Merge "Special:Upload should not crash on failing previews"

[mediawiki.git] / includes / api / ApiUpload.php

<?php
/**
 *
 *
 * Created on Aug 21, 2008
 *
 * Copyright © 2008 - 2010 Bryan Tong Minh <Bryan.TongMinh@Gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

/**
 * @ingroup API
 */
class ApiUpload extends ApiBase {
        /** @var UploadBase|UploadFromChunks */
        protected $mUpload = null;

        protected $mParams;

        public function execute() {
                // Check whether upload is enabled
                if ( !UploadBase::isEnabled() ) {
                        $this->dieWithError( 'uploaddisabled' );
                }

                $user = $this->getUser();

                // Parameter handling
                $this->mParams = $this->extractRequestParams();
                $request = $this->getMain()->getRequest();
                // Check if async mode is actually supported (jobs done in cli mode)
                $this->mParams['async'] = ( $this->mParams['async'] &&
                        $this->getConfig()->get( 'EnableAsyncUploads' ) );
                // Add the uploaded file to the params array
                $this->mParams['file'] = $request->getFileName( 'file' );
                $this->mParams['chunk'] = $request->getFileName( 'chunk' );

                // Copy the session key to the file key, for backward compatibility.
                if ( !$this->mParams['filekey'] && $this->mParams['sessionkey'] ) {
                        $this->mParams['filekey'] = $this->mParams['sessionkey'];
                }

                // Select an upload module
                try {
                        if ( !$this->selectUploadModule() ) {
                                return; // not a true upload, but a status request or similar
                        } elseif ( !isset( $this->mUpload ) ) {
                                $this->dieDebug( __METHOD__, 'No upload module set' );
                        }
                } catch ( UploadStashException $e ) { // XXX: don't spam exception log
                        $this->dieStatus( $this->handleStashException( $e ) );
                }

                // First check permission to upload
                $this->checkPermissions( $user );

                // Fetch the file (usually a no-op)
                /** @var $status Status */
                $status = $this->mUpload->fetchFile();
                if ( !$status->isGood() ) {
                        $this->dieStatus( $status );
                }

                // Check if the uploaded file is sane
                if ( $this->mParams['chunk'] ) {
                        $maxSize = UploadBase::getMaxUploadSize();
                        if ( $this->mParams['filesize'] > $maxSize ) {
                                $this->dieWithError( 'file-too-large' );
                        }
                        if ( !$this->mUpload->getTitle() ) {
                                $this->dieWithError( 'illegal-filename' );
                        }
                } elseif ( $this->mParams['async'] && $this->mParams['filekey'] ) {
                        // defer verification to background process
                } else {
                        wfDebug( __METHOD__ . " about to verify\n" );
                        $this->verifyUpload();
                }

                // Check if the user has the rights to modify or overwrite the requested title
                // (This check is irrelevant if stashing is already requested, since the errors
                //  can always be fixed by changing the title)
                if ( !$this->mParams['stash'] ) {
                        $permErrors = $this->mUpload->verifyTitlePermissions( $user );
                        if ( $permErrors !== true ) {
                                $this->dieRecoverableError( $permErrors, 'filename' );
                        }
                }

                // Get the result based on the current upload context:
                try {
                        $result = $this->getContextResult();
                } catch ( UploadStashException $e ) { // XXX: don't spam exception log
                        $this->dieStatus( $this->handleStashException( $e ) );
                }
                $this->getResult()->addValue( null, $this->getModuleName(), $result );

                // Add 'imageinfo' in a separate addValue() call. File metadata can be unreasonably large,
                // so otherwise when it exceeded $wgAPIMaxResultSize, no result would be returned (T143993).
                if ( $result['result'] === 'Success' ) {
                        $imageinfo = $this->mUpload->getImageInfo( $this->getResult() );
                        $this->getResult()->addValue( $this->getModuleName(), 'imageinfo', $imageinfo );
                }

                // Cleanup any temporary mess
                $this->mUpload->cleanupTempFile();
        }

        /**
         * Get an upload result based on upload context
         * @return array
         */
        private function getContextResult() {
                $warnings = $this->getApiWarnings();
                if ( $warnings && !$this->mParams['ignorewarnings'] ) {
                        // Get warnings formatted in result array format
                        return $this->getWarningsResult( $warnings );
                } elseif ( $this->mParams['chunk'] ) {
                        // Add chunk, and get result
                        return $this->getChunkResult( $warnings );
                } elseif ( $this->mParams['stash'] ) {
                        // Stash the file and get stash result
                        return $this->getStashResult( $warnings );
                }

                // Check throttle after we've handled warnings
                if ( UploadBase::isThrottled( $this->getUser() )
                ) {
                        $this->dieWithError( 'apierror-ratelimited' );
                }

                // This is the most common case -- a normal upload with no warnings
                // performUpload will return a formatted properly for the API with status
                return $this->performUpload( $warnings );
        }

        /**
         * Get Stash Result, throws an exception if the file could not be stashed.
         * @param array $warnings Array of Api upload warnings
         * @return array
         */
        private function getStashResult( $warnings ) {
                $result = [];
                $result['result'] = 'Success';
                if ( $warnings && count( $warnings ) > 0 ) {
                        $result['warnings'] = $warnings;
                }
                // Some uploads can request they be stashed, so as not to publish them immediately.
                // In this case, a failure to stash ought to be fatal
                $this->performStash( 'critical', $result );

                return $result;
        }

        /**
         * Get Warnings Result
         * @param array $warnings Array of Api upload warnings
         * @return array
         */
        private function getWarningsResult( $warnings ) {
                $result = [];
                $result['result'] = 'Warning';
                $result['warnings'] = $warnings;
                // in case the warnings can be fixed with some further user action, let's stash this upload
                // and return a key they can use to restart it
                $this->performStash( 'optional', $result );

                return $result;
        }

        /**
         * Get the result of a chunk upload.
         * @param array $warnings Array of Api upload warnings
         * @return array
         */
        private function getChunkResult( $warnings ) {
                $result = [];

                if ( $warnings && count( $warnings ) > 0 ) {
                        $result['warnings'] = $warnings;
                }

                $request = $this->getMain()->getRequest();
                $chunkPath = $request->getFileTempname( 'chunk' );
                $chunkSize = $request->getUpload( 'chunk' )->getSize();
                $totalSoFar = $this->mParams['offset'] + $chunkSize;
                $minChunkSize = $this->getConfig()->get( 'MinUploadChunkSize' );

                // Sanity check sizing
                if ( $totalSoFar > $this->mParams['filesize'] ) {
                        $this->dieWithError( 'apierror-invalid-chunk' );
                }

                // Enforce minimum chunk size
                if ( $totalSoFar != $this->mParams['filesize'] && $chunkSize < $minChunkSize ) {
                        $this->dieWithError( [ 'apierror-chunk-too-small', Message::numParam( $minChunkSize ) ] );
                }

                if ( $this->mParams['offset'] == 0 ) {
                        $filekey = $this->performStash( 'critical' );
                } else {
                        $filekey = $this->mParams['filekey'];

                        // Don't allow further uploads to an already-completed session
                        $progress = UploadBase::getSessionStatus( $this->getUser(), $filekey );
                        if ( !$progress ) {
                                // Probably can't get here, but check anyway just in case
                                $this->dieWithError( 'apierror-stashfailed-nosession', 'stashfailed' );
                        } elseif ( $progress['result'] !== 'Continue' || $progress['stage'] !== 'uploading' ) {
                                $this->dieWithError( 'apierror-stashfailed-complete', 'stashfailed' );
                        }

                        $status = $this->mUpload->addChunk(
                                $chunkPath, $chunkSize, $this->mParams['offset'] );
                        if ( !$status->isGood() ) {
                                $extradata = [
                                        'offset' => $this->mUpload->getOffset(),
                                ];

                                $this->dieStatusWithCode( $status, 'stashfailed', $extradata );
                        }
                }

                // Check we added the last chunk:
                if ( $totalSoFar == $this->mParams['filesize'] ) {
                        if ( $this->mParams['async'] ) {
                                UploadBase::setSessionStatus(
                                        $this->getUser(),
                                        $filekey,
                                        [ 'result' => 'Poll',
                                                'stage' => 'queued', 'status' => Status::newGood() ]
                                );
                                JobQueueGroup::singleton()->push( new AssembleUploadChunksJob(
                                        Title::makeTitle( NS_FILE, $filekey ),
                                        [
                                                'filename' => $this->mParams['filename'],
                                                'filekey' => $filekey,
                                                'session' => $this->getContext()->exportSession()
                                        ]
                                ) );
                                $result['result'] = 'Poll';
                                $result['stage'] = 'queued';
                        } else {
                                $status = $this->mUpload->concatenateChunks();
                                if ( !$status->isGood() ) {
                                        UploadBase::setSessionStatus(
                                                $this->getUser(),
                                                $filekey,
                                                [ 'result' => 'Failure', 'stage' => 'assembling', 'status' => $status ]
                                        );
                                        $this->dieStatusWithCode( $status, 'stashfailed' );
                                }

                                // We can only get warnings like 'duplicate' after concatenating the chunks
                                $warnings = $this->getApiWarnings();
                                if ( $warnings ) {
                                        $result['warnings'] = $warnings;
                                }

                                // The fully concatenated file has a new filekey. So remove
                                // the old filekey and fetch the new one.
                                UploadBase::setSessionStatus( $this->getUser(), $filekey, false );
                                $this->mUpload->stash->removeFile( $filekey );
                                $filekey = $this->mUpload->getStashFile()->getFileKey();

                                $result['result'] = 'Success';
                        }
                } else {
                        UploadBase::setSessionStatus(
                                $this->getUser(),
                                $filekey,
                                [
                                        'result' => 'Continue',
                                        'stage' => 'uploading',
                                        'offset' => $totalSoFar,
                                        'status' => Status::newGood(),
                                ]
                        );
                        $result['result'] = 'Continue';
                        $result['offset'] = $totalSoFar;
                }

                $result['filekey'] = $filekey;

                return $result;
        }

        /**
         * Stash the file and add the file key, or error information if it fails, to the data.
         *
         * @param string $failureMode What to do on failure to stash:
         *   - When 'critical', use dieStatus() to produce an error response and throw an exception.
         *     Use this when stashing the file was the primary purpose of the API request.
         *   - When 'optional', only add a 'stashfailed' key to the data and return null.
         *     Use this when some error happened for a non-stash upload and we're stashing the file
         *     only to save the client the trouble of re-uploading it.
         * @param array &$data API result to which to add the information
         * @return string|null File key
         */
        private function performStash( $failureMode, &$data = null ) {
                $isPartial = (bool)$this->mParams['chunk'];
                try {
                        $status = $this->mUpload->tryStashFile( $this->getUser(), $isPartial );

                        if ( $status->isGood() && !$status->getValue() ) {
                                // Not actually a 'good' status...
                                $status->fatal( new ApiMessage( 'apierror-stashinvalidfile', 'stashfailed' ) );
                        }
                } catch ( Exception $e ) {
                        $debugMessage = 'Stashing temporary file failed: ' . get_class( $e ) . ' ' . $e->getMessage();
                        wfDebug( __METHOD__ . ' ' . $debugMessage . "\n" );
                        $status = Status::newFatal( $this->getErrorFormatter()->getMessageFromException(
                                $e, [ 'wrap' => new ApiMessage( 'apierror-stashexception', 'stashfailed' ) ]
                        ) );
                }

                if ( $status->isGood() ) {
                        $stashFile = $status->getValue();
                        $data['filekey'] = $stashFile->getFileKey();
                        // Backwards compatibility
                        $data['sessionkey'] = $data['filekey'];
                        return $data['filekey'];
                }

                if ( $status->getMessage()->getKey() === 'uploadstash-exception' ) {
                        // The exceptions thrown by upload stash code and pretty silly and UploadBase returns poor
                        // Statuses for it. Just extract the exception details and parse them ourselves.
                        list( $exceptionType, $message ) = $status->getMessage()->getParams();
                        $debugMessage = 'Stashing temporary file failed: ' . $exceptionType . ' ' . $message;
                        wfDebug( __METHOD__ . ' ' . $debugMessage . "\n" );
                }

                // Bad status
                if ( $failureMode !== 'optional' ) {
                        $this->dieStatus( $status );
                } else {
                        $data['stasherrors'] = $this->getErrorFormatter()->arrayFromStatus( $status );
                        return null;
                }
        }

        /**
         * Throw an error that the user can recover from by providing a better
         * value for $parameter
         *
         * @param array $errors Array of Message objects, message keys, key+param
         *  arrays, or StatusValue::getErrors()-style arrays
         * @param string|null $parameter Parameter that needs revising
         * @throws ApiUsageException
         */
        private function dieRecoverableError( $errors, $parameter = null ) {
                $this->performStash( 'optional', $data );

                if ( $parameter ) {
                        $data['invalidparameter'] = $parameter;
                }

                $sv = StatusValue::newGood();
                foreach ( $errors as $error ) {
                        $msg = ApiMessage::create( $error );
                        $msg->setApiData( $msg->getApiData() + $data );
                        $sv->fatal( $msg );
                }
                $this->dieStatus( $sv );
        }

        /**
         * Like dieStatus(), but always uses $overrideCode for the error code, unless the code comes from
         * IApiMessage.
         *
         * @param Status $status
         * @param string $overrideCode Error code to use if there isn't one from IApiMessage
         * @param array|null $moreExtraData
         * @throws ApiUsageException
         */
        public function dieStatusWithCode( $status, $overrideCode, $moreExtraData = null ) {
                $sv = StatusValue::newGood();
                foreach ( $status->getErrors() as $error ) {
                        $msg = ApiMessage::create( $error, $overrideCode );
                        if ( $moreExtraData ) {
                                $msg->setApiData( $msg->getApiData() + $moreExtraData );
                        }
                        $sv->fatal( $msg );
                }
                $this->dieStatus( $sv );
        }

        /**
         * Select an upload module and set it to mUpload. Dies on failure. If the
         * request was a status request and not a true upload, returns false;
         * otherwise true
         *
         * @return bool
         */
        protected function selectUploadModule() {
                $request = $this->getMain()->getRequest();

                // chunk or one and only one of the following parameters is needed
                if ( !$this->mParams['chunk'] ) {
                        $this->requireOnlyOneParameter( $this->mParams,
                                'filekey', 'file', 'url' );
                }

                // Status report for "upload to stash"/"upload from stash"
                if ( $this->mParams['filekey'] && $this->mParams['checkstatus'] ) {
                        $progress = UploadBase::getSessionStatus( $this->getUser(), $this->mParams['filekey'] );
                        if ( !$progress ) {
                                $this->dieWithError( 'api-upload-missingresult', 'missingresult' );
                        } elseif ( !$progress['status']->isGood() ) {
                                $this->dieStatusWithCode( $progress['status'], 'stashfailed' );
                        }
                        if ( isset( $progress['status']->value['verification'] ) ) {
                                $this->checkVerification( $progress['status']->value['verification'] );
                        }
                        if ( isset( $progress['status']->value['warnings'] ) ) {
                                $warnings = $this->transformWarnings( $progress['status']->value['warnings'] );
                                if ( $warnings ) {
                                        $progress['warnings'] = $warnings;
                                }
                        }
                        unset( $progress['status'] ); // remove Status object
                        $imageinfo = null;
                        if ( isset( $progress['imageinfo'] ) ) {
                                $imageinfo = $progress['imageinfo'];
                                unset( $progress['imageinfo'] );
                        }

                        $this->getResult()->addValue( null, $this->getModuleName(), $progress );
                        // Add 'imageinfo' in a separate addValue() call. File metadata can be unreasonably large,
                        // so otherwise when it exceeded $wgAPIMaxResultSize, no result would be returned (T143993).
                        if ( $imageinfo ) {
                                $this->getResult()->addValue( $this->getModuleName(), 'imageinfo', $imageinfo );
                        }

                        return false;
                }

                // The following modules all require the filename parameter to be set
                if ( is_null( $this->mParams['filename'] ) ) {
                        $this->dieWithError( [ 'apierror-missingparam', 'filename' ] );
                }

                if ( $this->mParams['chunk'] ) {
                        // Chunk upload
                        $this->mUpload = new UploadFromChunks( $this->getUser() );
                        if ( isset( $this->mParams['filekey'] ) ) {
                                if ( $this->mParams['offset'] === 0 ) {
                                        $this->dieWithError( 'apierror-upload-filekeynotallowed', 'filekeynotallowed' );
                                }

                                // handle new chunk
                                $this->mUpload->continueChunks(
                                        $this->mParams['filename'],
                                        $this->mParams['filekey'],
                                        $request->getUpload( 'chunk' )
                                );
                        } else {
                                if ( $this->mParams['offset'] !== 0 ) {
                                        $this->dieWithError( 'apierror-upload-filekeyneeded', 'filekeyneeded' );
                                }

                                // handle first chunk
                                $this->mUpload->initialize(
                                        $this->mParams['filename'],
                                        $request->getUpload( 'chunk' )
                                );
                        }
                } elseif ( isset( $this->mParams['filekey'] ) ) {
                        // Upload stashed in a previous request
                        if ( !UploadFromStash::isValidKey( $this->mParams['filekey'] ) ) {
                                $this->dieWithError( 'apierror-invalid-file-key' );
                        }

                        $this->mUpload = new UploadFromStash( $this->getUser() );
                        // This will not download the temp file in initialize() in async mode.
                        // We still have enough information to call checkWarnings() and such.
                        $this->mUpload->initialize(
                                $this->mParams['filekey'], $this->mParams['filename'], !$this->mParams['async']
                        );
                } elseif ( isset( $this->mParams['file'] ) ) {
                        $this->mUpload = new UploadFromFile();
                        $this->mUpload->initialize(
                                $this->mParams['filename'],
                                $request->getUpload( 'file' )
                        );
                } elseif ( isset( $this->mParams['url'] ) ) {
                        // Make sure upload by URL is enabled:
                        if ( !UploadFromUrl::isEnabled() ) {
                                $this->dieWithError( 'copyuploaddisabled' );
                        }

                        if ( !UploadFromUrl::isAllowedHost( $this->mParams['url'] ) ) {
                                $this->dieWithError( 'apierror-copyuploadbaddomain' );
                        }

                        if ( !UploadFromUrl::isAllowedUrl( $this->mParams['url'] ) ) {
                                $this->dieWithError( 'apierror-copyuploadbadurl' );
                        }

                        $this->mUpload = new UploadFromUrl;
                        $this->mUpload->initialize( $this->mParams['filename'],
                                $this->mParams['url'] );
                }

                return true;
        }

        /**
         * Checks that the user has permissions to perform this upload.
         * Dies with usage message on inadequate permissions.
         * @param User $user The user to check.
         */
        protected function checkPermissions( $user ) {
                // Check whether the user has the appropriate permissions to upload anyway
                $permission = $this->mUpload->isAllowed( $user );

                if ( $permission !== true ) {
                        if ( !$user->isLoggedIn() ) {
                                $this->dieWithError( [ 'apierror-mustbeloggedin', $this->msg( 'action-upload' ) ] );
                        }

                        $this->dieStatus( User::newFatalPermissionDeniedStatus( $permission ) );
                }

                // Check blocks
                if ( $user->isBlocked() ) {
                        $this->dieBlocked( $user->getBlock() );
                }

                // Global blocks
                if ( $user->isBlockedGlobally() ) {
                        $this->dieBlocked( $user->getGlobalBlock() );
                }
        }

        /**
         * Performs file verification, dies on error.
         */
        protected function verifyUpload() {
                $verification = $this->mUpload->verifyUpload();
                if ( $verification['status'] === UploadBase::OK ) {
                        return;
                }

                $this->checkVerification( $verification );
        }

        /**
         * Performs file verification, dies on error.
         * @param array $verification
         */
        protected function checkVerification( array $verification ) {
                switch ( $verification['status'] ) {
                        // Recoverable errors
                        case UploadBase::MIN_LENGTH_PARTNAME:
                                $this->dieRecoverableError( [ 'filename-tooshort' ], 'filename' );
                                break;
                        case UploadBase::ILLEGAL_FILENAME:
                                $this->dieRecoverableError(
                                        [ ApiMessage::create(
                                                'illegal-filename', null, [ 'filename' => $verification['filtered'] ]
                                        ) ], 'filename'
                                );
                                break;
                        case UploadBase::FILENAME_TOO_LONG:
                                $this->dieRecoverableError( [ 'filename-toolong' ], 'filename' );
                                break;
                        case UploadBase::FILETYPE_MISSING:
                                $this->dieRecoverableError( [ 'filetype-missing' ], 'filename' );
                                break;
                        case UploadBase::WINDOWS_NONASCII_FILENAME:
                                $this->dieRecoverableError( [ 'windows-nonascii-filename' ], 'filename' );
                                break;

                        // Unrecoverable errors
                        case UploadBase::EMPTY_FILE:
                                $this->dieWithError( 'empty-file' );
                                break;
                        case UploadBase::FILE_TOO_LARGE:
                                $this->dieWithError( 'file-too-large' );
                                break;

                        case UploadBase::FILETYPE_BADTYPE:
                                $extradata = [
                                        'filetype' => $verification['finalExt'],
                                        'allowed' => array_values( array_unique( $this->getConfig()->get( 'FileExtensions' ) ) )
                                ];
                                $extensions = array_unique( $this->getConfig()->get( 'FileExtensions' ) );
                                $msg = [
                                        'filetype-banned-type',
                                        null, // filled in below
                                        Message::listParam( $extensions, 'comma' ),
                                        count( $extensions ),
                                        null, // filled in below
                                ];
                                ApiResult::setIndexedTagName( $extradata['allowed'], 'ext' );

                                if ( isset( $verification['blacklistedExt'] ) ) {
                                        $msg[1] = Message::listParam( $verification['blacklistedExt'], 'comma' );
                                        $msg[4] = count( $verification['blacklistedExt'] );
                                        $extradata['blacklisted'] = array_values( $verification['blacklistedExt'] );
                                        ApiResult::setIndexedTagName( $extradata['blacklisted'], 'ext' );
                                } else {
                                        $msg[1] = $verification['finalExt'];
                                        $msg[4] = 1;
                                }

                                $this->dieWithError( $msg, 'filetype-banned', $extradata );
                                break;

                        case UploadBase::VERIFICATION_ERROR:
                                $msg = ApiMessage::create( $verification['details'], 'verification-error' );
                                if ( $verification['details'][0] instanceof MessageSpecifier ) {
                                        $details = array_merge( [ $msg->getKey() ], $msg->getParams() );
                                } else {
                                        $details = $verification['details'];
                                }
                                ApiResult::setIndexedTagName( $details, 'detail' );
                                $msg->setApiData( $msg->getApiData() + [ 'details' => $details ] );
                                $this->dieWithError( $msg );
                                break;

                        case UploadBase::HOOK_ABORTED:
                                $msg = $verification['error'] === '' ? 'hookaborted' : $verification['error'];
                                $this->dieWithError( $msg, 'hookaborted', [ 'details' => $verification['error'] ] );
                                break;
                        default:
                                $this->dieWithError( 'apierror-unknownerror-nocode', 'unknown-error',
                                        [ 'details' => [ 'code' => $verification['status'] ] ] );
                                break;
                }
        }

        /**
         * Check warnings.
         * Returns a suitable array for inclusion into API results if there were warnings
         * Returns the empty array if there were no warnings
         *
         * @return array
         */
        protected function getApiWarnings() {
                $warnings = $this->mUpload->checkWarnings();

                return $this->transformWarnings( $warnings );
        }

        protected function transformWarnings( $warnings ) {
                if ( $warnings ) {
                        // Add indices
                        ApiResult::setIndexedTagName( $warnings, 'warning' );

                        if ( isset( $warnings['duplicate'] ) ) {
                                $dupes = [];
                                /** @var File $dupe */
                                foreach ( $warnings['duplicate'] as $dupe ) {
                                        $dupes[] = $dupe->getName();
                                }
                                ApiResult::setIndexedTagName( $dupes, 'duplicate' );
                                $warnings['duplicate'] = $dupes;
                        }

                        if ( isset( $warnings['exists'] ) ) {
                                $warning = $warnings['exists'];
                                unset( $warnings['exists'] );
                                /** @var LocalFile $localFile */
                                $localFile = isset( $warning['normalizedFile'] )
                                        ? $warning['normalizedFile']
                                        : $warning['file'];
                                $warnings[$warning['warning']] = $localFile->getName();
                        }

                        if ( isset( $warnings['no-change'] ) ) {
                                /** @var File $file */
                                $file = $warnings['no-change'];
                                unset( $warnings['no-change'] );

                                $warnings['nochange'] = [
                                        'timestamp' => wfTimestamp( TS_ISO_8601, $file->getTimestamp() )
                                ];
                        }

                        if ( isset( $warnings['duplicate-version'] ) ) {
                                $dupes = [];
                                /** @var File $dupe */
                                foreach ( $warnings['duplicate-version'] as $dupe ) {
                                        $dupes[] = [
                                                'timestamp' => wfTimestamp( TS_ISO_8601, $dupe->getTimestamp() )
                                        ];
                                }
                                unset( $warnings['duplicate-version'] );

                                ApiResult::setIndexedTagName( $dupes, 'ver' );
                                $warnings['duplicateversions'] = $dupes;
                        }
                }

                return $warnings;
        }

        /**
         * Handles a stash exception, giving a useful error to the user.
         * @todo Internationalize the exceptions then get rid of this
         * @param Exception $e
         * @return StatusValue
         */
        protected function handleStashException( $e ) {
                switch ( get_class( $e ) ) {
                        case 'UploadStashFileNotFoundException':
                                $wrap = 'apierror-stashedfilenotfound';
                                break;
                        case 'UploadStashBadPathException':
                                $wrap = 'apierror-stashpathinvalid';
                                break;
                        case 'UploadStashFileException':
                                $wrap = 'apierror-stashfilestorage';
                                break;
                        case 'UploadStashZeroLengthFileException':
                                $wrap = 'apierror-stashzerolength';
                                break;
                        case 'UploadStashNotLoggedInException':
                                return StatusValue::newFatal( ApiMessage::create(
                                        [ 'apierror-mustbeloggedin', $this->msg( 'action-upload' ) ], 'stashnotloggedin'
                                ) );
                        case 'UploadStashWrongOwnerException':
                                $wrap = 'apierror-stashwrongowner';
                                break;
                        case 'UploadStashNoSuchKeyException':
                                $wrap = 'apierror-stashnosuchfilekey';
                                break;
                        default:
                                $wrap = [ 'uploadstash-exception', get_class( $e ) ];
                                break;
                }
                return StatusValue::newFatal(
                        $this->getErrorFormatter()->getMessageFromException( $e, [ 'wrap' => $wrap ] )
                );
        }

        /**
         * Perform the actual upload. Returns a suitable result array on success;
         * dies on failure.
         *
         * @param array $warnings Array of Api upload warnings
         * @return array
         */
        protected function performUpload( $warnings ) {
                // Use comment as initial page text by default
                if ( is_null( $this->mParams['text'] ) ) {
                        $this->mParams['text'] = $this->mParams['comment'];
                }

                /** @var $file LocalFile */
                $file = $this->mUpload->getLocalFile();

                // For preferences mode, we want to watch if 'watchdefault' is set,
                // or if the *file* doesn't exist, and either 'watchuploads' or
                // 'watchcreations' is set. But getWatchlistValue()'s automatic
                // handling checks if the *title* exists or not, so we need to check
                // all three preferences manually.
                $watch = $this->getWatchlistValue(
                        $this->mParams['watchlist'], $file->getTitle(), 'watchdefault'
                );

                if ( !$watch && $this->mParams['watchlist'] == 'preferences' && !$file->exists() ) {
                        $watch = (
                                $this->getWatchlistValue( 'preferences', $file->getTitle(), 'watchuploads' ) ||
                                $this->getWatchlistValue( 'preferences', $file->getTitle(), 'watchcreations' )
                        );
                }

                // Deprecated parameters
                if ( $this->mParams['watch'] ) {
                        $watch = true;
                }

                if ( $this->mParams['tags'] ) {
                        $status = ChangeTags::canAddTagsAccompanyingChange( $this->mParams['tags'], $this->getUser() );
                        if ( !$status->isOK() ) {
                                $this->dieStatus( $status );
                        }
                }

                // No errors, no warnings: do the upload
                if ( $this->mParams['async'] ) {
                        $progress = UploadBase::getSessionStatus( $this->getUser(), $this->mParams['filekey'] );
                        if ( $progress && $progress['result'] === 'Poll' ) {
                                $this->dieWithError( 'apierror-upload-inprogress', 'publishfailed' );
                        }
                        UploadBase::setSessionStatus(
                                $this->getUser(),
                                $this->mParams['filekey'],
                                [ 'result' => 'Poll', 'stage' => 'queued', 'status' => Status::newGood() ]
                        );
                        JobQueueGroup::singleton()->push( new PublishStashedFileJob(
                                Title::makeTitle( NS_FILE, $this->mParams['filename'] ),
                                [
                                        'filename' => $this->mParams['filename'],
                                        'filekey' => $this->mParams['filekey'],
                                        'comment' => $this->mParams['comment'],
                                        'tags' => $this->mParams['tags'],
                                        'text' => $this->mParams['text'],
                                        'watch' => $watch,
                                        'session' => $this->getContext()->exportSession()
                                ]
                        ) );
                        $result['result'] = 'Poll';
                        $result['stage'] = 'queued';
                } else {
                        /** @var $status Status */
                        $status = $this->mUpload->performUpload( $this->mParams['comment'],
                                $this->mParams['text'], $watch, $this->getUser(), $this->mParams['tags'] );

                        if ( !$status->isGood() ) {
                                $this->dieRecoverableError( $status->getErrors() );
                        }
                        $result['result'] = 'Success';
                }

                $result['filename'] = $file->getName();
                if ( $warnings && count( $warnings ) > 0 ) {
                        $result['warnings'] = $warnings;
                }

                return $result;
        }

        public function mustBePosted() {
                return true;
        }

        public function isWriteMode() {
                return true;
        }

        public function getAllowedParams() {
                $params = [
                        'filename' => [
                                ApiBase::PARAM_TYPE => 'string',
                        ],
                        'comment' => [
                                ApiBase::PARAM_DFLT => ''
                        ],
                        'tags' => [
                                ApiBase::PARAM_TYPE => 'tags',
                                ApiBase::PARAM_ISMULTI => true,
                        ],
                        'text' => [
                                ApiBase::PARAM_TYPE => 'text',
                        ],
                        'watch' => [
                                ApiBase::PARAM_DFLT => false,
                                ApiBase::PARAM_DEPRECATED => true,
                        ],
                        'watchlist' => [
                                ApiBase::PARAM_DFLT => 'preferences',
                                ApiBase::PARAM_TYPE => [
                                        'watch',
                                        'preferences',
                                        'nochange'
                                ],
                        ],
                        'ignorewarnings' => false,
                        'file' => [
                                ApiBase::PARAM_TYPE => 'upload',
                        ],
                        'url' => null,
                        'filekey' => null,
                        'sessionkey' => [
                                ApiBase::PARAM_DEPRECATED => true,
                        ],
                        'stash' => false,

                        'filesize' => [
                                ApiBase::PARAM_TYPE => 'integer',
                                ApiBase::PARAM_MIN => 0,
                                ApiBase::PARAM_MAX => UploadBase::getMaxUploadSize(),
                        ],
                        'offset' => [
                                ApiBase::PARAM_TYPE => 'integer',
                                ApiBase::PARAM_MIN => 0,
                        ],
                        'chunk' => [
                                ApiBase::PARAM_TYPE => 'upload',
                        ],

                        'async' => false,
                        'checkstatus' => false,
                ];

                return $params;
        }

        public function needsToken() {
                return 'csrf';
        }

        protected function getExamplesMessages() {
                return [
                        'action=upload&filename=Wiki.png' .
                                '&url=http%3A//upload.wikimedia.org/wikipedia/en/b/bc/Wiki.png&token=123ABC'
                                => 'apihelp-upload-example-url',
                        'action=upload&filename=Wiki.png&filekey=filekey&ignorewarnings=1&token=123ABC'
                                => 'apihelp-upload-example-filekey',
                ];
        }

        public function getHelpUrls() {
                return 'https://www.mediawiki.org/wiki/API:Upload';
        }
}