auth-get-task.swift

    public func get(request: HTTPRequest, response: HTTPResponse) {
        do {
            guard let stringId = request.urlVariables["id"], let id = UUID(uuidString: stringId) else {
                return response.sendBadRequestError()
            }
                
            guard let task = try self.tasksService.get(byId: id) else {
                return response.sendNotFoundError()
            }
            
            guard let user = request.getUserCredentials() else {
                return response.sendUnauthorizedError()
            }
            
            if try !self.authorizationService.authorize(user: user,
                    resource: task,
                    requirement: OperationAuthorizationRequirement(operation: .read)) {
                return response.sendForbiddenError()
            }
            
            let taskDto = TaskDto(task: task)
            return response.sendJson(taskDto)
        }
        catch {
            response.sendInternalServerError(error: error)
        }
    }