PgnGameParser.php

<?php


class PgnGameParser{

    private $pgnGame;
    private $defaultFen = 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1';

    private $gameData = array();

    private $specialMetadata = array(
        'event','site','white','black','result','plycount','eco','fen',
        'timecontrol','round','date','annotator','termination'
    );

    public function __construct($pgnGame = null){
        if(isset($pgnGame)){
            $this->pgnGame = trim($pgnGame);
            $this->moveBuilder = new MoveBuilder();
        }
    }

    public function setPgn($pgnGame){
        $this->pgnGame = trim($pgnGame);
        $this->gameData = array();
        $this->moveBuilder = new MoveBuilder();
    }

    public function getParsedData(){
        $this->gameData = $this->getMetadata();
        $this->gameData[CHESS_JSON::MOVE_MOVES] = $this->getMoves();
        return $this->gameData;
    }

    public function getMetadata(){
        $ret = array(
            CHESS_JSON::GAME_METADATA=>array()
        );
        // TODO set lastmoves property by reading last 3-4 moves in moves array
        $lines = explode("\n", $this->pgnGame);
        foreach($lines as $line){
            $line = trim($line);
            if(substr($line, 0, 1) === '[' && substr($line, strlen($line)-1, 1) === ']'){
                $metadata = $this->getMetadataKeyAndValue($line);
                if(in_array($metadata['key'], $this->specialMetadata)){
                    $ret[$metadata['key']] = $metadata['value'];
                }else{
                    $ret[CHESS_JSON::GAME_METADATA][$metadata['key']] = $metadata['value'];
                }
            }
        }
        if(!isset($ret[CHESS_JSON::FEN])) {
            $ret[CHESS_JSON::FEN] = $this->defaultFen;
        }

        return $ret;
    }

    public function getMetadataKeyAndValue($metadataString){
        $metadataString = preg_replace("/[\[\]]/s", "", $metadataString);
        $metadataString = str_replace('"', '', $metadataString);
        $tokens = explode(" ", $metadataString);

        $key = $tokens[0];
        $value = implode(" ", array_slice($tokens, 1));
        $ret = array('key' => $this->getValidKey($key),  'value' => $value );
        return $ret;
    }

    public function getValidKey($key){
        $key = strtolower($key);
        return $key;
    }

    public function getMoves(){
        $parts = $this->getMovesAndComments();
        for($i=0, $count = count($parts); $i<$count; $i++){
            $move = trim($parts[$i]);

            switch($move){
                case '{':
                    if($i==0){
                        $this->moveBuilder->addCommentBeforeFirstMove($parts[$i+1]);
                    }else{
                        $this->moveBuilder->addComment($parts[$i+1]);
                    }
                    $i+=2;
                    break;
                default:
                    $moves = $this->getMovesAndVariationFromString($move);
                    foreach($moves as $move){
                        switch($move){
                            case '(':
                                $this->moveBuilder->startVariation();
                                break;
                            case ')':
                                $this->moveBuilder->endVariation();
                                break;
                            default:
                                $this->moveBuilder->addMoves($move);
                        }
                    }
            }
        }


        return $this->moveBuilder->getMoves();
    }

    public function addGameComment($comment){
        $this->gameData[CHESS_JSON::GAME_METADATA][CHESS_JSON::MOVE_COMMENT] = $comment;
    }

    public function getMovesAndComments(){
        $ret = preg_split("/({|})/s", $this->getMoveString(), 0, PREG_SPLIT_DELIM_CAPTURE);
        if(!$ret[0]){
            $ret = array_slice($ret, 1);
        }
        return $ret;
    }

    public function getMovesAndVariationFromString($string){
        $string = " ". $string;

        $string = preg_replace("/[0-9]+?\./s", "", $string);
        $string = str_replace(" ..", "", $string);
        $string = str_replace("  ", " ", $string);
        $string = trim($string);

        return preg_split("/(\(|\))/s", $string, 0, PREG_SPLIT_DELIM_CAPTURE);
    }

    public function getMoveString() {
        $tokens = preg_split("/\]\n\n/s", $this->pgnGame);
        
        // try again, this time making an allowance for extra whitespace (chess.com)
        if (count($tokens) < 2) {
            $tokens = preg_split("/\]\n(\s+)\n/s", $this->pgnGame);
        }

        if (count($tokens) < 2) {
            return '';
        }

        $gameData = $tokens[1];
        $gameData = str_replace("\n", " ", $gameData);
        $gameData = preg_replace("/(\s+)/", " ", $gameData);

        $gameData = $this->fixPgnInlineComments($gameData);

        return trim($gameData);
    }

    /**
     * https://stackoverflow.com/questions/22487483/regular-expression-to-add-curly-brackets-around-the-comments-in-a-pgn-chess
     */
    public function fixPgnInlineComments($str) {
        $re = '/((?:\s?[\(\)]?\s?[\(\)]?\s?[0-9]{1,3}\.{1,3}\s[NBRQK]?[a-h1-8]?x?[a-hO][1-8-][O-]{0,3}[!?+#=]{0,2}[NBRQ]?[!?+#]{0,2}(?:\s[NBRQK]?[a-h1-8]?x?[a-hO][1-8-][O-]{0,3}[!?+#=]{0,2}[NBRQ]?[!?+#]{0,2})?\s?[()]?\s?[()]?\s?)+)|((?:(?!\s?[\(\)]?\s?[\(\)]?\s?[0-9]{1,3}\.{1,3}\s[NBRQK]?[a-h1-8]?x?[a-hO][1-8-][O-]{0,3}[!?+#=]{0,2}[NBRQ]?[!?+#]{0,2}).)+)/';

        preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);

        $reconstructedPgn = '';

        if (count($matches) === 1) {
            return $matches[0][0];
        }

        foreach ($matches as $match) {
            if (count($match) === 3) {
                $reconstructedPgn .= '{' . $match[0] . '}';
            } else {
                $reconstructedPgn .= $match[0];
            }
        }

        return $reconstructedPgn;
    }
}