<?php

/*
 * This file is part of PHP CS Fixer.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *     Dariusz Rumiński <dariusz.ruminski@gmail.com>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

namespace PhpCsFixer\Fixer\PhpUnit;

use PhpCsFixer\AbstractFixer;
use PhpCsFixer\Fixer\ConfigurationDefinitionFixerInterface;
use PhpCsFixer\FixerConfiguration\FixerConfigurationResolver;
use PhpCsFixer\FixerConfiguration\FixerOptionBuilder;
use PhpCsFixer\FixerDefinition\CodeSample;
use PhpCsFixer\FixerDefinition\FixerDefinition;
use PhpCsFixer\Tokenizer\Token;
use PhpCsFixer\Tokenizer\Tokens;

/**
 * @author Dariusz Rumiński <dariusz.ruminski@gmail.com>
 */
final class PhpUnitNamespacedFixer extends AbstractFixer implements ConfigurationDefinitionFixerInterface
{
    /**
     * @var string
     */
    private $originalClassRegEx;

    /**
     * {@inheritdoc}
     */
    public function getDefinition()
    {
        return new FixerDefinition(
            'PHPUnit classes MUST be used in namespaced version, eg `\PHPUnit\Framework\TestCase` instead of `\PHPUnit_Framework_TestCase`.',
            [
                new CodeSample(
'<?php
final class MyTest extends \PHPUnit_Framework_TestCase
{
}
'
                ),
            ],
            "PHPUnit v6 has finally fully switched to namespaces.\n"
            ."You could start preparing the upgrade by switching from non-namespaced TestCase to namespaced one.\n"
            .'Forward compatibility layer (`\PHPUnit\Framework\TestCase` class) was backported to PHPUnit v4.8.35 and PHPUnit v5.4.0.'."\n"
            .'Extended forward compatibility layer (`PHPUnit\Framework\Assert`, `PHPUnit\Framework\BaseTestListener`, `PHPUnit\Framework\TestListener` classes) was introduced in v5.7.0.'."\n",
            'Risky when PHPUnit classes are overridden or not accessible, or when project has PHPUnit incompatibilities.'
        );
    }

    /**
     * {@inheritdoc}
     */
    public function isCandidate(Tokens $tokens)
    {
        return $tokens->isTokenKindFound(T_STRING);
    }

    /**
     * {@inheritdoc}
     */
    public function isRisky()
    {
        return true;
    }

    /**
     * {@inheritdoc}
     */
    public function configure(array $configuration = null)
    {
        parent::configure($configuration);

        if (PhpUnitTargetVersion::fulfills($this->configuration['target'], PhpUnitTargetVersion::VERSION_6_0)) {
            $this->originalClassRegEx = '/^PHPUnit_\w+$/i';
        } elseif (PhpUnitTargetVersion::fulfills($this->configuration['target'], PhpUnitTargetVersion::VERSION_5_7)) {
            $this->originalClassRegEx = '/^PHPUnit_Framework_TestCase|PHPUnit_Framework_Assert|PHPUnit_Framework_BaseTestListener|PHPUnit_Framework_TestListener$/i';
        } else {
            $this->originalClassRegEx = '/^PHPUnit_Framework_TestCase$/i';
        }
    }

    /**
     * {@inheritdoc}
     */
    protected function applyFix(\SplFileInfo $file, Tokens $tokens)
    {
        $importedOriginalClassesMap = [];
        $currIndex = 0;

        while (null !== $currIndex) {
            $currIndex = $tokens->getNextTokenOfKind($currIndex, [[T_STRING]]);

            if (null === $currIndex) {
                break;
            }

            $originalClass = $tokens[$currIndex]->getContent();

            if (1 !== preg_match($this->originalClassRegEx, $originalClass)) {
                ++$currIndex;

                continue;
            }

            $substituteTokens = $this->generateReplacement($originalClass);

            $tokens->clearAt($currIndex);
            $tokens->insertAt(
                $currIndex,
                isset($importedOriginalClassesMap[$originalClass]) ? $substituteTokens[$substituteTokens->getSize() - 1] : $substituteTokens
            );

            $prevIndex = $tokens->getPrevMeaningfulToken($currIndex);
            if ($tokens[$prevIndex]->isGivenKind(T_USE)) {
                $importedOriginalClassesMap[$originalClass] = true;
            } elseif ($tokens[$prevIndex]->isGivenKind(T_NS_SEPARATOR)) {
                $prevIndex = $tokens->getPrevMeaningfulToken($prevIndex);

                if ($tokens[$prevIndex]->isGivenKind(T_USE)) {
                    $importedOriginalClassesMap[$originalClass] = true;
                }
            }
        }
    }

    /**
     * {@inheritdoc}
     */
    protected function createConfigurationDefinition()
    {
        return new FixerConfigurationResolver([
            (new FixerOptionBuilder('target', 'Target version of PHPUnit.'))
                ->setAllowedTypes(['string'])
                ->setAllowedValues([PhpUnitTargetVersion::VERSION_4_8, PhpUnitTargetVersion::VERSION_5_7, PhpUnitTargetVersion::VERSION_6_0, PhpUnitTargetVersion::VERSION_NEWEST])
                ->setDefault(PhpUnitTargetVersion::VERSION_NEWEST)
                ->getOption(),
        ]);
    }

    /**
     * @param string $originalClassName
     *
     * @return Tokens
     */
    private function generateReplacement($originalClassName)
    {
        $parts = explode('_', $originalClassName);

        $tokensArray = [];
        while (!empty($parts)) {
            $tokensArray[] = new Token([T_STRING, array_shift($parts)]);
            if (!empty($parts)) {
                $tokensArray[] = new Token([T_NS_SEPARATOR, '\\']);
            }
        }

        return Tokens::fromArray($tokensArray);
    }
}
