//  Vikunja is a todo-list application to facilitate your life.
//  Copyright 2018 Vikunja and contributors. All rights reserved.
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <https://www.gnu.org/licenses/>.

package models

import (
	"code.vikunja.io/api/pkg/log"
	"code.vikunja.io/web"
)

// CanCreate checks if a user can add a label to a task
func (lt *LabelTask) CanCreate(a web.Auth) bool {
	label, err := getLabelByIDSimple(lt.LabelID)
	if err != nil {
		log.Log.Errorf("Error during CanCreate for LabelTask: %v", err)
		return false
	}

	return label.hasAccessToLabel(a) && canDoLabelTask(lt.TaskID, a)
}

// CanDelete checks if a user can delete a label from a task
func (lt *LabelTask) CanDelete(a web.Auth) bool {
	if !canDoLabelTask(lt.TaskID, a) {
		return false
	}

	// We don't care here if the label exists or not. The only relevant thing here is if the relation already exists,
	// throw an error.
	exists, err := x.Exist(&LabelTask{LabelID: lt.LabelID, TaskID: lt.TaskID})
	if err != nil {
		log.Log.Errorf("Error during CanDelete for LabelTask: %v", err)
		return false
	}
	return exists
}

// CanCreate determines if a user can update a labeltask
func (ltb *LabelTaskBulk) CanCreate(a web.Auth) bool {
	return canDoLabelTask(ltb.TaskID, a)
}

// Helper function to check if a user can write to a task
// + is able to see the label
// always the same check for either deleting or adding a label to a task
func canDoLabelTask(taskID int64, a web.Auth) bool {
	// A user can add a label to a task if he can write to the task
	task, err := getTaskByIDSimple(taskID)
	if err != nil {
		log.Log.Error("Error occurred during canDoLabelTask for LabelTask: %v", err)
		return false
	}
	return task.CanUpdate(a)
}