MM-45899: Insights: least active channels (#20796)

* Add api endpoints, app layers for top inactive channels with dummy store calls

* Add store functions for top inactive channels

* Add model, store, app tests.

* Add client function and api tests

* Add participants information to TopInactiveChannel

* Translation fix

* Style fix while writing response

* Return channelmember IDs instead of profiles, query in batch avoiding inside the loop

* Make the following changes

 - move DeleteAt to subqueries, to avoid select, group by
 - Remove TeamId from response
 - Count bots and webhook posts

* SQL query lint fix, store test fix to include bot messages

* make app-layers

* Fix empty participant lists being sent as [""]

* Track channel joins, to distinguish 0 activity channels vs new channels

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

model/client4.go

@@ -3642,6 +3642,41 @@ func (c *Client4) GetTopChannelsForUserSince(teamId string, timeRange string, pa
 	return topChannels, BuildResponse(r), nil
 }
 
+// GetTopInactiveChannelsForTeamSince will return an ordered list of the top channels in a given team.
+func (c *Client4) GetTopInactiveChannelsForTeamSince(teamId string, timeRange string, page int, perPage int) (*TopInactiveChannelList, *Response, error) {
+	query := fmt.Sprintf("?time_range=%v&page=%v&per_page=%v", timeRange, page, perPage)
+	r, err := c.DoAPIGet(c.teamRoute(teamId)+"/top/inactive_channels"+query, "")
+	if err != nil {
+		return nil, BuildResponse(r), err
+	}
+	defer closeBody(r)
+	var topInactiveChannels *TopInactiveChannelList
+	if jsonErr := json.NewDecoder(r.Body).Decode(&topInactiveChannels); jsonErr != nil {
+		return nil, nil, NewAppError("GetTopInactiveChannelsForTeamSince", "api.unmarshal_error", nil, jsonErr.Error(), http.StatusInternalServerError)
+	}
+	return topInactiveChannels, BuildResponse(r), nil
+}
+
+// GetTopInactiveChannelsForUserSince will return an ordered list of your top channels in a given team.
+func (c *Client4) GetTopInactiveChannelsForUserSince(teamId string, timeRange string, page int, perPage int) (*TopInactiveChannelList, *Response, error) {
+	query := fmt.Sprintf("?time_range=%v&page=%v&per_page=%v", timeRange, page, perPage)
+
+	if teamId != "" {
+		query += fmt.Sprintf("&team_id=%v", teamId)
+	}
+
+	r, err := c.DoAPIGet(c.usersRoute()+"/me/top/inactive_channels"+query, "")
+	if err != nil {
+		return nil, BuildResponse(r), err
+	}
+	defer closeBody(r)
+	var topInactiveChannels *TopInactiveChannelList
+	if jsonErr := json.NewDecoder(r.Body).Decode(&topInactiveChannels); jsonErr != nil {
+		return nil, nil, NewAppError("GetTopInactiveChannelsForUserSince", "api.unmarshal_error", nil, jsonErr.Error(), http.StatusInternalServerError)
+	}
+	return topInactiveChannels, BuildResponse(r), nil
+}
+
 // Post Section
 
 // CreatePost creates a post based on the provided post struct.

model/insights.go

@@ -63,6 +63,22 @@ type TopChannel struct {
 	MessageCount int64       `json:"message_count"`
 }
 
+// Top Channels
+type TopInactiveChannelList struct {
+	InsightsListData
+	Items []*TopInactiveChannel `json:"items"`
+}
+
+type TopInactiveChannel struct {
+	ID             string      `json:"id"`
+	Type           ChannelType `json:"type"`
+	DisplayName    string      `json:"display_name"`
+	Name           string      `json:"name"`
+	LastActivityAt int64       `json:"last_activity_at"`
+	Participants   StringArray `json:"participants"`
+	MessageCount   int64       `json:"-"`
+}
+
 // Top Threads
 type TopThreadList struct {
 	InsightsListData
@@ -286,6 +302,20 @@ func GetTopThreadListWithPagination(threads []*TopThread, limit int) *TopThreadL
 	return &TopThreadList{InsightsListData: InsightsListData{HasNext: hasNext}, Items: threads}
 }
 
+// GetTopInactiveChannelListWithPagination adds a rank to each item in the given list of TopInactiveChannel and checks if there is
+// another page that can be fetched based on the given limit and offset. The given list of TopInactiveChannel is assumed to be
+// sorted by Score. Returns a TopInactiveChannelList.
+func GetTopInactiveChannelListWithPagination(channels []*TopInactiveChannel, limit int) *TopInactiveChannelList {
+	// Add pagination support
+	var hasNext bool
+	if (limit != 0) && (len(channels) == limit+1) {
+		hasNext = true
+		channels = channels[:len(channels)-1]
+	}
+
+	return &TopInactiveChannelList{InsightsListData: InsightsListData{HasNext: hasNext}, Items: channels}
+}
+
 // GetTopDMListWithPagination adds a rank to each item in the given list of TopDM and checks if there is
 // another page that can be fetched based on the given limit and offset. The given list of TopDM is assumed to be
 // sorted by MessageCount(score). Returns a TopDMList.

model/insights_test.go

@@ -121,6 +121,43 @@ func TestGetTopThreadListWithPagination(t *testing.T) {
 	}
 }
 
+func TestGetTopInactiveChannelListWithPagination(t *testing.T) {
+	channels := []*TopInactiveChannel{
+		{ID: NewId(), MessageCount: 2},
+		{ID: NewId(), MessageCount: 5},
+		{ID: NewId(), MessageCount: 7},
+		{ID: NewId(), MessageCount: 80},
+		{ID: NewId(), MessageCount: 85},
+		{ID: NewId(), MessageCount: 92}}
+
+	hasNextTC := []struct {
+		Description string
+		Limit       int
+		Offset      int
+		Expected    *TopInactiveChannelList
+	}{
+		{
+			Description: "has one page",
+			Limit:       len(channels),
+			Offset:      0,
+			Expected:    &TopInactiveChannelList{InsightsListData: InsightsListData{HasNext: false}, Items: channels},
+		},
+		{
+			Description: "has more than one page",
+			Limit:       len(channels) - 1,
+			Offset:      0,
+			Expected:    &TopInactiveChannelList{InsightsListData: InsightsListData{HasNext: true}, Items: channels},
+		},
+	}
+
+	for _, test := range hasNextTC {
+		t.Run(test.Description, func(t *testing.T) {
+			actual := GetTopInactiveChannelListWithPagination(channels, test.Limit)
+			assert.Equal(t, test.Expected.HasNext, actual.HasNext)
+		})
+	}
+}
+
 func TestGetTopDMsListWithPagination(t *testing.T) {
 	dms := []*TopDM{
 		{SecondParticipant: &TopDMInsightUserInformation{InsightUserInformation: InsightUserInformation{Id: NewId()}}, MessageCount: 100},