<?php

/**
 * @copyright 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
 *
 * @author 2017 Christoph Wurst <christoph@winzerhof-wurst.at>
 *
 * @license GNU AGPL version 3 or any later version
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

namespace OC\Contacts\ContactsMenu;

use OC\Share\Share;
use OCP\Contacts\ContactsMenu\IEntry;
use OCP\Contacts\IManager;
use OCP\IConfig;
use OCP\IGroupManager;
use OCP\IUser;
use OCP\IUserManager;
use OCP\IUserSession;

class ContactsStore {

	/** @var IManager */
	private $contactsManager;

	/** @var IConfig */
	private $config;

	/** @var IUserManager */
	private $userManager;

	/** @var IGroupManager */
	private $groupManager;

	/**
	 * @param IManager $contactsManager
	 * @param IConfig $config
	 * @param IUserManager $userManager
	 * @param IGroupManager $groupManager
	 */
	public function __construct(IManager $contactsManager, IConfig $config, IUserManager $userManager, IGroupManager $groupManager) {
		$this->contactsManager = $contactsManager;
		$this->config = $config;
		$this->userManager = $userManager;
		$this->groupManager = $groupManager;
	}

	/**
	 * @param IUser $user
	 * @param string|null $filter
	 * @return IEntry[]
	 */
	public function getContacts(IUser $user, $filter) {
		$allContacts = $this->contactsManager->search($filter ?: '', [
			'FN',
		]);

		$entries = array_map(function(array $contact) {
			return $this->contactArrayToEntry($contact);
		}, $allContacts);
		return $this->filterContacts($user, $entries);
	}

	/**
	 * @brief filters the contacts. Applies 3 filters:
	 *  1. filter the current user
	 *  2. if the `shareapi_exclude_groups` config option is enabled and the
	 * current user is in an excluded group it will filter all local users.
	 *  3. if the ``shareapi_only_share_with_group_members config option is
	 * enabled it will filter all users which doens't have a common group
	 * with the current user.
	 * @param IUser $self
	 * @param $entries Entry[]
	 * @return array the filtered contacts
	 */
	private function filterContacts(IUser $self, Array $entries) {
		$excludedGroups = $this->config->getAppValue('core', 'shareapi_exclude_groups', 'no') === 'yes' ? true : false;

		$skipLocal = false; // whether to filter out local users
		$ownGroupsOnly = Share::shareWithGroupMembersOnly(); // whether to filter out all users which doesn't have the same group as the current user

		$selfGroups = $this->groupManager->getUserGroupIds($self);

		if ($excludedGroups) {
			$excludedGroups = $this->config->getAppValue('core', 'shareapi_exclude_groups_list', '');
			$excludeGroupsList = !is_null(json_decode($excludedGroups)) ? json_decode($excludedGroups, true) :  [];

			if (count(array_intersect($excludeGroupsList, $selfGroups)) !== 0) {
				// a group of the current user is excluded -> filter all local users
				$skipLocal = true;
			}
		}

		$selfUID = $self->getUID();

		return array_filter($entries, function(IEntry $entry) use ($self, $skipLocal, $ownGroupsOnly, $selfGroups, $selfUID) {

			if ($skipLocal && $entry->getProperty('isLocalSystemBook') === true) {
				return false;
			}

			if ($ownGroupsOnly && $entry->getProperty('isLocalSystemBook') === true) {
				$contactGroups = $this->groupManager->getUserGroupIds($this->userManager->get($entry->getProperty('UID')));
				if (count(array_intersect($contactGroups, $selfGroups)) === 0) {
					// no groups in common, so shouldn't see the contact
					return false;
				}
			}

			return $entry->getProperty('UID') !== $selfUID;
		});


	}

	/**
	 * @param IUser $user
	 * @param integer $shareType
	 * @param string $shareWith
	 * @return IEntry|null
	 */
	public function findOne(IUser $user, $shareType, $shareWith) {
		switch($shareType) {
			case 0:
			case 6:
				$filter = ['UID'];
				break;
			case 4:
				$filter = ['EMAIL'];
				break;
			default:
				return null;
		}

		$userId = $user->getUID();
		$allContacts = $this->contactsManager->search($shareWith, $filter);
		$contacts = array_filter($allContacts, function($contact) use ($userId) {
			return $contact['UID'] !== $userId;
		});
		$match = null;

		foreach ($contacts as $contact) {
			if ($shareType === 4 && isset($contact['EMAIL'])) {
				if (in_array($shareWith, $contact['EMAIL'])) {
					$match = $contact;
					break;
				}
			}
			if ($shareType === 0 || $shareType === 6) {
				if ($contact['UID'] === $shareWith && $contact['isLocalSystemBook'] === true) {
					$match = $contact;
					break;
				}
			}
		}

		return $match ? $this->contactArrayToEntry($match) : null;
	}

	/**
	 * @param array $contact
	 * @return Entry
	 */
	private function contactArrayToEntry(array $contact) {
		$entry = new Entry();

		if (isset($contact['id'])) {
			$entry->setId($contact['id']);
		}

		if (isset($contact['FN'])) {
			$entry->setFullName($contact['FN']);
		}

		$avatarPrefix = "VALUE=uri:";
		if (isset($contact['PHOTO']) && strpos($contact['PHOTO'], $avatarPrefix) === 0) {
			$entry->setAvatar(substr($contact['PHOTO'], strlen($avatarPrefix)));
		}

		if (isset($contact['EMAIL'])) {
			foreach ($contact['EMAIL'] as $email) {
				$entry->addEMailAddress($email);
			}
		}

		// Attach all other properties to the entry too because some
		// providers might make use of it.
		$entry->setProperties($contact);

		return $entry;
	}

}