LibreChat/api/server/routes/files/files.js

const fs = require('fs').promises;
const express = require('express');
const { EnvVar } = require('@librechat/agents');
const {
  Time,
  isUUID,
  CacheKeys,
  FileSources,
  PERMISSION_BITS,
  EModelEndpoint,
  isAgentsEndpoint,
  checkOpenAIStorage,
} = require('librechat-data-provider');
const {
  filterFile,
  processFileUpload,
  processDeleteRequest,
  processAgentFileUpload,
} = require('~/server/services/Files/process');
const { getStrategyFunctions } = require('~/server/services/Files/strategies');
const { getOpenAIClient } = require('~/server/controllers/assistants/helpers');
const { checkPermission } = require('~/server/services/PermissionService');
const { loadAuthValues } = require('~/server/services/Tools/credentials');
const { refreshS3FileUrls } = require('~/server/services/Files/S3/crud');
const { hasAccessToFilesViaAgent } = require('~/server/services/Files');
const { getFiles, batchUpdateFiles } = require('~/models/File');
const { getAssistant } = require('~/models/Assistant');
const { getAgent } = require('~/models/Agent');
const { cleanFileName } = require('~/server/utils/files');
const { getLogStores } = require('~/cache');
const { logger } = require('~/config');

/**
 * Checks if user has access to shared agent file through agent ownership or permissions
 */
const checkSharedFileAccess = async (userId, fileId) => {
  try {
    // Find agents that have this file in their tool_resources
    const agentsWithFile = await getAgent({
      $or: [
        { 'tool_resources.file_search.file_ids': fileId },
        { 'tool_resources.execute_code.file_ids': fileId },
        { 'tool_resources.ocr.file_ids': fileId },
      ],
    });

    if (!agentsWithFile || agentsWithFile.length === 0) {
      return false;
    }

    // Check if user has access to any of these agents
    for (const agent of Array.isArray(agentsWithFile) ? agentsWithFile : [agentsWithFile]) {
      // Check if user is the agent author
      if (agent.author && agent.author.toString() === userId) {
        return true;
      }

      // Check if agent is collaborative
      if (agent.isCollaborative) {
        return true;
      }

      // Check if user has access through project membership
      if (agent.projectIds && agent.projectIds.length > 0) {
        // For now, return true if agent has project IDs (simplified check)
        // This could be enhanced to check actual project membership
        return true;
      }
    }

    return false;
  } catch (error) {
    logger.error('[checkSharedFileAccess] Error:', error);
    return false;
  }
};

const router = express.Router();

router.get('/', async (req, res) => {
  try {
    const files = await getFiles({ user: req.user.id });
    if (req.app.locals.fileStrategy === FileSources.s3) {
      try {
        const cache = getLogStores(CacheKeys.S3_EXPIRY_INTERVAL);
        const alreadyChecked = await cache.get(req.user.id);
        if (!alreadyChecked) {
          await refreshS3FileUrls(files, batchUpdateFiles);
          await cache.set(req.user.id, true, Time.THIRTY_MINUTES);
        }
      } catch (error) {
        logger.warn('[/files] Error refreshing S3 file URLs:', error);
      }
    }
    res.status(200).send(files);
  } catch (error) {
    logger.error('[/files] Error getting files:', error);
    res.status(400).json({ message: 'Error in request', error: error.message });
  }
});

/**
 * Get files specific to an agent
 * @route GET /files/agent/:agent_id
 * @param {string} agent_id - The agent ID to get files for
 * @returns {Promise<TFile[]>} Array of files attached to the agent
 */
router.get('/agent/:agent_id', async (req, res) => {
  try {
    const { agent_id } = req.params;
    const userId = req.user.id;

    if (!agent_id) {
      return res.status(400).json({ error: 'Agent ID is required' });
    }

    // Get the agent to check ownership and attached files
    const agent = await getAgent({ id: agent_id });

    if (!agent) {
      // No agent found, return empty array
      return res.status(200).json([]);
    }

    // Check if user has access to the agent
    if (agent.author.toString() !== userId) {
      // Non-authors need at least EDIT permission to view agent files
      const hasEditPermission = await checkPermission({
        userId,
        resourceType: 'agent',
        resourceId: agent._id,
        requiredPermission: PERMISSION_BITS.EDIT,
      });

      if (!hasEditPermission) {
        return res.status(200).json([]);
      }
    }

    // Collect all file IDs from agent's tool resources
    const agentFileIds = [];
    if (agent.tool_resources) {
      for (const [, resource] of Object.entries(agent.tool_resources)) {
        if (resource?.file_ids && Array.isArray(resource.file_ids)) {
          agentFileIds.push(...resource.file_ids);
        }
      }
    }

    // If no files attached to agent, return empty array
    if (agentFileIds.length === 0) {
      return res.status(200).json([]);
    }

    // Get only the files attached to this agent
    const files = await getFiles({ file_id: { $in: agentFileIds } }, null, { text: 0 });

    res.status(200).json(files);
  } catch (error) {
    logger.error('[/files/agent/:agent_id] Error fetching agent files:', error);
    res.status(500).json({ error: 'Failed to fetch agent files' });
  }
});

router.get('/config', async (req, res) => {
  try {
    res.status(200).json(req.app.locals.fileConfig);
  } catch (error) {
    logger.error('[/files] Error getting fileConfig', error);
    res.status(400).json({ message: 'Error in request', error: error.message });
  }
});

router.delete('/', async (req, res) => {
  try {
    const { files: _files } = req.body;

    /** @type {MongoFile[]} */
    const files = _files.filter((file) => {
      if (!file.file_id) {
        return false;
      }
      if (!file.filepath) {
        return false;
      }

      if (/^(file|assistant)-/.test(file.file_id)) {
        return true;
      }

      return isUUID.safeParse(file.file_id).success;
    });

    if (files.length === 0) {
      res.status(204).json({ message: 'Nothing provided to delete' });
      return;
    }

    const fileIds = files.map((file) => file.file_id);
    const dbFiles = await getFiles({ file_id: { $in: fileIds } });

    const ownedFiles = [];
    const nonOwnedFiles = [];
    const fileMap = new Map();

    for (const file of dbFiles) {
      fileMap.set(file.file_id, file);
      if (file.user.toString() === req.user.id) {
        ownedFiles.push(file);
      } else {
        nonOwnedFiles.push(file);
      }
    }

    // If all files are owned by the user, no need for further checks
    if (nonOwnedFiles.length === 0) {
      await processDeleteRequest({ req, files: ownedFiles });
      logger.debug(
        `[/files] Files deleted successfully: ${ownedFiles
          .filter((f) => f.file_id)
          .map((f) => f.file_id)
          .join(', ')}`,
      );
      res.status(200).json({ message: 'Files deleted successfully' });
      return;
    }

    // Check access for non-owned files
    let authorizedFiles = [...ownedFiles];
    let unauthorizedFiles = [];

    if (req.body.agent_id && nonOwnedFiles.length > 0) {
      // Batch check access for all non-owned files
      const nonOwnedFileIds = nonOwnedFiles.map((f) => f.file_id);
      const accessMap = await hasAccessToFilesViaAgent(
        req.user.id,
        nonOwnedFileIds,
        req.body.agent_id,
      );

      // Separate authorized and unauthorized files
      for (const file of nonOwnedFiles) {
        if (accessMap.get(file.file_id)) {
          authorizedFiles.push(file);
        } else {
          unauthorizedFiles.push(file);
        }
      }
    } else {
      // No agent context, all non-owned files are unauthorized
      unauthorizedFiles = nonOwnedFiles;
    }

    if (unauthorizedFiles.length > 0) {
      return res.status(403).json({
        message: 'You can only delete files you have access to',
        unauthorizedFiles: unauthorizedFiles.map((f) => f.file_id),
      });
    }

    /* Handle agent unlinking even if no valid files to delete */
    if (req.body.agent_id && req.body.tool_resource && dbFiles.length === 0) {
      const agent = await getAgent({
        id: req.body.agent_id,
      });

      const toolResourceFiles = agent.tool_resources?.[req.body.tool_resource]?.file_ids ?? [];
      const agentFiles = files.filter((f) => toolResourceFiles.includes(f.file_id));

      await processDeleteRequest({ req, files: agentFiles });
      res.status(200).json({ message: 'File associations removed successfully from agent' });
      return;
    }

    /* Handle assistant unlinking even if no valid files to delete */
    if (req.body.assistant_id && req.body.tool_resource && dbFiles.length === 0) {
      const assistant = await getAssistant({
        id: req.body.assistant_id,
      });

      const toolResourceFiles = assistant.tool_resources?.[req.body.tool_resource]?.file_ids ?? [];
      const assistantFiles = files.filter((f) => toolResourceFiles.includes(f.file_id));

      await processDeleteRequest({ req, files: assistantFiles });
      res.status(200).json({ message: 'File associations removed successfully from assistant' });
      return;
    } else if (
      req.body.assistant_id &&
      req.body.files?.[0]?.filepath === EModelEndpoint.azureAssistants
    ) {
      await processDeleteRequest({ req, files: req.body.files });
      return res
        .status(200)
        .json({ message: 'File associations removed successfully from Azure Assistant' });
    }

    await processDeleteRequest({ req, files: authorizedFiles });

    logger.debug(
      `[/files] Files deleted successfully: ${authorizedFiles
        .filter((f) => f.file_id)
        .map((f) => f.file_id)
        .join(', ')}`,
    );
    res.status(200).json({ message: 'Files deleted successfully' });
  } catch (error) {
    logger.error('[/files] Error deleting files:', error);
    res.status(400).json({ message: 'Error in request', error: error.message });
  }
});

function isValidID(str) {
  return /^[A-Za-z0-9_-]{21}$/.test(str);
}

router.get('/code/download/:session_id/:fileId', async (req, res) => {
  try {
    const { session_id, fileId } = req.params;
    const logPrefix = `Session ID: ${session_id} | File ID: ${fileId} | Code output download requested by user `;
    logger.debug(logPrefix);

    if (!session_id || !fileId) {
      return res.status(400).send('Bad request');
    }

    if (!isValidID(session_id) || !isValidID(fileId)) {
      logger.debug(`${logPrefix} invalid session_id or fileId`);
      return res.status(400).send('Bad request');
    }

    const { getDownloadStream } = getStrategyFunctions(FileSources.execute_code);
    if (!getDownloadStream) {
      logger.warn(
        `${logPrefix} has no stream method implemented for ${FileSources.execute_code} source`,
      );
      return res.status(501).send('Not Implemented');
    }

    const result = await loadAuthValues({ userId: req.user.id, authFields: [EnvVar.CODE_API_KEY] });

    /** @type {AxiosResponse<ReadableStream> | undefined} */
    const response = await getDownloadStream(
      `${session_id}/${fileId}`,
      result[EnvVar.CODE_API_KEY],
    );
    res.set(response.headers);
    response.data.pipe(res);
  } catch (error) {
    logger.error('Error downloading file:', error);
    res.status(500).send('Error downloading file');
  }
});

router.get('/download/:userId/:file_id', async (req, res) => {
  try {
    const { userId, file_id } = req.params;
    logger.debug(`File download requested by user ${userId}: ${file_id}`);

    const errorPrefix = `File download requested by user ${userId}`;
    const [file] = await getFiles({ file_id });

    if (!file) {
      logger.warn(`${errorPrefix} not found: ${file_id}`);
      return res.status(404).send('File not found');
    }

    // Extract actual file owner from S3 filepath (e.g., /uploads/ownerId/filename)
    let actualFileOwner = userId;
    if (file.filepath && file.filepath.includes('/uploads/')) {
      const pathMatch = file.filepath.match(/\/uploads\/([^/]+)\//);
      if (pathMatch) {
        actualFileOwner = pathMatch[1];
      }
    }

    // Check access: either own the file or have shared access through conversations
    const isFileOwner = req.user.id === actualFileOwner;
    const hasSharedAccess = !isFileOwner && (await checkSharedFileAccess(req.user.id, file_id));

    if (!isFileOwner && !hasSharedAccess) {
      return res.status(403).send('Forbidden');
    }

    if (isFileOwner && userId !== actualFileOwner) {
      return res.status(403).send('Forbidden');
    }

    if (checkOpenAIStorage(file.source) && !file.model) {
      logger.warn(`${errorPrefix} has no associated model: ${file_id}`);
      return res.status(400).send('The model used when creating this file is not available');
    }

    const { getDownloadStream } = getStrategyFunctions(file.source);
    if (!getDownloadStream) {
      logger.warn(`${errorPrefix} has no stream method implemented: ${file.source}`);
      return res.status(501).send('Not Implemented');
    }

    const setHeaders = () => {
      const cleanedFilename = cleanFileName(file.filename);
      res.setHeader('Content-Disposition', `attachment; filename="${cleanedFilename}"`);
      res.setHeader('Content-Type', 'application/octet-stream');
      res.setHeader('X-File-Metadata', JSON.stringify(file));
    };

    /** @type {{ body: import('stream').PassThrough } | undefined} */
    let passThrough;
    /** @type {ReadableStream | undefined} */
    let fileStream;

    if (checkOpenAIStorage(file.source)) {
      req.body = { model: file.model };
      const endpointMap = {
        [FileSources.openai]: EModelEndpoint.assistants,
        [FileSources.azure]: EModelEndpoint.azureAssistants,
      };
      const { openai } = await getOpenAIClient({
        req,
        res,
        overrideEndpoint: endpointMap[file.source],
      });
      logger.debug(`Downloading file ${file_id} from OpenAI`);
      passThrough = await getDownloadStream(file_id, openai);
      setHeaders();
      logger.debug(`File ${file_id} downloaded from OpenAI`);
      passThrough.body.pipe(res);
    } else {
      fileStream = await getDownloadStream(req, file.filepath);

      fileStream.on('error', (streamError) => {
        logger.error('[DOWNLOAD ROUTE] Stream error:', streamError);
      });

      setHeaders();
      fileStream.pipe(res);
    }
  } catch (error) {
    logger.error('[DOWNLOAD ROUTE] Error downloading file:', error);
    res.status(500).send('Error downloading file');
  }
});

router.post('/', async (req, res) => {
  const metadata = req.body;
  let cleanup = true;

  try {
    filterFile({ req });

    metadata.temp_file_id = metadata.file_id;
    metadata.file_id = req.file_id;

    if (isAgentsEndpoint(metadata.endpoint)) {
      return await processAgentFileUpload({ req, res, metadata });
    }

    await processFileUpload({ req, res, metadata });
  } catch (error) {
    let message = 'Error processing file';
    logger.error('[/files] Error processing file:', error);

    if (error.message?.includes('file_ids')) {
      message += ': ' + error.message;
    }

    if (
      error.message?.includes('Invalid file format') ||
      error.message?.includes('No OCR result')
    ) {
      message = error.message;
    }

    try {
      await fs.unlink(req.file.path);
      cleanup = false;
    } catch (error) {
      logger.error('[/files] Error deleting file:', error);
    }
    res.status(500).json({ message });
  } finally {
    if (cleanup) {
      try {
        await fs.unlink(req.file.path);
      } catch (error) {
        logger.error('[/files] Error deleting file after file processing:', error);
      }
    } else {
      logger.debug('[/files] File processing completed without cleanup');
    }
  }
});

module.exports = router;