<?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\FixerDefinition\CodeSample;
use PhpCsFixer\FixerDefinition\FixerDefinition;
use PhpCsFixer\FixerDefinition\FixerDefinitionInterface;
use PhpCsFixer\FixerDefinition\VersionSpecification;
use PhpCsFixer\FixerDefinition\VersionSpecificCodeSample;
use PhpCsFixer\Tokenizer\Token;
use PhpCsFixer\Tokenizer\Tokens;
use PhpCsFixer\Tokenizer\TokensAnalyzer;

final class SelfStaticAccessorFixer extends AbstractFixer
{
    private TokensAnalyzer $tokensAnalyzer;

    public function getDefinition(): FixerDefinitionInterface
    {
        return new FixerDefinition(
            'Inside an enum or `final`/anonymous class, `self` should be preferred over `static`.',
            [
                new CodeSample(
                    '<?php
final class Sample
{
    private static $A = 1;

    public function getBar()
    {
        return static::class.static::test().static::$A;
    }

    private static function test()
    {
        return \'test\';
    }
}
'
                ),
                new CodeSample(
                    '<?php
final class Foo
{
    public function bar()
    {
        return new static();
    }
}
'
                ),
                new CodeSample(
                    '<?php
final class Foo
{
    public function isBar()
    {
        return $foo instanceof static;
    }
}
'
                ),
                new CodeSample(
                    '<?php
$a = new class() {
    public function getBar()
    {
        return static::class;
    }
};
'
                ),
                new VersionSpecificCodeSample(
                    '<?php
enum Foo
{
    public const A = 123;

    public static function bar(): void
    {
        echo static::A;
    }
}
',
                    new VersionSpecification(8_01_00)
                ),
            ]
        );
    }

    public function isCandidate(Tokens $tokens): bool
    {
        $classyTypes = [T_CLASS];

        if (\defined('T_ENUM')) { // @TODO: drop condition when PHP 8.1+ is required
            $classyTypes[] = T_ENUM;
        }

        return $tokens->isTokenKindFound(T_STATIC)
            && $tokens->isAnyTokenKindsFound($classyTypes)
            && $tokens->isAnyTokenKindsFound([T_DOUBLE_COLON, T_NEW, T_INSTANCEOF]);
    }

    /**
     * {@inheritdoc}
     *
     * Must run after FinalClassFixer, FinalInternalClassFixer, FunctionToConstantFixer, PhpUnitTestCaseStaticMethodCallsFixer.
     */
    public function getPriority(): int
    {
        return -10;
    }

    protected function applyFix(\SplFileInfo $file, Tokens $tokens): void
    {
        $classyTokensOfInterest = [[T_CLASS]];

        if (\defined('T_ENUM')) {
            $classyTokensOfInterest[] = [T_ENUM]; // @TODO drop condition when PHP 8.1+ is required
        }

        $this->tokensAnalyzer = new TokensAnalyzer($tokens);
        $classyIndex = $tokens->getNextTokenOfKind(0, $classyTokensOfInterest);

        while (null !== $classyIndex) {
            if ($tokens[$classyIndex]->isGivenKind(T_CLASS)) {
                $modifiers = $this->tokensAnalyzer->getClassyModifiers($classyIndex);

                if (
                    isset($modifiers['final'])
                    || $this->tokensAnalyzer->isAnonymousClass($classyIndex)
                ) {
                    $classyIndex = $this->fixClassy($tokens, $classyIndex);
                }
            } else {
                $classyIndex = $this->fixClassy($tokens, $classyIndex);
            }

            $classyIndex = $tokens->getNextTokenOfKind($classyIndex, $classyTokensOfInterest);
        }
    }

    private function fixClassy(Tokens $tokens, int $index): int
    {
        $index = $tokens->getNextTokenOfKind($index, ['{']);
        $classOpenCount = 1;

        while ($classOpenCount > 0) {
            ++$index;

            if ($tokens[$index]->equals('{')) {
                ++$classOpenCount;

                continue;
            }

            if ($tokens[$index]->equals('}')) {
                --$classOpenCount;

                continue;
            }

            if ($tokens[$index]->isGivenKind(T_FUNCTION)) {
                // do not fix inside lambda
                if ($this->tokensAnalyzer->isLambda($index)) {
                    // figure out where the lambda starts
                    $index = $tokens->getNextTokenOfKind($index, ['{']);
                    $openCount = 1;

                    do {
                        $index = $tokens->getNextTokenOfKind($index, ['}', '{', [T_CLASS]]);
                        if ($tokens[$index]->equals('}')) {
                            --$openCount;
                        } elseif ($tokens[$index]->equals('{')) {
                            ++$openCount;
                        } else {
                            $index = $this->fixClassy($tokens, $index);
                        }
                    } while ($openCount > 0);
                }

                continue;
            }

            if ($tokens[$index]->isGivenKind([T_NEW, T_INSTANCEOF])) {
                $index = $tokens->getNextMeaningfulToken($index);

                if ($tokens[$index]->isGivenKind(T_STATIC)) {
                    $tokens[$index] = new Token([T_STRING, 'self']);
                }

                continue;
            }

            if (!$tokens[$index]->isGivenKind(T_STATIC)) {
                continue;
            }

            $staticIndex = $index;
            $index = $tokens->getNextMeaningfulToken($index);

            if (!$tokens[$index]->isGivenKind(T_DOUBLE_COLON)) {
                continue;
            }

            $tokens[$staticIndex] = new Token([T_STRING, 'self']);
        }

        return $index;
    }
}