<?php

declare(strict_types=1);

namespace Phpml;


< class Pipeline implements Estimator



> use Phpml\Exception\InvalidOperationException;
> 
> class Pipeline implements Estimator, Transformer


{
    /**
     * @var Transformer[]
     */
    private $transformers = [];

    /**

<      * @var Estimator



>      * @var Estimator|null


     */
    private $estimator;

    /**
     * @param Transformer[] $transformers
     */

<     public function __construct(array $transformers, Estimator $estimator)
<     {
<         foreach ($transformers as $transformer) {
<             $this->addTransformer($transformer);
<         }
< 
<         $this->estimator = $estimator;
<     }
< 
<     public function addTransformer(Transformer $transformer): void
<     {
<         $this->transformers[] = $transformer;
<     }
< 
<     public function setEstimator(Estimator $estimator): void



>     public function __construct(array $transformers, ?Estimator $estimator = null)


    {

>         $this->transformers = array_map(static function (Transformer $transformer): Transformer {
        $this->estimator = $estimator;
>             return $transformer;
    }
>         }, $transformers);



    /**
     * @return Transformer[]
     */
    public function getTransformers(): array
    {
        return $this->transformers;
    }


<     public function getEstimator(): Estimator



>     public function getEstimator(): ?Estimator


    {
        return $this->estimator;
    }

    public function train(array $samples, array $targets): void
    {

>         if ($this->estimator === null) {
        foreach ($this->transformers as $transformer) {
>             throw new InvalidOperationException('Pipeline without estimator can\'t use train method');
            $transformer->fit($samples, $targets);
>         }
            $transformer->transform($samples);
> 



<             $transformer->transform($samples);



>             $transformer->transform($samples, $targets);



        $this->estimator->train($samples, $targets);
    }

    /**
     * @return mixed
     */
    public function predict(array $samples)
    {

<         $this->transformSamples($samples);



>         $this->transform($samples);
> 
>         if ($this->estimator === null) {
>             throw new InvalidOperationException('Pipeline without estimator can\'t use predict method');
>         }



        return $this->estimator->predict($samples);
    }


<     private function transformSamples(array &$samples): void



>     public function fit(array $samples, ?array $targets = null): void
>     {
>         foreach ($this->transformers as $transformer) {
>             $transformer->fit($samples, $targets);
>             $transformer->transform($samples, $targets);
>         }
>     }
> 
>     public function transform(array &$samples, ?array &$targets = null): void


    {
        foreach ($this->transformers as $transformer) {

<             $transformer->transform($samples);



>             $transformer->transform($samples, $targets);


        }
    }
}