<?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\ControlStructure;

use PhpCsFixer\AbstractFixer;
use PhpCsFixer\Fixer\ConfigurableFixerInterface;
use PhpCsFixer\Fixer\WhitespacesAwareFixerInterface;
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\Preg;
use PhpCsFixer\Tokenizer\Analyzer\WhitespacesAnalyzer;
use PhpCsFixer\Tokenizer\Token;
use PhpCsFixer\Tokenizer\Tokens;
use Symfony\Component\OptionsResolver\Exception\InvalidOptionsException;
use Symfony\Component\OptionsResolver\Options;

/**
 * Fixer for rule defined in PSR2 ¶5.2.
 */
final class NoBreakCommentFixer extends AbstractFixer implements ConfigurableFixerInterface, WhitespacesAwareFixerInterface
{
    public function getDefinition(): FixerDefinitionInterface
    {
        return new FixerDefinition(
            'There must be a comment when fall-through is intentional in a non-empty case body.',
            [
                new CodeSample(
                    '<?php
switch ($foo) {
    case 1:
        foo();
    case 2:
        bar();
        // no break
        break;
    case 3:
        baz();
}
'
                ),
                new CodeSample(
                    '<?php
switch ($foo) {
    case 1:
        foo();
    case 2:
        foo();
}
',
                    ['comment_text' => 'some comment']
                ),
            ],
            'Adds a "no break" comment before fall-through cases, and removes it if there is no fall-through.'
        );
    }

    public function isCandidate(Tokens $tokens): bool
    {
        return $tokens->isTokenKindFound(T_SWITCH);
    }

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

    protected function createConfigurationDefinition(): FixerConfigurationResolverInterface
    {
        return new FixerConfigurationResolver([
            (new FixerOptionBuilder('comment_text', 'The text to use in the added comment and to detect it.'))
                ->setAllowedTypes(['string'])
                ->setAllowedValues([
                    static function (string $value): bool {
                        if (Preg::match('/\R/', $value)) {
                            throw new InvalidOptionsException('The comment text must not contain new lines.');
                        }

                        return true;
                    },
                ])
                ->setNormalizer(static fn (Options $options, string $value): string => rtrim($value))
                ->setDefault('no break')
                ->getOption(),
        ]);
    }

    protected function applyFix(\SplFileInfo $file, Tokens $tokens): void
    {
        for ($index = \count($tokens) - 1; $index >= 0; --$index) {
            if ($tokens[$index]->isGivenKind(T_DEFAULT)) {
                if ($tokens[$tokens->getNextMeaningfulToken($index)]->isGivenKind(T_DOUBLE_ARROW)) {
                    continue; // this is "default" from "match"
                }
            } elseif (!$tokens[$index]->isGivenKind(T_CASE)) {
                continue;
            }

            $this->fixCase($tokens, $tokens->getNextTokenOfKind($index, [':', ';']));
        }
    }

    private function fixCase(Tokens $tokens, int $casePosition): void
    {
        $empty = true;
        $fallThrough = true;
        $commentPosition = null;

        for ($i = $casePosition + 1, $max = \count($tokens); $i < $max; ++$i) {
            if ($tokens[$i]->isGivenKind([...self::getParenthesisedStructureKinds(), T_ELSE, T_DO, T_CLASS])) {
                $empty = false;
                $i = $this->getStructureEnd($tokens, $i);

                continue;
            }

            if ($tokens[$i]->isGivenKind([T_BREAK, T_CONTINUE, T_RETURN, T_EXIT, T_GOTO])) {
                $fallThrough = false;

                continue;
            }

            if ($tokens[$i]->isGivenKind(T_THROW)) {
                $previousIndex = $tokens->getPrevMeaningfulToken($i);

                if ($previousIndex === $casePosition || $tokens[$previousIndex]->equalsAny(['{', ';', '}', [T_OPEN_TAG]])) {
                    $fallThrough = false;
                }

                continue;
            }

            if ($tokens[$i]->equals('}') || $tokens[$i]->isGivenKind(T_ENDSWITCH)) {
                if (null !== $commentPosition) {
                    $this->removeComment($tokens, $commentPosition);
                }

                break;
            }

            if ($this->isNoBreakComment($tokens[$i])) {
                $commentPosition = $i;

                continue;
            }

            if ($tokens[$i]->isGivenKind([T_CASE, T_DEFAULT])) {
                if (!$empty && $fallThrough) {
                    if (null !== $commentPosition && $tokens->getPrevNonWhitespace($i) !== $commentPosition) {
                        $this->removeComment($tokens, $commentPosition);
                        $commentPosition = null;
                    }

                    if (null === $commentPosition) {
                        $this->insertCommentAt($tokens, $i);
                    } else {
                        $text = $this->configuration['comment_text'];
                        $tokens[$commentPosition] = new Token([
                            $tokens[$commentPosition]->getId(),
                            str_ireplace($text, $text, $tokens[$commentPosition]->getContent()),
                        ]);

                        $this->ensureNewLineAt($tokens, $commentPosition);
                    }
                } elseif (null !== $commentPosition) {
                    $this->removeComment($tokens, $commentPosition);
                }

                break;
            }

            if (!$tokens[$i]->isGivenKind([T_COMMENT, T_WHITESPACE])) {
                $empty = false;
            }
        }
    }

    private function isNoBreakComment(Token $token): bool
    {
        if (!$token->isComment()) {
            return false;
        }

        $text = preg_quote($this->configuration['comment_text'], '~');

        return Preg::match("~^((//|#)\\s*{$text}\\s*)|(/\\*\\*?\\s*{$text}(\\s+.*)*\\*/)$~i", $token->getContent());
    }

    private function insertCommentAt(Tokens $tokens, int $casePosition): void
    {
        $lineEnding = $this->whitespacesConfig->getLineEnding();
        $newlinePosition = $this->ensureNewLineAt($tokens, $casePosition);
        $newlineToken = $tokens[$newlinePosition];
        $nbNewlines = substr_count($newlineToken->getContent(), $lineEnding);

        if ($newlineToken->isGivenKind(T_OPEN_TAG) && Preg::match('/\R/', $newlineToken->getContent())) {
            ++$nbNewlines;
        } elseif ($tokens[$newlinePosition - 1]->isGivenKind(T_OPEN_TAG) && Preg::match('/\R/', $tokens[$newlinePosition - 1]->getContent())) {
            ++$nbNewlines;

            if (!Preg::match('/\R/', $newlineToken->getContent())) {
                $tokens[$newlinePosition] = new Token([$newlineToken->getId(), $lineEnding.$newlineToken->getContent()]);
            }
        }

        if ($nbNewlines > 1) {
            Preg::match('/^(.*?)(\R\h*)$/s', $newlineToken->getContent(), $matches);

            $indent = WhitespacesAnalyzer::detectIndent($tokens, $newlinePosition - 1);
            $tokens[$newlinePosition] = new Token([$newlineToken->getId(), $matches[1].$lineEnding.$indent]);
            $tokens->insertAt(++$newlinePosition, new Token([T_WHITESPACE, $matches[2]]));
        }

        $tokens->insertAt($newlinePosition, new Token([T_COMMENT, '// '.$this->configuration['comment_text']]));
        $this->ensureNewLineAt($tokens, $newlinePosition);
    }

    /**
     * @return int The newline token position
     */
    private function ensureNewLineAt(Tokens $tokens, int $position): int
    {
        $lineEnding = $this->whitespacesConfig->getLineEnding();
        $content = $lineEnding.WhitespacesAnalyzer::detectIndent($tokens, $position);
        $whitespaceToken = $tokens[$position - 1];

        if (!$whitespaceToken->isGivenKind(T_WHITESPACE)) {
            if ($whitespaceToken->isGivenKind(T_OPEN_TAG)) {
                $content = Preg::replace('/\R/', '', $content);

                if (!Preg::match('/\R/', $whitespaceToken->getContent())) {
                    $tokens[$position - 1] = new Token([T_OPEN_TAG, Preg::replace('/\s+$/', $lineEnding, $whitespaceToken->getContent())]);
                }
            }

            if ('' !== $content) {
                $tokens->insertAt($position, new Token([T_WHITESPACE, $content]));

                return $position;
            }

            return $position - 1;
        }

        if ($tokens[$position - 2]->isGivenKind(T_OPEN_TAG) && Preg::match('/\R/', $tokens[$position - 2]->getContent())) {
            $content = Preg::replace('/^\R/', '', $content);
        }

        if (!Preg::match('/\R/', $whitespaceToken->getContent())) {
            $tokens[$position - 1] = new Token([T_WHITESPACE, $content]);
        }

        return $position - 1;
    }

    private function removeComment(Tokens $tokens, int $commentPosition): void
    {
        if ($tokens[$tokens->getPrevNonWhitespace($commentPosition)]->isGivenKind(T_OPEN_TAG)) {
            $whitespacePosition = $commentPosition + 1;
            $regex = '/^\R\h*/';
        } else {
            $whitespacePosition = $commentPosition - 1;
            $regex = '/\R\h*$/';
        }

        $whitespaceToken = $tokens[$whitespacePosition];

        if ($whitespaceToken->isGivenKind(T_WHITESPACE)) {
            $content = Preg::replace($regex, '', $whitespaceToken->getContent());

            $tokens->ensureWhitespaceAtIndex($whitespacePosition, 0, $content);
        }

        $tokens->clearTokenAndMergeSurroundingWhitespace($commentPosition);
    }

    private function getStructureEnd(Tokens $tokens, int $position): int
    {
        $initialToken = $tokens[$position];

        if ($initialToken->isGivenKind(self::getParenthesisedStructureKinds())) {
            $position = $tokens->findBlockEnd(
                Tokens::BLOCK_TYPE_PARENTHESIS_BRACE,
                $tokens->getNextTokenOfKind($position, ['('])
            );
        } elseif ($initialToken->isGivenKind(T_CLASS)) {
            $openParenthesisPosition = $tokens->getNextMeaningfulToken($position);

            if ('(' === $tokens[$openParenthesisPosition]->getContent()) {
                $position = $tokens->findBlockEnd(
                    Tokens::BLOCK_TYPE_PARENTHESIS_BRACE,
                    $openParenthesisPosition
                );
            }
        }

        $position = $tokens->getNextMeaningfulToken($position);

        if ('{' !== $tokens[$position]->getContent()) {
            return $tokens->getNextTokenOfKind($position, [';']);
        }

        $position = $tokens->findBlockEnd(Tokens::BLOCK_TYPE_CURLY_BRACE, $position);

        if ($initialToken->isGivenKind(T_DO)) {
            $position = $tokens->findBlockEnd(
                Tokens::BLOCK_TYPE_PARENTHESIS_BRACE,
                $tokens->getNextTokenOfKind($position, ['('])
            );

            return $tokens->getNextTokenOfKind($position, [';']);
        }

        return $position;
    }

    /**
     * @return array<int>
     */
    private static function getParenthesisedStructureKinds(): array
    {
        static $structureKinds = null;

        if (null === $structureKinds) {
            $structureKinds = [T_FOR, T_FOREACH, T_WHILE, T_IF, T_ELSEIF, T_SWITCH, T_FUNCTION];
            if (\defined('T_MATCH')) { // @TODO: drop condition when PHP 8.0+ is required
                $structureKinds[] = T_MATCH;
            }
        }

        return $structureKinds;
    }
}
