuilderV2().
		WithBroadcast([]string{vchannel}).
		WithHeader(&message.SchemaChangeMessageHeader{
			CollectionId:      0,
			FlushedSegmentIds: []int64{1},
		}).
		WithBody(&message.SchemaChangeMessageBody{}).
		MustBuildBroadcast().
		WithBroadcastID(1).
		SplitIntoMutableMessage()[0]

	handler := newMsgHandler(wbMgr)
	msgID := mock_message.NewMockMessageID(t)
	im := message.MustAsImmutableSchemaChangeMessageV2(msg.IntoImmutableMessage(msgID))
	err := handler.HandleSchemaChange(context.Background(), im)
	assert.Error(t, err)

	// test normal
	wbMgr.EXPECT().SealSegments(mock.Anything, mock.Anything, mock.Anything).Unset()
	wbMgr.EXPECT().SealSegments(mock.Anything, mock.Anything, mock.Anything).Return(nil)

	err = handler.HandleSchemaChange(context.Background(), im)
	assert.NoError(t, err)
}

func TestFlushMsgHandler_HandleTruncateCollection(t *testing.T) {
	vchannel := "ch-0"

	// test failed - SealSegments error
	wbMgr := writebuffer.NewMockBufferManager(t)
	wbMgr.EXPECT().SealSegments(mock.Anything, mock.Anything, mock.Anything).Return(errors.New("mock err"))

	msg := message.NewTruncateCollectionMessageBuilderV2().
		WithBroadcast([]string{vchannel}).
		WithHeader(&message.TruncateCollectionMessageHeader{
			CollectionId: 0,
			SegmentIds:   []int64{1, 2},
		}).
		WithBody(&message.TruncateCollectionMessageBody{}).
		MustBuildBroadcast().
		WithBroadcastID(1).
		SplitIntoMutableMessage()[0]
	msg.WithTimeTick(1000)

	handler := newMsgHandler(wbMgr)
	msgID := mock_message.NewMockMessageID(t)
	im, err := message.AsImmutableTruncateCollectionMessageV2(msg.IntoImmutableMessage(msgID))
	assert.NoError(t, err)
	err = handler.HandleTruncateCollection(im)
	assert.Error(t, err)

	// test failed - SealSegments success but FlushChannel error
	wbMgr.EXPECT().SealSegments(mock.Anything, mock.Anything, mock.Anything).Unset()
	wbMgr.EXPECT().SealSegments(mock.Anything, mock.Anything, mock.Anything).Return(nil)
	wbMgr.EXPECT().FlushChannel(mock.Anything, mock.Anything, mock.Anything).Return(errors.New("mock err"))

	err = handler.HandleTruncateCollection(im)
	assert.Error(t, err)

	// test normal
	wbMgr.EXPECT().FlushChannel(mock.Anything, mock.Anything, mock.Anything).Unset()
	wbMgr.EXPECT().FlushChannel(mock.Anything, mock.Anything, mock.Anything).Return(nil)

	err = handler.HandleTruncateCollection(im)
	assert.NoError(t, err)
}
