XYZ-37: Advanced Permissions Phase 1 Backend. (#8159)

* XYZ-13: Update Permission and Role structs to new design.

* XYZ-10: Role store.

* XYZ-9/XYZ-44: Roles API endpoints and WebSocket message.

* XYZ-8: Switch server permissions checks to store backed roles.

* XYZ-58: Proper validation of roles where required.

* XYZ-11/XYZ-55: Migration to store backed roles from policy config.

* XYZ-37: Update unit tests to work with database roles.

* XYZ-56: Remove the "guest" role.

* Changes to SetDefaultRolesFromConfig.

* Short-circuit the store if nothing has changed.

* Address first round of review comments.

* Address second round of review comments.

app/role.go

@@ -1,19 +1,91 @@
-// Copyright (c) 2016-present Mattermost, Inc. All Rights Reserved.
+// Copyright (c) 2018-present Mattermost, Inc. All Rights Reserved.
 // See License.txt for license information.
 
 package app
 
 import (
+	"reflect"
+
 	"github.com/mattermost/mattermost-server/model"
-	"github.com/mattermost/mattermost-server/utils"
+	"net/http"
 )
 
-func (a *App) Role(id string) *model.Role {
-	return a.roles[id]
+func (a *App) GetRole(id string) (*model.Role, *model.AppError) {
+	if result := <-a.Srv.Store.Role().Get(id); result.Err != nil {
+		return nil, result.Err
+	} else {
+		return result.Data.(*model.Role), nil
+	}
 }
 
-// Updates the roles based on the app config and the global license check. You may need to invoke
-// this when license changes are made.
-func (a *App) SetDefaultRolesBasedOnConfig() {
-	a.roles = utils.DefaultRolesBasedOnConfig(a.Config())
+func (a *App) GetRoleByName(name string) (*model.Role, *model.AppError) {
+	if result := <-a.Srv.Store.Role().GetByName(name); result.Err != nil {
+		return nil, result.Err
+	} else {
+		return result.Data.(*model.Role), nil
+	}
+}
+
+func (a *App) GetRolesByNames(names []string) ([]*model.Role, *model.AppError) {
+	if result := <-a.Srv.Store.Role().GetByNames(names); result.Err != nil {
+		return nil, result.Err
+	} else {
+		return result.Data.([]*model.Role), nil
+	}
+}
+
+func (a *App) PatchRole(role *model.Role, patch *model.RolePatch) (*model.Role, *model.AppError) {
+	// If patch is a no-op then short-circuit the store.
+	if patch.Permissions != nil && reflect.DeepEqual(*patch.Permissions, role.Permissions) {
+		return role, nil
+	}
+
+	role.Patch(patch)
+	role, err := a.UpdateRole(role)
+	if err != nil {
+		return nil, err
+	}
+
+	return role, err
+}
+
+func (a *App) UpdateRole(role *model.Role) (*model.Role, *model.AppError) {
+	if result := <-a.Srv.Store.Role().Save(role); result.Err != nil {
+		return nil, result.Err
+	} else {
+		a.sendUpdatedRoleEvent(role)
+
+		return role, nil
+	}
+}
+
+func (a *App) CheckRolesExist(roleNames []string) *model.AppError {
+	roles, err := a.GetRolesByNames(roleNames)
+	if err != nil {
+		return err
+	}
+
+	for _, name := range roleNames {
+		nameFound := false
+		for _, role := range roles {
+			if name == role.Name {
+				nameFound = true
+				break
+			}
+		}
+		if !nameFound {
+			return model.NewAppError("CheckRolesExist", "app.role.check_roles_exist.role_not_found", nil, "role="+name, http.StatusBadRequest)
+		}
+	}
+
+	return nil
+}
+
+func (a *App) sendUpdatedRoleEvent(role *model.Role) {
+	message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_ROLE_UPDATED, "", "", "", nil)
+	message.Add("role", role.ToJson())
+
+	a.Go(func() {
+		a.Publish(message)
+	})
 }