<?php

//namespace WebPConvert\Convert\Converters\BaseTraits;
namespace WebPConvert\Convert\Converters\ConverterTraits;

/**
 * Trait for converters that supports lossless encoding and thus the "lossless:auto" option.
 *
 * @package    WebPConvert
 * @author     Bjørn Rosell <it@rosell.dk>
 * @since      Class available since Release 2.0.0
 */
trait EncodingAutoTrait
{

    abstract protected function doActualConvert();
    abstract public function getSource();
    abstract public function getDestination();
    abstract public function setDestination($destination);
    abstract public function getOptions();
    abstract protected function setOption($optionName, $optionValue);
    abstract protected function logLn($msg, $style = '');
    abstract protected function log($msg, $style = '');
    abstract protected function ln();
    abstract protected function logReduction($source, $destination);

    public function supportsLossless()
    {
        return true;
    }

    /** Default is to not pass "lossless:auto" on, but implement it.
     *
     *  The Stack converter passes it on (it does not even use this trait)
     *  WPC currently implements it, but this might be configurable in the future.
     *
     */
    public function passOnEncodingAuto()
    {
        return false;
    }

    private function convertTwoAndSelectSmallest()
    {
        $destination = $this->getDestination();
        $destinationLossless = $destination . '.lossless.webp';
        $destinationLossy = $destination . '.lossy.webp';

        $this->logLn(
            'Encoding is set to auto - converting to both lossless and lossy and selecting the smallest file'
        );

        $this->ln();
        $this->logLn('Converting to lossy');
        $this->setDestination($destinationLossy);
        $this->setOption('encoding', 'lossy');
        $this->doActualConvert();
        $this->log('Reduction: ');
        $this->logReduction($this->getSource(), $destinationLossy);
        $this->ln();

        $this->logLn('Converting to lossless');
        $this->setDestination($destinationLossless);
        $this->setOption('encoding', 'lossless');
        $this->doActualConvert();
        $this->log('Reduction: ');
        $this->logReduction($this->getSource(), $destinationLossless);
        $this->ln();

        if (filesize($destinationLossless) > filesize($destinationLossy)) {
            $this->logLn('Picking lossy');
            @unlink($destinationLossless);
            @rename($destinationLossy, $destination);
        } else {
            $this->logLn('Picking lossless');
            @unlink($destinationLossy);
            @rename($destinationLossless, $destination);
        }
        $this->setDestination($destination);
        $this->setOption('encoding', 'auto');
    }

    protected function runActualConvert()
    {
        if (!$this->passOnEncodingAuto() && ($this->getOptions()['encoding'] == 'auto') && $this->supportsLossless()) {
            $this->convertTwoAndSelectSmallest();
        } else {
            $this->doActualConvert();
        }
    }
}
