<?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\Phpdoc;

use PhpCsFixer\AbstractFixer;
use PhpCsFixer\FixerDefinition\CodeSample;
use PhpCsFixer\FixerDefinition\FixerDefinition;
use PhpCsFixer\Preg;
use PhpCsFixer\Tokenizer\Token;
use PhpCsFixer\Tokenizer\Tokens;

/**
 * @author Graham Campbell <graham@alt-three.com>
 */
final class PhpdocTrimFixer extends AbstractFixer
{
    /**
     * {@inheritdoc}
     */
    public function getDefinition()
    {
        return new FixerDefinition(
            'PHPDoc should start and end with content, excluding the very first and last line of the docblocks.',
            [new CodeSample('<?php
/**
 *
 * Foo must be final class.
 *
 *
 */
final class Foo {}
')]
        );
    }

    /**
     * {@inheritdoc}
     */
    public function getPriority()
    {
        /*
         * Should be run after all phpdoc fixers that add or remove tags, or
         * alter descriptions. This is so that they don't leave behind blank
         * lines this fixer would have otherwise cleaned up.
         */
        return -5;
    }

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

    /**
     * {@inheritdoc}
     */
    protected function applyFix(\SplFileInfo $file, Tokens $tokens)
    {
        foreach ($tokens as $index => $token) {
            if (!$token->isGivenKind(T_DOC_COMMENT)) {
                continue;
            }

            $content = $token->getContent();
            $content = $this->fixStart($content);
            // we need re-parse the docblock after fixing the start before
            // fixing the end in order for the lines to be correctly indexed
            $content = $this->fixEnd($content);
            $tokens[$index] = new Token([T_DOC_COMMENT, $content]);
        }
    }

    /**
     * Make sure the first useful line starts immediately after the first line.
     *
     * @param string $content
     *
     * @return string
     */
    private function fixStart($content)
    {
        return Preg::replace(
            '~
                (^/\*\*)                  # DocComment begin
                (?:
                    \R[ \t]*(?:\*[ \t]*)? # lines without useful content
                    (?!\R[ \t]*\*/)       # not followed by a DocComment end
                )+
                (\R[ \t]*(?:\*[ \t]*)?\S) # first line with useful content
            ~x',
            '$1$2',
            $content
        );
    }

    /**
     * Make sure the last useful line is immediately before the final line.
     *
     * @param string $content
     *
     * @return string
     */
    private function fixEnd($content)
    {
        return Preg::replace(
            '~
                (\R[ \t]*(?:\*[ \t]*)?\S.*?) # last line with useful content
                (?:
                    (?<!/\*\*)               # not preceded by a DocComment start
                    \R[ \t]*(?:\*[ \t]*)?    # lines without useful content
                )+
                (\R[ \t]*\*/$)               # DocComment end
            ~xu',
            '$1$2',
            $content
        );
    }
}