<?php

// Copyright (C) 2014-2024 Combodo SAS
//
//   This file is part of iTop.
//
//   iTop 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.
//
//   iTop 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 iTop. If not, see <http://www.gnu.org/licenses/>

class DBRestore extends DBBackup
{
	/** @var string */
	private $sDBPwd;
	/** @var string */
	private $sDBUser;

	public function __construct(?\Config $oConfig = null)
	{
		parent::__construct($oConfig);

		$this->sDBUser = $this->oConfig->Get('db_user');
		$this->sDBPwd = $this->oConfig->Get('db_pwd');
	}

	protected function LogInfo($sMsg)
	{
		//IssueLog::Info('non juste info: '.$sMsg);
	}

	protected function LogError($sMsg)
	{
		IssueLog::Error($sMsg);
	}

	protected function LoadDatabase($sDataFile)
	{
		$this->LogInfo("Loading data onto $this->sDBHost/$this->sDBName(suffix:'$this->sDBSubName')");

		// Just to check the connection to the DB (more accurate than getting the retcode of mysql)
		$oMysqli = $this->DBConnect();

		$sHost = self::EscapeShellArg($this->sDBHost);
		$sUser = self::EscapeShellArg($this->sDBUser);
		$sPwd = self::EscapeShellArg($this->sDBPwd);
		$sDBName = self::EscapeShellArg($this->sDBName);
		$sMySQLExe = DBBackup::MakeSafeMySQLCommand($this->sMySQLBinDir, 'mysql');
		if (is_null($this->iDBPort)) {
			$sPortOption = '';
		} else {
			$sPortOption = '--port='.$this->iDBPort.' ';
		}
		$sTlsOptions = self::GetMysqlCliTlsOptions($this->oConfig);

		$sDataFileEscaped = self::EscapeShellArg($sDataFile);
		$sCommand = "$sMySQLExe --default-character-set=".DEFAULT_CHARACTER_SET." --host=$sHost $sPortOption --user=$sUser --password=$sPwd $sTlsOptions $sDBName <$sDataFileEscaped 2>&1";
		$sCommandDisplay = "$sMySQLExe --default-character-set=".DEFAULT_CHARACTER_SET." --host=$sHost $sPortOption --user=xxxx --password=xxxx $sTlsOptions $sDBName <$sDataFileEscaped 2>&1";

		// Now run the command for real
		$this->LogInfo("Executing command: $sCommandDisplay");
		$aOutput = [];
		$iRetCode = 0;
		exec($sCommand, $aOutput, $iRetCode);
		foreach ($aOutput as $sLine) {
			$this->LogInfo("mysql said: $sLine");
		}
		if ($iRetCode != 0) {
			$this->LogError("Failed to execute: $sCommandDisplay. The command returned:$iRetCode");
			foreach ($aOutput as $sLine) {
				$this->LogError("mysql said: $sLine");
			}
			if (count($aOutput) == 1) {
				$sMoreInfo = trim($aOutput[0]);
			} else {
				$sMoreInfo = "Check the log file '".realpath(APPROOT.'/log/error.log')."' for more information.";
			}
			throw new BackupException("Failed to execute mysql: ".$sMoreInfo);
		}
	}

	/**
	 * <strong>Warning</strong> : can't be called with a loaded DataModel as we're compiling after restore
	 *
	 * @param string $sFile A file with the extension .zip or .tar.gz
	 * @param string $sEnvironment Target environment
	 *
	 * @throws \BackupException
	 *
	 * @uses \RunTimeEnvironment::CompileFrom()
	 */
	public function RestoreFromCompressedBackup($sFile, $sEnvironment = ITOP_DEFAULT_ENV)
	{
		$oRestoreMutex = new iTopMutex('restore.'.$sEnvironment);
		IssueLog::Info("Backup Restore - Acquiring the LOCK 'restore.$sEnvironment'");
		$oRestoreMutex->Lock();

		try {
			IssueLog::Info('Backup Restore - LOCK acquired, executing...');
			$bReadonlyBefore = SetupUtils::EnterMaintenanceMode(MetaModel::GetConfig());

			try {
				//safe zone for db backup => cron is stopped/ itop in readonly
				$this->LogInfo("Starting restore of ".basename($sFile));

				$sNormalizedFile = strtolower(basename($sFile));
				if (substr($sNormalizedFile, -4) == '.zip') {
					$this->LogInfo('zip file detected');
					$oArchive = new ZipArchiveEx();
					$oArchive->open($sFile);
				} elseif (substr($sNormalizedFile, -7) == '.tar.gz') {
					$this->LogInfo('tar.gz file detected');
					$oArchive = new TarGzArchive($sFile);
				} else {
					throw new BackupException('Unsupported format for a backup file: '.$sFile);
				}

				// Load the database
				//
				$sDataDir = utils::GetDataPath().'tmp-backup-'.rand(10000, getrandmax());

				SetupUtils::builddir($sDataDir); // Here is the directory
				$oArchive->extractTo($sDataDir);

				$sDataFile = $sDataDir.'/itop-dump.sql';
				$this->LoadDatabase($sDataFile);

				// Update the code
				//
				$sDeltaFile = utils::GetDataPath().$sEnvironment.'.delta.xml';

				if (is_file($sDataDir.'/delta.xml')) {
					// Extract and rename delta.xml => <env>.delta.xml;
					rename($sDataDir.'/delta.xml', $sDeltaFile);
				} else {
					@unlink($sDeltaFile);
				}
				if (is_dir(utils::GetDataPath().'production-modules/')) {
					try {
						SetupUtils::rrmdir(utils::GetDataPath().'production-modules/');
					} catch (Exception $e) {
						throw new BackupException("Can't remove production-modules dir", 0, $e);
					}
				}
				if (is_dir($sDataDir.'/production-modules')) {
					rename($sDataDir.'/production-modules', utils::GetDataPath().'production-modules/');
				}

				$sConfigFile = APPROOT.'conf/'.$sEnvironment.'/config-itop.php';
				@chmod($sConfigFile, 0770); // Allow overwriting the file
				rename($sDataDir.'/config-itop.php', $sConfigFile);
				@chmod($sConfigFile, 0440); // Read-only

				$aExtraFiles = $this->ListExtraFiles($sDataDir);
				foreach ($aExtraFiles as $sSourceFilePath => $sDestinationFilePath) {
					SetupUtils::builddir(dirname($sDestinationFilePath));
					rename($sSourceFilePath, $sDestinationFilePath);
				}

				try {
					SetupUtils::rrmdir($sDataDir);
				} catch (Exception $e) {
					throw new BackupException("Can't remove data dir", 0, $e);
				}

				$oEnvironment = new RunTimeEnvironment($sEnvironment);
				$oEnvironment->CompileFrom($sEnvironment);
			} finally {
				if (! $bReadonlyBefore) {
					SetupUtils::ExitMaintenanceMode();
				} else {
					//we are in the scope of main process that needs to handle/keep readonly mode.
					$this->LogInfo("Keep maintenance mode after restore");
				}
			}
		} finally {
			IssueLog::Info('Backup Restore - LOCK released.');
			$oRestoreMutex->Unlock();
		}
	}

	/**
	 * List the 'extra files' found in the decompressed archive
	 * (i.e. files other than config-itop.php, delta.xml, itop-dump.sql or production-modules/*
	 * @param string $sDataDir
	 * @return string[]
	 */
	protected function ListExtraFiles(string $sDataDir)
	{
		$aExtraFiles = [];
		$aStandardFiles = ['config-itop.php', 'itop-dump.sql', 'production-modules', 'delta.xml'];
		$oDirectoryIterator = new RecursiveDirectoryIterator($sDataDir, FilesystemIterator::CURRENT_AS_FILEINFO | FilesystemIterator::SKIP_DOTS);
		$oIterator = new RecursiveIteratorIterator($oDirectoryIterator);
		foreach ($oIterator as $oFileInfo) {
			if (in_array($oFileInfo->getFilename(), $aStandardFiles)) {
				continue;
			}
			// Normalize filenames to cope with Windows backslashes
			$sPath = str_replace('\\', '/', $oFileInfo->getPathname());
			$sRefPath = str_replace('\\', '/', $sDataDir.'/production-modules');
			if (strncmp($sPath, $sRefPath, strlen($sRefPath)) == 0) {
				continue;
			}

			$aExtraFiles[$oFileInfo->getPathname()] = APPROOT.substr($oFileInfo->getPathname(), strlen($sDataDir));
		}

		return $aExtraFiles;
	}
}
