<?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_Votings {
	
	public $fileSystem;
	public $baseDir;
	public $dataDir;
	public $eventsClass;


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


	public function set_base_dir( $baseDir ){
		$this->baseDir = trim( $baseDir, '/' );
	}


	public function get_dir( $id ){
		return ( $this->baseDir ? "{$this->baseDir}/" : '' ) . "votings/{$id}";
	}


	public function get_list( $status = NULL, $sortColumn = NULL, $sortDesc = FALSE ){
		$dir = ( $this->baseDir ? "{$this->baseDir}/" : '' ) . 'votings';
		$dirList = $this->fileSystem->get_listing( $dir );
		$votings = array ();
		foreach ( $dirList as $item ){
			if ( ! ( $data = $this->get_data( $item ) ) ){
				continue;
			}
			if ( empty( $status ) || $status == 'all'
				|| in_array( $data['status'], (array) $status )
			){
				$votings[] = $data;
			}
		}
		if ( $votings && $sortColumn ){
			$sortValues = array_column( $votings, $sortColumn );
			$sortValues = array_pad( $sortValues, count( $votings ), NULL );
			$sortOrder = $sortDesc ? SORT_DESC : SORT_ASC;
			array_multisort( $sortValues, $sortOrder, $votings );
		}
		return $votings;
	}


	public function count(){
		$votingList = $this->get_list();
		$stats = [ 'idle' => 0, 'open' => 0, 'closed' => 0, 'finished' => 0 ];
		foreach ( $votingList as $voting ){
			$stats[ $voting['status'] ]++;
		}
		return $stats;
	}


	public function get_data( $id ){
		$dir = $this->get_dir( $id );
		if ( ! $this->fileSystem->exists( $dir ) ){
			return FALSE;
		}
		$msg = $this->fileSystem->get_recent_contents( $dir, '[0-9]*' );
		if ( $msg ){
			$receipt = yaml_parse( $msg );
			$data = $receipt['Voting-Data'] ?? FALSE;
		}
		else {
			$msg = $this->fileSystem->get_contents( "{$dir}/voting-definition" );
			if ( $msg ){
				$receipt = yaml_parse( $msg );
				$data = $receipt['Voting-Data'] ?? FALSE;
			}
		}
		if ( empty( $data ) ){
			return FALSE;
		}
		if ( ! empty( $data['link_target'] ) ){
			$oldBaseDir = $this->baseDir;
			$this->set_base_dir( $this->eventsClass->get_dir( $data['link_target'] ) );
			$targetData = $this->get_data( $id );
			$this->baseDir = $oldBaseDir;
			unset( $targetData['event_id'], $targetData['administrable'],
				$targetData['voting_result'] );
			$data = array_merge( $data, $targetData );
		}
		else {
			$this->update_calculated_fields( $data );
		}

		// Count ballots
		if ( is_object( $GLOBALS['Counter'] ) && $data['status'] != 'idle' ){
			$GLOBALS['Counter']->set_base_dir( $dir );
			$data['ballots_count'] = $GLOBALS['Counter']->get_value('ballots');
			$data['ballots_received'] = $GLOBALS['Counter']->get_value('ballots_received');
		}
		return $data;
	}


	public function purge_data( $data ){
		$validKeys = [
			'id' => 0,
			'name' => 0,
			'type' => 0,
			'title' => 0,
			'short_description' => 0,
			'description' => 0,
			'link_url' => 0,
			'sequence_number' => 0,
			'prerequisites' => 0,
			'selection_limit' => 0,
			'single_vote_only' => 0,
			'segments' => 0,
			'confirm_segment_results' => 0,
			'period_start' => 0,
			'period_end' => 0,
			'options' => 0,
			'comment_rules' => 0,
			'client_data' => 0
		];
		return array_intersect_key( $data, $validKeys );
	}


	public function update_calculated_fields( &$data ){
		$now = time();
		$start = empty( $data['period_start'] ) ? NULL : strtotime( $data['period_start'] );
		$end = empty( $data['period_end'] ) ? NULL : strtotime( $data['period_end'] );
		if ( ! $start || $start > $now ){
			$data['status'] = 'idle';
		}
		elseif ( ! $end || $end > $now ){
			$data['status'] = 'open';
		}
		elseif ( empty( $data['voting_result'] ) ){
			$data['status'] = 'closed';
		}
		else {
			$data['status'] = 'finished';
		}
	}


	public function count_ballots( $votingId ){
		$dir = $this->get_dir( $votingId ) . '/ballots';
		$dirList = $this->fileSystem->get_listing( $dir );
		return count( $dirList ?: [] );
	}


	public function create_interim_count_confirmation( $votingId, $localId, $count ){
		$votingDir = $this->get_dir( $votingId );
		$dir = "{$votingDir}/interim";
		$mtime = $this->fileSystem->get_mtime( $dir );
		if ( $mtime && time() - $mtime <= 5	){
			return;
		}
		require_once 'lib/locker/locker.class.php';
		$locker = new Locker( "{$this->dataDir}/{$votingDir}" );
		if ( $locker->get_lock( 'interim', 5, 1 ) ){
			$msg = new ParTCP_Outgoing_Message( NULL, $localId, 'interim-count-confirmation' );
			$msg->set( 'Ballots-Received', $count );
			$fileName = date('Ymd-His') . '-interim-count-confirmation';
			$this->fileSystem->put_contents( "{$dir}/{$fileName}", $msg->dump( TRUE ) );
			$locker->release_lock('interim');
		}
	}


	public function count_votes( $votingId ){
		$votingData = $this->get_data( $votingId );
		if ( ! $votingData ){
			throw new Exception('Unknown voting');
		}
		$participantCount = 0;
		$invalidVoteCount = 0;
		$result = array ();
		$ballotsDir = $this->get_dir( $votingId ) . '/ballots';
		$dirList = $this->fileSystem->get_listing( $ballotsDir );
		set_time_limit(0);
		foreach ( $dirList as $participant ){
			if ( $participant[0] == '.' ){
				continue;
			}
			$participantCount++;
			$votes = $this->get_participant_votes( $ballotsDir, $participant );
			if ( ! $votes || ! $this->votes_are_valid( $votes, $votingData ) ){
				$invalidVoteCount++;
				continue;
			}
			foreach ( $votes as $vote ){
				if ( empty( $vote['vote'] ) && $vote['vote'] !== 0 ){
					continue;
				}
				$idxOption = 'option:' . $vote['id'];
				$idxVote = 'vote:' . $vote['vote'];
				if ( empty( $result[ $idxOption ][ $idxVote ] ) ){
					$result[ $idxOption ][ $idxVote ] = 1;
				}
				else {
					$result[ $idxOption ][ $idxVote ]++;
				}
			}
		}
		return array (
			'participants' => $participantCount,
			'invalid' => $invalidVoteCount,
			'options' => $result
		);
	}


	public function get_comments( $votingId ){
		$result = [ 'general' => [], 'options' => [] ];
		$ballotsDir = $this->get_dir( $votingId, TRUE ) . '/ballots';
		$dirList = $this->fileSystem->get_listing( $ballotsDir );
		set_time_limit(0);
		foreach ( $dirList as $participant ){
			if ( $participant[0] == '.' ){
				continue;
			}
			$comments = $this->get_participant_comments( $ballotsDir, $participant );
			if ( ! $comments ){
				continue;
			}
			$result = array_merge_recursive( $result, $comments );
		}
		foreach ( $result['options'] as $key => $option ){
			ksort( $option, SORT_NATURAL );
			$result['options'][ $key ] = $option;
		}
		ksort( $result['options'] );
		return $result;
	}


	public function get_all_votes( $votingId ){
		$result = [];
		$ballotsDir = $this->get_dir( $votingId, TRUE ) . '/ballots';
		$dirList = $this->fileSystem->get_listing( $ballotsDir );
		set_time_limit(0);
		foreach ( $dirList as $participant ){
			if ( $participant[0] == '.' ){
				continue;
			}
			$votes = $this->get_participant_votes( $ballotsDir, $participant );
			if ( ! $votes ){
				continue;
			}
			$result[ $participant ] = $votes;
		}
		return $result;
	}


	public function get_participant_segments( $eventData, $ptcpId ){
		$segments = [];
		$votes = [];
		foreach( $eventData['segments'] ?? [] as $segmentId => $segmentDef ){
			$votingId = $segmentDef['voting_id'];
			$optionId = $segmentDef['option_id'];
			if ( ! isset( $votes[ $votingId ] ) ){
				$ballotsDir = "{$this->get_dir( $votingId )}/ballots";
				$ptcpVotes = $this->get_participant_votes( $ballotsDir, $ptcpId );
				$votes[ $votingId ] = $ptcpVotes ?
					array_column( $ptcpVotes, 'data', 'id' ) : [];
			}
			$segments[ $segmentId ] = $votes[ $votingId ][ $optionId ] ?? NULL;
		}
		return $segments;
	}


	public function has_participant_voted( $votingId, $ptcpId ){
		$dir = $this->get_dir( $votingId ) . "/ballots/{$ptcpId}";
		return $this->fileSystem->is_not_empty( $dir );
	}


	public function get_segment_results( $eventData, $votingData, $ptcpId ){
		$segmentId = $votingData['confirm_segment_results'];
		$ptcpSegments = $this->get_participant_segments( $eventData, $ptcpId );
		if ( empty( $ptcpSegments[ $segmentId ] ) ){
			return NULL;
		}
		$dir = "{$this->dataDir}/event_segments/{$eventData['shortcode']}/"
			. "{$segmentId}/{$ptcpSegments[ $segmentId ]}";
		$list = glob( "{$dir}/*" ) OR [];
		// collect voting options to be included in segment results
		//$options = array_filter( $votingData['options'], function( $o ){
		//	return ! empty( $o['confirm_segment_results'] );
		//});
		//$optionsIds = array_column( $options, 'id' );
		$options = array_combine( array_column( $votingData['options'], 'id' ),
			$votingData['options'] );
		// compile result sets
		$sets = [];
		$allVotes = [];
		//$setIdx = 97; // ASCII value of letter 'a'
		$i = 0;
		foreach ( $list as $path ){
		//for ( $i = 0; $i < count( $list ); $i++ ){
			$setIdx = chr( $i + 97 ); // 97 = ASCII value of letter 'a'
			//$ptcpId = basename( $list[ $i ] );
			$ptcpId = basename( $path );
			$votingDir = $this->get_dir( $votingData['id'] );
			$votes = $this->get_participant_votes( "{$votingDir}/ballots", $ptcpId );
			if ( ! $votes ){
				continue;
			}
			//$votes = array_filter( $votes, function( $v ) use( $optionsIds ){
			//	return in_array( $v['id'], $optionsIds );
			//});
			//array_walk( $votes, function( &$v ) use( $optionsIds ){
			//	if ( ! in_array( $v['id'], $optionsIds ) ){
			//		$v['data'] = NULL;
			//	}
			//});
			array_walk( $votes, function( &$vote ) use( $options, $i ){
				$rules = $options[ $vote['id'] ]['confirm_segment_results_rules'] ?? [];
				//var_dump( $rules );
				foreach ( $rules as $rule ){
					if ( $rule['round'] <= $i + 1 ){
						$vote['data'] = $rule['value'];
					}
				}
			});
			$keys = array_keys( $allVotes, $votes );
			if ( $keys ){
				array_push( $sets[ $keys[0] ], $ptcpId );
			}
			else {
				$sets[ $setIdx ] = [ $ptcpId ];
				$allVotes[ $setIdx ] = $votes;
			}
			$i++;
		}
		//var_dump( $allVotes );
		// compile result options
		$options = [];
		for ( $i = 0; $i < count( $allVotes ); $i++ ){
			$setIdx = chr( $i + 97 );
			$votes = $allVotes[ $setIdx ] ?? [];
			foreach ( $votes as $key => $vote ){
				if ( ! isset( $vote['vote'] ) || is_null( $vote['vote'] ) ){
					continue;
				}
				$idxOption = "option:{$vote['id']}";
				$idxSet = "set:{$setIdx}";
				$options[ $idxOption ][ $idxSet ] = $vote['vote'];
			}
		}
		return [ 'result_sets' => $sets, 'options' => $options ];
	}


	private function get_participant_votes( $ballotsDir, $ptcpId ){
		$dir = "{$ballotsDir}/{$ptcpId}";
		$listing = $this->fileSystem->get_listing( $dir, 'ballot*', TRUE );
		foreach ( $listing as $fileName ){
			$receipt = yaml_parse( $this->fileSystem->get_contents( "{$dir}/{$fileName}" ) );
			if ( empty( $receipt['Original-Message'] )
				|| ! empty( $receipt['Error'] )
			){
				continue;
			}
			$ballot = yaml_parse( $receipt['Original-Message'] );
			if ( empty( $ballot['Votes'] ) ){
				continue;
			}
			return $ballot['Votes'];
		}
		return FALSE;
	}


	private function get_participant_comments( $ballotsDir, $ptcpId ){
		$dir = "{$ballotsDir}/{$ptcpId}";
		$listing = $this->fileSystem->get_listing( $dir, 'ballot*', TRUE );
		foreach ( $listing as $fileName ){
			$receipt = yaml_parse( $this->fileSystem->get_contents( "{$dir}/{$fileName}" ) );
			if ( empty( $receipt['Original-Message'] )
				|| ! empty( $receipt['Error'] )
			){
				continue;
			}
			$ballot = yaml_parse( $receipt['Original-Message'] );
			$general = empty( $ballot['Comment'] ) ? [] : [ $ballot['Comment'] ];
			$options = [];
			foreach ( $ballot['Votes'] as $vote ){
				if ( empty( $vote['comment'] ) ){
					continue;
				}
				$idxOption = 'option:' . $vote['id'];
				$idxVote = 'vote:' . $vote['vote'];
				$options[ $idxOption ][ $idxVote ][] = $vote['comment'];
			}
			return compact( 'general', 'options' );
		}
		return FALSE;
	}


	private function votes_are_valid( $votes, $votingData ){
		$votes = array_column( $votes, NULL, 'id' );
		$options = array_column( $votingData['options'], NULL, 'id' );
		foreach ( $votes as $id => $data ){
			$option = $options[ $id ] ?? NULL;
			if ( ! $option ){
				return FALSE;
			}
			$type = $votingData['type'] == 'mixed' ?
				( $option['type'] ?? NULL ) : $votingData['type'];
			if ( ! $type ){
				return FALSE;
			}
			if ( $type == 'checkbox' && $data['vote'] !== 1 && $data['vote'] !== 0 ){
				return FALSE;
			}
		}
		// TODO: bei multiple-choice prüfen, ob Anzahl der gewählten Optionen korrekt ist
		foreach ( $options as $id => $data ){
			if ( ! empty( $data['required'] ) && empty( $votes[ $id ] ) ){
				return FALSE; // required element is missing
			}
		}
		return TRUE;
	}
}

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