<?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\ClassNotation;

use PhpCsFixer\AbstractFixer;
use PhpCsFixer\Fixer\ConfigurableFixerInterface;
use PhpCsFixer\FixerConfiguration\AllowedValueSubset;
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\CT;
use PhpCsFixer\Tokenizer\Token;
use PhpCsFixer\Tokenizer\Tokens;
use PhpCsFixer\Tokenizer\TokensAnalyzer;

/**
 * Fixer for rules defined in PSR2 ¶4.3, ¶4.5.
 *
 * @author Dariusz Rumiński <dariusz.ruminski@gmail.com>
 */
final class VisibilityRequiredFixer extends AbstractFixer implements ConfigurableFixerInterface
{
    /**
     * {@inheritdoc}
     */
    public function getDefinition(): FixerDefinitionInterface
    {
        return new FixerDefinition(
            'Visibility MUST be declared on all properties and methods; `abstract` and `final` MUST be declared before the visibility; `static` MUST be declared after the visibility.',
            [
                new CodeSample(
                    '<?php
class Sample
{
    var $a;
    static protected $var_foo2;

    function A()
    {
    }
}
'
                ),
                new CodeSample(
                    '<?php
class Sample
{
    const SAMPLE = 1;
}
',
                    ['elements' => ['const']]
                ),
            ]
        );
    }

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

    /**
     * {@inheritdoc}
     */
    protected function createConfigurationDefinition(): FixerConfigurationResolverInterface
    {
        return new FixerConfigurationResolver([
            (new FixerOptionBuilder('elements', 'The structural elements to fix (PHP >= 7.1 required for `const`).'))
                ->setAllowedTypes(['array'])
                ->setAllowedValues([new AllowedValueSubset(['property', 'method', 'const'])])
                ->setDefault(['property', 'method', 'const'])
                ->getOption(),
        ]);
    }

    /**
     * {@inheritdoc}
     */
    protected function applyFix(\SplFileInfo $file, Tokens $tokens): void
    {
        $tokensAnalyzer = new TokensAnalyzer($tokens);

        $propertyTypeDeclarationKinds = [T_STRING, T_NS_SEPARATOR, CT::T_NULLABLE_TYPE, CT::T_ARRAY_TYPEHINT, CT::T_TYPE_ALTERNATION, CT::T_TYPE_INTERSECTION];

        if (\defined('T_READONLY')) { // @TODO: drop condition when PHP 8.1+ is required
            $propertyReadOnlyType = T_READONLY;
            $propertyTypeDeclarationKinds[] = T_READONLY;
        } else {
            $propertyReadOnlyType = -999;
        }

        $expectedKindsGeneric = [T_ABSTRACT, T_FINAL, T_PRIVATE, T_PROTECTED, T_PUBLIC, T_STATIC, T_VAR];
        $expectedKindsPropertyKinds = array_merge($expectedKindsGeneric, $propertyTypeDeclarationKinds);

        foreach (array_reverse($tokensAnalyzer->getClassyElements(), true) as $index => $element) {
            if (!\in_array($element['type'], $this->configuration['elements'], true)) {
                continue;
            }

            $abstractFinalIndex = null;
            $visibilityIndex = null;
            $staticIndex = null;
            $typeIndex = null;
            $readOnlyIndex = null;
            $prevIndex = $tokens->getPrevMeaningfulToken($index);
            $expectedKinds = 'property' === $element['type']
                ? $expectedKindsPropertyKinds
                : $expectedKindsGeneric
            ;

            while ($tokens[$prevIndex]->isGivenKind($expectedKinds)) {
                if ($tokens[$prevIndex]->isGivenKind([T_ABSTRACT, T_FINAL])) {
                    $abstractFinalIndex = $prevIndex;
                } elseif ($tokens[$prevIndex]->isGivenKind(T_STATIC)) {
                    $staticIndex = $prevIndex;
                } elseif ($tokens[$prevIndex]->isGivenKind($propertyReadOnlyType)) {
                    $readOnlyIndex = $prevIndex;
                } elseif ($tokens[$prevIndex]->isGivenKind($propertyTypeDeclarationKinds)) {
                    $typeIndex = $prevIndex;
                } else {
                    $visibilityIndex = $prevIndex;
                }

                $prevIndex = $tokens->getPrevMeaningfulToken($prevIndex);
            }

            if (null !== $typeIndex) {
                $index = $typeIndex;
            }

            if ($tokens[$prevIndex]->equals(',')) {
                continue;
            }

            $swapIndex = $staticIndex ?? $readOnlyIndex; // "static" property cannot be "readonly", so there can always be at most one swap

            if (null !== $swapIndex) {
                if ($this->isKeywordPlacedProperly($tokens, $swapIndex, $index)) {
                    $index = $swapIndex;
                } else {
                    $this->moveTokenAndEnsureSingleSpaceFollows($tokens, $swapIndex, $index);
                }
            }

            if (null === $visibilityIndex) {
                $tokens->insertAt($index, [new Token([T_PUBLIC, 'public']), new Token([T_WHITESPACE, ' '])]);
            } else {
                if ($tokens[$visibilityIndex]->isGivenKind(T_VAR)) {
                    $tokens[$visibilityIndex] = new Token([T_PUBLIC, 'public']);
                }
                if ($this->isKeywordPlacedProperly($tokens, $visibilityIndex, $index)) {
                    $index = $visibilityIndex;
                } else {
                    $this->moveTokenAndEnsureSingleSpaceFollows($tokens, $visibilityIndex, $index);
                }
            }

            if (null === $abstractFinalIndex) {
                continue;
            }

            if ($this->isKeywordPlacedProperly($tokens, $abstractFinalIndex, $index)) {
                continue;
            }

            $this->moveTokenAndEnsureSingleSpaceFollows($tokens, $abstractFinalIndex, $index);
        }
    }

    private function isKeywordPlacedProperly(Tokens $tokens, int $keywordIndex, int $comparedIndex): bool
    {
        return $keywordIndex + 2 === $comparedIndex && ' ' === $tokens[$keywordIndex + 1]->getContent();
    }

    private function moveTokenAndEnsureSingleSpaceFollows(Tokens $tokens, int $fromIndex, int $toIndex): void
    {
        $tokens->insertAt($toIndex, [$tokens[$fromIndex], new Token([T_WHITESPACE, ' '])]);
        $tokens->clearAt($fromIndex);

        if ($tokens[$fromIndex + 1]->isWhitespace()) {
            $tokens->clearAt($fromIndex + 1);
        }
    }
}
