<?php

/*
	This file is part of the ParTCP Server project
	Copyright (C) 2022 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_Local_Id {
	
	public $fileSystem;
	public $dataDir;
	public $baseDir = '';
	public $subdirDepth;
	public $subdirNameLength;


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


	public function set_base_dir( $baseDir = '', $estimatedTotal = NULL ){
		$this->baseDir = rtrim( $baseDir, '/' );
		if ( $estimatedTotal && function_exists('partcp_subdir_rules') ){
			$rules = partcp_subdir_rules( $estimatedTotal );
			$this->subdirDepth = $rules[0];
			$this->subdirNameLength = $rules[1];
		}
	}


	public function get_dir( $id = NULL ){
		if ( ! $id ){
			return 'participants_data';
		}
		if ( ! empty( $this->subdirDepth ) ){
			$parts = str_split( md5( $id ), $this->subdirNameLength ?? 2 );
			$subdirs = implode( '/', array_slice( $parts, 0, $this->subdirDepth ) );
			$id = "{$subdirs}/{$id}";
		}
		return ( $this->baseDir ? "{$this->baseDir}/" : '' ) . "participants/{$id}";
	}


	public function get_data( $id ){
		$dir = $this->get_dir( $id );
		$contents = $this->fileSystem->get_recent_contents( $dir, '[0-9]*' );
		if ( $contents ){
			$receipt = yaml_parse( $contents );
			if ( ! empty( $receipt['Participant-Data'] ) ){
				$data = $receipt['Participant-Data'];
				if ( ! empty( $data['attributes'] ) && is_string( $data['attributes'] ) ){
					$data['attributes'] = json_decode( ptcp_local_decrypt( $data['attributes'] ), TRUE );
				}
			}
		}
		$attr = $this->read_from_lookup_table( $id );
		if ( $attr ){
			if ( empty( $data ) ){
				$data['id'] = $id;
			}
			$data['attributes'] = array_merge( $data['attributes'] ?? [], $attr );
		}
		elseif ( empty( $data ) ){
			return FALSE;
		}
		return $data;
	}


	public function registrations_exist(){
		return $this->fileSystem->is_not_empty('participants');
	}


	public function count_registrations(){
		return $this->fileSystem->count_items( 'participants', '*registration*', TRUE );
	}


	public function get_metadata(){
		$result['registration_count'] = $this->count_registrations();
		$file = "{$this->dataDir}/local_id/lut.csv";
		if ( file_exists( $file ) ){
			$spl = new \SplFileObject( $file );
			while ( $spl->valid() ){
				$spl->fgets();
			}
			$result['lut_entries'] = $spl->key() - 1;
			$result['lut_modified_at'] = date( 'c', filemtime( $file ) );
			$result['lut_size'] = filesize( $file );
			$result['lut_columns'] = $this->read_from_lookup_table();
		}
		return $result;
	}


	public function read_from_lookup_table( $ptcpId = NULL ){
		$file = "{$this->dataDir}/local_id/lut.csv";
		if ( ! file_exists( $file ) ){
			return [];
		}
		$fh = fopen( $file, 'r' );
		while ( ( $line = fgets( $fh ) ) !== FALSE ){
			$data = str_getcsv( $line );
			if ( empty( $colTitles ) ){
				array_shift( $data );
				$colTitles = $data;
				if ( ! $ptcpId ){
					return $colTitles;
				}
				continue;
			}
			$id = array_shift( $data );
			if ( $id == $ptcpId ){
				return array_combine( $colTitles, $data );
			}
		}
		return [];
	}


	public function store_lookup_table( $csvString, $idTitle, $options = [] ){
		$delimiter = $options['delimiter'] ?? ',';
		$enclosure = $options['enclosure'] ?? '"';
		$escape = $options['escape'] ?? '\\';
		$lines = explode( "\n", trim( $csvString ) );
		$lineCount = count( $lines );
		if ( $lineCount > 999999 ){
			return _('CSV data has too many lines');
		}
		$fh = fopen( 'php://memory', 'w' );
		for ( $i = 0; $i < $lineCount; $i++ ){
			if ( strlen( $lines[ $i ] ) > 1024 ){
				return sprintf( _('Line %s is too long'), $i + 1 );
			}
			$arr = str_getcsv( $lines[ $i ], $delimiter, $enclosure, $escape );
			if ( $i == 0 ){
				$colTitles = $arr;
				$colCount = count( $colTitles );
				$idCol = array_search( $idTitle, $colTitles );
				if ( $idCol === FALSE ){
					return _('Specified ID column does not exist');
				}
			}
			if ( count( $arr ) != $colCount ){
				return sprintf( _('Invalid number of columns in line %s'), $i + 1 );
			}
			if ( $idCol ){ // ensure that id is first element
				$id = $arr[ $idCol ];
				unset( $arr[ $idCol ] );
				array_unshift( $arr, $id );
			}
			fputcsv( $fh, $arr );
		}
		rewind( $fh );
		$data = stream_get_contents( $fh );
		if ( ! $data ){
			return -7; // Unknown error
		}
		$dir = "{$this->dataDir}/local_id";
		if ( ! is_dir( $dir ) && ! mkdir( $dir, 0700, TRUE ) ){
			return '!' . _('Could not create storage directory');
		}
		$result = file_put_contents( "{$dir}/lut.csv", rtrim( $data ) );
		if ( ! $result ){
			return '!' . _('Could not store data');
		}
		return TRUE;
	}
}

// end of file local_id.class.php