<?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\ClassNotation;

use PhpCsFixer\AbstractFixer;
use PhpCsFixer\Fixer\ConfigurationDefinitionFixerInterface;
use PhpCsFixer\Fixer\WhitespacesAwareFixerInterface;
use PhpCsFixer\FixerConfiguration\AliasedFixerOptionBuilder;
use PhpCsFixer\FixerConfiguration\FixerConfigurationResolver;
use PhpCsFixer\FixerConfiguration\FixerOptionBuilder;
use PhpCsFixer\FixerDefinition\CodeSample;
use PhpCsFixer\FixerDefinition\FixerDefinition;
use PhpCsFixer\FixerDefinition\VersionSpecification;
use PhpCsFixer\FixerDefinition\VersionSpecificCodeSample;
use PhpCsFixer\Tokenizer\Token;
use PhpCsFixer\Tokenizer\Tokens;
use PhpCsFixer\Tokenizer\TokensAnalyzer;

/**
 * Fixer for part of the rules defined in PSR2 ¶4.1 Extends and Implements and PSR12 ¶8. Anonymous Classes.
 *
 * @author SpacePossum
 */
final class ClassDefinitionFixer extends AbstractFixer implements ConfigurationDefinitionFixerInterface, WhitespacesAwareFixerInterface
{
    /**
     * {@inheritdoc}
     */
    public function getDefinition()
    {
        return new FixerDefinition(
            'Whitespace around the keywords of a class, trait or interfaces definition should be one space.',
            [
                new CodeSample(
'<?php

class  Foo  extends  Bar  implements  Baz,  BarBaz
{
}

final  class  Foo  extends  Bar  implements  Baz,  BarBaz
{
}

trait  Foo
{
}
'
                ),
                new VersionSpecificCodeSample(
'<?php

$foo = new  class  extends  Bar  implements  Baz,  BarBaz {};
',
                    new VersionSpecification(70100)
                ),
                new CodeSample(
'<?php

class Foo
extends Bar
implements Baz, BarBaz
{}
',
                    ['single_line' => true]
                ),
                new CodeSample(
'<?php

class Foo
extends Bar
implements Baz
{}
',
                    ['single_item_single_line' => true]
                ),
                new CodeSample(
'<?php

interface Bar extends
    Bar, BarBaz, FooBarBaz
{}
',
                    ['multi_line_extends_each_single_line' => true]
                ),
            ]
        );
    }

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

    /**
     * {@inheritdoc}
     */
    protected function applyFix(\SplFileInfo $file, Tokens $tokens)
    {
        // -4, one for count to index, 3 because min. of tokens for a classy location.
        for ($index = $tokens->getSize() - 4; $index > 0; --$index) {
            if ($tokens[$index]->isClassy()) {
                $this->fixClassyDefinition($tokens, $index);
            }
        }
    }

    /**
     * {@inheritdoc}
     */
    protected function createConfigurationDefinition()
    {
        return new FixerConfigurationResolver([
            (new AliasedFixerOptionBuilder(
                new FixerOptionBuilder('multi_line_extends_each_single_line', 'Whether definitions should be multiline.'),
                'multiLineExtendsEachSingleLine'
            ))
                ->setAllowedTypes(['bool'])
                ->setDefault(false)
                ->getOption(),
            (new AliasedFixerOptionBuilder(
                new FixerOptionBuilder('single_item_single_line', 'Whether definitions should be single line when including a single item.'),
                'singleItemSingleLine'
            ))
                ->setAllowedTypes(['bool'])
                ->setDefault(false)
                ->getOption(),
            (new AliasedFixerOptionBuilder(
                new FixerOptionBuilder('single_line', 'Whether definitions should be single line.'),
                'singleLine'
            ))
                ->setAllowedTypes(['bool'])
                ->setDefault(false)
                ->getOption(),
        ]);
    }

    /**
     * @param Tokens $tokens
     * @param int    $classyIndex Class definition token start index
     */
    private function fixClassyDefinition(Tokens $tokens, $classyIndex)
    {
        $classDefInfo = $this->getClassyDefinitionInfo($tokens, $classyIndex);

        // PSR2 4.1 Lists of implements MAY be split across multiple lines, where each subsequent line is indented once.
        // When doing so, the first item in the list MUST be on the next line, and there MUST be only one interface per line.

        if (false !== $classDefInfo['implements']) {
            $classDefInfo['implements'] = $this->fixClassyDefinitionImplements(
                $tokens,
                $classDefInfo['open'],
                $classDefInfo['implements']
            );
        }

        if (false !== $classDefInfo['extends']) {
            $classDefInfo['extends'] = $this->fixClassyDefinitionExtends(
                $tokens,
                false === $classDefInfo['implements'] ? $classDefInfo['open'] : $classDefInfo['implements']['start'],
                $classDefInfo['extends']
            );
        }

        // PSR2: class definition open curly brace must go on a new line.
        // PSR12: anonymous class curly brace on same line if not multi line implements.

        $classDefInfo['open'] = $this->fixClassyDefinitionOpenSpacing($tokens, $classDefInfo);
        if ($classDefInfo['implements']) {
            $end = $classDefInfo['implements']['start'];
        } elseif ($classDefInfo['extends']) {
            $end = $classDefInfo['extends']['start'];
        } else {
            $end = $tokens->getPrevNonWhitespace($classDefInfo['open']);
        }

        // 4.1 The extends and implements keywords MUST be declared on the same line as the class name.
        $this->makeClassyDefinitionSingleLine(
            $tokens,
            $classDefInfo['anonymousClass'] ? $tokens->getPrevMeaningfulToken($classyIndex) : $classDefInfo['start'],
            $end
        );
    }

    /**
     * @param Tokens $tokens
     * @param int    $classOpenIndex
     * @param array  $classExtendsInfo
     *
     * @return array
     */
    private function fixClassyDefinitionExtends(Tokens $tokens, $classOpenIndex, array $classExtendsInfo)
    {
        $endIndex = $tokens->getPrevNonWhitespace($classOpenIndex);

        if ($this->configuration['single_line'] || false === $classExtendsInfo['multiLine']) {
            $this->makeClassyDefinitionSingleLine($tokens, $classExtendsInfo['start'], $endIndex);
            $classExtendsInfo['multiLine'] = false;
        } elseif ($this->configuration['single_item_single_line'] && 1 === $classExtendsInfo['numberOfExtends']) {
            $this->makeClassyDefinitionSingleLine($tokens, $classExtendsInfo['start'], $endIndex);
            $classExtendsInfo['multiLine'] = false;
        } elseif ($this->configuration['multi_line_extends_each_single_line'] && $classExtendsInfo['multiLine']) {
            $this->makeClassyInheritancePartMultiLine($tokens, $classExtendsInfo['start'], $endIndex);
            $classExtendsInfo['multiLine'] = true;
        }

        return $classExtendsInfo;
    }

    /**
     * @param Tokens $tokens
     * @param int    $classOpenIndex
     * @param array  $classImplementsInfo
     *
     * @return array
     */
    private function fixClassyDefinitionImplements(Tokens $tokens, $classOpenIndex, array $classImplementsInfo)
    {
        $endIndex = $tokens->getPrevNonWhitespace($classOpenIndex);

        if ($this->configuration['single_line'] || false === $classImplementsInfo['multiLine']) {
            $this->makeClassyDefinitionSingleLine($tokens, $classImplementsInfo['start'], $endIndex);
            $classImplementsInfo['multiLine'] = false;
        } elseif ($this->configuration['single_item_single_line'] && 1 === $classImplementsInfo['numberOfImplements']) {
            $this->makeClassyDefinitionSingleLine($tokens, $classImplementsInfo['start'], $endIndex);
            $classImplementsInfo['multiLine'] = false;
        } else {
            $this->makeClassyInheritancePartMultiLine($tokens, $classImplementsInfo['start'], $endIndex);
            $classImplementsInfo['multiLine'] = true;
        }

        return $classImplementsInfo;
    }

    /**
     * @param Tokens $tokens
     * @param array  $classDefInfo
     *
     * @return int
     */
    private function fixClassyDefinitionOpenSpacing(Tokens $tokens, array $classDefInfo)
    {
        if ($classDefInfo['anonymousClass']) {
            if (false !== $classDefInfo['implements']) {
                $spacing = $classDefInfo['implements']['multiLine'] ? $this->whitespacesConfig->getLineEnding() : ' ';
            } elseif (false !== $classDefInfo['extends']) {
                $spacing = $classDefInfo['extends']['multiLine'] ? $this->whitespacesConfig->getLineEnding() : ' ';
            } else {
                $spacing = ' ';
            }
        } else {
            $spacing = $this->whitespacesConfig->getLineEnding();
        }

        $openIndex = $tokens->getNextTokenOfKind($classDefInfo['classy'], ['{']);
        if (' ' !== $spacing && false !== strpos($tokens[$openIndex - 1]->getContent(), "\n")) {
            return $openIndex;
        }

        if ($tokens[$openIndex - 1]->isWhitespace()) {
            if (' ' !== $spacing || !$tokens[$tokens->getPrevNonWhitespace($openIndex - 1)]->isComment()) {
                $tokens[$openIndex - 1] = new Token([T_WHITESPACE, $spacing]);
            }

            return $openIndex;
        }

        $tokens->insertAt($openIndex, new Token([T_WHITESPACE, $spacing]));

        return $openIndex + 1;
    }

    /**
     * @param Tokens $tokens
     * @param int    $classyIndex
     *
     * @return array
     */
    private function getClassyDefinitionInfo(Tokens $tokens, $classyIndex)
    {
        $openIndex = $tokens->getNextTokenOfKind($classyIndex, ['{']);
        $prev = $tokens->getPrevMeaningfulToken($classyIndex);
        $startIndex = $tokens[$prev]->isGivenKind([T_FINAL, T_ABSTRACT]) ? $prev : $classyIndex;

        $extends = false;
        $implements = false;
        $anonymousClass = false;

        if (!$tokens[$classyIndex]->isGivenKind(T_TRAIT)) {
            $extends = $tokens->findGivenKind(T_EXTENDS, $classyIndex, $openIndex);
            $extends = \count($extends) ? $this->getClassyInheritanceInfo($tokens, key($extends), 'numberOfExtends') : false;

            if (!$tokens[$classyIndex]->isGivenKind(T_INTERFACE)) {
                $implements = $tokens->findGivenKind(T_IMPLEMENTS, $classyIndex, $openIndex);
                $implements = \count($implements) ? $this->getClassyInheritanceInfo($tokens, key($implements), 'numberOfImplements') : false;
                $tokensAnalyzer = new TokensAnalyzer($tokens);
                $anonymousClass = $tokensAnalyzer->isAnonymousClass($classyIndex);
            }
        }

        return [
            'start' => $startIndex,
            'classy' => $classyIndex,
            'open' => $openIndex,
            'extends' => $extends,
            'implements' => $implements,
            'anonymousClass' => $anonymousClass,
        ];
    }

    /**
     * @param Tokens $tokens
     * @param int    $startIndex
     * @param string $label
     *
     * @return array
     */
    private function getClassyInheritanceInfo(Tokens $tokens, $startIndex, $label)
    {
        $implementsInfo = ['start' => $startIndex, $label => 1, 'multiLine' => false];
        ++$startIndex;
        $endIndex = $tokens->getNextTokenOfKind($startIndex, ['{', [T_IMPLEMENTS], [T_EXTENDS]]);
        $endIndex = $tokens[$endIndex]->equals('{') ? $tokens->getPrevNonWhitespace($endIndex) : $endIndex;
        for ($i = $startIndex; $i < $endIndex; ++$i) {
            if ($tokens[$i]->equals(',')) {
                ++$implementsInfo[$label];

                continue;
            }

            if (!$implementsInfo['multiLine'] && false !== strpos($tokens[$i]->getContent(), "\n")) {
                $implementsInfo['multiLine'] = true;
            }
        }

        return $implementsInfo;
    }

    /**
     * @param Tokens $tokens
     * @param int    $startIndex
     * @param int    $endIndex
     */
    private function makeClassyDefinitionSingleLine(Tokens $tokens, $startIndex, $endIndex)
    {
        for ($i = $endIndex; $i >= $startIndex; --$i) {
            if ($tokens[$i]->isWhitespace()) {
                $prevNonWhite = $tokens->getPrevNonWhitespace($i);
                $nextNonWhite = $tokens->getNextNonWhitespace($i);

                if ($tokens[$prevNonWhite]->isComment() || $tokens[$nextNonWhite]->isComment()) {
                    $content = $tokens[$prevNonWhite]->getContent();
                    if (!('#' === $content || '//' === substr($content, 0, 2))) {
                        $content = $tokens[$nextNonWhite]->getContent();
                        if (!('#' === $content || '//' === substr($content, 0, 2))) {
                            $tokens[$i] = new Token([T_WHITESPACE, ' ']);
                        }
                    }

                    continue;
                }

                if ($tokens[$i + 1]->equalsAny([',', '(', ')']) || $tokens[$i - 1]->equals('(')) {
                    $tokens->clearAt($i);

                    continue;
                }

                $tokens[$i] = new Token([T_WHITESPACE, ' ']);

                continue;
            }

            if ($tokens[$i]->equals(',') && !$tokens[$i + 1]->isWhitespace()) {
                $tokens->insertAt($i + 1, new Token([T_WHITESPACE, ' ']));

                continue;
            }

            if (!$tokens[$i]->isComment()) {
                continue;
            }

            if (!$tokens[$i + 1]->isWhitespace() && !$tokens[$i + 1]->isComment() && false === strpos($tokens[$i]->getContent(), "\n")) {
                $tokens->insertAt($i + 1, new Token([T_WHITESPACE, ' ']));
            }

            if (!$tokens[$i - 1]->isWhitespace() && !$tokens[$i - 1]->isComment()) {
                $tokens->insertAt($i, new Token([T_WHITESPACE, ' ']));
            }
        }
    }

    /**
     * @param Tokens $tokens
     * @param int    $startIndex
     * @param int    $endIndex
     */
    private function makeClassyInheritancePartMultiLine(Tokens $tokens, $startIndex, $endIndex)
    {
        for ($i = $endIndex; $i > $startIndex; --$i) {
            $previousInterfaceImplementingIndex = $tokens->getPrevTokenOfKind($i, [',', [T_IMPLEMENTS], [T_EXTENDS]]);
            $breakAtIndex = $tokens->getNextMeaningfulToken($previousInterfaceImplementingIndex);
            // make the part of a ',' or 'implements' single line
            $this->makeClassyDefinitionSingleLine(
                $tokens,
                $breakAtIndex,
                $i
            );

            // make sure the part is on its own line
            $isOnOwnLine = false;
            for ($j = $breakAtIndex; $j > $previousInterfaceImplementingIndex; --$j) {
                if (false !== strpos($tokens[$j]->getContent(), "\n")) {
                    $isOnOwnLine = true;

                    break;
                }
            }

            if (!$isOnOwnLine) {
                if ($tokens[$breakAtIndex - 1]->isWhitespace()) {
                    $tokens[$breakAtIndex - 1] = new Token([
                        T_WHITESPACE,
                        $this->whitespacesConfig->getLineEnding().$this->whitespacesConfig->getIndent(),
                    ]);
                } else {
                    $tokens->insertAt($breakAtIndex, new Token([T_WHITESPACE, $this->whitespacesConfig->getLineEnding().$this->whitespacesConfig->getIndent()]));
                }
            }

            $i = $previousInterfaceImplementingIndex + 1;
        }
    }
}