<?php

namespace Bitrix\Bizproc\Api\Service;

use Bitrix\Bizproc\Api\Response\TaskAccessService\CheckDelegateTasksResponse;
use Bitrix\Main\Error;
use Bitrix\Main\Loader;
use Bitrix\Main\Localization\Loc;
use Bitrix\Main\Result;

class TaskAccessService
{
	private int $userId;
	private bool $isUserAdmin;

	public function __construct(int $userId)
	{
		$this->userId = $userId;
		$currentUser = \Bitrix\Main\Engine\CurrentUser::get();
		$userGroups =
			!is_null($currentUser) && $currentUser->getId() === $userId
				? $currentUser->getUserGroups()
				: \CUser::GetUserGroup($userId);
		$this->isUserAdmin = in_array(1, $userGroups, false);
	}

	public function isCurrentUser(int $userId): bool
	{
		return $this->userId === $userId;
	}

	public function checkDelegateTask(int $toUserId, int $fromUserId): CheckDelegateTasksResponse
	{
		$response = new CheckDelegateTasksResponse();

		if (Loader::includeModule('intranet'))
		{
			if (
				!\Bitrix\Intranet\Util::isIntranetUser($toUserId)
				|| !\Bitrix\Intranet\Util::isIntranetUser($this->userId)
			)
			{
				return $response->addError(
					new Error(Loc::getMessage('BIZPROC_LIB_API_TASK_ACCESS_SERVICE_DELEGATE_ERROR_ONLY_INTRANET_USER'))
				);
			}
		}

		if (!$this->canUserViewTasks($fromUserId))
		{
			return $response->addError(new Error(Loc::getMessage('BIZPROC_LIB_API_TASK_ACCESS_SERVICE_DELEGATE_ERROR_SUBORDINATION')));
		}

		$isHead = \CBPHelper::checkUserSubordination($this->userId, $toUserId);
		$allowedDelegationTypes = [\CBPTaskDelegationType::AllEmployees];
		if ($isHead)
		{
			$allowedDelegationTypes[] = \CBPTaskDelegationType::Subordinate;
		}

		$response->setData([
			'allowedDelegationTypes' => $this->isUserAdmin ? null : $allowedDelegationTypes,
		]);

		return $response;
	}

	public function checkViewTasks(int $targetUserId): Result
	{
		$result = new Result();

		if (Loader::includeModule('intranet') && !\Bitrix\Intranet\Util::isIntranetUser($this->userId))
		{
			return $result->addError(new Error(Loc::getMessage('BIZPROC_LIB_API_TASK_ACCESS_SERVICE_VIEW_TASKS_ERROR_ONLY_INTRANET_USER')));
		}

		if (!$this->canUserViewTasks($targetUserId))
		{
			return $result->addError(new Error(Loc::getMessage('BIZPROC_LIB_API_TASK_ACCESS_SERVICE_ERROR_SUBORDINATION_MSGVER_1')));
		}

		return $result;
	}

	public function checkDoTasks(int $targetUserId): Result
	{
		$result = new Result();

		if (!$this->canUserViewTasks($targetUserId))
		{
			return $result->addError(new Error(Loc::getMessage('BIZPROC_LIB_API_TASK_ACCESS_SERVICE_ERROR_SUBORDINATION_MSGVER_1')));
		}

		return $result;
	}

	private function canUserViewTasks(int $targetUserId): bool
	{
		if ($this->isCurrentUser($targetUserId))
		{
			return true;
		}

		if ($this->isUserAdmin)
		{
			return true;
		}

		return \CBPHelper::checkUserSubordination($this->userId, $targetUserId);
	}
}