package agentapi_test

import (
	"context"
	"database/sql"
	"sync/atomic"
	"testing"
	"time"

	"github.com/google/uuid"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"go.uber.org/mock/gomock"
	"google.golang.org/protobuf/types/known/durationpb"

	agentproto "github.com/coder/coder/v2/agent/proto"
	"github.com/coder/coder/v2/coderd/agentapi"
	"github.com/coder/coder/v2/coderd/database"
	"github.com/coder/coder/v2/coderd/database/dbmock"
	"github.com/coder/coder/v2/coderd/database/dbtime"
	"github.com/coder/coder/v2/coderd/database/pubsub"
	"github.com/coder/coder/v2/coderd/prometheusmetrics"
	"github.com/coder/coder/v2/coderd/schedule"
	"github.com/coder/coder/v2/coderd/workspacestats"
	"github.com/coder/coder/v2/coderd/workspacestats/workspacestatstest"
	"github.com/coder/coder/v2/coderd/wspubsub"
	"github.com/coder/coder/v2/codersdk"
	"github.com/coder/coder/v2/testutil"
)

func TestUpdateStates(t *testing.T) {
	t.Parallel()

	var (
		user = database.User{
			ID:       uuid.New(),
			Username: "bill",
		}
		template = database.Template{
			ID:   uuid.New(),
			Name: "tpl",
		}
		workspace = database.Workspace{
			ID:           uuid.New(),
			OwnerID:      user.ID,
			TemplateID:   template.ID,
			Name:         "xyz",
			TemplateName: template.Name,
		}
		agent = database.WorkspaceAgent{
			ID:   uuid.New(),
			Name: "abc",
		}
	)

	t.Run("OK", func(t *testing.T) {
		t.Parallel()

		var (
			now = dbtime.Now()
			dbM = dbmock.NewMockStore(gomock.NewController(t))
			ps  = pubsub.NewInMemory()

			templateScheduleStore = schedule.MockTemplateScheduleStore{
				GetFn: func(context.Context, database.Store, uuid.UUID) (schedule.TemplateScheduleOptions, error) {
					panic("should not be called")
				},
				SetFn: func(context.Context, database.Store, database.Template, schedule.TemplateScheduleOptions) (database.Template, error) {
					panic("not implemented")
				},
			}
			batcher                    = &workspacestatstest.StatsBatcher{}
			updateAgentMetricsFnCalled = false
			tickCh                     = make(chan time.Time)
			flushCh                    = make(chan int, 1)
			wut                        = workspacestats.NewTracker(dbM,
				workspacestats.TrackerWithTickFlush(tickCh, flushCh),
			)

			req = &agentproto.UpdateStatsRequest{
				Stats: &agentproto.Stats{
					ConnectionsByProto: map[string]int64{
						"tcp":  1,
						"dean": 2,
					},
					ConnectionCount:             3,
					ConnectionMedianLatencyMs:   23,
					RxPackets:                   120,
					RxBytes:                     1000,
					TxPackets:                   130,
					TxBytes:                     2000,
					SessionCountVscode:          1,
					SessionCountJetbrains:       2,
					SessionCountReconnectingPty: 3,
					SessionCountSsh:             4,
					Metrics: []*agentproto.Stats_Metric{
						{
							Name:  "awesome metric",
							Value: 42,
						},
						{
							Name:  "uncool metric",
							Value: 0,
						},
					},
				},
			}
		)
		api := agentapi.StatsAPI{
			AgentFn: func(context.Context) (database.WorkspaceAgent, error) {
				return agent, nil
			},
			Database: dbM,
			StatsReporter: workspacestats.NewReporter(workspacestats.ReporterOptions{
				Database:              dbM,
				Pubsub:                ps,
				StatsBatcher:          batcher,
				UsageTracker:          wut,
				TemplateScheduleStore: templateScheduleStorePtr(templateScheduleStore),
				UpdateAgentMetricsFn: func(ctx context.Context, labels prometheusmetrics.AgentMetricLabels, metrics []*agentproto.Stats_Metric) {
					updateAgentMetricsFnCalled = true
					assert.Equal(t, prometheusmetrics.AgentMetricLabels{
						Username:      user.Username,
						WorkspaceName: workspace.Name,
						AgentName:     agent.Name,
						TemplateName:  template.Name,
					}, labels)
					assert.Equal(t, req.Stats.Metrics, metrics)
				},
			}),
			AgentStatsRefreshInterval: 10 * time.Second,
			TimeNowFn: func() time.Time {
				return now
			},
		}
		defer wut.Close()

		// Workspace gets fetched.
		dbM.EXPECT().GetWorkspaceByAgentID(gomock.Any(), agent.ID).Return(workspace, nil)

		// User gets fetched to hit the UpdateAgentMetricsFn.
		dbM.EXPECT().GetUserByID(gomock.Any(), user.ID).Return(user, nil)

		// We expect an activity bump because ConnectionCount > 0.
		dbM.EXPECT().ActivityBumpWorkspace(gomock.Any(), database.ActivityBumpWorkspaceParams{
			WorkspaceID:   workspace.ID,
			NextAutostart: time.Time{}.UTC(),
		}).Return(nil)

		// Workspace last used at gets bumped.
		dbM.EXPECT().BatchUpdateWorkspaceLastUsedAt(gomock.Any(), database.BatchUpdateWorkspaceLastUsedAtParams{
			IDs:        []uuid.UUID{workspace.ID},
			LastUsedAt: now,
		}).Return(nil)

		// Ensure that pubsub notifications are sent.
		notifyDescription := make(chan struct{})
		ps.SubscribeWithErr(wspubsub.WorkspaceEventChannel(workspace.OwnerID),
			wspubsub.HandleWorkspaceEvent(
				func(_ context.Context, e wspubsub.WorkspaceEvent, err error) {
					if err != nil {
						return
					}
					if e.Kind == wspubsub.WorkspaceEventKindStatsUpdate && e.WorkspaceID == workspace.ID {
						go func() {
							notifyDescription <- struct{}{}
						}()
					}
				}))

		resp, err := api.UpdateStats(context.Background(), req)
		require.NoError(t, err)
		require.Equal(t, &agentproto.UpdateStatsResponse{
			ReportInterval: durationpb.New(10 * time.Second),
		}, resp)

		tickCh <- now
		count := <-flushCh
		require.Equal(t, 1, count, "expected one flush with one id")

		batcher.Mu.Lock()
		defer batcher.Mu.Unlock()
		require.Equal(t, int64(1), batcher.Called)
		require.Equal(t, now, batcher.LastTime)
		require.Equal(t, agent.ID, batcher.LastAgentID)
		require.Equal(t, template.ID, batcher.LastTemplateID)
		require.Equal(t, user.ID, batcher.LastUserID)
		require.Equal(t, workspace.ID, batcher.LastWorkspaceID)
		require.Equal(t, req.Stats, batcher.LastStats)
		ctx := testutil.Context(t, testutil.WaitShort)
		select {
		case <-ctx.Done():
			t.Error("timed out while waiting for pubsub notification")
		case <-notifyDescription:
		}
		require.True(t, updateAgentMetricsFnCalled)
	})

	t.Run("ConnectionCountZero", func(t *testing.T) {
		t.Parallel()

		var (
			now                   = dbtime.Now()
			dbM                   = dbmock.NewMockStore(gomock.NewController(t))
			ps                    = pubsub.NewInMemory()
			templateScheduleStore = schedule.MockTemplateScheduleStore{
				GetFn: func(context.Context, database.Store, uuid.UUID) (schedule.TemplateScheduleOptions, error) {
					panic("should not be called")
				},
				SetFn: func(context.Context, database.Store, database.Template, schedule.TemplateScheduleOptions) (database.Template, error) {
					panic("not implemented")
				},
			}
			batcher = &workspacestatstest.StatsBatcher{}

			req = &agentproto.UpdateStatsRequest{
				Stats: &agentproto.Stats{
					ConnectionsByProto:        map[string]int64{},
					ConnectionCount:           0,
					ConnectionMedianLatencyMs: 23,
				},
			}
		)
		api := agentapi.StatsAPI{
			AgentFn: func(context.Context) (database.WorkspaceAgent, error) {
				return agent, nil
			},
			Database: dbM,
			StatsReporter: workspacestats.NewReporter(workspacestats.ReporterOptions{
				Database:              dbM,
				Pubsub:                ps,
				UsageTracker:          workspacestats.NewTracker(dbM),
				StatsBatcher:          batcher,
				TemplateScheduleStore: templateScheduleStorePtr(templateScheduleStore),
				// Ignored when nil.
				UpdateAgentMetricsFn: nil,
			}),
			AgentStatsRefreshInterval: 10 * time.Second,
			TimeNowFn: func() time.Time {
				return now
			},
		}

		// Workspace gets fetched.
		dbM.EXPECT().GetWorkspaceByAgentID(gomock.Any(), agent.ID).Return(workspace, nil)

		_, err := api.UpdateStats(context.Background(), req)
		require.NoError(t, err)
	})

	t.Run("NoStats", func(t *testing.T) {
		t.Parallel()

		var (
			dbM = dbmock.NewMockStore(gomock.NewController(t))
			ps  = pubsub.NewInMemory()
			req = &agentproto.UpdateStatsRequest{
				Stats: nil,
			}
		)
		api := agentapi.StatsAPI{
			AgentFn: func(context.Context) (database.WorkspaceAgent, error) {
				return agent, nil
			},
			Database: dbM,
			StatsReporter: workspacestats.NewReporter(workspacestats.ReporterOptions{
				Database:              dbM,
				Pubsub:                ps,
				StatsBatcher:          nil, // should not be called
				TemplateScheduleStore: nil, // should not be called
				UpdateAgentMetricsFn:  nil, // should not be called
			}),
			AgentStatsRefreshInterval: 10 * time.Second,
			TimeNowFn: func() time.Time {
				panic("should not be called")
			},
		}

		resp, err := api.UpdateStats(context.Background(), req)
		require.NoError(t, err)
		require.Equal(t, &agentproto.UpdateStatsResponse{
			ReportInterval: durationpb.New(10 * time.Second),
		}, resp)
	})

	t.Run("AutostartAwareBump", func(t *testing.T) {
		t.Parallel()

		// Use a workspace with an autostart schedule.
		workspace := workspace
		workspace.AutostartSchedule = sql.NullString{
			String: "CRON_TZ=Australia/Sydney 0 8 * * *",
			Valid:  true,
		}

		// Use a custom time for now which would trigger the autostart aware
		// bump.
		now, err := time.Parse("2006-01-02 15:04:05 -0700 MST", "2023-12-19 07:30:00 +1100 AEDT")
		require.NoError(t, err)
		now = dbtime.Time(now)
		nextAutostart := now.Add(30 * time.Minute).UTC() // always sent to DB as UTC

		var (
			dbM = dbmock.NewMockStore(gomock.NewController(t))
			ps  = pubsub.NewInMemory()

			templateScheduleStore = schedule.MockTemplateScheduleStore{
				GetFn: func(context.Context, database.Store, uuid.UUID) (schedule.TemplateScheduleOptions, error) {
					return schedule.TemplateScheduleOptions{
						UserAutostartEnabled: true,
						AutostartRequirement: schedule.TemplateAutostartRequirement{
							DaysOfWeek: 0b01111111, // every day
						},
					}, nil
				},
				SetFn: func(context.Context, database.Store, database.Template, schedule.TemplateScheduleOptions) (database.Template, error) {
					panic("not implemented")
				},
			}
			batcher                    = &workspacestatstest.StatsBatcher{}
			updateAgentMetricsFnCalled = false
			tickCh                     = make(chan time.Time)
			flushCh                    = make(chan int, 1)
			wut                        = workspacestats.NewTracker(dbM,
				workspacestats.TrackerWithTickFlush(tickCh, flushCh),
			)

			req = &agentproto.UpdateStatsRequest{
				Stats: &agentproto.Stats{
					ConnectionsByProto: map[string]int64{
						"tcp":  1,
						"dean": 2,
					},
					ConnectionCount: 3,
				},
			}
		)
		api := agentapi.StatsAPI{
			AgentFn: func(context.Context) (database.WorkspaceAgent, error) {
				return agent, nil
			},
			Database: dbM,
			StatsReporter: workspacestats.NewReporter(workspacestats.ReporterOptions{
				Database:              dbM,
				Pubsub:                ps,
				UsageTracker:          wut,
				StatsBatcher:          batcher,
				TemplateScheduleStore: templateScheduleStorePtr(templateScheduleStore),
				UpdateAgentMetricsFn: func(ctx context.Context, labels prometheusmetrics.AgentMetricLabels, metrics []*agentproto.Stats_Metric) {
					updateAgentMetricsFnCalled = true
					assert.Equal(t, prometheusmetrics.AgentMetricLabels{
						Username:      user.Username,
						WorkspaceName: workspace.Name,
						AgentName:     agent.Name,
						TemplateName:  template.Name,
					}, labels)
					assert.Equal(t, req.Stats.Metrics, metrics)
				},
			}),
			AgentStatsRefreshInterval: 15 * time.Second,
			TimeNowFn: func() time.Time {
				return now
			},
		}
		defer wut.Close()

		// Workspace gets fetched.
		dbM.EXPECT().GetWorkspaceByAgentID(gomock.Any(), agent.ID).Return(workspace, nil)

		// We expect an activity bump because ConnectionCount > 0. However, the
		// next autostart time will be set on the bump.
		dbM.EXPECT().ActivityBumpWorkspace(gomock.Any(), database.ActivityBumpWorkspaceParams{
			WorkspaceID:   workspace.ID,
			NextAutostart: nextAutostart,
		}).Return(nil)

		// Workspace last used at gets bumped.
		dbM.EXPECT().BatchUpdateWorkspaceLastUsedAt(gomock.Any(), database.BatchUpdateWorkspaceLastUsedAtParams{
			IDs:        []uuid.UUID{workspace.ID},
			LastUsedAt: now.UTC(),
		}).Return(nil)

		// User gets fetched to hit the UpdateAgentMetricsFn.
		dbM.EXPECT().GetUserByID(gomock.Any(), user.ID).Return(user, nil)

		resp, err := api.UpdateStats(context.Background(), req)
		require.NoError(t, err)
		require.Equal(t, &agentproto.UpdateStatsResponse{
			ReportInterval: durationpb.New(15 * time.Second),
		}, resp)

		tickCh <- now
		count := <-flushCh
		require.Equal(t, 1, count, "expected one flush with one id")

		require.True(t, updateAgentMetricsFnCalled)
	})

	t.Run("WorkspaceUsageExperiment", func(t *testing.T) {
		t.Parallel()

		var (
			now = dbtime.Now()
			dbM = dbmock.NewMockStore(gomock.NewController(t))
			ps  = pubsub.NewInMemory()

			templateScheduleStore = schedule.MockTemplateScheduleStore{
				GetFn: func(context.Context, database.Store, uuid.UUID) (schedule.TemplateScheduleOptions, error) {
					t.Fatal("getfn should not be called")
					return schedule.TemplateScheduleOptions{}, nil
				},
				SetFn: func(context.Context, database.Store, database.Template, schedule.TemplateScheduleOptions) (database.Template, error) {
					t.Fatal("setfn not implemented")
					return database.Template{}, nil
				},
			}
			batcher                    = &workspacestatstest.StatsBatcher{}
			updateAgentMetricsFnCalled = false
			tickCh                     = make(chan time.Time)
			flushCh                    = make(chan int, 1)
			wut                        = workspacestats.NewTracker(dbM,
				workspacestats.TrackerWithTickFlush(tickCh, flushCh),
			)

			req = &agentproto.UpdateStatsRequest{
				Stats: &agentproto.Stats{
					ConnectionsByProto: map[string]int64{
						"tcp":  1,
						"dean": 2,
					},
					ConnectionCount:             3,
					ConnectionMedianLatencyMs:   23,
					RxPackets:                   120,
					RxBytes:                     1000,
					TxPackets:                   130,
					TxBytes:                     2000,
					SessionCountVscode:          1,
					SessionCountJetbrains:       2,
					SessionCountReconnectingPty: 3,
					SessionCountSsh:             4,
					Metrics: []*agentproto.Stats_Metric{
						{
							Name:  "awesome metric",
							Value: 42,
						},
						{
							Name:  "uncool metric",
							Value: 0,
						},
					},
				},
			}
		)
		defer wut.Close()
		api := agentapi.StatsAPI{
			AgentFn: func(context.Context) (database.WorkspaceAgent, error) {
				return agent, nil
			},
			Database: dbM,
			StatsReporter: workspacestats.NewReporter(workspacestats.ReporterOptions{
				Database:              dbM,
				Pubsub:                ps,
				StatsBatcher:          batcher,
				UsageTracker:          wut,
				TemplateScheduleStore: templateScheduleStorePtr(templateScheduleStore),
				UpdateAgentMetricsFn: func(ctx context.Context, labels prometheusmetrics.AgentMetricLabels, metrics []*agentproto.Stats_Metric) {
					updateAgentMetricsFnCalled = true
					assert.Equal(t, prometheusmetrics.AgentMetricLabels{
						Username:      user.Username,
						WorkspaceName: workspace.Name,
						AgentName:     agent.Name,
						TemplateName:  template.Name,
					}, labels)
					assert.Equal(t, req.Stats.Metrics, metrics)
				},
			}),
			AgentStatsRefreshInterval: 10 * time.Second,
			TimeNowFn: func() time.Time {
				return now
			},
			Experiments: codersdk.Experiments{
				codersdk.ExperimentWorkspaceUsage,
			},
		}

		// Workspace gets fetched.
		dbM.EXPECT().GetWorkspaceByAgentID(gomock.Any(), agent.ID).Return(workspace, nil)

		// We expect an activity bump because ConnectionCount > 0.
		dbM.EXPECT().ActivityBumpWorkspace(gomock.Any(), database.ActivityBumpWorkspaceParams{
			WorkspaceID:   workspace.ID,
			NextAutostart: time.Time{}.UTC(),
		}).Return(nil)

		// Workspace last used at gets bumped.
		dbM.EXPECT().BatchUpdateWorkspaceLastUsedAt(gomock.Any(), database.BatchUpdateWorkspaceLastUsedAtParams{
			IDs:        []uuid.UUID{workspace.ID},
			LastUsedAt: now,
		}).Return(nil)

		// User gets fetched to hit the UpdateAgentMetricsFn.
		dbM.EXPECT().GetUserByID(gomock.Any(), user.ID).Return(user, nil)

		// Ensure that pubsub notifications are sent.
		notifyDescription := make(chan struct{})
		ps.SubscribeWithErr(wspubsub.WorkspaceEventChannel(workspace.OwnerID),
			wspubsub.HandleWorkspaceEvent(
				func(_ context.Context, e wspubsub.WorkspaceEvent, err error) {
					if err != nil {
						return
					}
					if e.Kind == wspubsub.WorkspaceEventKindStatsUpdate && e.WorkspaceID == workspace.ID {
						go func() {
							notifyDescription <- struct{}{}
						}()
					}
				}))

		resp, err := api.UpdateStats(context.Background(), req)
		require.NoError(t, err)
		require.Equal(t, &agentproto.UpdateStatsResponse{
			ReportInterval: durationpb.New(10 * time.Second),
		}, resp)

		tickCh <- now
		count := <-flushCh
		require.Equal(t, 1, count, "expected one flush with one id")

		batcher.Mu.Lock()
		defer batcher.Mu.Unlock()
		require.EqualValues(t, 1, batcher.Called)
		require.EqualValues(t, 0, batcher.LastStats.SessionCountSsh)
		require.EqualValues(t, 0, batcher.LastStats.SessionCountJetbrains)
		require.EqualValues(t, 0, batcher.LastStats.SessionCountVscode)
		require.EqualValues(t, 0, batcher.LastStats.SessionCountReconnectingPty)
		ctx := testutil.Context(t, testutil.WaitShort)
		select {
		case <-ctx.Done():
			t.Error("timed out while waiting for pubsub notification")
		case <-notifyDescription:
		}
		require.True(t, updateAgentMetricsFnCalled)
	})
}

func templateScheduleStorePtr(store schedule.TemplateScheduleStore) *atomic.Pointer[schedule.TemplateScheduleStore] {
	var ptr atomic.Pointer[schedule.TemplateScheduleStore]
	ptr.Store(&store)
	return &ptr
}