<?php

declare(strict_types=1);

/*
 * 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\LanguageConstruct;

use PhpCsFixer\AbstractFixer;
use PhpCsFixer\Fixer\ConfigurableFixerInterface;
use PhpCsFixer\FixerConfiguration\FixerConfigurationResolver;
use PhpCsFixer\FixerConfiguration\FixerConfigurationResolverInterface;
use PhpCsFixer\FixerConfiguration\FixerOptionBuilder;
use PhpCsFixer\FixerDefinition\CodeSample;
use PhpCsFixer\FixerDefinition\FixerDefinition;
use PhpCsFixer\FixerDefinition\FixerDefinitionInterface;
use PhpCsFixer\Tokenizer\Token;
use PhpCsFixer\Tokenizer\Tokens;

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

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

        $this->callback = 'none' === $this->configuration['space'] ? 'removeWhitespaceAroundToken' : 'ensureWhitespaceAroundToken';
    }

    /**
     * {@inheritdoc}
     */
    public function getDefinition(): FixerDefinitionInterface
    {
        return new FixerDefinition(
            'Equal sign in declare statement should be surrounded by spaces or not following configuration.',
            [
                new CodeSample("<?php\ndeclare(ticks =  1);\n"),
                new CodeSample("<?php\ndeclare(ticks=1);\n", ['space' => 'single']),
            ]
        );
    }

    /**
     * {@inheritdoc}
     *
     * Must run after DeclareStrictTypesFixer.
     */
    public function getPriority(): int
    {
        return 0;
    }

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

    /**
     * {@inheritdoc}
     */
    protected function applyFix(\SplFileInfo $file, Tokens $tokens): void
    {
        $callback = $this->callback;
        for ($index = 0, $count = $tokens->count(); $index < $count - 6; ++$index) {
            if (!$tokens[$index]->isGivenKind(T_DECLARE)) {
                continue;
            }

            while (!$tokens[++$index]->equals('='));

            $this->{$callback}($tokens, $index);
        }
    }

    /**
     * {@inheritdoc}
     */
    protected function createConfigurationDefinition(): FixerConfigurationResolverInterface
    {
        return new FixerConfigurationResolver([
            (new FixerOptionBuilder('space', 'Spacing to apply around the equal sign.'))
                ->setAllowedValues(['single', 'none'])
                ->setDefault('none')
                ->getOption(),
        ]);
    }

    /**
     * @param int $index of `=` token
     */
    private function ensureWhitespaceAroundToken(Tokens $tokens, int $index): void
    {
        if ($tokens[$index + 1]->isWhitespace()) {
            if (' ' !== $tokens[$index + 1]->getContent()) {
                $tokens[$index + 1] = new Token([T_WHITESPACE, ' ']);
            }
        } else {
            $tokens->insertAt($index + 1, new Token([T_WHITESPACE, ' ']));
        }

        if ($tokens[$index - 1]->isWhitespace()) {
            if (' ' !== $tokens[$index - 1]->getContent() && !$tokens[$tokens->getPrevNonWhitespace($index - 1)]->isComment()) {
                $tokens[$index - 1] = new Token([T_WHITESPACE, ' ']);
            }
        } else {
            $tokens->insertAt($index, new Token([T_WHITESPACE, ' ']));
        }
    }

    /**
     * @param int $index of `=` token
     */
    private function removeWhitespaceAroundToken(Tokens $tokens, int $index): void
    {
        if (!$tokens[$tokens->getPrevNonWhitespace($index)]->isComment()) {
            $tokens->removeLeadingWhitespace($index);
        }

        $tokens->removeTrailingWhitespace($index);
    }
}
