[MM-22206] Add PATCH channel moderations (PUT /moderations/patch) (#13845)

* MM-22205 Add get channel moderations endpoint

* MM-22206 Add patch channel moderations endpoint

Add api tests for patch channel moderations

* MM-22205 Ensure ordered permissions returned and create struct ChannelModeratedRoles

* MM-22206 Use structs instead of map

* MM-22206 Add test cases for GetChannelModeratedPermissions

* MM-22206 Add tests for ChannelModeratedPermissionsChangedByPatch

* MM-22206 Use NewBool instead of defining booleans

* MM-22206 Tie Channel Mentions to Create Posts when building Channel Moderations

* Revert "MM-22206 Tie Channel Mentions to Create Posts when building Channel Moderations"

This reverts commit a0bfc95f1732955c5ef5fc3e4b05ea8ab954acea.

* MM-22206 Review changes

Modify GetSchemeRolesForChannel to return named variables
Change calls to SessionHasPermissionToChannel to SessionHasPermissionTo
Add a CreateChannelScheme method
Add a DeleteChannelScheme method
Move GetChannelModeratedPermissions to Role model

* Fix lint

* Add ChannelModeration methods to App interface

* MM-22206 Rename method to GetTeamSchemeChannelRoles

* MM-22206 Check CHANNEL_MODERATED_PERMISSIONS_MAP for existing permission before iterating through it

* Modify wording to higherScoped to match #13813

* MM-22206 Delete channel scheme between tests

* MM-22206 Fix tests

* Actually patch role

* MM-22206 Shadow declaration of err

api4/api.go

@@ -45,6 +45,7 @@ type Routes struct {
 	ChannelMembers           *mux.Router // 'api/v4/channels/{channel_id:[A-Za-z0-9]+}/members'
 	ChannelMember            *mux.Router // 'api/v4/channels/{channel_id:[A-Za-z0-9]+}/members/{user_id:[A-Za-z0-9]+}'
 	ChannelMembersForUser    *mux.Router // 'api/v4/users/{user_id:[A-Za-z0-9]+}/teams/{team_id:[A-Za-z0-9]+}/channels/members'
+	ChannelModerations       *mux.Router // 'api/v4/channels/{channel_id:[A-Za-z0-9]+}/moderations'
 
 	Posts           *mux.Router // 'api/v4/posts'
 	Post            *mux.Router // 'api/v4/posts/{post_id:[A-Za-z0-9]+}'
@@ -156,6 +157,7 @@ func Init(configservice configservice.ConfigService, globalOptionsFunc app.AppOp
 	api.BaseRoutes.ChannelMembers = api.BaseRoutes.Channel.PathPrefix("/members").Subrouter()
 	api.BaseRoutes.ChannelMember = api.BaseRoutes.ChannelMembers.PathPrefix("/{user_id:[A-Za-z0-9]+}").Subrouter()
 	api.BaseRoutes.ChannelMembersForUser = api.BaseRoutes.User.PathPrefix("/teams/{team_id:[A-Za-z0-9]+}/channels/members").Subrouter()
+	api.BaseRoutes.ChannelModerations = api.BaseRoutes.Channel.PathPrefix("/moderations").Subrouter()
 
 	api.BaseRoutes.Posts = api.BaseRoutes.ApiRoot.PathPrefix("/posts").Subrouter()
 	api.BaseRoutes.Post = api.BaseRoutes.Posts.PathPrefix("/{post_id:[A-Za-z0-9]+}").Subrouter()

api4/apitestlib.go

@@ -1009,3 +1009,25 @@ func (me *TestHelper) AddPermissionToRole(permission string, roleName string) {
 
 	utils.EnableDebugLogForTest()
 }
+
+func (me *TestHelper) SetupTeamScheme() *model.Scheme {
+	return me.SetupScheme(model.SCHEME_SCOPE_TEAM)
+}
+
+func (me *TestHelper) SetupChannelScheme() *model.Scheme {
+	return me.SetupScheme(model.SCHEME_SCOPE_CHANNEL)
+}
+
+func (me *TestHelper) SetupScheme(scope string) *model.Scheme {
+	scheme := model.Scheme{
+		Name:        model.NewId(),
+		DisplayName: model.NewId(),
+		Scope:       scope,
+	}
+
+	if scheme, err := me.App.CreateScheme(&scheme); err == nil {
+		return scheme
+	} else {
+		panic(err)
+	}
+}

api4/channel.go

@@ -43,6 +43,7 @@ func (api *API) InitChannel() {
 	api.BaseRoutes.Channel.Handle("/pinned", api.ApiSessionRequired(getPinnedPosts)).Methods("GET")
 	api.BaseRoutes.Channel.Handle("/timezones", api.ApiSessionRequired(getChannelMembersTimezones)).Methods("GET")
 	api.BaseRoutes.Channel.Handle("/members_minus_group_members", api.ApiSessionRequired(channelMembersMinusGroupMembers)).Methods("GET")
+
 	api.BaseRoutes.ChannelForUser.Handle("/unread", api.ApiSessionRequired(getChannelUnread)).Methods("GET")
 
 	api.BaseRoutes.ChannelByName.Handle("", api.ApiSessionRequired(getChannelByName)).Methods("GET")
@@ -57,6 +58,9 @@ func (api *API) InitChannel() {
 	api.BaseRoutes.ChannelMember.Handle("/roles", api.ApiSessionRequired(updateChannelMemberRoles)).Methods("PUT")
 	api.BaseRoutes.ChannelMember.Handle("/schemeRoles", api.ApiSessionRequired(updateChannelMemberSchemeRoles)).Methods("PUT")
 	api.BaseRoutes.ChannelMember.Handle("/notify_props", api.ApiSessionRequired(updateChannelMemberNotifyProps)).Methods("PUT")
+
+	api.BaseRoutes.ChannelModerations.Handle("", api.ApiSessionRequired(getChannelModerations)).Methods("GET")
+	api.BaseRoutes.ChannelModerations.Handle("/patch", api.ApiSessionRequired(patchChannelModerations)).Methods("PUT")
 }
 
 func createChannel(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -1453,7 +1457,7 @@ func updateChannelScheme(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if !c.App.SessionHasPermissionToChannel(*c.App.Session(), c.Params.ChannelId, model.PERMISSION_MANAGE_SYSTEM) {
+	if !c.App.SessionHasPermissionTo(*c.App.Session(), model.PERMISSION_MANAGE_SYSTEM) {
 		c.SetPermissionError(model.PERMISSION_MANAGE_SYSTEM)
 		return
 	}
@@ -1535,3 +1539,78 @@ func channelMembersMinusGroupMembers(c *Context, w http.ResponseWriter, r *http.
 
 	w.Write(b)
 }
+
+func getChannelModerations(c *Context, w http.ResponseWriter, r *http.Request) {
+	if c.App.License() == nil {
+		c.Err = model.NewAppError("Api4.GetChannelModerations", "api.channel.get_channel_moderations.license.error", nil, "", http.StatusNotImplemented)
+		return
+	}
+
+	c.RequireChannelId()
+	if c.Err != nil {
+		return
+	}
+
+	if !c.App.SessionHasPermissionTo(*c.App.Session(), model.PERMISSION_MANAGE_SYSTEM) {
+		c.SetPermissionError(model.PERMISSION_MANAGE_SYSTEM)
+		return
+	}
+
+	channel, err := c.App.GetChannel(c.Params.ChannelId)
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	channelModerations, err := c.App.GetChannelModerationsForChannel(channel)
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	b, marshalErr := json.Marshal(channelModerations)
+	if marshalErr != nil {
+		c.Err = model.NewAppError("Api4.getChannelModerations", "api.marshal_error", nil, marshalErr.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	w.Write(b)
+}
+
+func patchChannelModerations(c *Context, w http.ResponseWriter, r *http.Request) {
+	if c.App.License() == nil {
+		c.Err = model.NewAppError("Api4.patchChannelModerations", "api.channel.patch_channel_moderations.license.error", nil, "", http.StatusNotImplemented)
+		return
+	}
+
+	c.RequireChannelId()
+	if c.Err != nil {
+		return
+	}
+
+	if !c.App.SessionHasPermissionTo(*c.App.Session(), model.PERMISSION_MANAGE_SYSTEM) {
+		c.SetPermissionError(model.PERMISSION_MANAGE_SYSTEM)
+		return
+	}
+
+	channel, err := c.App.GetChannel(c.Params.ChannelId)
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	channelModerationsPatch := model.ChannelModerationsPatchFromJson(r.Body)
+	channelModerations, err := c.App.PatchChannelModerationsForChannel(channel, channelModerationsPatch)
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	b, marshalErr := json.Marshal(channelModerations)
+	if marshalErr != nil {
+		c.Err = model.NewAppError("Api4.patchChannelModerations", "api.marshal_error", nil, marshalErr.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	w.Write(b)
+}

api4/channel_test.go

@@ -3001,3 +3001,227 @@ func TestChannelMembersMinusGroupMembers(t *testing.T) {
 		})
 	}
 }
+
+func TestGetChannelModerations(t *testing.T) {
+	th := Setup(t).InitBasic()
+	defer th.TearDown()
+
+	channel := th.BasicChannel
+	team := th.BasicTeam
+
+	th.App.SetPhase2PermissionsMigrationStatus(true)
+
+	t.Run("Errors without a license", func(t *testing.T) {
+		_, res := th.SystemAdminClient.GetChannelModerations(channel.Id, "")
+		require.Equal(t, "api.channel.get_channel_moderations.license.error", res.Error.Id)
+	})
+
+	th.App.SetLicense(model.NewTestLicense())
+
+	t.Run("Errors as a non sysadmin", func(t *testing.T) {
+		_, res := th.Client.GetChannelModerations(channel.Id, "")
+		require.Equal(t, "api.context.permissions.app_error", res.Error.Id)
+	})
+
+	th.App.SetLicense(model.NewTestLicense())
+
+	t.Run("Returns default moderations with default roles", func(t *testing.T) {
+		moderations, res := th.SystemAdminClient.GetChannelModerations(channel.Id, "")
+		require.Nil(t, res.Error)
+		require.Equal(t, len(moderations), 4)
+		for _, moderation := range moderations {
+			if moderation.Name == "manage_members" {
+				require.Empty(t, moderation.Roles.Guests)
+			} else {
+				require.Equal(t, moderation.Roles.Guests.Value, true)
+				require.Equal(t, moderation.Roles.Guests.Enabled, true)
+			}
+
+			require.Equal(t, moderation.Roles.Members.Value, true)
+			require.Equal(t, moderation.Roles.Members.Enabled, true)
+		}
+	})
+
+	t.Run("Returns value false and enabled false for permissions that are not present in higher scoped scheme when no channel scheme present", func(t *testing.T) {
+		scheme := th.SetupTeamScheme()
+		team.SchemeId = &scheme.Id
+		_, err := th.App.UpdateTeamScheme(team)
+		require.Nil(t, err)
+
+		th.RemovePermissionFromRole(model.PERMISSION_CREATE_POST.Id, scheme.DefaultChannelGuestRole)
+		defer th.AddPermissionToRole(model.PERMISSION_CREATE_POST.Id, scheme.DefaultChannelGuestRole)
+
+		moderations, res := th.SystemAdminClient.GetChannelModerations(channel.Id, "")
+		require.Nil(t, res.Error)
+		for _, moderation := range moderations {
+			if moderation.Name == model.PERMISSION_CREATE_POST.Id {
+				require.Equal(t, moderation.Roles.Members.Value, true)
+				require.Equal(t, moderation.Roles.Members.Enabled, true)
+				require.Equal(t, moderation.Roles.Guests.Value, false)
+				require.Equal(t, moderation.Roles.Guests.Enabled, false)
+			}
+		}
+	})
+
+	t.Run("Returns value false and enabled true for permissions that are not present in channel scheme but present in team scheme", func(t *testing.T) {
+		scheme := th.SetupChannelScheme()
+		channel.SchemeId = &scheme.Id
+		_, err := th.App.UpdateChannelScheme(channel)
+		require.Nil(t, err)
+
+		th.RemovePermissionFromRole(model.PERMISSION_CREATE_POST.Id, scheme.DefaultChannelGuestRole)
+		defer th.AddPermissionToRole(model.PERMISSION_CREATE_POST.Id, scheme.DefaultChannelGuestRole)
+
+		moderations, res := th.SystemAdminClient.GetChannelModerations(channel.Id, "")
+		require.Nil(t, res.Error)
+		for _, moderation := range moderations {
+			if moderation.Name == model.PERMISSION_CREATE_POST.Id {
+				require.Equal(t, moderation.Roles.Members.Value, true)
+				require.Equal(t, moderation.Roles.Members.Enabled, true)
+				require.Equal(t, moderation.Roles.Guests.Value, false)
+				require.Equal(t, moderation.Roles.Guests.Enabled, true)
+			}
+		}
+	})
+
+	t.Run("Returns value false and enabled false for permissions that are not present in channel & team scheme", func(t *testing.T) {
+		teamScheme := th.SetupTeamScheme()
+		team.SchemeId = &teamScheme.Id
+		th.App.UpdateTeamScheme(team)
+
+		scheme := th.SetupChannelScheme()
+		channel.SchemeId = &scheme.Id
+		th.App.UpdateChannelScheme(channel)
+
+		th.RemovePermissionFromRole(model.PERMISSION_CREATE_POST.Id, scheme.DefaultChannelGuestRole)
+		th.RemovePermissionFromRole(model.PERMISSION_CREATE_POST.Id, teamScheme.DefaultChannelGuestRole)
+
+		defer th.AddPermissionToRole(model.PERMISSION_CREATE_POST.Id, scheme.DefaultChannelGuestRole)
+		defer th.AddPermissionToRole(model.PERMISSION_CREATE_POST.Id, teamScheme.DefaultChannelGuestRole)
+
+		moderations, res := th.SystemAdminClient.GetChannelModerations(channel.Id, "")
+		require.Nil(t, res.Error)
+		for _, moderation := range moderations {
+			if moderation.Name == model.PERMISSION_CREATE_POST.Id {
+				require.Equal(t, moderation.Roles.Members.Value, true)
+				require.Equal(t, moderation.Roles.Members.Enabled, true)
+				require.Equal(t, moderation.Roles.Guests.Value, false)
+				require.Equal(t, moderation.Roles.Guests.Enabled, false)
+			}
+		}
+	})
+}
+
+func TestPatchChannelModerations(t *testing.T) {
+	th := Setup(t).InitBasic()
+	defer th.TearDown()
+
+	channel := th.BasicChannel
+
+	emptyPatch := []*model.ChannelModerationPatch{}
+
+	createPosts := model.CHANNEL_MODERATED_PERMISSIONS[0]
+
+	th.App.SetPhase2PermissionsMigrationStatus(true)
+
+	t.Run("Errors without a license", func(t *testing.T) {
+		_, res := th.SystemAdminClient.PatchChannelModerations(channel.Id, emptyPatch)
+		require.Equal(t, "api.channel.patch_channel_moderations.license.error", res.Error.Id)
+	})
+
+	th.App.SetLicense(model.NewTestLicense())
+
+	t.Run("Errors as a non sysadmin", func(t *testing.T) {
+		_, res := th.Client.PatchChannelModerations(channel.Id, emptyPatch)
+		require.Equal(t, "api.context.permissions.app_error", res.Error.Id)
+	})
+
+	th.App.SetLicense(model.NewTestLicense())
+
+	t.Run("Returns default moderations with empty patch", func(t *testing.T) {
+		moderations, res := th.SystemAdminClient.PatchChannelModerations(channel.Id, emptyPatch)
+		require.Nil(t, res.Error)
+		require.Equal(t, len(moderations), 4)
+		for _, moderation := range moderations {
+			if moderation.Name == "manage_members" {
+				require.Empty(t, moderation.Roles.Guests)
+			} else {
+				require.Equal(t, moderation.Roles.Guests.Value, true)
+				require.Equal(t, moderation.Roles.Guests.Enabled, true)
+			}
+
+			require.Equal(t, moderation.Roles.Members.Value, true)
+			require.Equal(t, moderation.Roles.Members.Enabled, true)
+		}
+
+		require.Nil(t, channel.SchemeId)
+	})
+
+	t.Run("Creates a scheme and returns the updated channel moderations when patching an existing permission", func(t *testing.T) {
+		patch := []*model.ChannelModerationPatch{
+			{
+				Name:  &createPosts,
+				Roles: &model.ChannelModeratedRolesPatch{Members: model.NewBool(false)},
+			},
+		}
+
+		moderations, res := th.SystemAdminClient.PatchChannelModerations(channel.Id, patch)
+		require.Nil(t, res.Error)
+		require.Equal(t, len(moderations), 4)
+		for _, moderation := range moderations {
+			if moderation.Name == "manage_members" {
+				require.Empty(t, moderation.Roles.Guests)
+			} else {
+				require.Equal(t, moderation.Roles.Guests.Value, true)
+				require.Equal(t, moderation.Roles.Guests.Enabled, true)
+			}
+
+			if moderation.Name == createPosts {
+				require.Equal(t, moderation.Roles.Members.Value, false)
+				require.Equal(t, moderation.Roles.Members.Enabled, true)
+			} else {
+				require.Equal(t, moderation.Roles.Members.Value, true)
+				require.Equal(t, moderation.Roles.Members.Enabled, true)
+			}
+		}
+		channel, _ = th.App.GetChannel(channel.Id)
+		require.NotNil(t, channel.SchemeId)
+	})
+
+	t.Run("Removes the existing scheme when moderated permissions are set back to higher scoped values", func(t *testing.T) {
+		channel, _ = th.App.GetChannel(channel.Id)
+		schemeId := channel.SchemeId
+
+		scheme, _ := th.App.GetScheme(*schemeId)
+		require.Equal(t, scheme.DeleteAt, int64(0))
+
+		patch := []*model.ChannelModerationPatch{
+			{
+				Name:  &createPosts,
+				Roles: &model.ChannelModeratedRolesPatch{Members: model.NewBool(true)},
+			},
+		}
+
+		moderations, res := th.SystemAdminClient.PatchChannelModerations(channel.Id, patch)
+		require.Nil(t, res.Error)
+		require.Equal(t, len(moderations), 4)
+		for _, moderation := range moderations {
+			if moderation.Name == "manage_members" {
+				require.Empty(t, moderation.Roles.Guests)
+			} else {
+				require.Equal(t, moderation.Roles.Guests.Value, true)
+				require.Equal(t, moderation.Roles.Guests.Enabled, true)
+			}
+
+			require.Equal(t, moderation.Roles.Members.Value, true)
+			require.Equal(t, moderation.Roles.Members.Enabled, true)
+		}
+
+		channel, _ = th.App.GetChannel(channel.Id)
+		require.Nil(t, channel.SchemeId)
+
+		scheme, _ = th.App.GetScheme(*schemeId)
+		require.NotEqual(t, scheme.DeleteAt, int64(0))
+	})
+
+}

app/app_iface.go

@@ -461,6 +461,7 @@ type AppIface interface {
 	GetChannelMembersForUserWithPagination(teamId, userId string, page, perPage int) ([]*model.ChannelMember, *model.AppError)
 	GetChannelMembersPage(channelId string, page, perPage int) (*model.ChannelMembers, *model.AppError)
 	GetChannelMembersTimezones(channelId string) ([]string, *model.AppError)
+	GetChannelModerationsForChannel(channel *model.Channel) ([]*model.ChannelModeration, *model.AppError)
 	GetChannelPinnedPostCount(channelId string) (int64, *model.AppError)
 	GetChannelUnread(channelId, userId string) (*model.ChannelUnread, *model.AppError)
 	GetChannelsByNames(channelNames []string, teamId string) ([]*model.Channel, *model.AppError)
@@ -715,6 +716,7 @@ type AppIface interface {
 	OpenInteractiveDialog(request model.OpenDialogRequest) *model.AppError
 	OriginChecker() func(*http.Request) bool
 	PatchChannel(channel *model.Channel, patch *model.ChannelPatch, userId string) (*model.Channel, *model.AppError)
+	PatchChannelModerationsForChannel(channel *model.Channel, channelModerationsPatch []*model.ChannelModerationPatch) ([]*model.ChannelModeration, *model.AppError)
 	PatchPost(postId string, patch *model.PostPatch) (*model.Post, *model.AppError)
 	PatchRole(role *model.Role, patch *model.RolePatch) (*model.Role, *model.AppError)
 	PatchScheme(scheme *model.Scheme, patch *model.SchemePatch) (*model.Scheme, *model.AppError)

app/channel.go

@@ -547,6 +547,34 @@ func (a *App) UpdateChannel(channel *model.Channel) (*model.Channel, *model.AppE
 	return channel, nil
 }
 
+// CreateChannelScheme creates a new Scheme of scope channel and assigns it to the channel.
+func (a *App) CreateChannelScheme(channel *model.Channel) (*model.Scheme, *model.AppError) {
+	scheme, err := a.CreateScheme(&model.Scheme{
+		Name:        model.NewId(),
+		DisplayName: model.NewId(),
+		Scope:       model.SCHEME_SCOPE_CHANNEL,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	channel.SchemeId = &scheme.Id
+	if _, err := a.UpdateChannelScheme(channel); err != nil {
+		return nil, err
+	}
+	return scheme, nil
+}
+
+// DeleteChannelScheme deletes a channels scheme and sets its SchemeId to nil.
+func (a *App) DeleteChannelScheme(channel *model.Channel) (*model.Channel, *model.AppError) {
+	if _, err := a.DeleteScheme(*channel.SchemeId); err != nil {
+		return nil, err
+	}
+	channel.SchemeId = nil
+	return a.UpdateChannelScheme(channel)
+}
+
+// UpdateChannelScheme saves the new SchemeId of the channel passed.
 func (a *App) UpdateChannelScheme(channel *model.Channel) (*model.Channel, *model.AppError) {
 	var oldChannel *model.Channel
 	var err *model.AppError
@@ -555,13 +583,7 @@ func (a *App) UpdateChannelScheme(channel *model.Channel) (*model.Channel, *mode
 	}
 
 	oldChannel.SchemeId = channel.SchemeId
-
+	return a.UpdateChannel(oldChannel)
-	newChannel, err := a.UpdateChannel(oldChannel)
-	if err != nil {
-		return nil, err
-	}
-
-	return newChannel, nil
 }
 
 func (a *App) UpdateChannelPrivacy(oldChannel *model.Channel, user *model.User) (*model.Channel, *model.AppError) {
@@ -685,35 +707,185 @@ func (a *App) PatchChannel(channel *model.Channel, patch *model.ChannelPatch, us
 	return channel, nil
 }
 
-func (a *App) GetSchemeRolesForChannel(channelId string) (string, string, string, *model.AppError) {
+// GetSchemeRolesForChannel Checks if a channel or its team has an override scheme for channel roles and returns the scheme roles or default channel roles.
+func (a *App) GetSchemeRolesForChannel(channelId string) (guestRoleName, userRoleName, adminRoleName string, err *model.AppError) {
 	channel, err := a.GetChannel(channelId)
 	if err != nil {
-		return "", "", "", err
+		return
 	}
 
 	if channel.SchemeId != nil && len(*channel.SchemeId) != 0 {
 		var scheme *model.Scheme
 		scheme, err = a.GetScheme(*channel.SchemeId)
 		if err != nil {
-			return "", "", "", err
+			return
 		}
-		return scheme.DefaultChannelGuestRole, scheme.DefaultChannelUserRole, scheme.DefaultChannelAdminRole, nil
+
+		guestRoleName = scheme.DefaultChannelGuestRole
+		userRoleName = scheme.DefaultChannelUserRole
+		adminRoleName = scheme.DefaultChannelAdminRole
+
+		return
 	}
 
-	team, err := a.GetTeam(channel.TeamId)
+	return a.GetTeamSchemeChannelRoles(channel.TeamId)
+}
+
+// GetTeamSchemeChannelRoles Checks if a team has an override scheme and returns the scheme channel role names or default channel role names.
+func (a *App) GetTeamSchemeChannelRoles(teamId string) (guestRoleName, userRoleName, adminRoleName string, err *model.AppError) {
+	team, err := a.GetTeam(teamId)
 	if err != nil {
-		return "", "", "", err
+		return
 	}
 
 	if team.SchemeId != nil && len(*team.SchemeId) != 0 {
-		scheme, err := a.GetScheme(*team.SchemeId)
+		var scheme *model.Scheme
+		scheme, err = a.GetScheme(*team.SchemeId)
 		if err != nil {
-			return "", "", "", err
+			return
 		}
-		return scheme.DefaultChannelGuestRole, scheme.DefaultChannelUserRole, scheme.DefaultChannelAdminRole, nil
+
+		guestRoleName = scheme.DefaultChannelGuestRole
+		userRoleName = scheme.DefaultChannelUserRole
+		adminRoleName = scheme.DefaultChannelAdminRole
+	} else {
+		guestRoleName = model.CHANNEL_GUEST_ROLE_ID
+		userRoleName = model.CHANNEL_USER_ROLE_ID
+		adminRoleName = model.CHANNEL_ADMIN_ROLE_ID
 	}
 
-	return model.CHANNEL_GUEST_ROLE_ID, model.CHANNEL_USER_ROLE_ID, model.CHANNEL_ADMIN_ROLE_ID, nil
+	return
+}
+
+// PatchChannelModerationsForChannel Gets a channels ChannelModerations from either the higherScoped roles or from the channel scheme roles.
+func (a *App) GetChannelModerationsForChannel(channel *model.Channel) ([]*model.ChannelModeration, *model.AppError) {
+	guestRoleName, memberRoleName, _, _ := a.GetSchemeRolesForChannel(channel.Id)
+	memberRole, err := a.GetRoleByName(memberRoleName)
+	if err != nil {
+		return nil, err
+	}
+
+	guestRole, err := a.GetRoleByName(guestRoleName)
+	if err != nil {
+		return nil, err
+	}
+
+	higherScopedGuestRoleName, higherScopedMemberRoleName, _, _ := a.GetTeamSchemeChannelRoles(channel.TeamId)
+	higherScopedMemberRole, err := a.GetRoleByName(higherScopedMemberRoleName)
+	if err != nil {
+		return nil, err
+	}
+
+	higherScopedGuestRole, err := a.GetRoleByName(higherScopedGuestRoleName)
+	if err != nil {
+		return nil, err
+	}
+
+	return buildChannelModerations(memberRole, guestRole, higherScopedMemberRole, higherScopedGuestRole), nil
+}
+
+// PatchChannelModerationsForChannel Updates a channels scheme roles based on a given ChannelModerationPatch, if the permissions match the higher scoped role the scheme is deleted.
+func (a *App) PatchChannelModerationsForChannel(channel *model.Channel, channelModerationsPatch []*model.ChannelModerationPatch) ([]*model.ChannelModeration, *model.AppError) {
+	higherScopedGuestRoleName, higherScopedMemberRoleName, _, _ := a.GetTeamSchemeChannelRoles(channel.TeamId)
+	higherScopedMemberRole, err := a.GetRoleByName(higherScopedMemberRoleName)
+	if err != nil {
+		return nil, err
+	}
+
+	higherScopedGuestRole, err := a.GetRoleByName(higherScopedGuestRoleName)
+	if err != nil {
+		return nil, err
+	}
+
+	higherScopedMemberPermissions := higherScopedMemberRole.GetChannelModeratedPermissions()
+	higherScopedGuestPermissions := higherScopedGuestRole.GetChannelModeratedPermissions()
+
+	for _, moderationPatch := range channelModerationsPatch {
+		if moderationPatch.Roles.Members != nil && *moderationPatch.Roles.Members && !higherScopedMemberPermissions[*moderationPatch.Name] {
+			return nil, &model.AppError{Message: "Cannot add a permission that is restricted by the team or system permission scheme"}
+		}
+		if moderationPatch.Roles.Guests != nil && *moderationPatch.Roles.Guests && !higherScopedGuestPermissions[*moderationPatch.Name] {
+			return nil, &model.AppError{Message: "Cannot add a permission that is restricted by the team or system permission scheme"}
+		}
+	}
+
+	// Channel has no scheme so create one
+	if channel.SchemeId == nil || len(*channel.SchemeId) == 0 {
+		if _, err = a.CreateChannelScheme(channel); err != nil {
+			return nil, err
+		}
+	}
+
+	guestRoleName, memberRoleName, _, _ := a.GetSchemeRolesForChannel(channel.Id)
+	memberRole, err := a.GetRoleByName(memberRoleName)
+	if err != nil {
+		return nil, err
+	}
+
+	guestRole, err := a.GetRoleByName(guestRoleName)
+	if err != nil {
+		return nil, err
+	}
+
+	memberRolePatch := memberRole.RolePatchFromChannelModerationsPatch(channelModerationsPatch, "members")
+	guestRolePatch := guestRole.RolePatchFromChannelModerationsPatch(channelModerationsPatch, "guests")
+
+	memberRolePermissionsUnmodified := len(model.ChannelModeratedPermissionsChangedByPatch(higherScopedMemberRole, memberRolePatch)) == 0
+	guestRolePermissionsUnmodified := len(model.ChannelModeratedPermissionsChangedByPatch(higherScopedGuestRole, guestRolePatch)) == 0
+	if memberRolePermissionsUnmodified && guestRolePermissionsUnmodified {
+		// The channel scheme matches the permissions of its higherScoped scheme so delete the scheme
+		if _, err = a.DeleteChannelScheme(channel); err != nil {
+			return nil, err
+		}
+		memberRole = higherScopedMemberRole
+		guestRole = higherScopedGuestRole
+	} else {
+		memberRole, err = a.PatchRole(memberRole, memberRolePatch)
+		if err != nil {
+			return nil, err
+		}
+		guestRole, err = a.PatchRole(guestRole, guestRolePatch)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return buildChannelModerations(memberRole, guestRole, higherScopedMemberRole, higherScopedGuestRole), nil
+}
+
+func buildChannelModerations(memberRole *model.Role, guestRole *model.Role, higherScopedMemberRole *model.Role, higherScopedGuestRole *model.Role) []*model.ChannelModeration {
+	memberPermissions := memberRole.GetChannelModeratedPermissions()
+	guestPermissions := guestRole.GetChannelModeratedPermissions()
+	higherScopedMemberPermissions := higherScopedMemberRole.GetChannelModeratedPermissions()
+	higherScopedGuestPermissions := higherScopedGuestRole.GetChannelModeratedPermissions()
+
+	var channelModerations []*model.ChannelModeration
+	for _, permissionKey := range model.CHANNEL_MODERATED_PERMISSIONS {
+		roles := &model.ChannelModeratedRoles{}
+
+		roles.Members = &model.ChannelModeratedRole{
+			Value:   memberPermissions[permissionKey],
+			Enabled: higherScopedMemberPermissions[permissionKey],
+		}
+
+		if permissionKey == "manage_members" {
+			roles.Guests = nil
+		} else {
+			roles.Guests = &model.ChannelModeratedRole{
+				Value:   guestPermissions[permissionKey],
+				Enabled: higherScopedGuestPermissions[permissionKey],
+			}
+		}
+
+		moderation := &model.ChannelModeration{
+			Name:  permissionKey,
+			Roles: roles,
+		}
+
+		channelModerations = append(channelModerations, moderation)
+	}
+
+	return channelModerations
 }
 
 func (a *App) UpdateChannelMemberRoles(channelId string, userId string, newRoles string) (*model.ChannelMember, *model.AppError) {

app/channel_test.go

@@ -1301,3 +1301,350 @@ func TestRemoveUserFromChannel(t *testing.T) {
 	err = th.App.RemoveUserFromChannel(botUser.Id, th.SystemAdminUser.Id, privateChannel)
 	require.Nil(t, err)
 }
+
+func TestPatchChannelModerationsForChannel(t *testing.T) {
+	th := Setup(t).InitBasic()
+	defer th.TearDown()
+
+	th.App.SetPhase2PermissionsMigrationStatus(true)
+	channel := th.BasicChannel
+
+	createPosts := model.CHANNEL_MODERATED_PERMISSIONS[0]
+	createReactions := model.CHANNEL_MODERATED_PERMISSIONS[1]
+	manageMembers := model.CHANNEL_MODERATED_PERMISSIONS[2]
+	channelMentions := model.CHANNEL_MODERATED_PERMISSIONS[3]
+
+	nonChannelModeratedPermission := model.PERMISSION_CREATE_BOT.Id
+
+	testCases := []struct {
+		Name                          string
+		ChannelModerationsPatch       []*model.ChannelModerationPatch
+		PermissionsModeratedByPatch   map[string]*model.ChannelModeratedRoles
+		RevertChannelModerationsPatch []*model.ChannelModerationPatch
+		HigherScopedMemberPermissions []string
+		HigherScopedGuestPermissions  []string
+		ShouldError                   bool
+		ShouldHaveNoChannelScheme     bool
+	}{
+		{
+			Name: "Removing create posts from members role",
+			ChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &createPosts,
+					Roles: &model.ChannelModeratedRolesPatch{Members: model.NewBool(false)},
+				},
+			},
+			PermissionsModeratedByPatch: map[string]*model.ChannelModeratedRoles{
+				createPosts: {
+					Members: &model.ChannelModeratedRole{Value: false, Enabled: true},
+				},
+			},
+			RevertChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &createPosts,
+					Roles: &model.ChannelModeratedRolesPatch{Members: model.NewBool(true)},
+				},
+			},
+		},
+		{
+			Name: "Removing create reactions from members role",
+			ChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &createReactions,
+					Roles: &model.ChannelModeratedRolesPatch{Members: model.NewBool(false)},
+				},
+			},
+			PermissionsModeratedByPatch: map[string]*model.ChannelModeratedRoles{
+				createReactions: {
+					Members: &model.ChannelModeratedRole{Value: false, Enabled: true},
+				},
+			},
+			RevertChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &createReactions,
+					Roles: &model.ChannelModeratedRolesPatch{Members: model.NewBool(true)},
+				},
+			},
+		},
+		{
+			Name: "Removing channel mentions from members role",
+			ChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &channelMentions,
+					Roles: &model.ChannelModeratedRolesPatch{Members: model.NewBool(false)},
+				},
+			},
+			PermissionsModeratedByPatch: map[string]*model.ChannelModeratedRoles{
+				channelMentions: {
+					Members: &model.ChannelModeratedRole{Value: false, Enabled: true},
+				},
+			},
+			RevertChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &channelMentions,
+					Roles: &model.ChannelModeratedRolesPatch{Members: model.NewBool(true)},
+				},
+			},
+		},
+		{
+			Name: "Removing manage members from members role",
+			ChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &manageMembers,
+					Roles: &model.ChannelModeratedRolesPatch{Members: model.NewBool(false)},
+				},
+			},
+			PermissionsModeratedByPatch: map[string]*model.ChannelModeratedRoles{
+				manageMembers: {
+					Members: &model.ChannelModeratedRole{Value: false, Enabled: true},
+				},
+			},
+			RevertChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &manageMembers,
+					Roles: &model.ChannelModeratedRolesPatch{Members: model.NewBool(true)},
+				},
+			},
+		},
+		{
+			Name: "Removing create posts from guests role",
+			ChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &createPosts,
+					Roles: &model.ChannelModeratedRolesPatch{Guests: model.NewBool(false)},
+				},
+			},
+			PermissionsModeratedByPatch: map[string]*model.ChannelModeratedRoles{
+				createPosts: {
+					Guests: &model.ChannelModeratedRole{Value: false, Enabled: true},
+				},
+			},
+			RevertChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &createPosts,
+					Roles: &model.ChannelModeratedRolesPatch{Guests: model.NewBool(true)},
+				},
+			},
+		},
+		{
+			Name: "Removing create reactions from guests role",
+			ChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &createReactions,
+					Roles: &model.ChannelModeratedRolesPatch{Guests: model.NewBool(false)},
+				},
+			},
+			PermissionsModeratedByPatch: map[string]*model.ChannelModeratedRoles{
+				createReactions: {
+					Guests: &model.ChannelModeratedRole{Value: false, Enabled: true},
+				},
+			},
+			RevertChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &createReactions,
+					Roles: &model.ChannelModeratedRolesPatch{Guests: model.NewBool(true)},
+				},
+			},
+		},
+		{
+			Name: "Removing channel mentions from guests role",
+			ChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &channelMentions,
+					Roles: &model.ChannelModeratedRolesPatch{Guests: model.NewBool(false)},
+				},
+			},
+			PermissionsModeratedByPatch: map[string]*model.ChannelModeratedRoles{
+				channelMentions: {
+					Guests: &model.ChannelModeratedRole{Value: false, Enabled: true},
+				},
+			},
+			RevertChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &channelMentions,
+					Roles: &model.ChannelModeratedRolesPatch{Guests: model.NewBool(true)},
+				},
+			},
+		},
+		{
+			Name: "Removing manage members from guests role should error",
+			ChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name:  &manageMembers,
+					Roles: &model.ChannelModeratedRolesPatch{Guests: model.NewBool(false)},
+				},
+			},
+			PermissionsModeratedByPatch: map[string]*model.ChannelModeratedRoles{},
+			ShouldError:                 true,
+		},
+		{
+			Name: "Removing a permission that is not channel moderated should error",
+			ChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name: &nonChannelModeratedPermission,
+					Roles: &model.ChannelModeratedRolesPatch{
+						Members: model.NewBool(false),
+						Guests:  model.NewBool(false),
+					},
+				},
+			},
+			PermissionsModeratedByPatch: map[string]*model.ChannelModeratedRoles{},
+			ShouldError:                 true,
+		},
+		{
+			Name: "Error when adding a permission that is disabled in the parent member role",
+			ChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name: &createPosts,
+					Roles: &model.ChannelModeratedRolesPatch{
+						Members: model.NewBool(true),
+						Guests:  model.NewBool(false),
+					},
+				},
+			},
+			PermissionsModeratedByPatch:   map[string]*model.ChannelModeratedRoles{},
+			HigherScopedMemberPermissions: []string{},
+			ShouldError:                   true,
+		},
+		{
+			Name: "Error when adding a permission that is disabled in the parent guest role",
+			ChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name: &createPosts,
+					Roles: &model.ChannelModeratedRolesPatch{
+						Members: model.NewBool(false),
+						Guests:  model.NewBool(true),
+					},
+				},
+			},
+			PermissionsModeratedByPatch:  map[string]*model.ChannelModeratedRoles{},
+			HigherScopedGuestPermissions: []string{},
+			ShouldError:                  true,
+		},
+		{
+			Name: "Removing a permission from the member role that is disabled in the parent guest role",
+			ChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name: &createPosts,
+					Roles: &model.ChannelModeratedRolesPatch{
+						Members: model.NewBool(false),
+					},
+				},
+			},
+			PermissionsModeratedByPatch: map[string]*model.ChannelModeratedRoles{
+				createPosts: {
+					Members: &model.ChannelModeratedRole{Value: false, Enabled: true},
+					Guests:  &model.ChannelModeratedRole{Value: false, Enabled: false},
+				},
+				createReactions: {
+					Guests: &model.ChannelModeratedRole{Value: false, Enabled: false},
+				},
+				channelMentions: {
+					Guests: &model.ChannelModeratedRole{Value: false, Enabled: false},
+				},
+			},
+			HigherScopedGuestPermissions: []string{},
+			ShouldError:                  false,
+		},
+		{
+			Name: "Channel should have no scheme when all moderated permissions are equivalent to higher scoped role",
+			ChannelModerationsPatch: []*model.ChannelModerationPatch{
+				{
+					Name: &createPosts,
+					Roles: &model.ChannelModeratedRolesPatch{
+						Members: model.NewBool(true),
+						Guests:  model.NewBool(true),
+					},
+				},
+				{
+					Name: &createReactions,
+					Roles: &model.ChannelModeratedRolesPatch{
+						Members: model.NewBool(true),
+						Guests:  model.NewBool(true),
+					},
+				},
+				{
+					Name: &channelMentions,
+					Roles: &model.ChannelModeratedRolesPatch{
+						Members: model.NewBool(true),
+						Guests:  model.NewBool(true),
+					},
+				},
+				{
+					Name: &manageMembers,
+					Roles: &model.ChannelModeratedRolesPatch{
+						Members: model.NewBool(true),
+					},
+				},
+			},
+			PermissionsModeratedByPatch: map[string]*model.ChannelModeratedRoles{},
+			ShouldHaveNoChannelScheme:   true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.Name, func(t *testing.T) {
+			higherScopedPermissionsOverriden := tc.HigherScopedMemberPermissions != nil || tc.HigherScopedGuestPermissions != nil
+			// If the test case restricts higher scoped permissions.
+			if higherScopedPermissionsOverriden {
+				higherScopedGuestRoleName, higherScopedMemberRoleName, _, _ := th.App.GetTeamSchemeChannelRoles(channel.TeamId)
+				if tc.HigherScopedMemberPermissions != nil {
+					higherScopedMemberRole, err := th.App.GetRoleByName(higherScopedMemberRoleName)
+					require.Nil(t, err)
+					originalPermissions := higherScopedMemberRole.Permissions
+
+					th.App.PatchRole(higherScopedMemberRole, &model.RolePatch{Permissions: &tc.HigherScopedMemberPermissions})
+					defer th.App.PatchRole(higherScopedMemberRole, &model.RolePatch{Permissions: &originalPermissions})
+				}
+
+				if tc.HigherScopedGuestPermissions != nil {
+					higherScopedGuestRole, err := th.App.GetRoleByName(higherScopedGuestRoleName)
+					require.Nil(t, err)
+					originalPermissions := higherScopedGuestRole.Permissions
+
+					th.App.PatchRole(higherScopedGuestRole, &model.RolePatch{Permissions: &tc.HigherScopedGuestPermissions})
+					defer th.App.PatchRole(higherScopedGuestRole, &model.RolePatch{Permissions: &originalPermissions})
+				}
+			}
+
+			moderations, err := th.App.PatchChannelModerationsForChannel(channel, tc.ChannelModerationsPatch)
+			if tc.ShouldError {
+				require.Error(t, err)
+				return
+			}
+			require.Nil(t, err)
+
+			updatedChannel, _ := th.App.GetChannel(channel.Id)
+			if tc.ShouldHaveNoChannelScheme {
+				require.Nil(t, updatedChannel.SchemeId)
+			} else {
+				require.NotNil(t, updatedChannel.SchemeId)
+			}
+
+			for _, moderation := range moderations {
+				// If the permission is not found in the expected modified permissions table then require it to be true
+				if permission, found := tc.PermissionsModeratedByPatch[moderation.Name]; found && permission.Members != nil {
+					require.Equal(t, moderation.Roles.Members.Value, permission.Members.Value)
+					require.Equal(t, moderation.Roles.Members.Enabled, permission.Members.Enabled)
+				} else {
+					require.Equal(t, moderation.Roles.Members.Value, true)
+					require.Equal(t, moderation.Roles.Members.Enabled, true)
+				}
+
+				if permission, found := tc.PermissionsModeratedByPatch[moderation.Name]; found && permission.Guests != nil {
+					require.Equal(t, moderation.Roles.Guests.Value, permission.Guests.Value)
+					require.Equal(t, moderation.Roles.Guests.Enabled, permission.Guests.Enabled)
+				} else if moderation.Name == manageMembers {
+					require.Empty(t, moderation.Roles.Guests)
+				} else {
+					require.Equal(t, moderation.Roles.Guests.Value, true)
+					require.Equal(t, moderation.Roles.Guests.Enabled, true)
+				}
+			}
+
+			if tc.RevertChannelModerationsPatch != nil {
+				th.App.PatchChannelModerationsForChannel(channel, tc.RevertChannelModerationsPatch)
+			}
+		})
+	}
+}

i18n/en.json

@@ -299,6 +299,10 @@
     "id": "api.channel.delete_channel.type.invalid",
     "translation": "Unable to delete direct or group message channels"
   },
+  {
+    "id": "api.channel.get_channel_moderations.license.error",
+    "translation": "Your license does not support channel moderation"
+  },
   {
     "id": "api.channel.guest_join_channel.post_and_forget",
     "translation": "%v joined the channel as guest."
@@ -327,6 +331,10 @@
     "id": "api.channel.leave.left",
     "translation": "%v left the channel."
   },
+  {
+    "id": "api.channel.patch_channel_moderations.license.error",
+    "translation": "Your license does not support channel moderation"
+  },
   {
     "id": "api.channel.patch_update_channel.forbidden.app_error",
     "translation": "Failed to update the channel."

model/channel.go

@@ -84,6 +84,31 @@ type DirectChannelForExport struct {
 	Members *[]string
 }
 
+type ChannelModeration struct {
+	Name  string                 `json:"name"`
+	Roles *ChannelModeratedRoles `json:"roles"`
+}
+
+type ChannelModeratedRoles struct {
+	Guests  *ChannelModeratedRole `json:"guests"`
+	Members *ChannelModeratedRole `json:"members"`
+}
+
+type ChannelModeratedRole struct {
+	Value   bool `json:"value"`
+	Enabled bool `json:"enabled"`
+}
+
+type ChannelModerationPatch struct {
+	Name  *string                     `json:"name"`
+	Roles *ChannelModeratedRolesPatch `json:"roles"`
+}
+
+type ChannelModeratedRolesPatch struct {
+	Guests  *bool `json:"guests"`
+	Members *bool `json:"members"`
+}
+
 // ChannelSearchOpts contains options for searching channels.
 //
 // NotAssociatedToGroup will exclude channels that have associated, active GroupChannels records.
@@ -144,6 +169,18 @@ func ChannelPatchFromJson(data io.Reader) *ChannelPatch {
 	return o
 }
 
+func ChannelModerationsFromJson(data io.Reader) []*ChannelModeration {
+	var o []*ChannelModeration
+	json.NewDecoder(data).Decode(&o)
+	return o
+}
+
+func ChannelModerationsPatchFromJson(data io.Reader) []*ChannelModerationPatch {
+	var o []*ChannelModerationPatch
+	json.NewDecoder(data).Decode(&o)
+	return o
+}
+
 func (o *Channel) Etag() string {
 	return Etag(o.Id, o.UpdateAt)
 }

model/client4.go

@@ -4912,3 +4912,22 @@ func (c *Client4) PatchConfig(config *Config) (*Config, *Response) {
 	defer closeBody(r)
 	return ConfigFromJson(r.Body), BuildResponse(r)
 }
+
+func (c *Client4) GetChannelModerations(channelID string, etag string) ([]*ChannelModeration, *Response) {
+	r, err := c.DoApiGet(c.GetChannelRoute(channelID)+"/moderations", etag)
+	if err != nil {
+		return nil, BuildErrorResponse(r, err)
+	}
+	defer closeBody(r)
+	return ChannelModerationsFromJson(r.Body), BuildResponse(r)
+}
+
+func (c *Client4) PatchChannelModerations(channelID string, patch []*ChannelModerationPatch) ([]*ChannelModeration, *Response) {
+	payload, _ := json.Marshal(patch)
+	r, err := c.DoApiPut(c.GetChannelRoute(channelID)+"/moderations/patch", string(payload))
+	if err != nil {
+		return nil, BuildErrorResponse(r, err)
+	}
+	defer closeBody(r)
+	return ChannelModerationsFromJson(r.Body), BuildResponse(r)
+}

model/permission.go

@@ -99,6 +99,9 @@ var PERMISSION_MANAGE_SYSTEM *Permission
 
 var ALL_PERMISSIONS []*Permission
 
+var CHANNEL_MODERATED_PERMISSIONS []string
+var CHANNEL_MODERATED_PERMISSIONS_MAP map[string]string
+
 func initializePermissions() {
 	PERMISSION_INVITE_USER = &Permission{
 		"invite_user",
@@ -641,6 +644,22 @@ func initializePermissions() {
 		PERMISSION_DEMOTE_TO_GUEST,
 		PERMISSION_USE_CHANNEL_MENTIONS,
 	}
+
+	CHANNEL_MODERATED_PERMISSIONS = []string{
+		PERMISSION_CREATE_POST.Id,
+		"create_reactions",
+		"manage_members",
+		PERMISSION_USE_CHANNEL_MENTIONS.Id,
+	}
+
+	CHANNEL_MODERATED_PERMISSIONS_MAP = map[string]string{
+		PERMISSION_CREATE_POST.Id:                    CHANNEL_MODERATED_PERMISSIONS[0],
+		PERMISSION_ADD_REACTION.Id:                   CHANNEL_MODERATED_PERMISSIONS[1],
+		PERMISSION_REMOVE_REACTION.Id:                CHANNEL_MODERATED_PERMISSIONS[1],
+		PERMISSION_MANAGE_PUBLIC_CHANNEL_MEMBERS.Id:  CHANNEL_MODERATED_PERMISSIONS[2],
+		PERMISSION_MANAGE_PRIVATE_CHANNEL_MEMBERS.Id: CHANNEL_MODERATED_PERMISSIONS[2],
+		PERMISSION_USE_CHANNEL_MENTIONS.Id:           CHANNEL_MODERATED_PERMISSIONS[3],
+	}
 }
 
 func init() {

model/role.go

@@ -123,6 +123,115 @@ func PermissionsChangedByPatch(role *Role, patch *RolePatch) []string {
 	return result
 }
 
+func ChannelModeratedPermissionsChangedByPatch(role *Role, patch *RolePatch) []string {
+	var result []string
+
+	if patch.Permissions == nil {
+		return result
+	}
+
+	roleMap := make(map[string]bool)
+	patchMap := make(map[string]bool)
+
+	for _, permission := range role.Permissions {
+		if channelModeratedPermissionName, found := CHANNEL_MODERATED_PERMISSIONS_MAP[permission]; found {
+			roleMap[channelModeratedPermissionName] = true
+		}
+	}
+
+	for _, permission := range *patch.Permissions {
+		if channelModeratedPermissionName, found := CHANNEL_MODERATED_PERMISSIONS_MAP[permission]; found {
+			patchMap[channelModeratedPermissionName] = true
+		}
+	}
+
+	for permissionKey := range roleMap {
+		if !patchMap[permissionKey] {
+			result = append(result, permissionKey)
+		}
+	}
+
+	for permissionKey := range patchMap {
+		if !roleMap[permissionKey] {
+			result = append(result, permissionKey)
+		}
+	}
+
+	return result
+}
+
+// GetChannelModeratedPermissions returns a map of channel moderated permissions that the role has access to
+func (r *Role) GetChannelModeratedPermissions() map[string]bool {
+	moderatedPermissions := make(map[string]bool)
+	for _, permission := range r.Permissions {
+		if _, found := CHANNEL_MODERATED_PERMISSIONS_MAP[permission]; !found {
+			continue
+		}
+
+		for moderated, moderatedPermissionValue := range CHANNEL_MODERATED_PERMISSIONS_MAP {
+			if moderated == permission {
+				moderatedPermissions[moderatedPermissionValue] = true
+			}
+		}
+	}
+
+	return moderatedPermissions
+}
+
+// RolePatchFromChannelModerationsPatch Creates and returns a RolePatch based on a slice of ChannelModerationPatchs, roleName is expected to be either "members" or "guests".
+func (r *Role) RolePatchFromChannelModerationsPatch(channelModerationsPatch []*ChannelModerationPatch, roleName string) *RolePatch {
+	permissionsToAddToPatch := make(map[string]bool)
+
+	// Iterate through the list of existing permissions on the role and append permissions that we want to keep.
+	for _, permission := range r.Permissions {
+		// Permission is not moderated so dont add it to the patch and skip the channelModerationsPatch
+		if _, isModerated := CHANNEL_MODERATED_PERMISSIONS_MAP[permission]; !isModerated {
+			continue
+		}
+
+		permissionEnabled := true
+		// Check if permission has a matching moderated permission name inside the channel moderation patch
+		for _, channelModerationPatch := range channelModerationsPatch {
+			if *channelModerationPatch.Name == CHANNEL_MODERATED_PERMISSIONS_MAP[permission] {
+				// Permission key exists in patch with a value of false so skip over it
+				if roleName == "members" {
+					if channelModerationPatch.Roles.Members != nil && !*channelModerationPatch.Roles.Members {
+						permissionEnabled = false
+					}
+				} else if roleName == "guests" {
+					if channelModerationPatch.Roles.Guests != nil && !*channelModerationPatch.Roles.Guests {
+						permissionEnabled = false
+					}
+				}
+			}
+		}
+
+		if permissionEnabled {
+			permissionsToAddToPatch[permission] = true
+		}
+	}
+
+	// Iterate through the patch and add any permissions that dont already exist on the role
+	for _, channelModerationPatch := range channelModerationsPatch {
+		for permission, moderatedPermissionName := range CHANNEL_MODERATED_PERMISSIONS_MAP {
+			if roleName == "members" && channelModerationPatch.Roles.Members != nil && *channelModerationPatch.Roles.Members && *channelModerationPatch.Name == moderatedPermissionName {
+				permissionsToAddToPatch[permission] = true
+			}
+
+			if roleName == "guests" && channelModerationPatch.Roles.Guests != nil && *channelModerationPatch.Roles.Guests && *channelModerationPatch.Name == moderatedPermissionName {
+				permissionsToAddToPatch[permission] = true
+			}
+		}
+	}
+
+	patchPermissions := make([]string, 0, len(permissionsToAddToPatch))
+	for permission := range permissionsToAddToPatch {
+		patchPermissions = append(patchPermissions, permission)
+	}
+
+	return &RolePatch{Permissions: &patchPermissions}
+}
+
 func (r *Role) IsValid() bool {
 	if len(r.Id) != 26 {
 		return false

model/role_test.go

@@ -0,0 +1,273 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestChannelModeratedPermissionsChangedByPatch(t *testing.T) {
+	testCases := []struct {
+		Name             string
+		Permissions      []string
+		PatchPermissions []string
+		Expected         []string
+	}{
+		{
+			"Empty patch returns empty slice",
+			[]string{},
+			[]string{},
+			[]string{},
+		},
+		{
+			"Adds permissions to empty initial permissions list",
+			[]string{},
+			[]string{PERMISSION_CREATE_POST.Id, PERMISSION_ADD_REACTION.Id},
+			[]string{CHANNEL_MODERATED_PERMISSIONS[0], CHANNEL_MODERATED_PERMISSIONS[1]},
+		},
+		{
+			"Ignores non moderated permissions in initial permissions list",
+			[]string{PERMISSION_ASSIGN_BOT.Id},
+			[]string{PERMISSION_CREATE_POST.Id, PERMISSION_REMOVE_REACTION.Id},
+			[]string{CHANNEL_MODERATED_PERMISSIONS[0], CHANNEL_MODERATED_PERMISSIONS[1]},
+		},
+		{
+			"Adds removed moderated permissions from initial permissions list",
+			[]string{PERMISSION_CREATE_POST.Id},
+			[]string{},
+			[]string{PERMISSION_CREATE_POST.Id},
+		},
+		{
+			"No changes returns empty slice",
+			[]string{PERMISSION_CREATE_POST.Id, PERMISSION_ASSIGN_BOT.Id},
+			[]string{PERMISSION_CREATE_POST.Id},
+			[]string{},
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.Name, func(t *testing.T) {
+			baseRole := &Role{Permissions: tc.Permissions}
+			rolePatch := &RolePatch{Permissions: &tc.PatchPermissions}
+			result := ChannelModeratedPermissionsChangedByPatch(baseRole, rolePatch)
+			assert.ElementsMatch(t, tc.Expected, result)
+		})
+	}
+}
+
+func TestRolePatchFromChannelModerationsPatch(t *testing.T) {
+	createPosts := CHANNEL_MODERATED_PERMISSIONS[0]
+	createReactions := CHANNEL_MODERATED_PERMISSIONS[1]
+	manageMembers := CHANNEL_MODERATED_PERMISSIONS[2]
+	channelMentions := CHANNEL_MODERATED_PERMISSIONS[3]
+
+	basePermissions := []string{
+		PERMISSION_ADD_REACTION.Id,
+		PERMISSION_REMOVE_REACTION.Id,
+		PERMISSION_CREATE_POST.Id,
+		PERMISSION_USE_CHANNEL_MENTIONS.Id,
+		PERMISSION_MANAGE_PUBLIC_CHANNEL_MEMBERS.Id,
+		PERMISSION_UPLOAD_FILE.Id,
+		PERMISSION_GET_PUBLIC_LINK.Id,
+		PERMISSION_USE_SLASH_COMMANDS.Id,
+	}
+
+	baseModeratedPermissions := []string{
+		PERMISSION_ADD_REACTION.Id,
+		PERMISSION_REMOVE_REACTION.Id,
+		PERMISSION_CREATE_POST.Id,
+		PERMISSION_MANAGE_PUBLIC_CHANNEL_MEMBERS.Id,
+		PERMISSION_USE_CHANNEL_MENTIONS.Id,
+	}
+
+	testCases := []struct {
+		Name                     string
+		Permissions              []string
+		ChannelModerationsPatch  []*ChannelModerationPatch
+		RoleName                 string
+		ExpectedPatchPermissions []string
+	}{
+		{
+			"Patch to member role adding a permission that already exists",
+			basePermissions,
+			[]*ChannelModerationPatch{
+				{
+					Name:  &createReactions,
+					Roles: &ChannelModeratedRolesPatch{Members: NewBool(true)},
+				},
+			},
+			"members",
+			baseModeratedPermissions,
+		},
+		{
+			"Patch to member role with moderation patch for guest role",
+			basePermissions,
+			[]*ChannelModerationPatch{
+				{
+					Name:  &createReactions,
+					Roles: &ChannelModeratedRolesPatch{Guests: NewBool(true)},
+				},
+			},
+			"members",
+			baseModeratedPermissions,
+		},
+		{
+			"Patch to guest role with moderation patch for member role",
+			basePermissions,
+			[]*ChannelModerationPatch{
+				{
+					Name:  &createReactions,
+					Roles: &ChannelModeratedRolesPatch{Members: NewBool(true)},
+				},
+			},
+			"guests",
+			baseModeratedPermissions,
+		},
+		{
+			"Patch to member role removing multiple channel moderated permissions",
+			basePermissions,
+			[]*ChannelModerationPatch{
+				{
+					Name:  &createReactions,
+					Roles: &ChannelModeratedRolesPatch{Members: NewBool(false)},
+				},
+				{
+					Name:  &manageMembers,
+					Roles: &ChannelModeratedRolesPatch{Members: NewBool(false)},
+				},
+				{
+					Name:  &channelMentions,
+					Roles: &ChannelModeratedRolesPatch{Members: NewBool(false)},
+				},
+			},
+			"members",
+			[]string{PERMISSION_CREATE_POST.Id},
+		},
+		{
+			"Patch to guest role removing multiple channel moderated permissions",
+			basePermissions,
+			[]*ChannelModerationPatch{
+				{
+					Name:  &createReactions,
+					Roles: &ChannelModeratedRolesPatch{Guests: NewBool(false)},
+				},
+				{
+					Name:  &manageMembers,
+					Roles: &ChannelModeratedRolesPatch{Guests: NewBool(false)},
+				},
+				{
+					Name:  &channelMentions,
+					Roles: &ChannelModeratedRolesPatch{Guests: NewBool(false)},
+				},
+			},
+			"guests",
+			[]string{PERMISSION_CREATE_POST.Id},
+		},
+		{
+			"Patch enabling and removing multiple channel moderated permissions ",
+			[]string{PERMISSION_ADD_REACTION.Id, PERMISSION_MANAGE_PUBLIC_CHANNEL_MEMBERS.Id},
+			[]*ChannelModerationPatch{
+				{
+					Name:  &createReactions,
+					Roles: &ChannelModeratedRolesPatch{Members: NewBool(false)},
+				},
+				{
+					Name:  &manageMembers,
+					Roles: &ChannelModeratedRolesPatch{Members: NewBool(false)},
+				},
+				{
+					Name:  &channelMentions,
+					Roles: &ChannelModeratedRolesPatch{Members: NewBool(true)},
+				},
+				{
+					Name:  &createPosts,
+					Roles: &ChannelModeratedRolesPatch{Members: NewBool(true)},
+				},
+			},
+			"members",
+			[]string{PERMISSION_CREATE_POST.Id, PERMISSION_USE_CHANNEL_MENTIONS.Id},
+		},
+		{
+			"Patch enabling a partially enabled permission",
+			[]string{PERMISSION_ADD_REACTION.Id},
+			[]*ChannelModerationPatch{
+				{
+					Name:  &createReactions,
+					Roles: &ChannelModeratedRolesPatch{Members: NewBool(true)},
+				},
+			},
+			"members",
+			[]string{PERMISSION_ADD_REACTION.Id, PERMISSION_REMOVE_REACTION.Id},
+		},
+		{
+			"Patch disabling a partially disabled permission",
+			[]string{PERMISSION_ADD_REACTION.Id},
+			[]*ChannelModerationPatch{
+				{
+					Name:  &createReactions,
+					Roles: &ChannelModeratedRolesPatch{Members: NewBool(false)},
+				},
+				{
+					Name:  &createPosts,
+					Roles: &ChannelModeratedRolesPatch{Members: NewBool(true)},
+				},
+			},
+			"members",
+			[]string{PERMISSION_CREATE_POST.Id},
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.Name, func(t *testing.T) {
+			baseRole := &Role{Permissions: tc.Permissions}
+			rolePatch := baseRole.RolePatchFromChannelModerationsPatch(tc.ChannelModerationsPatch, tc.RoleName)
+			assert.ElementsMatch(t, tc.ExpectedPatchPermissions, *rolePatch.Permissions)
+		})
+	}
+}
+
+func TestGetChannelModeratedPermissions(t *testing.T) {
+	tests := []struct {
+		Name        string
+		Permissions []string
+		Expected    map[string]bool
+	}{
+		{
+			"Filters non moderated permissions",
+			[]string{PERMISSION_CREATE_BOT.Id},
+			map[string]bool{},
+		},
+		{
+			"Returns a map of moderated permissions",
+			[]string{PERMISSION_CREATE_POST.Id, PERMISSION_ADD_REACTION.Id, PERMISSION_REMOVE_REACTION.Id, PERMISSION_MANAGE_PUBLIC_CHANNEL_MEMBERS.Id, PERMISSION_MANAGE_PRIVATE_CHANNEL_MEMBERS.Id, PERMISSION_USE_CHANNEL_MENTIONS.Id},
+			map[string]bool{
+				CHANNEL_MODERATED_PERMISSIONS[0]: true,
+				CHANNEL_MODERATED_PERMISSIONS[1]: true,
+				CHANNEL_MODERATED_PERMISSIONS[2]: true,
+				CHANNEL_MODERATED_PERMISSIONS[3]: true,
+			},
+		},
+		{
+			"Returns a map of moderated permissions when non moderated present",
+			[]string{PERMISSION_CREATE_POST.Id, PERMISSION_CREATE_DIRECT_CHANNEL.Id},
+			map[string]bool{
+				CHANNEL_MODERATED_PERMISSIONS[0]: true,
+			},
+		},
+		{
+			"Returns a nothing when no permissions present",
+			[]string{},
+			map[string]bool{},
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.Name, func(t *testing.T) {
+			role := &Role{Permissions: tc.Permissions}
+			moderatedPermissions := role.GetChannelModeratedPermissions()
+			for permission := range moderatedPermissions {
+				assert.Equal(t, moderatedPermissions[permission], tc.Expected[permission])
+			}
+		})
+	}
+}