<?php

/*
	This file is part of the ParTCP Server project
	Copyright (C) 2024 Martin Wandelt

	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 <https://www.gnu.org/licenses/>
*/

class ParTCP_Issue_Services {

	public $fileSystem;
	public $dataDir;
	public $lastResponse;
	public $partcp;  // ParTCP object for sending messages
	public $poolMax = 100; // maximum number of lotcodes in the pool
	public $poolMin = 50; // minimum number of lotcodes in the pool


	public function __construct( $fileSystem, $dataDir, &$partcp ){
		$this->fileSystem = $fileSystem;
		$this->dataDir = $dataDir;
		$this->partcp = $partcp;
	}


	public function get_id( $server, $eventId ){
		$eventName = basename( $eventId );
		return substr( $eventName, 0, 8 ) . '-' . md5( "{$server}:{$eventId}" );
	}


	public function get_dir( $id ){
		$subdir = substr( $id, 0, 6 );
		return "issue_services/{$subdir}/{$id}";
	}


	public function get_list(){
		if ( ! $this->fileSystem->exists('issue_services') ){
			return [];
		}
		$folderList = $this->fileSystem->get_listing('issue_services');
		$services = [];
		foreach ( $folderList as $dir ){
			$list = $this->fileSystem->get_listing( "issue_services/{$dir}" );
			foreach ( $list as $serviceId ){
				$services[] = $this->get_data( $serviceId );
			}
		}
		return $services;
	}


	public function get_data( $id ){
		$dir = $this->get_dir( $id );
		$msg = $this->fileSystem->get_recent_contents( $dir, '[0-9]*-{update,definition}*' );
		if ( empty( $msg ) ){
			return FALSE;
		}
		$receipt = yaml_parse( $msg );
		if ( empty( $receipt['Issue-Service-Data'] ) ){
			return FALSE;
		}
		return $receipt['Issue-Service-Data'];
	}


	public function purge_data( $data ){
		$validKeys = [
			'id' => 0,
			'name' => 0,
			'voting_server' => 0,
			'event_id' => 0,
		];
		return array_intersect_key( $data, $validKeys );
	}


	public function fetch_event_data( $serviceData ){
		if ( empty( $serviceData['id'] ) || empty( $serviceData['voting_server'] )
			|| empty( $serviceData['event_id'] )
		){
			return -1;
		}
		$this->partcp->set_remote_id( $serviceData['voting_server'] );
		$this->lastResponse = $this->partcp->send_message([
			'Message-Type' => 'event-details-request',
			'Event-Id' => $serviceData['event_id']
		]);
		if ( ! $this->lastResponse ){
			return -2;
		}
		return $this->lastResponse->get('Event-Data');
	}


	public function initialize_service( $serviceId ){
		$dir = $this->get_dir( $serviceId );
		if ( ! mkdir( "{$this->dataDir}/{$dir}/lotcodes", 0755, TRUE ) ){
			return FALSE;
		}
		if ( ! $this->fill_up_lot_codes( $serviceId ) ){
			return FALSE;
		}
		return TRUE;
	}


	public function fill_up_lot_codes( $serviceId ){
		$dir = $this->get_dir( $serviceId );
		$path = "{$this->dataDir}/{$dir}/lotcodes";
		$existing = count( glob( "{$path}/*" ) );
		if ( $existing > $this->poolMin ){
			return TRUE;
		}
		$data = $this->get_data( $serviceId );
		$this->partcp->set_remote_id( $data['voting_server'] );
		$msg = [
			'Message-Type' => 'multi-registration',
			'Event-Id' => $data['event_id'],
			'Count' => $this->poolMax - $existing,
		];
		$this->lastResponse = $this->partcp->send_message( $msg );
		if ( ! $this->lastResponse ){
			return FALSE;
		}
		$codes = $this->lastResponse->get('Lot-Codes');
		foreach ( $codes as $code ){
			file_put_contents( "{$path}/" . uniqid(), ptcp_local_encrypt( $code ) );
		}
		return TRUE;
	}


	public function check_if_terms_are_matched( $sender, $terms, $attr = [] ){
		if ( ! $attr ){
			list ( $ptcpId, $server ) = explode( '@', $sender ) + ['',''];
			if ( ! $server ){
				return FALSE;
			}
			$this->partcp->set_remote_id( $server );
			$msg = [
				'Message-Type' => 'participant-details-request',
				'Participant-Id' => $ptcpId,
				'Attributes' => array_keys( $terms ),
				'Encryption' => false,
			];
			$this->lastResponse = $this->partcp->send_message( $msg );
			if ( ! $this->lastResponse ){
				return FALSE;
			}
			$ptcpData = $this->lastResponse->get('Participant-Data');
			$attr = $ptcpData['attributes'] ?? NULL;
			if ( ! $attr ){
				return FALSE;
			}
		}
		foreach ( $terms as $name => $pattern ){
			if ( empty( $attr[ $name ] )
				|| ! preg_match( $pattern, $attr[ $name ] )
			){
				return FALSE;
			}
		}
		return TRUE;
	}


	public function get_lot_code( $serviceId ){
		$dir = $this->get_dir( $serviceId );
		$lotcodeDir = "{$this->dataDir}/{$dir}/lotcodes";
		if ( ! is_dir( $lotcodeDir ) ){
			if ( ! $this->initialize_service( $serviceId ) ){
				return FALSE;
			}
		}
		require_once 'lib/locker/locker.class.php';
		$locker = new Locker( "{$this->dataDir}/{$dir}" );
		if ( ! $locker->get_lock( 'lock', 180 ) ){
			return FALSE;
		}
		$codes = glob( "{$lotcodeDir}/*" );
		if ( ! $codes ){
			if ( ! $this->fill_up_lot_codes( $serviceId ) ){
				return FALSE;
			}
			$codes = glob( "{$lotcodeDir}/*" );
		}
		$code = ptcp_local_decrypt( file_get_contents( $codes[0] ) );
		unlink( $codes[0] );
		$locker->release_lock('lock');
		// TODO: update counter
		// TODO: if counter < poolMin, set marker to trigger fill-up on next cron execution
		return $code;
	}

}

// end of file models/issue_services.class.php