abcParser/src/Parser.php

<?php
namespace XaiCorp\AbcParser;

use XaiCorp\AbcParser\Interfaces\Builder;

class Parser {
    /**
     * the abc passed to the parser might be a single tune or
     * it might be a collection of tunes, with extra data outside
     * of each tune. This external data should be applied to each
     * tune and the collection.
     *
     * When reading the abc, the parser should create a new collection
     * and a new Tune object for each tune encountered in the abc.
     * External tools can then deal with that collection as they like.
     *
     */

    //regexp patterns for different lines
    const LN_VERSION = '/^%abc(-\d\.\d)?$/';
    const LN_BLANK = '/^\s*$/';
    const LN_FIELD = '/^\w:(.+)$/';

    const MODE_NO_DATA = 0;
    const MODE_FILE_HEADER = 1;
    const MODE_TUNE_HEADER = 2;
    const MODE_TUNE_BODY = 3;

    const SINGLE_VALUE_KEYS = ['P','Q','L','M','K'];

    public function __construct(Builder $builder)
    {
        $this->builder = $builder;
    }

    /**
     * extract the attributes from the raw abc
     * @param <string> $abc string containing the raw abc
     *
     * @return
     */
    public function parseABC($abc)
    {
        //tune is either new or existing data has been loaded
        //create new setting
        $mode = self::MODE_FILE_HEADER;
        $this->builder->newCollection();
        $tune = null;
        $setting = null;
        $inHistory = false;
        $inTunes = false;
        $music = "";
        $keys_for_Settings = '/K|L|M|P|Q|B|N|D|S|W|Z|F/';
        $keys_for_Tunes = '/H|A|C|G|R|T|O/';
        //scan abc by line and see what the first char is
        foreach (preg_split("/(\r?\n)/", $abc) as $line) {

            if (preg_match(self::LN_BLANK, $line)) {
                if ($mode === self::MODE_TUNE_BODY || $mode === self::MODE_TUNE_HEADER) {
                    $this->builder->storeTune($music);
                    $music = '';
                }

                $mode = self::MODE_NO_DATA;
            } elseif ($mode === self::MODE_TUNE_BODY) {
                $music .= $line . PHP_EOL;
            } elseif (preg_match(self::LN_VERSION, $line)) {
                //this line might contain the abc version.
                //What do we want to do with it?
            } elseif (preg_match(self::LN_FIELD, $line) || $inHistory) {
                if (preg_match(self::LN_FIELD, $line)) { $inHistory = FALSE; }
                //split the line "key:data"
                if($inHistory) {
                    $key  = 'H';
                    $data = $line;
                } else {
                    $key  = substr($line, 0, 1);
                    $data = trim(substr($line, 2));
                }

                if ($key === 'X') {
                    $mode = self::MODE_TUNE_HEADER;
                    $inTunes = true;
                    $this->builder->newTune();
                    $this->builder->newSetting();
                    $music = '';

                    $this->builder->setOnTune('X', $data);

                } elseif (preg_match($keys_for_Tunes, $key)) {
                    if ($key === 'H') {
                        $inHistory = TRUE;
                    } else {
                        $inHistory = FALSE;
                    }
                    if ($key === 'A' || $key === 'C') {
                        $data = $this->builder->newPerson(['name'=>$data]);
                    }
                    if ($mode === self::MODE_FILE_HEADER) {
                        if (in_array($key, self::SINGLE_VALUE_KEYS)) {
                            $this->builder->setOnCollection($key, $data);
                        } else {
                            $this->builder->appendToCollection($key, $data);
                        }
                    } elseif($inTunes) {
                        if (in_array($key, self::SINGLE_VALUE_KEYS)) {
                            $this->builder->setOnTune($key, $data);
                        } else {
                            $this->builder->appendToTune($key, $data);
                        }
                    }

                } elseif (preg_match($keys_for_Settings, $key)) {
                    if ($key === 'K' && $mode === self::MODE_TUNE_HEADER) {
                        $mode = self::MODE_TUNE_BODY;
                    }

                    if ($key === 'Z') {
                        $data = $this->builder->newPerson(['name'=>$data]);
                    }


                    if ($mode == self::MODE_FILE_HEADER) {
                        if (in_array($key, self::SINGLE_VALUE_KEYS)) {
                            $this->builder->setOnCollection($key, $data);
                        } else {
                            $this->builder->appendToCollection($key, $data);
                        }
                    } elseif($inTunes){
                        if (in_array($key, self::SINGLE_VALUE_KEYS)) {
                            $this->builder->setOnSetting($key, $data);
                        } else {
                            $this->builder->appendToSetting($key, $data);
                        }
                    }
                }

            }
        }

        return $this->builder->getCollection();
    }

//    private static function _storeTune($music, &$setting, &$tune, &$tuneCollection) {
//        $setting -> set('music', trim($music));
//        $tune -> append('collection', $setting);
//        $tuneCollection -> append('collection', $tune);
//    }

}