<?php
declare(strict_types = 1);

namespace TYPO3\CMS\Install\UpgradeAnalysis;

/*
 * This file is part of the TYPO3 CMS project.
 *
 * It is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, either version 2
 * of the License, or any later version.
 *
 * For the full copyright and license information, please read the
 * LICENSE.txt file that was distributed with this source code.
 *
 * The TYPO3 project - inspiring people to share!
 */

use Symfony\Component\Finder\Finder;
use Symfony\Component\Finder\SplFileInfo;
use TYPO3\CMS\Core\Registry;
use TYPO3\CMS\Core\Utility\ExtensionManagementUtility;
use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\Core\Utility\PathUtility;

/**
 * Provide information about documentation files
 * @internal This class is only meant to be used within EXT:install and is not part of the TYPO3 Core API.
 */
class DocumentationFile
{
    /**
     * @var Registry
     */
    protected $registry;

    /**
     * @var array Unified array of used tags
     */
    protected $tagsTotal = [];

    /**
     * all files handled in this Class need to reside inside the changelog dir
     * this is a security measure to protect system files
     *
     * @var string
     */
    protected $changelogPath = '';

    /**
     * DocumentationFile constructor.
     * @param Registry|null $registry
     * @param string $changelogDir
     */
    public function __construct(Registry $registry = null, $changelogDir = '')
    {
        $this->registry = $registry;
        if ($this->registry === null) {
            $this->registry = new Registry();
        }
        $this->changelogPath = $changelogDir !== '' ? $changelogDir : realpath(ExtensionManagementUtility::extPath('core') . 'Documentation/Changelog');
        $this->changelogPath = str_replace('\\', '/', $this->changelogPath);
    }

    /**
     * Traverse given directory, select directories
     *
     * @param string $path
     * @return string[] Version directories
     * @throws \InvalidArgumentException
     */
    public function findDocumentationDirectories(string $path): array
    {
        if (strcasecmp($path, $this->changelogPath) < 0 || strpos($path, $this->changelogPath) === false) {
            throw new \InvalidArgumentException('the given path does not belong to the changelog dir. Aborting', 1537158043);
        }

        $finder = new Finder();
        $finder
            ->depth(0)
            ->sortByName()
            ->in($path);

        $directories = [];
        foreach ($finder->directories() as $directory) {
            /** @var $directory SplFileInfo */
            $directories[] = $directory->getBasename();
        }

        return $directories;
    }

    /**
     * Traverse given directory, select files
     *
     * @param string $path
     * @return array file details of affected documentation files
     * @throws \InvalidArgumentException
     */
    public function findDocumentationFiles(string $path): array
    {
        if (strcasecmp($path, $this->changelogPath) < 0 || strpos($path, $this->changelogPath) === false) {
            throw new \InvalidArgumentException('the given path does not belong to the changelog dir. Aborting', 1485425530);
        }

        $documentationFiles = $this->getDocumentationFilesForVersion($path);
        $this->tagsTotal = $this->collectTagTotal($documentationFiles);

        return $documentationFiles;
    }

    /**
     * Get main information from a .rst file
     *
     * @param string $file Absolute path to documentation file
     * @return array
     * @throws \InvalidArgumentException
     */
    public function getListEntry(string $file): array
    {
        if (strcasecmp($file, $this->changelogPath) < 0 || strpos($file, $this->changelogPath) === false) {
            throw new \InvalidArgumentException('the given file does not belong to the changelog dir. Aborting', 1485425531);
        }
        $lines = file($file, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
        $headline = $this->extractHeadline($lines);
        $entry['version'] = PathUtility::basename(PathUtility::dirname($file));
        $entry['headline'] = $headline;
        $entry['filepath'] = $file;
        $entry['filename'] = pathinfo($file)['filename'];
        $entry['tags'] = $this->extractTags($lines);
        $entry['class'] = 'default';
        foreach ($entry['tags'] as $key => $tag) {
            if (strpos($tag, 'cat:') === 0) {
                $substr = substr($tag, 4);
                $entry['class'] = strtolower($substr);
                $entry['tags'][$key] = $substr;
            }
        }
        $entry['tagList'] = implode(',', $entry['tags']);
        $entry['content'] = file_get_contents($file);
        $entry['parsedContent'] = $this->parseContent($entry['content']);
        $entry['file_hash'] = md5($entry['content']);
        if ($entry['version'] !== '') {
            $entry['url']['documentation'] = sprintf(
                'https://docs.typo3.org/c/typo3/cms-core/master/en-us/Changelog/%s/%s.html',
                $entry['version'],
                $entry['filename']
            );
        }
        $issueId = $this->parseIssueId($entry['filename']);
        if ($issueId) {
            $entry['url']['issue'] = sprintf('https://forge.typo3.org/issues/%s', $issueId);
        }

        return [md5($file) => $entry];
    }

    /**
     * True if file should be considered
     *
     * @param array $fileInfo
     * @return bool
     */
    protected function isRelevantFile(array $fileInfo): bool
    {
        $isRelevantFile = $fileInfo['extension'] === 'rst' && $fileInfo['filename'] !== 'Index';
        // file might be ignored by users choice
        if ($isRelevantFile && $this->isFileIgnoredByUsersChoice($fileInfo['basename'])) {
            $isRelevantFile = false;
        }

        return $isRelevantFile;
    }

    /**
     * Add tags from file
     *
     * @param array $file file content, each line is an array item
     * @return array
     */
    protected function extractTags(array $file): array
    {
        $tags = $this->extractTagsFromFile($file);
        // Headline starting with the category like Breaking, Important or Feature
        $tags[] = $this->extractCategoryFromHeadline($file);
        natcasesort($tags);

        return $tags;
    }

    /**
     * Files must contain an index entry, detailing any number of manual tags
     * each of these tags is extracted and added to the general tag structure for the file
     *
     * @param array $file file content, each line is an array item
     * @return array extracted tags
     */
    protected function extractTagsFromFile(array $file): array
    {
        foreach ($file as $line) {
            if (strpos($line, '.. index::') === 0) {
                $tagString = substr($line, strlen('.. index:: '));
                return GeneralUtility::trimExplode(',', $tagString, true);
            }
        }

        return [];
    }

    /**
     * Files contain a headline (provided as input parameter,
     * it starts with the category string.
     * This will used as a tag
     *
     * @param array $lines
     * @return string
     */
    protected function extractCategoryFromHeadline(array $lines): string
    {
        $headline = $this->extractHeadline($lines);
        if (strpos($headline, ':') !== false) {
            return 'cat:' . substr($headline, 0, strpos($headline, ':'));
        }

        return '';
    }

    /**
     * Skip include line and markers, use the first line actually containing text
     *
     * @param array $lines
     * @return string
     */
    protected function extractHeadline(array $lines): string
    {
        $index = 0;
        while (strpos($lines[$index], '..') === 0 || strpos($lines[$index], '==') === 0) {
            $index++;
        }
        return trim($lines[$index]);
    }

    /**
     * @param string $docDirectory
     * @param string $version
     * @return bool
     */
    protected function versionHasDocumentationFiles(string $docDirectory, string $version): bool
    {
        $absolutePath = str_replace('\\', '/', $docDirectory) . '/' . $version;
        $finder = $this->getDocumentFinder()->in($absolutePath);

        return $finder->files()->count() > 0;
    }

    /**
     * Handle a single directory
     *
     * @param string $docDirectory
     * @return array
     */
    protected function getDocumentationFilesForVersion(string $docDirectory): array
    {
        $documentationFiles = [[]];
        $absolutePath = str_replace('\\', '/', $docDirectory);
        $finder = $this->getDocumentFinder()->in($absolutePath);

        foreach ($finder->files() as $file) {
            /** @var $file SplFileInfo */
            $documentationFiles[] = $this->getListEntry($file->getPathname());
        }

        return array_merge(...$documentationFiles);
    }

    /**
     * Merge tag list
     *
     * @param $documentationFiles
     * @return array
     */
    protected function collectTagTotal($documentationFiles): array
    {
        $tags = [[]];
        foreach ($documentationFiles as $fileArray) {
            $tags[] = $fileArray['tags'];
        }

        return array_unique(array_merge(...$tags));
    }

    /**
     * Return full tag list
     *
     * @return array
     */
    public function getTagsTotal(): array
    {
        return $this->tagsTotal;
    }

    /**
     * whether that file has been removed from users view
     *
     * @param string $filename
     * @return bool
     */
    protected function isFileIgnoredByUsersChoice(string $filename): bool
    {
        $isFileIgnoredByUsersChoice = false;

        $ignoredFiles = $this->registry->get('upgradeAnalysisIgnoreFilter', 'ignoredDocumentationFiles');
        if (is_array($ignoredFiles)) {
            foreach ($ignoredFiles as $filePath) {
                if ($filePath !== null && strlen($filePath) > 0) {
                    if (strpos($filePath, $filename) !== false) {
                        $isFileIgnoredByUsersChoice = true;
                        break;
                    }
                }
            }
        }
        return $isFileIgnoredByUsersChoice;
    }

    /**
     * @param string $rstContent
     *
     * @return string
     */
    protected function parseContent(string $rstContent): string
    {
        $content = htmlspecialchars($rstContent);
        $content = preg_replace('/:issue:`([\d]*)`/', '<a href="https://forge.typo3.org/issues/\\1" target="_blank" rel="noopener noreferrer">\\1</a>', $content);
        $content = preg_replace('/#([\d]*)/', '#<a href="https://forge.typo3.org/issues/\\1" target="_blank" rel="noopener noreferrer">\\1</a>', $content);
        $content = preg_replace('/(\n([=]*)\n(.*)\n([=]*)\n)/', '', $content, 1);
        $content = preg_replace('/.. index::(.*)/', '', $content);
        $content = preg_replace('/.. include::(.*)/', '', $content);
        return trim($content);
    }

    /**
     * @param string $filename
     *
     * @return string|null
     */
    protected function parseIssueId(string $filename): ?string
    {
        return GeneralUtility::trimExplode('-', $filename)[1] ?? null;
    }

    /**
     * @return Finder
     */
    protected function getDocumentFinder(): Finder
    {
        $finder = new Finder();
        $finder
            ->depth(0)
            ->sortByName()
            ->name('/^(Feature|Breaking|Deprecation|Important)\-\d+.+\.rst$/i');

        return $finder;
    }
}