[MM-59361] custom groups & read only channels (#28892)

* added group mention, read only view and post event tracking

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/channels/store/opentracinglayer/opentracinglayer.go

@@ -2059,6 +2059,42 @@ func (s *OpenTracingLayerChannelStore) InvalidatePinnedPostCount(channelID strin
 
 }
 
+func (s *OpenTracingLayerChannelStore) IsChannelReadOnlyScheme(schemeID string) (bool, error) {
+	origCtx := s.Root.Store.Context()
+	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "ChannelStore.IsChannelReadOnlyScheme")
+	s.Root.Store.SetContext(newCtx)
+	defer func() {
+		s.Root.Store.SetContext(origCtx)
+	}()
+
+	defer span.Finish()
+	result, err := s.ChannelStore.IsChannelReadOnlyScheme(schemeID)
+	if err != nil {
+		span.LogFields(spanlog.Error(err))
+		ext.Error.Set(span, true)
+	}
+
+	return result, err
+}
+
+func (s *OpenTracingLayerChannelStore) IsReadOnlyChannel(channelID string) (bool, error) {
+	origCtx := s.Root.Store.Context()
+	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "ChannelStore.IsReadOnlyChannel")
+	s.Root.Store.SetContext(newCtx)
+	defer func() {
+		s.Root.Store.SetContext(origCtx)
+	}()
+
+	defer span.Finish()
+	result, err := s.ChannelStore.IsReadOnlyChannel(channelID)
+	if err != nil {
+		span.LogFields(spanlog.Error(err))
+		ext.Error.Set(span, true)
+	}
+
+	return result, err
+}
+
 func (s *OpenTracingLayerChannelStore) MigrateChannelMembers(fromChannelID string, fromUserID string) (map[string]string, error) {
 	origCtx := s.Root.Store.Context()
 	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "ChannelStore.MigrateChannelMembers")

server/channels/store/retrylayer/retrylayer.go

@@ -2252,6 +2252,48 @@ func (s *RetryLayerChannelStore) InvalidatePinnedPostCount(channelID string) {
 
 }
 
+func (s *RetryLayerChannelStore) IsChannelReadOnlyScheme(schemeID string) (bool, error) {
+
+	tries := 0
+	for {
+		result, err := s.ChannelStore.IsChannelReadOnlyScheme(schemeID)
+		if err == nil {
+			return result, nil
+		}
+		if !isRepeatableError(err) {
+			return result, err
+		}
+		tries++
+		if tries >= 3 {
+			err = errors.Wrap(err, "giving up after 3 consecutive repeatable transaction failures")
+			return result, err
+		}
+		timepkg.Sleep(100 * timepkg.Millisecond)
+	}
+
+}
+
+func (s *RetryLayerChannelStore) IsReadOnlyChannel(channelID string) (bool, error) {
+
+	tries := 0
+	for {
+		result, err := s.ChannelStore.IsReadOnlyChannel(channelID)
+		if err == nil {
+			return result, nil
+		}
+		if !isRepeatableError(err) {
+			return result, err
+		}
+		tries++
+		if tries >= 3 {
+			err = errors.Wrap(err, "giving up after 3 consecutive repeatable transaction failures")
+			return result, err
+		}
+		timepkg.Sleep(100 * timepkg.Millisecond)
+	}
+
+}
+
 func (s *RetryLayerChannelStore) MigrateChannelMembers(fromChannelID string, fromUserID string) (map[string]string, error) {
 
 	tries := 0

server/channels/store/sqlstore/channel_store.go

@@ -17,6 +17,7 @@ import (
 	"github.com/pkg/errors"
 
 	"github.com/mattermost/mattermost/server/public/model"
+	"github.com/mattermost/mattermost/server/public/shared/mlog"
 	"github.com/mattermost/mattermost/server/public/shared/request"
 	"github.com/mattermost/mattermost/server/v8/channels/store"
 	"github.com/mattermost/mattermost/server/v8/einterfaces"
@@ -4322,3 +4323,40 @@ func (s SqlChannelStore) GetTeamForChannel(channelID string) (*model.Team, error
 	}
 	return &team, nil
 }
+
+func (s SqlChannelStore) IsReadOnlyChannel(channelID string) (bool, error) {
+	query := s.getQueryBuilder().Select("schemeid").From("channels").Where(sq.Eq{"id": channelID}).Limit(1)
+	squery, args, err := query.ToSql()
+	if err != nil {
+		return false, err
+	}
+	// we look for schemeID to look for a custom scheme, if there is none chances are it is a writeable
+	// there might be in effect a custom scheme for the user that doesn't allow to create posts, but that wouldn't
+	// be a readonly channel but a readonly user
+	var schemaId string
+	err = s.GetReplicaX().Get(&schemaId, squery, args...)
+	if err != nil {
+		return false, nil
+	}
+	if schemaId == "" {
+		return false, nil
+	}
+	return s.IsChannelReadOnlyScheme(schemaId)
+}
+
+func (s SqlChannelStore) IsChannelReadOnlyScheme(schemeID string) (bool, error) {
+	query := s.getQueryBuilder().Select("roles.permissions").From("roles").InnerJoin("schemes ON roles.name = schemes.defaultchanneluserrole").Where(sq.Eq{"schemes.id": schemeID}).Limit(1)
+	squery, args, err := query.ToSql()
+	if err != nil {
+		mlog.Err(err)
+		return false, err
+	}
+	var permissions string
+	err = s.GetReplicaX().Get(&permissions, squery, args...)
+	if err != nil {
+		mlog.Err(err)
+		return false, err
+	}
+	permissionList := strings.Split(permissions, " ")
+	return slices.Index(permissionList, model.PermissionCreatePost.Id) == -1, nil
+}

server/channels/store/store.go

@@ -310,6 +310,8 @@ type ChannelStore interface {
 	SetShared(channelId string, shared bool) error
 	// GetTeamForChannel returns the team for a given channelID.
 	GetTeamForChannel(channelID string) (*model.Team, error)
+	IsReadOnlyChannel(channelID string) (bool, error)
+	IsChannelReadOnlyScheme(schemeID string) (bool, error)
 }
 
 type ChannelMemberHistoryStore interface {

server/channels/store/storetest/mocks/ChannelStore.go

@@ -2199,6 +2199,62 @@ func (_m *ChannelStore) InvalidatePinnedPostCount(channelID string) {
 	_m.Called(channelID)
 }
 
+// IsChannelReadOnlyScheme provides a mock function with given fields: schemeID
+func (_m *ChannelStore) IsChannelReadOnlyScheme(schemeID string) (bool, error) {
+	ret := _m.Called(schemeID)
+
+	if len(ret) == 0 {
+		panic("no return value specified for IsChannelReadOnlyScheme")
+	}
+
+	var r0 bool
+	var r1 error
+	if rf, ok := ret.Get(0).(func(string) (bool, error)); ok {
+		return rf(schemeID)
+	}
+	if rf, ok := ret.Get(0).(func(string) bool); ok {
+		r0 = rf(schemeID)
+	} else {
+		r0 = ret.Get(0).(bool)
+	}
+
+	if rf, ok := ret.Get(1).(func(string) error); ok {
+		r1 = rf(schemeID)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// IsReadOnlyChannel provides a mock function with given fields: channelID
+func (_m *ChannelStore) IsReadOnlyChannel(channelID string) (bool, error) {
+	ret := _m.Called(channelID)
+
+	if len(ret) == 0 {
+		panic("no return value specified for IsReadOnlyChannel")
+	}
+
+	var r0 bool
+	var r1 error
+	if rf, ok := ret.Get(0).(func(string) (bool, error)); ok {
+		return rf(channelID)
+	}
+	if rf, ok := ret.Get(0).(func(string) bool); ok {
+		r0 = rf(channelID)
+	} else {
+		r0 = ret.Get(0).(bool)
+	}
+
+	if rf, ok := ret.Get(1).(func(string) error); ok {
+		r1 = rf(channelID)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
 // MigrateChannelMembers provides a mock function with given fields: fromChannelID, fromUserID
 func (_m *ChannelStore) MigrateChannelMembers(fromChannelID string, fromUserID string) (map[string]string, error) {
 	ret := _m.Called(fromChannelID, fromUserID)

server/channels/store/timerlayer/timerlayer.go

@@ -1918,6 +1918,38 @@ func (s *TimerLayerChannelStore) InvalidatePinnedPostCount(channelID string) {
 	}
 }
 
+func (s *TimerLayerChannelStore) IsChannelReadOnlyScheme(schemeID string) (bool, error) {
+	start := time.Now()
+
+	result, err := s.ChannelStore.IsChannelReadOnlyScheme(schemeID)
+
+	elapsed := float64(time.Since(start)) / float64(time.Second)
+	if s.Root.Metrics != nil {
+		success := "false"
+		if err == nil {
+			success = "true"
+		}
+		s.Root.Metrics.ObserveStoreMethodDuration("ChannelStore.IsChannelReadOnlyScheme", success, elapsed)
+	}
+	return result, err
+}
+
+func (s *TimerLayerChannelStore) IsReadOnlyChannel(channelID string) (bool, error) {
+	start := time.Now()
+
+	result, err := s.ChannelStore.IsReadOnlyChannel(channelID)
+
+	elapsed := float64(time.Since(start)) / float64(time.Second)
+	if s.Root.Metrics != nil {
+		success := "false"
+		if err == nil {
+			success = "true"
+		}
+		s.Root.Metrics.ObserveStoreMethodDuration("ChannelStore.IsReadOnlyChannel", success, elapsed)
+	}
+	return result, err
+}
+
 func (s *TimerLayerChannelStore) MigrateChannelMembers(fromChannelID string, fromUserID string) (map[string]string, error) {
 	start := time.Now()