models/permission.go

@@ -0,0 +1,16 @@
+// Copyright (c) 2025 Zeni Kim <zenik@smarteching.com>
+// Use of this source code is governed by MIT-style
+// license that can be found in the LICENSE file.
+
+package models
+
+type Permission struct {
+	BaseModel
+	Name string
+	Slug string
+}
+
+// TableName sets the table name
+func (Permission) TableName() string {
+	return "permissions"
+}

models/role-permissions.go

@@ -0,0 +1,16 @@
+// Copyright (c) 2025 Zeni Kim <zenik@smarteching.com>
+// Use of this source code is governed by MIT-style
+// license that can be found in the LICENSE file.
+
+package models
+
+type RolePermission struct {
+	BaseModel
+	RoleID       uint // Role id
+	PermissionID uint // Permission id
+}
+
+// TableName sets the table name
+func (RolePermission) TableName() string {
+	return "role_permissions"
+}

models/roles.go

@@ -0,0 +1,16 @@
+// Copyright (c) 2025 Zeni Kim <zenik@smarteching.com>
+// Use of this source code is governed by MIT-style
+// license that can be found in the LICENSE file.
+
+package models
+
+type Role struct {
+	BaseModel
+	Name string // The name of the role
+	Slug string // String based unique identifier of the role, (use hyphen seperated role name '-', instead of space)
+}
+
+// TableName sets the table name
+func (Role) TableName() string {
+	return "roles"
+}

models/user-roles.go

@@ -0,0 +1,16 @@
+// Copyright (c) 2025 Zeni Kim <zenik@smarteching.com>
+// Use of this source code is governed by MIT-style
+// license that can be found in the LICENSE file.
+
+package models
+
+type UserRole struct {
+	BaseModel
+	UserID string // The user id
+	RoleID uint   // The role id
+}
+
+// TableName sets the table name
+func (UserRole) TableName() string {
+	return "user_roles"
+}

run-auto-migrations.go

@@ -18,4 +18,8 @@ func RunAutoMigrations() {
 
 	// Add auto migrations for your models here...
 	db.AutoMigrate(&models.User{})
+	db.AutoMigrate(&models.UserRole{})
+	db.AutoMigrate(&models.Role{})
+	db.AutoMigrate(&models.RolePermission{})
+	db.AutoMigrate(&models.Permission{})
 }

utils/authority.go

@@ -0,0 +1,408 @@
+// Copyright (c) 2025 Zeni Kim <zenik@smarteching.com>
+// Use of this source code is governed by MIT-style
+// license that can be found in the LICENSE file.
+
+package utils
+
+import (
+	"errors"
+	"fmt"
+
+	"git.smarteching.com/goffee/core"
+	"git.smarteching.com/goffee/cup/models"
+	"gorm.io/gorm"
+)
+
+type Authority struct{}
+
+var auth *Authority
+
+var (
+	ErrPermissionInUse    = errors.New("cannot delete assigned permission")
+	ErrPermissionNotFound = errors.New("permission not found")
+	ErrRoleInUse          = errors.New("cannot delete assigned role")
+	ErrRoleNotFound       = errors.New("role not found")
+)
+
+// Add a new role to the database
+func (a *Authority) CreateRole(c *core.Context, r models.Role) error {
+	roleSlug := r.Slug
+	var dbRole models.Role
+	res := c.GetGorm().Where("slug = ?", roleSlug).First(&dbRole)
+	if res.Error != nil {
+		if errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			// create
+			createRes := c.GetGorm().Create(&r)
+			if createRes.Error != nil {
+				return createRes.Error
+			}
+			return nil
+		}
+		return res.Error
+	}
+
+	return errors.New(fmt.Sprintf("role '%v' already exists", roleSlug))
+}
+
+// Add a new permission to the database
+func (a *Authority) CreatePermission(c *core.Context, p models.Permission) error {
+	permSlug := p.Slug
+	var dbPerm models.Permission
+	res := c.GetGorm().Where("slug = ?", permSlug).First(&dbPerm)
+	if res.Error != nil {
+		if errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			// create
+			createRes := c.GetGorm().Create(&p)
+			if createRes.Error != nil {
+				return createRes.Error
+			}
+			return nil
+		}
+		return res.Error
+	}
+
+	return errors.New(fmt.Sprintf("permission '%v' already exists", permSlug))
+}
+
+// Assigns a group of permissions to a given role
+func (a *Authority) AssignPermissionsToRole(c *core.Context, roleSlug string, permSlugs []string) error {
+	var role models.Role
+	rRes := c.GetGorm().Where("slug = ?", roleSlug).First(&role)
+	if rRes.Error != nil {
+		if errors.Is(rRes.Error, gorm.ErrRecordNotFound) {
+			return ErrRoleNotFound
+		}
+		return rRes.Error
+	}
+	var perms []models.Permission
+	for _, permSlug := range permSlugs {
+		var perm models.Permission
+		pRes := c.GetGorm().Where("slug = ?", permSlug).First(&perm)
+		if pRes.Error != nil {
+			if errors.Is(pRes.Error, gorm.ErrRecordNotFound) {
+				return ErrPermissionNotFound
+			}
+			return pRes.Error
+		}
+		perms = append(perms, perm)
+	}
+	tx := c.GetGorm().Begin()
+	for _, perm := range perms {
+		var rolePerm models.RolePermission
+		res := c.GetGorm().Where("role_id = ?", role.ID).Where("permission_id =?", perm.ID).First(&rolePerm)
+		if res.Error != nil && errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			cRes := tx.Create(&models.RolePermission{RoleID: role.ID, PermissionID: perm.ID})
+			if cRes.Error != nil {
+				tx.Rollback()
+				return cRes.Error
+			}
+		}
+		if res.Error != nil && !errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			tx.Rollback()
+			return res.Error
+		}
+		if rolePerm != (models.RolePermission{}) {
+			tx.Rollback()
+			return errors.New(fmt.Sprintf("permission '%v' is aleady assigned to the role '%v'", perm.Name, role.Name))
+		}
+		rolePerm = models.RolePermission{}
+	}
+	return tx.Commit().Error
+}
+
+// Assigns a role to a given user
+func (a *Authority) AssignRoleToUser(c *core.Context, userID interface{}, roleSlug string) error {
+	userIDStr := fmt.Sprintf("%v", userID)
+	var role models.Role
+	res := c.GetGorm().Where("slug = ?", roleSlug).First(&role)
+	if res.Error != nil {
+		if errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			return ErrRoleNotFound
+		}
+		return res.Error
+	}
+	var userRole models.UserRole
+	res = c.GetGorm().Where("user_id = ?", userIDStr).Where("role_id = ?", role.ID).First(&userRole)
+	if res.Error != nil && errors.Is(res.Error, gorm.ErrRecordNotFound) {
+		c.GetGorm().Create(&models.UserRole{UserID: userIDStr, RoleID: role.ID})
+		return nil
+	}
+	if res.Error != nil && !errors.Is(res.Error, gorm.ErrRecordNotFound) {
+		return res.Error
+	}
+
+	return errors.New(fmt.Sprintf("this role '%v' is aleady assigned to the user", roleSlug))
+}
+
+// Checks if a role is assigned to a user
+func (a *Authority) CheckUserRole(c *core.Context, userID interface{}, roleSlug string) (bool, error) {
+	userIDStr := fmt.Sprintf("%v", userID)
+	// find the role
+	var role models.Role
+	res := c.GetGorm().Where("slug = ?", roleSlug).First(&role)
+	if res.Error != nil {
+		if errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			return false, ErrRoleNotFound
+		}
+		return false, res.Error
+	}
+
+	// check if the role is a assigned
+	var userRole models.UserRole
+	res = c.GetGorm().Where("user_id = ?", userIDStr).Where("role_id = ?", role.ID).First(&userRole)
+	if res.Error != nil {
+		if errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			return false, nil
+		}
+		return false, res.Error
+	}
+
+	return true, nil
+}
+
+// Checks if a permission is assigned to a user
+func (a *Authority) CheckUserPermission(c *core.Context, userID interface{}, permSlug string) (bool, error) {
+	userIDStr := fmt.Sprintf("%v", userID)
+	// the user role
+	var userRoles []models.UserRole
+	res := c.GetGorm().Where("user_id = ?", userIDStr).Find(&userRoles)
+	if res.Error != nil {
+		if errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			return false, nil
+		}
+		return false, res.Error
+	}
+
+	//prepare an array of role ids
+	var roleIDs []interface{}
+	for _, r := range userRoles {
+		roleIDs = append(roleIDs, r.RoleID)
+	}
+
+	// find the permission
+	var perm models.Permission
+	res = c.GetGorm().Where("slug = ?", permSlug).First(&perm)
+	if res.Error != nil {
+		if errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			return false, ErrPermissionNotFound
+		}
+		return false, res.Error
+	}
+
+	// find the role permission
+	var rolePermission models.RolePermission
+	res = c.GetGorm().Where("role_id IN (?)", roleIDs).Where("permission_id = ?", perm.ID).First(&rolePermission)
+	if res.Error != nil && errors.Is(res.Error, gorm.ErrRecordNotFound) {
+		return false, nil
+	}
+	if res.Error != nil && !errors.Is(res.Error, gorm.ErrRecordNotFound) {
+		return false, res.Error
+	}
+
+	return true, nil
+}
+
+// Checks if a permission is assigned to a role
+func (a *Authority) CheckRolePermission(c *core.Context, roleSlug string, permSlug string) (bool, error) {
+	// find the role
+	var role models.Role
+	res := c.GetGorm().Where("slug = ?", roleSlug).First(&role)
+	if res.Error != nil {
+		if errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			return false, ErrRoleNotFound
+		}
+		return false, res.Error
+	}
+
+	// find the permission
+	var perm models.Permission
+	res = c.GetGorm().Where("slug = ?", permSlug).First(&perm)
+	if res.Error != nil {
+		if errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			return false, ErrPermissionNotFound
+		}
+		return false, res.Error
+	}
+
+	// find the rolePermission
+	var rolePermission models.RolePermission
+	res = c.GetGorm().Where("role_id = ?", role.ID).Where("permission_id = ?", perm.ID).First(&rolePermission)
+	if res.Error != nil {
+		if errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			return false, nil
+		}
+		return false, res.Error
+	}
+
+	return true, nil
+}
+
+// Revokes a roles's permission
+func (a *Authority) RevokeRolePermission(c *core.Context, roleSlug string, permSlug string) error {
+	// find the role
+	var role models.Role
+	res := c.GetGorm().Where("slug = ?", roleSlug).First(&role)
+	if res.Error != nil {
+		if errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			return ErrRoleNotFound
+		}
+		return res.Error
+	}
+
+	// find the permission
+	var perm models.Permission
+	res = c.GetGorm().Where("slug = ?", permSlug).First(&perm)
+	if res.Error != nil {
+		if errors.Is(res.Error, gorm.ErrRecordNotFound) {
+			return ErrPermissionNotFound
+		}
+		return res.Error
+	}
+
+	// revoke the permission
+	rRes := c.GetGorm().Where("role_id = ?", role.ID).Where("permission_id = ?", perm.ID).Delete(models.RolePermission{})
+	if rRes.Error != nil {
+		return rRes.Error
+	}
+
+	return nil
+}
+
+// Returns all stored roles
+func (a *Authority) GetAllRoles(c *core.Context) ([]models.Role, error) {
+	var roles []models.Role
+	res := c.GetGorm().Find(&roles)
+	if res.Error != nil {
+		return nil, res.Error
+	}
+
+	return roles, nil
+}
+
+// Returns all user assigned roles
+func (a *Authority) GetUserRoles(c *core.Context, userID interface{}) ([]models.Role, error) {
+	userIDStr := fmt.Sprintf("%v", userID)
+	var userRoles []models.UserRole
+	res := c.GetGorm().Where("user_id = ?", userIDStr).Find(&userRoles)
+	if res.Error != nil {
+		return nil, res.Error
+	}
+
+	var roleIDs []interface{}
+	for _, r := range userRoles {
+		roleIDs = append(roleIDs, r.RoleID)
+	}
+
+	var roles []models.Role
+	res = c.GetGorm().Where("id IN (?)", roleIDs).Find(&roles)
+	if res.Error != nil {
+		return nil, res.Error
+	}
+
+	return roles, nil
+}
+
+// Returns all role assigned permissions
+func (a *Authority) GetRolePermissions(c *core.Context, roleSlug string) ([]models.Permission, error) {
+	var role models.Role
+	res := c.GetGorm().Where("slug = ?", roleSlug).Find(&role)
+	if res.Error != nil {
+		return nil, res.Error
+	}
+
+	var rolePerms []models.RolePermission
+	res = c.GetGorm().Where("role_id = ?", role.ID).Find(&rolePerms)
+	if res.Error != nil {
+		return nil, res.Error
+	}
+	var permIDs []interface{}
+	for _, rolePerm := range rolePerms {
+		permIDs = append(permIDs, rolePerm.PermissionID)
+	}
+
+	var perms []models.Permission
+	res = c.GetGorm().Where("id IN (?)", permIDs).Find(&perms)
+	if res.Error != nil {
+		return nil, res.Error
+	}
+
+	return perms, nil
+}
+
+// Returns all stored permissions
+func (a *Authority) GetAllPermissions(c *core.Context) ([]models.Permission, error) {
+	var perms []models.Permission
+	res := c.GetGorm().Find(&perms)
+	if res.Error != nil {
+		return nil, res.Error
+	}
+
+	return perms, nil
+}
+
+// Deletes a given role even if it's has assigned permissions
+func (a *Authority) DeleteRole(c *core.Context, roleSlug string) error {
+	// find the role
+	var role models.Role
+	res := c.GetGorm().Where("slug = ?", roleSlug).First(&role)
+	if res.Error != nil {
+		return res.Error
+	}
+
+	// check if the role is assigned to a user
+	var ca int64
+	res = c.GetGorm().Model(models.UserRole{}).Where("role_id = ?", role.ID).Count(&ca)
+	if res.Error != nil {
+		return res.Error
+	}
+
+	if ca != 0 {
+		// role is assigned
+		return ErrRoleInUse
+	}
+	tx := c.GetGorm().Begin()
+	// revoke the assignment of permissions before deleting the role
+	dRes := tx.Where("role_id = ?", role.ID).Delete(models.RolePermission{})
+	if dRes.Error != nil {
+		tx.Rollback()
+		return dRes.Error
+	}
+
+	// delete the role
+	dRes = c.GetGorm().Where("slug = ?", roleSlug).Delete(models.Role{})
+	if dRes.Error != nil {
+		tx.Rollback()
+		return dRes.Error
+	}
+
+	return tx.Commit().Error
+}
+
+// Deletes a given permission
+func (a *Authority) DeletePermission(c *core.Context, permSlug string) error {
+	// find the permission
+	var perm models.Permission
+	res := c.GetGorm().Where("slug = ?", permSlug).First(&perm)
+	if res.Error != nil {
+		return res.Error
+	}
+
+	// check if the permission is assigned to a role
+	var rolePermission models.RolePermission
+	res = c.GetGorm().Where("permission_id = ?", perm.ID).First(&rolePermission)
+	if res.Error != nil && !errors.Is(res.Error, gorm.ErrRecordNotFound) {
+		return res.Error
+	}
+
+	if res.Error == nil {
+		return ErrPermissionInUse
+	}
+
+	// delete the permission
+	dRes := c.GetGorm().Where("slug = ?", permSlug).Delete(models.Permission{})
+	if dRes.Error != nil {
+		return dRes.Error
+	}
+
+	return nil
+}