<?php

namespace Chill\MainBundle\Doctrine\Type;

use Doctrine\DBAL\Types\DateIntervalType;
use Doctrine\DBAL\Platforms\AbstractPlatform;
use Doctrine\DBAL\Types\ConversionException;

/**
 * Re-declare the date interval to use the implementation of date interval in
 * postgreql
 *
 * @author Julien Fastré <julien.fastre@champs-libres.coop>
 */
class NativeDateIntervalType extends DateIntervalType
{
    const FORMAT = '%rP%YY%MM%DDT%HH%IM%SS';
    
    public function getName(): string
    {
        return \Doctrine\DBAL\Types\Type::DATEINTERVAL;
    }

    public function getSQLDeclaration(array $fieldDeclaration, AbstractPlatform $platform): string
    {
        return 'INTERVAL';
    }
    
    /**
     * {@inheritdoc}
     */
    public function convertToDatabaseValue($value, AbstractPlatform $platform)
    {
        if (null === $value) {
            return null;
        }

        if ($value instanceof \DateInterval) {
            return $value->format(self::FORMAT);
        }

        throw ConversionException::conversionFailedInvalidType($value, $this->getName(), ['null', 'DateInterval']);
    }
    
    public function convertToPHPValue($value, AbstractPlatform $platform)
    {
        if ($value === null || $value instanceof \DateInterval) {
            return $value;
        }
        
        try {
            $strings = explode(' ', $value);
            
            if (count($strings) === 0) {
                return null;
            }
            $intervalSpec = 'P';
            \reset($strings);
            
            do {
                $intervalSpec .= $this->convertEntry($strings);
            } while (next($strings) !== FALSE);
            
            return new \DateInterval($intervalSpec);
        } catch (\Exception $exception) {
            throw $this->createConversionException($value, $exception);
        }
    }
    
    private function convertEntry(&$strings)
    {
        $current = \current($strings);
        
        if (is_numeric($current)) {
            $next = \next($strings);
            switch($next) {
                case 'year':
                case 'years':
                    $unit = 'Y';
                    break;
                case 'mon':
                case 'mons': 
                    $unit = 'M';
                    break;
                case 'day':
                case 'days':
                    $unit = 'D';
                    break;
                default:
                    throw $this->createConversionException(implode('', $strings));
            }
            
            return $current.$unit;
            
        } elseif (\preg_match('/([0-9]{2}\:[0-9]{2}:[0-9]{2})/', $current) === 1) {
            $tExploded = explode(':', $current);
            $intervalSpec = 'T';
            $intervalSpec.= $tExploded[0].'H';
            $intervalSpec.= $tExploded[1].'M';
            $intervalSpec.= $tExploded[2].'S';
            
            return $intervalSpec;
        }
    }
    
    protected function createConversionException($value, $exception = null)
    {
        return ConversionException::conversionFailedFormat($value, $this->getName(), 'xx year xx mons xx days 01:02:03', $exception);
    }

}