<?php

declare(strict_types=1);

namespace OCA\SCIMServiceProvider\Service;

use Exception;
use OCA\SCIMServiceProvider\AppInfo\Application;
use OCP\IGroup;
use OCP\IGroupManager;
use OCP\IUserManager;
use Opf\Models\SCIM\Standard\Groups\CoreGroup;
use Opf\Models\SCIM\Standard\Meta;
use Opf\Models\SCIM\Standard\MultiValuedAttribute;
use Psr\Log\LoggerInterface;

class GroupService {

	private LoggerInterface $logger;
	private IGroupManager $groupManager;
	private IUserManager $userManager;


	public function __construct(LoggerInterface $logger, IGroupManager $groupManager, IUserManager $userManager) {
		$this->logger = $logger;
		$this->groupManager = $groupManager;
		$this->userManager = $userManager;
	}


	private function toSCIM(IGroup $ncGroup): CoreGroup {
		$scimGroup = new CoreGroup();
		$scimGroup->setId($ncGroup->getGID());
		$scimGroup->setDisplayName($ncGroup->getDisplayName());

		$meta = new Meta();
		$meta->setResourceType("Group");
		$scimGroup->setMeta($meta);

		return $scimGroup;
	}


	private function getSCIMMembers(IGroup $ncGroup): array {
		$members = [];
		foreach ($ncGroup->getUsers() as $ncGroupMember) {
			$this->logger->info($ncGroupMember->getUID());
			$member = new MultiValuedAttribute();
			$member->setType("User");
			$member->setRef("Users/" . $ncGroupMember->getUID());
			$member->setValue($ncGroupMember->getUID());
			$member->setDisplay($ncGroupMember->getDisplayName());

			$members[] = $member;
		}
		return $members;
	}

	private function updateGroup(IGroup $ncGroup, CoreGroup $scimGroup) {
		$displayName = $scimGroup->getDisplayName();
		if (isset($displayName)) {
			$ncGroup->setDisplayName($displayName);
		}

		$scimMembers = $scimGroup->getMembers();
		if (isset($scimMembers)) {
			foreach ($ncGroup->getUsers() as $ncUser) {
				$found = false;
				foreach ($scimMembers as $scimMember) {
					if ($ncUser->getUID() === $scimMember->getValue()) {
						$found = true;
						break;
					}
				}
				if (!$found) {
					$this->logger->info("remove " . $ncUser->getUID() . " from " . $ncGroup->getGID());
					$ncGroup->removeUser($ncUser);
				}
			}
			foreach ($scimMembers as $scimMember) {
				$this->logger->info($scimMember->getValue());
				$this->logger->info(json_encode($scimMember->jsonSerialize()));
				$user = $this->userManager->get($scimMember->getValue());
				if (!isset($user)) {
					throw new Exception("User " . $scimMember->getValue() . " not found", 404);
				}
				if (!$ncGroup->inGroup($user)) {
					$this->logger->info("add " . $user->getUID() . " from " . $ncGroup->getGID());
					$ncGroup->addUser($user);
					$this->logger->info(json_encode($ncGroup->getUsers()));
				}
			}
		}
	}

	public function countAll(): int {
		$ncGroups = $this->groupManager->search("");
		return sizeof($ncGroups);
	}

	/*
	* @param string $filter
	* @return OCP\IGroup\IGroup[]
	*/
	public function getAll(int $startIndex, int $count = null): array {
		$this->logger->info("Reading all groups");

		if ($count === 0) {
			return [];
		}

		$ncGroups = $this->groupManager->search("", $count, $startIndex - 1);

		$scimGroups = [];
		foreach ($ncGroups as $ncGroup) {
			$scimGroup = $this->toSCIM($ncGroup);
			$members = $this->getSCIMMembers($ncGroup);
			$scimGroup->setMembers($members);
			$scimGroups[] = $scimGroup;
		}

		return $scimGroups;
	}

	public function get(string $id): CoreGroup {
		if (!$this->groupManager->groupExists($id)) {
			throw new Exception("Not found", 404);
		}

		$ncGroup = $this->groupManager->get($id);
		$scimGroup = $this->toSCIM($ncGroup);


		$members = $this->getSCIMMembers($ncGroup);
		$scimGroup->setMembers($members);

		return $scimGroup;
	}


	public function create(CoreGroup $scimGroup): CoreGroup {
		// Validate name
		if (empty($scimGroup->getDisplayName())) {
			$this->logger->error('Group name not supplied', ['app' => 'provisioning_api']);
			throw new Exception('Invalid group name', 400);
		}
		// Check if it exists
		if ($this->groupManager->groupExists($scimGroup->getDisplayName())) {
			$this->logger->error("Group to be created already exists");
			throw new Exception('Group exists', 409);
		}

		try {
			$this->logger->info("Creating group with displayName: " . $scimGroup->getDisplayName());

			$ncGroup = $this->groupManager->createGroup($scimGroup->getDisplayName());
			$this->updateGroup($ncGroup, $scimGroup);
		} catch (Exception $e) {
			$this->logger->warning('Failed createGroup attempt with SCIMException exception.', ['app' => Application::APP_ID]);
			throw $e;
		}

		return $this->get($ncGroup->getGID());
	}

	public function update(string $id, CoreGroup $scimGroup): CoreGroup {
		$this->logger->info("Updating group with ID: " . $id);

		if (!$this->groupManager->groupExists($id)) {
			throw new Exception('Group not found', 404);
		}

		$this->logger->info($scimGroup->toSCIM());
		// $this->atomic(function () use ($id, $scimGroup) {
		$ncGroup = $this->groupManager->get($id);
		$this->updateGroup($ncGroup, $scimGroup);
		// }, $this->db);


		$this->logger->info(json_encode($ncGroup->getUsers()));

		return $this->get($id);
	}

	public function destroy(string $id): void {
		$this->logger->info("Deleting group with ID: " . $id);

		if ($id === 'admin') {
			// Cannot delete admin group
			$this->logger->error("Deleting admin group is not allowed");
			throw new Exception('Can\'t delete admin group', 403);
		}


		if (!$this->groupManager->groupExists($id)) {
			throw new Exception('Group not found', 404);
		}
		$ncGroup = $this->groupManager->get($id);
		$ncGroup->delete();
	}
}