<?php
/**
 * Created by PhpStorm.
 * User: lucas
 * Date: 15/03/18
 * Time: 15:50
 */

namespace api\module\department;


use database\core\Repo;
use error\core\Error;
use error\core\Err;
use database\repo\department;
use Ifsnop\Mysqldump\Mysqldump;

class versionController{


	/* Attributes
	---------------------------------------------------------*/
	private $backup_path;
	private $origin_dbname;


	/* (1) Initialize object
	*
	---------------------------------------------------------*/
	public function __construct(){
		$this->backup_path   = null;
		$this->origin_dbname = null;
	}


	/* (2) Initializes a directory
	*
	* @db_name<String>					The database name
	*
	* @return outName<outType>			outDesc
	*
	--------------------------------------------------------*/
	private function initDir(string $db_name){

		/* (1) Manage 'BACKUP' root directory
		---------------------------------------------------------*/
		/* (1) If not exists -> try to create it */
		if( !is_dir(__BACKUP__) )
			mkdir(__BACKUP__);

		/* (2) Try to override permissions */
		chmod(__BACKUP__, 0775);


		/* (2) Manage sub-directory
		---------------------------------------------------------*/
		/* (1) If @db_name is 'preview_@database_hash' -> extract @database */
		if( preg_match('/^preview_(\w+)_[a-f0-9]+$/', $db_name, $m) )
			$db_name = $m[1];

		/* (2) Store @db_name as origin */
		$this->origin_dbname = $db_name;

		/* (3) Store backup path */
		$this->backup_path =__BACKUP__."/$db_name";

		/* (4) If dir. already exists -> do nothing more */
		if( is_dir($this->backup_path) )
			return;

		/* (4) Else -> try to create + set permissions */
		mkdir($this->backup_path);
		chmod($this->backup_path, 0775);

	}


	/* (3) Scan directory files
	*
	* @path<String>						Directory path
	*
	* @return files<array>				Array containing file names
	*
	---------------------------------------------------------*/
	private function scandir(string $path) : array {

		/* (1) Return [] if not a directory */
		if( !is_dir($path) )
			return [];

		/* (2) Scan the directory */
		$files = scandir($path);

		/* (3) Remove '.' and '..' (2 first elements) */
		$files = array_slice($files, 2);

		/* (4) Return file list */
		return $files;

	}


	/* (4) List available versions for this department
	*
	* @return versions<array>			Version list
	*
	---------------------------------------------------------*/
	public function get($args){

		/* (1) Initialize directory for current database (department) */
		$this->initDir( $_SESSION['CurrentDatabase'] );

		/* (2) Strip extensions */
		$versions = array_map(
			function($e){ return pathinfo($e, PATHINFO_FILENAME); },
			$this->scandir($this->backup_path)
		);

		/* (3) Return versions */
		return ['versions' => $versions];

	}


	/* (5) Remove an existing version for this department
	*
	* @version<String>					Version name (typically snapshot date)
	*
	* @return deleted<bool>				Whether the version has been deleted
	*
	---------------------------------------------------------*/
	public function delete($args){
		$version = null;
		extract($args);

		/* (1) Initialize directory for current database (department) */
		$this->initDir( $_SESSION['CurrentDatabase'] );

		/* (2) Dispatch 'unlink' result */
		return [ 'deleted' => unlink($this->backup_path."/$version.sql") ];
	}


	/* (6) Creates a new version (snapshot of database) from now
	*
	* @return created_id<String>			The created version id (date)
	*
	---------------------------------------------------------*/
	public function post($args){


		/* (1) Initialize directory for current database (department) */
		$this->initDir( $_SESSION['CurrentDatabase'] );

		/* (2) Try to create the snapshot */
		try{

			/* (2.1) Get database configuration */
			$conf = Repo::getDBConfig();

			/* (2.2) Try to dump the database */
			$dump = new Mysqldump(
				'mysql:host='.$conf['host'].';dbname='.$conf['dbname'],
				$conf['username'],
				$conf['password'],
				[ "compress" => Mysqldump::GZIP ]
			);

			/* (2.3) Get current date (for naming the version) */
			$current_date = date('d-m-Y');

			/* (2.4) Store the version */
			$dump->start($this->backup_path."/$current_date.sql");

			/* (2.5) Return status */
			return ['created_id' => $current_date ];

		/* (3) On error -> dispatch error */
		}catch(\Exception $e){

			return ['error' => new Error(Err::RepoError)];

		}

	}


	/* (6) ( Switches to preview || Applies on prod ) for a version
	*
	* @apply<int>							If 0 -> preview version
	* 										If 1 -> apply version into prod database
	* @version<String>						[OPT] Version name to use (if ommited, switch back to prod database)
	*
	* @return created_id<String>			The created version id (date)
	*
	---------------------------------------------------------*/
	public function put($args){
		$apply   = null;
		$version = null;
		extract($args);


		/* (1) Initialisation
		---------------------------------------------------------*/
		/* (1) Initialize directory for current database (department) */
		$this->initDir( $_SESSION['CurrentDatabase'] );

		/* (2) Get department repository */
		/** @var department $dept_repo */
		$dept_repo = Repo::getRepo('department');

		/* (2) Check whether we have to [apply OR preview] */
		$apply = ( $apply === '1' );


		/* (2) If back to 'prod' database
		---------------------------------------------------------*/
		if( is_null($version) ){

			/* (1) Reset database to 'prod' */
			$_SESSION['CurrentDatabase'] = $this->origin_dbname;

			/* (2) Return success */
			return [ 'updated' => true ];

		}


		/* (3) Read the backup version
		---------------------------------------------------------*/
		/* (1) Start buffer */
		ob_start();

		/* (2) Read backup file */
		readgzfile($this->backup_path."/$version.sql");

		/* (3) Store & Flush buffer into variable */
		$snapshot = ob_get_clean();

		/* (4) Manage error */
		if( strlen($snapshot) === 0 )
			return ['error' => new Error(Err::RepoError)];


		/* (4) APPLY into 'prod' database
		---------------------------------------------------------*/
		if( $apply ){

			/* (1) Restore from this version */
			$restored = $dept_repo->restore($this->origin_dbname, $snapshot);

			/* (2) Dispatch repo execution status */
			return [ 'updated' => $restored ];

		}


		/* (5) PREVIEW version database
		---------------------------------------------------------*/
		/* (1) Try to get 'preview' database name */
		$preview_dbname = $dept_repo->previewExists($this->origin_dbname, $version);

		/* (2) If does not exist -> create it */
		if( is_null($preview_dbname) ){

			/* 1. Try to create preview */
			$preview_dbname = $dept_repo->createPreview($this->origin_dbname, $version);

			/* 2. Switch to preview */
			$dept_repo->restore($preview_dbname, $snapshot);

		}

		/* (3) Store 'preview' database in session */
		$_SESSION['CurrentDatabase'] = $preview_dbname;


		/* (4) Return status */
		return [ 'updated' => true ];

	}

}