// 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 datacoord

import (
	"context"
	"testing"

	"github.com/cockroachdb/errors"
	"github.com/stretchr/testify/assert"
	"google.golang.org/grpc"

	"github.com/milvus-io/milvus-proto/go-api/v2/milvuspb"
	"github.com/milvus-io/milvus/internal/datacoord/session"
	"github.com/milvus-io/milvus/internal/types"
	"github.com/milvus-io/milvus/pkg/util/merr"
	"github.com/milvus-io/milvus/pkg/util/metricsinfo"
	"github.com/milvus-io/milvus/pkg/util/typeutil"
)

type mockMetricDataNodeClient struct {
	types.DataNodeClient
	mock func() (*milvuspb.GetMetricsResponse, error)
}

func (c *mockMetricDataNodeClient) GetMetrics(ctx context.Context, req *milvuspb.GetMetricsRequest, opts ...grpc.CallOption) (*milvuspb.GetMetricsResponse, error) {
	if c.mock == nil {
		return c.DataNodeClient.GetMetrics(ctx, req)
	}
	return c.mock()
}

type mockMetricIndexNodeClient struct {
	types.IndexNodeClient
	mock func() (*milvuspb.GetMetricsResponse, error)
}

func (m *mockMetricIndexNodeClient) GetMetrics(ctx context.Context, req *milvuspb.GetMetricsRequest, opts ...grpc.CallOption) (*milvuspb.GetMetricsResponse, error) {
	if m.mock == nil {
		return m.IndexNodeClient.GetMetrics(ctx, req)
	}
	return m.mock()
}

func TestGetDataNodeMetrics(t *testing.T) {
	svr := newTestServer(t)
	defer closeTestServer(t, svr)

	ctx := context.Background()
	req := &milvuspb.GetMetricsRequest{}
	// nil node
	_, err := svr.getDataNodeMetrics(ctx, req, nil)
	assert.Error(t, err)

	// nil client node
	_, err = svr.getDataNodeMetrics(ctx, req, session.NewSession(&session.NodeInfo{}, nil))
	assert.Error(t, err)

	creator := func(ctx context.Context, addr string, nodeID int64) (types.DataNodeClient, error) {
		return newMockDataNodeClient(100, nil)
	}

	// mock datanode client
	sess := session.NewSession(&session.NodeInfo{}, creator)
	info, err := svr.getDataNodeMetrics(ctx, req, sess)
	assert.NoError(t, err)
	assert.False(t, info.HasError)
	assert.Equal(t, metricsinfo.ConstructComponentName(typeutil.DataNodeRole, 100), info.BaseComponentInfos.Name)

	getMockFailedClientCreator := func(mockFunc func() (*milvuspb.GetMetricsResponse, error)) session.DataNodeCreatorFunc {
		return func(ctx context.Context, addr string, nodeID int64) (types.DataNodeClient, error) {
			cli, err := creator(ctx, addr, nodeID)
			assert.NoError(t, err)
			return &mockMetricDataNodeClient{DataNodeClient: cli, mock: mockFunc}, nil
		}
	}

	mockFailClientCreator := getMockFailedClientCreator(func() (*milvuspb.GetMetricsResponse, error) {
		return nil, errors.New("mocked fail")
	})

	info, err = svr.getDataNodeMetrics(ctx, req, session.NewSession(&session.NodeInfo{}, mockFailClientCreator))
	assert.NoError(t, err)
	assert.True(t, info.HasError)

	mockErr := errors.New("mocked error")
	// mock status not success
	mockFailClientCreator = getMockFailedClientCreator(func() (*milvuspb.GetMetricsResponse, error) {
		return &milvuspb.GetMetricsResponse{
			Status: merr.Status(mockErr),
		}, nil
	})

	info, err = svr.getDataNodeMetrics(ctx, req, session.NewSession(&session.NodeInfo{}, mockFailClientCreator))
	assert.NoError(t, err)
	assert.True(t, info.HasError)
	assert.Equal(t, "mocked error", info.ErrorReason)

	// mock parse error
	mockFailClientCreator = getMockFailedClientCreator(func() (*milvuspb.GetMetricsResponse, error) {
		return &milvuspb.GetMetricsResponse{
			Status:   merr.Success(),
			Response: `{"error_reason": 1}`,
		}, nil
	})

	info, err = svr.getDataNodeMetrics(ctx, req, session.NewSession(&session.NodeInfo{}, mockFailClientCreator))
	assert.NoError(t, err)
	assert.True(t, info.HasError)
}

func TestGetIndexNodeMetrics(t *testing.T) {
	svr := newTestServer(t)
	defer closeTestServer(t, svr)

	ctx := context.Background()
	req := &milvuspb.GetMetricsRequest{}
	// nil node
	_, err := svr.getIndexNodeMetrics(ctx, req, nil)
	assert.Error(t, err)

	// return error
	info, err := svr.getIndexNodeMetrics(ctx, req, &mockMetricIndexNodeClient{mock: func() (*milvuspb.GetMetricsResponse, error) {
		return nil, errors.New("mock error")
	}})
	assert.NoError(t, err)
	assert.True(t, info.HasError)

	// failed
	mockErr := errors.New("mocked error")
	info, err = svr.getIndexNodeMetrics(ctx, req, &mockMetricIndexNodeClient{
		mock: func() (*milvuspb.GetMetricsResponse, error) {
			return &milvuspb.GetMetricsResponse{
				Status:        merr.Status(mockErr),
				ComponentName: "indexnode100",
			}, nil
		},
	})
	assert.NoError(t, err)
	assert.True(t, info.HasError)
	assert.Equal(t, metricsinfo.ConstructComponentName(typeutil.IndexNodeRole, 100), info.BaseComponentInfos.Name)

	// return unexpected
	info, err = svr.getIndexNodeMetrics(ctx, req, &mockMetricIndexNodeClient{
		mock: func() (*milvuspb.GetMetricsResponse, error) {
			return &milvuspb.GetMetricsResponse{
				Status:        merr.Success(),
				Response:      "XXXXXXXXXXXXX",
				ComponentName: "indexnode100",
			}, nil
		},
	})
	assert.NoError(t, err)
	assert.True(t, info.HasError)
	assert.Equal(t, metricsinfo.ConstructComponentName(typeutil.IndexNodeRole, 100), info.BaseComponentInfos.Name)

	// success
	info, err = svr.getIndexNodeMetrics(ctx, req, &mockMetricIndexNodeClient{
		mock: func() (*milvuspb.GetMetricsResponse, error) {
			nodeID = UniqueID(100)

			nodeInfos := metricsinfo.DataNodeInfos{
				BaseComponentInfos: metricsinfo.BaseComponentInfos{
					Name: metricsinfo.ConstructComponentName(typeutil.IndexNodeRole, nodeID),
					ID:   nodeID,
				},
			}
			resp, err := metricsinfo.MarshalComponentInfos(nodeInfos)
			if err != nil {
				return &milvuspb.GetMetricsResponse{
					Status:        merr.Status(err),
					ComponentName: metricsinfo.ConstructComponentName(typeutil.IndexNodeRole, nodeID),
				}, nil
			}

			return &milvuspb.GetMetricsResponse{
				Status:        merr.Success(),
				Response:      resp,
				ComponentName: metricsinfo.ConstructComponentName(typeutil.IndexNodeRole, nodeID),
			}, nil
		},
	})

	assert.NoError(t, err)
	assert.False(t, info.HasError)
	assert.Equal(t, metricsinfo.ConstructComponentName(typeutil.IndexNodeRole, 100), info.BaseComponentInfos.Name)
}

func TestGetSyncTaskMetrics(t *testing.T) {
	svr := Server{}
	t.Run("ReturnsCorrectJSON", func(t *testing.T) {
		req := &milvuspb.GetMetricsRequest{}
		ctx := context.Background()

		task := `[{"segment_id": 1, "batch_rows": 100, "segment_level": "L0", "ts_from": 1000, "ts_to": 2000,"delta_row_count": 10, "flush_size": 1024, "running_time": 2000000000}]`
		mockResp := &milvuspb.GetMetricsResponse{
			Status:   merr.Success(),
			Response: task,
		}

		mockClient := &mockMetricDataNodeClient{
			mock: func() (*milvuspb.GetMetricsResponse, error) {
				return mockResp, nil
			},
		}

		dataNodeCreator := func(ctx context.Context, addr string, nodeID int64) (types.DataNodeClient, error) {
			return mockClient, nil
		}

		mockCluster := NewMockCluster(t)
		mockCluster.EXPECT().GetSessions().Return([]*session.Session{session.NewSession(&session.NodeInfo{NodeID: 1}, dataNodeCreator)})
		svr.cluster = mockCluster

		actualJSON, err := svr.GetSyncTaskMetrics(ctx, req)
		assert.NoError(t, err)
		expectedJSON := `{"datanode1":[{"segment_id":1,"batch_rows":100,"segment_level":"L0","ts_from":1000,"ts_to":2000,"delta_row_count":10,"flush_size":1024,"running_time":2000000000}]}`
		assert.Equal(t, expectedJSON, actualJSON)
	})

	t.Run("ReturnsErrorOnRequestFailure", func(t *testing.T) {
		req := &milvuspb.GetMetricsRequest{}
		ctx := context.Background()

		mockClient := &mockMetricDataNodeClient{
			mock: func() (*milvuspb.GetMetricsResponse, error) {
				return nil, errors.New("request failed")
			},
		}

		dataNodeCreator := func(ctx context.Context, addr string, nodeID int64) (types.DataNodeClient, error) {
			return mockClient, nil
		}

		mockCluster := NewMockCluster(t)
		mockCluster.EXPECT().GetSessions().Return([]*session.Session{session.NewSession(&session.NodeInfo{NodeID: 1}, dataNodeCreator)})
		svr.cluster = mockCluster

		actualJSON, err := svr.GetSyncTaskMetrics(ctx, req)
		assert.Error(t, err)
		assert.Equal(t, "", actualJSON)
	})

	t.Run("ReturnsErrorOnUnmarshalFailure", func(t *testing.T) {
		req := &milvuspb.GetMetricsRequest{}
		ctx := context.Background()

		mockResp := &milvuspb.GetMetricsResponse{
			Status:   merr.Success(),
			Response: `invalid json`,
		}

		mockClient := &mockMetricDataNodeClient{
			mock: func() (*milvuspb.GetMetricsResponse, error) {
				return mockResp, nil
			},
		}

		dataNodeCreator := func(ctx context.Context, addr string, nodeID int64) (types.DataNodeClient, error) {
			return mockClient, nil
		}

		mockCluster := NewMockCluster(t)
		mockCluster.EXPECT().GetSessions().Return([]*session.Session{session.NewSession(&session.NodeInfo{NodeID: 1}, dataNodeCreator)})
		svr.cluster = mockCluster

		actualJSON, err := svr.GetSyncTaskMetrics(ctx, req)
		assert.Error(t, err)
		assert.Equal(t, "", actualJSON)
	})

	t.Run("ReturnsEmptyJSONWhenNoTasks", func(t *testing.T) {
		req := &milvuspb.GetMetricsRequest{}
		ctx := context.Background()

		mockResp := &milvuspb.GetMetricsResponse{
			Status:   merr.Success(),
			Response: "",
		}

		mockClient := &mockMetricDataNodeClient{
			mock: func() (*milvuspb.GetMetricsResponse, error) {
				return mockResp, nil
			},
		}

		dataNodeCreator := func(ctx context.Context, addr string, nodeID int64) (types.DataNodeClient, error) {
			return mockClient, nil
		}

		mockCluster := NewMockCluster(t)
		mockCluster.EXPECT().GetSessions().Return([]*session.Session{session.NewSession(&session.NodeInfo{NodeID: 1}, dataNodeCreator)})
		svr.cluster = mockCluster

		expectedJSON := ""
		actualJSON, err := svr.GetSyncTaskMetrics(ctx, req)
		assert.NoError(t, err)
		assert.Equal(t, expectedJSON, actualJSON)
	})
}