<?php

/*
 * 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!
 */

namespace TYPO3\CMS\Core\Resource\Index;

use Psr\Log\LoggerAwareInterface;
use Psr\Log\LoggerAwareTrait;
use TYPO3\CMS\Core\Resource\Exception\IllegalFileExtensionException;
use TYPO3\CMS\Core\Resource\Exception\InsufficientFileAccessPermissionsException;
use TYPO3\CMS\Core\Resource\Exception\InvalidHashException;
use TYPO3\CMS\Core\Resource\File;
use TYPO3\CMS\Core\Resource\ResourceFactory;
use TYPO3\CMS\Core\Resource\ResourceStorage;
use TYPO3\CMS\Core\Resource\Service\ExtractorService;
use TYPO3\CMS\Core\Type\File\ImageInfo;
use TYPO3\CMS\Core\Utility\GeneralUtility;

/**
 * The FAL Indexer
 */
class Indexer implements LoggerAwareInterface
{
    use LoggerAwareTrait;

    /**
     * @var array
     */
    protected $filesToUpdate = [];

    /**
     * @var int[]
     */
    protected $identifiedFileUids = [];

    /**
     * @var ResourceStorage
     */
    protected $storage;

    /**
     * @var ExtractorService
     */
    protected $extractorService;

    public function __construct(ResourceStorage $storage)
    {
        $this->storage = $storage;
    }

    /**
     * Create index entry
     *
     * @param string $identifier
     * @throws \InvalidArgumentException
     */
    public function createIndexEntry($identifier): File
    {
        if (!is_string($identifier) || $identifier === '') {
            throw new \InvalidArgumentException(
                'Invalid file identifier given. It must be of type string and not empty. "' . gettype($identifier) . '" given.',
                1401732565
            );
        }

        $fileProperties = $this->gatherFileInformationArray($identifier);
        $fileIndexRepository = $this->getFileIndexRepository();

        $record = $fileIndexRepository->addRaw($fileProperties);
        $fileObject = $this->getResourceFactory()->getFileObject($record['uid'], $record);
        $fileIndexRepository->updateIndexingTime($fileObject->getUid());

        $metaData = $this->extractRequiredMetaData($fileObject);
        if ($this->storage->autoExtractMetadataEnabled()) {
            $metaData = array_merge($metaData, $this->getExtractorService()->extractMetaData($fileObject));
        }
        $fileObject->getMetaData()->add($metaData)->save();

        return $fileObject;
    }

    /**
     * Update index entry
     */
    public function updateIndexEntry(File $fileObject): File
    {
        $updatedInformation = $this->gatherFileInformationArray($fileObject->getIdentifier());
        $fileObject->updateProperties($updatedInformation);

        $fileIndexRepository = $this->getFileIndexRepository();
        $fileIndexRepository->update($fileObject);
        $fileIndexRepository->updateIndexingTime($fileObject->getUid());

        $metaData = $this->extractRequiredMetaData($fileObject);
        if ($this->storage->autoExtractMetadataEnabled()) {
            $metaData = array_merge($metaData, $this->getExtractorService()->extractMetaData($fileObject));
        }
        $fileObject->getMetaData()->add($metaData)->save();

        return $fileObject;
    }

    public function processChangesInStorages()
    {
        // get all file-identifiers from the storage
        $availableFiles = $this->storage->getFileIdentifiersInFolder($this->storage->getRootLevelFolder(false)->getIdentifier(), true, true);
        $this->detectChangedFilesInStorage($availableFiles);
        $this->processChangedAndNewFiles();

        $this->detectMissingFiles();
    }

    /**
     * @param int $maximumFileCount
     */
    public function runMetaDataExtraction($maximumFileCount = -1)
    {
        $fileIndexRecords = $this->getFileIndexRepository()->findInStorageWithIndexOutstanding($this->storage, $maximumFileCount);
        foreach ($fileIndexRecords as $indexRecord) {
            $fileObject = $this->getResourceFactory()->getFileObject($indexRecord['uid'], $indexRecord);
            // Check for existence of file before extraction
            if ($fileObject->exists()) {
                try {
                    $this->extractMetaData($fileObject);
                } catch (InsufficientFileAccessPermissionsException $e) {
                    //  We skip files that are not accessible
                } catch (IllegalFileExtensionException $e) {
                    //  We skip files that have an extension that we don't allow
                }
            } else {
                // Mark file as missing and continue with next record
                $this->getFileIndexRepository()->markFileAsMissing($indexRecord['uid']);
            }
        }
    }

    /**
     * Extract metadata for given fileObject
     */
    public function extractMetaData(File $fileObject)
    {
        $metaData = array_merge([
            $fileObject->getMetaData()->get(),
        ], $this->getExtractorService()->extractMetaData($fileObject));

        $fileObject->getMetaData()->add($metaData)->save();

        $this->getFileIndexRepository()->updateIndexingTime($fileObject->getUid());
    }

    /**
     * Since by now all files in filesystem have been looked at, it is safe to assume,
     * that files that are indexed, but not touched in this run, are missing
     */
    protected function detectMissingFiles()
    {
        $allCurrentFiles = $this->getFileIndexRepository()->findInStorageAndNotInUidList(
            $this->storage,
            []
        );

        foreach ($allCurrentFiles as $record) {
            // Check if the record retrieved from the database was associated
            // with an existing file.
            // If yes: All is good, file is in index and in database.
            // If no: Database record may need to be marked as removed (extra check!)
            if (in_array($record['uid'], $this->identifiedFileUids, true)) {
                continue;
            }

            if (!$this->storage->hasFile($record['identifier'])) {
                $this->getFileIndexRepository()->markFileAsMissing($record['uid']);
            }
        }
    }

    /**
     * Check whether the extractor service supports this file according to file type restrictions.
     *
     * @return bool
     */
    protected function isFileTypeSupportedByExtractor(File $file, ExtractorInterface $extractor)
    {
        $isSupported = true;
        $fileTypeRestrictions = $extractor->getFileTypeRestrictions();
        if (!empty($fileTypeRestrictions) && !in_array($file->getType(), $fileTypeRestrictions)) {
            $isSupported = false;
        }
        return $isSupported;
    }

    /**
     * Adds updated files to the processing queue
     */
    protected function detectChangedFilesInStorage(array $fileIdentifierArray)
    {
        foreach ($fileIdentifierArray as $fileIdentifier) {
            // skip processed files
            if ($this->storage->isWithinProcessingFolder($fileIdentifier)) {
                continue;
            }
            // Get the modification time for file-identifier from the storage
            $modificationTime = $this->storage->getFileInfoByIdentifier($fileIdentifier, ['mtime']);
            // Look if the the modification time in FS is higher than the one in database (key needed on timestamps)
            $indexRecord = $this->getFileIndexRepository()->findOneByStorageAndIdentifier($this->storage, $fileIdentifier);

            if ($indexRecord !== false) {
                $this->identifiedFileUids[] = $indexRecord['uid'];

                if ((int)$indexRecord['modification_date'] !== $modificationTime['mtime'] || $indexRecord['missing']) {
                    $this->filesToUpdate[$fileIdentifier] = $indexRecord;
                }
            } else {
                $this->filesToUpdate[$fileIdentifier] = null;
            }
        }
    }

    /**
     * Processes the Files which have been detected as "changed or new"
     * in the storage
     */
    protected function processChangedAndNewFiles()
    {
        foreach ($this->filesToUpdate as $identifier => $data) {
            try {
                if ($data === null) {
                    // search for files with same content hash in indexed storage
                    $fileHash = $this->storage->hashFileByIdentifier($identifier, 'sha1');
                    $files = $this->getFileIndexRepository()->findByContentHash($fileHash);
                    $fileObject = null;
                    if (!empty($files)) {
                        foreach ($files as $fileIndexEntry) {
                            // check if file is missing then we assume it's moved/renamed
                            if (!$this->storage->hasFile($fileIndexEntry['identifier'])) {
                                $fileObject = $this->getResourceFactory()->getFileObject(
                                    $fileIndexEntry['uid'],
                                    $fileIndexEntry
                                );
                                $fileObject->updateProperties(
                                    [
                                        'identifier' => $identifier,
                                    ]
                                );
                                $this->updateIndexEntry($fileObject);
                                $this->identifiedFileUids[] = $fileObject->getUid();
                                break;
                            }
                        }
                    }
                    // create new index when no missing file with same content hash is found
                    if ($fileObject === null) {
                        $fileObject = $this->createIndexEntry($identifier);
                        $this->identifiedFileUids[] = $fileObject->getUid();
                    }
                } else {
                    // update existing file
                    $fileObject = $this->getResourceFactory()->getFileObject($data['uid'], $data);
                    $this->updateIndexEntry($fileObject);
                }
            } catch (InvalidHashException $e) {
                $this->logger->error('Unable to create hash for file: {identifier}', ['identifier' => $identifier]);
            } catch (\Exception $e) {
                $this->logger->error('Unable to index / update file with identifier {identifier}', [
                    'identifier' => $identifier,
                    'exception' => $e,
                ]);
            }
        }
    }

    /**
     * Since the core desperately needs image sizes in metadata table put them there
     * This should be called after every "content" update and "record" creation
     */
    protected function extractRequiredMetaData(File $fileObject): array
    {
        $metaData = [];

        // since the core desperately needs image sizes in metadata table do this manually
        // prevent doing this for remote storages, remote storages must provide the data with extractors
        if ($fileObject->isImage() && $this->storage->getDriverType() === 'Local') {
            $rawFileLocation = $fileObject->getForLocalProcessing(false);
            $imageInfo = GeneralUtility::makeInstance(ImageInfo::class, $rawFileLocation);
            $metaData = [
                'width' => $imageInfo->getWidth(),
                'height' => $imageInfo->getHeight(),
            ];
        }

        return $metaData;
    }

    /****************************
     *         UTILITY
     ****************************/
    /**
     * Collects the information to be cached in sys_file
     *
     * @param string $identifier
     * @throws \TYPO3\CMS\Core\Resource\Exception\InvalidHashException
     */
    protected function gatherFileInformationArray($identifier): array
    {
        $fileInfo = $this->storage->getFileInfoByIdentifier($identifier);
        $fileInfo = $this->transformFromDriverFileInfoArrayToFileObjectFormat($fileInfo);
        $fileInfo['type'] = $this->getFileType($fileInfo['mime_type']);
        $fileInfo['sha1'] = $this->storage->hashFileByIdentifier($identifier, 'sha1');
        $fileInfo['missing'] = 0;

        return $fileInfo;
    }

    /**
     * Maps the mimetype to a sys_file table type
     *
     * @param string $mimeType
     * @return string
     */
    protected function getFileType($mimeType)
    {
        [$fileType] = explode('/', $mimeType);
        switch (strtolower($fileType)) {
            case 'text':
                $type = File::FILETYPE_TEXT;
                break;
            case 'image':
                $type = File::FILETYPE_IMAGE;
                break;
            case 'audio':
                $type = File::FILETYPE_AUDIO;
                break;
            case 'video':
                $type = File::FILETYPE_VIDEO;
                break;
            case 'application':
            case 'software':
                $type = File::FILETYPE_APPLICATION;
                break;
            default:
                $type = File::FILETYPE_UNKNOWN;
        }
        return $type;
    }

    /**
     * However it happened, the properties of a file object which
     * are persisted to the database are named different than the
     * properties the driver returns in getFileInfo.
     * Therefore a mapping must happen.
     *
     * @return array
     */
    protected function transformFromDriverFileInfoArrayToFileObjectFormat(array $fileInfo)
    {
        $mappingInfo = [
            // 'driverKey' => 'fileProperty' Key is from the driver, value is for the property in the file
            'size' => 'size',
            'atime' => null,
            'mtime' => 'modification_date',
            'ctime' => 'creation_date',
            'mimetype' => 'mime_type',
        ];
        $mappedFileInfo = [];
        foreach ($fileInfo as $key => $value) {
            if (array_key_exists($key, $mappingInfo)) {
                if ($mappingInfo[$key] !== null) {
                    $mappedFileInfo[$mappingInfo[$key]] = $value;
                }
            } else {
                $mappedFileInfo[$key] = $value;
            }
        }
        return $mappedFileInfo;
    }

    /**
     * Returns an instance of the FileIndexRepository
     *
     * @return FileIndexRepository
     */
    protected function getFileIndexRepository()
    {
        return GeneralUtility::makeInstance(FileIndexRepository::class);
    }

    /**
     * Returns an instance of the FileIndexRepository
     *
     * @return MetaDataRepository
     */
    protected function getMetaDataRepository()
    {
        return GeneralUtility::makeInstance(MetaDataRepository::class);
    }

    /**
     * Returns the ResourceFactory
     *
     * @return ResourceFactory
     */
    protected function getResourceFactory()
    {
        return GeneralUtility::makeInstance(ResourceFactory::class);
    }

    protected function getExtractorService(): ExtractorService
    {
        if ($this->extractorService === null) {
            $this->extractorService = GeneralUtility::makeInstance(ExtractorService::class);
        }
        return $this->extractorService;
    }
}
