File Handling & Media Processing - 1/2

// Comprehensive file upload system with validation, security, and processing
class FileUploadManager {
  private storageProvider: StorageProvider;
  private validationEngine: FileValidationEngine;
  private processingQueue: MediaProcessingQueue;
  private securityScanner: FileSecurityScanner;
  private metadataExtractor: FileMetadataExtractor;
  private uploadMetrics: UploadMetrics;
  private virusScanner: VirusScanner;

  constructor(config: FileUploadConfig) {
    this.storageProvider = this.initializeStorageProvider(config.storage);
    this.validationEngine = new FileValidationEngine(config.validation);
    this.processingQueue = new MediaProcessingQueue(config.processing);
    this.securityScanner = new FileSecurityScanner(config.security);
    this.metadataExtractor = new FileMetadataExtractor();
    this.uploadMetrics = new UploadMetrics();
    this.virusScanner = new VirusScanner(config.virusScanning);

    this.setupCleanupTasks();
    this.setupMonitoring();
  }

  // Handle file upload with comprehensive validation and security
  async uploadFile(
    uploadRequest: FileUploadRequest,
    uploadOptions: UploadOptions = {}
  ): Promise<FileUploadResult> {
    const uploadId = this.generateUploadId();
    const startTime = Date.now();

    try {
      console.log(`Starting file upload: ${uploadId}`);

      // Pre-upload validation
      await this.validateUploadRequest(uploadRequest, uploadOptions);

      // Create temporary file for processing
      const tempFile = await this.createTemporaryFile(uploadRequest, uploadId);

      try {
        // Multi-stage validation pipeline
        const validationResult = await this.runValidationPipeline(
          tempFile,
          uploadRequest,
          uploadId
        );

        if (!validationResult.isValid) {
          throw new FileUploadError(
            "File validation failed",
            "VALIDATION_FAILED",
            400,
            { errors: validationResult.errors }
          );
        }

        // Extract file metadata
        const metadata = await this.extractFileMetadata(
          tempFile,
          uploadRequest
        );

        // Security scanning
        await this.performSecurityScan(tempFile, metadata, uploadId);

        // Move to permanent storage
        const storageResult = await this.moveToStorage(
          tempFile,
          metadata,
          uploadOptions
        );

        // Queue for async processing if needed
        if (this.requiresProcessing(metadata)) {
          await this.queueForProcessing(storageResult, metadata, uploadOptions);
        }

        // Record metrics
        await this.recordUploadMetrics(uploadId, metadata, startTime);

        const result: FileUploadResult = {
          uploadId,
          fileId: storageResult.fileId,
          filename: metadata.originalName,
          mimeType: metadata.mimeType,
          size: metadata.size,
          url: storageResult.url,
          thumbnailUrl: storageResult.thumbnailUrl,
          metadata: this.sanitizeMetadataForResponse(metadata),
          processingStatus: this.requiresProcessing(metadata)
            ? "queued"
            : "completed",
          uploadedAt: Date.now(),
          expiresAt: uploadOptions.ttl ? Date.now() + uploadOptions.ttl : null,
        };

        console.log(`File upload completed successfully: ${uploadId}`);
        return result;
      } finally {
        // Always cleanup temporary file
        await this.cleanupTemporaryFile(tempFile);
      }
    } catch (error) {
      await this.recordUploadError(uploadId, error, startTime);
      console.error(`File upload failed: ${uploadId}`, error);
      throw error;
    }
  }

  private async validateUploadRequest(
    request: FileUploadRequest,
    options: UploadOptions
  ): Promise<void> {
    // Check user permissions
    if (!request.userId) {
      throw new FileUploadError(
        "User authentication required",
        "UNAUTHORIZED",
        401
      );
    }

    // Check quota limits
    const userQuota = await this.checkUserQuota(request.userId);
    if (userQuota.used + request.size > userQuota.limit) {
      throw new FileUploadError(
        "Upload would exceed user quota",
        "QUOTA_EXCEEDED",
        413,
        {
          currentUsage: userQuota.used,
          limit: userQuota.limit,
          requestedSize: request.size,
        }
      );
    }

    // Rate limiting check
    const rateLimitResult = await this.checkRateLimit(request.userId);
    if (!rateLimitResult.allowed) {
      throw new FileUploadError(
        "Upload rate limit exceeded",
        "RATE_LIMITED",
        429,
        { retryAfter: rateLimitResult.retryAfter }
      );
    }

    // Basic file size validation
    if (request.size > this.getMaxFileSize(request.fileType)) {
      throw new FileUploadError(
        "File size exceeds limit",
        "FILE_TOO_LARGE",
        413,
        {
          size: request.size,
          maxSize: this.getMaxFileSize(request.fileType),
        }
      );
    }

    // File type validation
    if (!this.isAllowedFileType(request.mimeType, request.fileType)) {
      throw new FileUploadError(
        "File type not allowed",
        "INVALID_FILE_TYPE",
        400,
        {
          mimeType: request.mimeType,
          allowedTypes: this.getAllowedTypes(request.fileType),
        }
      );
    }
  }

  private async runValidationPipeline(
    tempFile: TemporaryFile,
    request: FileUploadRequest,
    uploadId: string
  ): Promise<ValidationResult> {
    const validators: FileValidator[] = [
      new MimeTypeValidator(),
      new FileSizeValidator(),
      new FileSignatureValidator(),
      new ImageValidator(),
      new VideoValidator(),
      new DocumentValidator(),
      new MalwareValidator(),
    ];

    const results: ValidationStepResult[] = [];

    for (const validator of validators) {
      if (await validator.shouldValidate(tempFile, request)) {
        try {
          console.log(`Running validator: ${validator.name} for ${uploadId}`);

          const stepResult = await validator.validate(tempFile, request);
          results.push(stepResult);

          if (!stepResult.isValid && stepResult.severity === "critical") {
            // Stop validation pipeline on critical failures
            break;
          }
        } catch (error) {
          console.error(
            `Validator ${validator.name} failed for ${uploadId}:`,
            error
          );
          results.push({
            validatorName: validator.name,
            isValid: false,
            severity: "critical",
            errors: [`Validation failed: ${error.message}`],
          });
        }
      }
    }

    const criticalErrors = results.filter(
      (r) => !r.isValid && r.severity === "critical"
    );
    const warnings = results.filter(
      (r) => !r.isValid && r.severity === "warning"
    );

    return {
      isValid: criticalErrors.length === 0,
      errors: criticalErrors.flatMap((r) => r.errors),
      warnings: warnings.flatMap((r) => r.errors),
      validationSteps: results,
    };
  }

  private async extractFileMetadata(
    tempFile: TemporaryFile,
    request: FileUploadRequest
  ): Promise<FileMetadata> {
    try {
      const basicMetadata = await this.getBasicFileMetadata(tempFile);
      const extendedMetadata = await this.metadataExtractor.extract(
        tempFile.path,
        request.mimeType
      );

      return {
        fileId: this.generateFileId(),
        originalName: request.filename,
        sanitizedName: this.sanitizeFilename(request.filename),
        mimeType: basicMetadata.mimeType,
        size: basicMetadata.size,
        checksum: basicMetadata.checksum,
        uploadedBy: request.userId,
        uploadedAt: Date.now(),

        // Extended metadata based on file type
        ...extendedMetadata,

        // Security metadata
        scanResults: [],
        riskLevel: "unknown",
      };
    } catch (error) {
      console.error("Metadata extraction failed:", error);
      throw new FileUploadError(
        "Failed to extract file metadata",
        "METADATA_EXTRACTION_FAILED",
        500,
        { originalError: error }
      );
    }
  }

  private async performSecurityScan(
    tempFile: TemporaryFile,
    metadata: FileMetadata,
    uploadId: string
  ): Promise<void> {
    console.log(`Performing security scan: ${uploadId}`);

    // File signature verification
    const signatureValid = await this.securityScanner.verifyFileSignature(
      tempFile.path,
      metadata.mimeType
    );

    if (!signatureValid) {
      throw new FileUploadError(
        "File signature does not match declared type",
        "INVALID_FILE_SIGNATURE",
        400
      );
    }

    // Executable detection
    if (await this.securityScanner.containsExecutableContent(tempFile.path)) {
      throw new FileUploadError(
        "File contains executable content",
        "EXECUTABLE_CONTENT_DETECTED",
        400
      );
    }

    // Virus scanning
    const virusScanResult = await this.virusScanner.scan(tempFile.path);
    if (virusScanResult.infected) {
      await this.quarantineFile(tempFile, virusScanResult);
      throw new FileUploadError(
        "File contains malware",
        "MALWARE_DETECTED",
        400,
        { threats: virusScanResult.threats }
      );
    }

    // Content-based security checks
    await this.performContentSecurityChecks(tempFile, metadata);

    // Update metadata with security scan results
    metadata.scanResults = [
      {
        scanner: "signature_verification",
        result: "clean",
        timestamp: Date.now(),
      },
      {
        scanner: "virus_scan",
        result: virusScanResult.clean ? "clean" : "infected",
        timestamp: Date.now(),
        details: virusScanResult,
      },
    ];

    metadata.riskLevel = this.calculateRiskLevel(metadata);
  }

  private async moveToStorage(
    tempFile: TemporaryFile,
    metadata: FileMetadata,
    options: UploadOptions
  ): Promise<StorageResult> {
    const storageKey = this.generateStorageKey(metadata, options);

    console.log(`Moving file to storage: ${metadata.fileId}`);

    try {
      // Upload to primary storage
      const uploadResult = await this.storageProvider.upload(
        tempFile.path,
        storageKey,
        {
          mimeType: metadata.mimeType,
          metadata: this.getStorageMetadata(metadata),
          encryption: options.encrypt !== false,
          redundancy: options.redundancy || "standard",
        }
      );

      // Generate optimized versions if needed
      let thumbnailUrl: string | null = null;
      if (this.shouldGenerateThumbnail(metadata)) {
        thumbnailUrl = await this.generateThumbnail(
          tempFile,
          metadata,
          storageKey
        );
      }

      return {
        fileId: metadata.fileId,
        storageKey,
        url: uploadResult.url,
        thumbnailUrl,
        size: uploadResult.size,
        etag: uploadResult.etag,
      };
    } catch (error) {
      console.error("Storage upload failed:", error);
      throw new FileUploadError("Failed to store file", "STORAGE_FAILED", 500, {
        originalError: error,
      });
    }
  }

  // Batch file upload with progress tracking
  async uploadFiles(
    files: FileUploadRequest[],
    options: BatchUploadOptions = {}
  ): Promise<BatchUploadResult> {
    const batchId = this.generateBatchId();
    const concurrency = options.concurrency || 3;

    console.log(`Starting batch upload: ${batchId} (${files.length} files)`);

    const results: FileUploadResult[] = [];
    const errors: BatchUploadError[] = [];
    const executing: Promise<any>[] = [];

    for (let i = 0; i < files.length; i++) {
      const file = files[i];

      const promise = this.uploadFile(file, {
        ...options,
        batchId,
        batchIndex: i,
      }).then(
        (result) => {
          results.push(result);
          return result;
        },
        (error) => {
          const batchError: BatchUploadError = {
            index: i,
            filename: file.filename,
            error: error.message,
            code: error.code,
          };
          errors.push(batchError);
          return batchError;
        }
      );

      executing.push(promise);

      // Control concurrency
      if (executing.length >= concurrency) {
        await Promise.race(executing);
        const completedIndex = executing.findIndex((p) => p === promise);
        if (completedIndex !== -1) {
          executing.splice(completedIndex, 1);
        }
      }
    }

    // Wait for all remaining uploads
    await Promise.allSettled(executing);

    return {
      batchId,
      totalFiles: files.length,
      successfulUploads: results.length,
      failedUploads: errors.length,
      results,
      errors,
      completedAt: Date.now(),
    };
  }

  // Chunked upload for large files
  async uploadLargeFile(
    request: LargeFileUploadRequest,
    options: LargeFileUploadOptions = {}
  ): Promise<FileUploadResult> {
    const uploadId = this.generateUploadId();
    const chunkSize = options.chunkSize || 5 * 1024 * 1024; // 5MB chunks
    const totalChunks = Math.ceil(request.totalSize / chunkSize);

    console.log(
      `Starting large file upload: ${uploadId} (${request.totalSize} bytes, ${totalChunks} chunks)`
    );

    try {
      // Initialize multipart upload
      const multipartUpload = await this.storageProvider.createMultipartUpload({
        key: this.generateStorageKey(
          { originalName: request.filename },
          options
        ),
        mimeType: request.mimeType,
        metadata: {
          originalName: request.filename,
          totalSize: request.totalSize,
          uploadId,
        },
      });

      // Track upload progress
      const uploadProgress = {
        uploadId,
        totalChunks,
        completedChunks: 0,
        uploadedBytes: 0,
        startTime: Date.now(),
      };

      const chunkResults: ChunkUploadResult[] = [];

      // Upload chunks with retry logic
      for (let chunkIndex = 0; chunkIndex < totalChunks; chunkIndex++) {
        const chunkStart = chunkIndex * chunkSize;
        const chunkEnd = Math.min(chunkStart + chunkSize, request.totalSize);
        const chunkData = request.getChunk(chunkStart, chunkEnd);

        const chunkResult = await this.uploadChunkWithRetry(
          multipartUpload.uploadId,
          chunkIndex + 1,
          chunkData,
          options.maxRetries || 3
        );

        chunkResults.push(chunkResult);
        uploadProgress.completedChunks++;
        uploadProgress.uploadedBytes += chunkData.length;

        // Report progress
        if (options.onProgress) {
          options.onProgress(uploadProgress);
        }
      }

      // Complete multipart upload
      const finalResult = await this.storageProvider.completeMultipartUpload(
        multipartUpload.uploadId,
        chunkResults
      );

      console.log(`Large file upload completed: ${uploadId}`);

      return {
        uploadId,
        fileId: finalResult.fileId,
        filename: request.filename,
        mimeType: request.mimeType,
        size: request.totalSize,
        url: finalResult.url,
        uploadedAt: Date.now(),
        processingStatus: "completed",
      };
    } catch (error) {
      console.error(`Large file upload failed: ${uploadId}`, error);

      // Cleanup failed multipart upload
      try {
        await this.storageProvider.abortMultipartUpload(uploadId);
      } catch (cleanupError) {
        console.error("Failed to cleanup aborted upload:", cleanupError);
      }

      throw error;
    }
  }

  private async uploadChunkWithRetry(
    uploadId: string,
    chunkNumber: number,
    chunkData: Buffer,
    maxRetries: number
  ): Promise<ChunkUploadResult> {
    let lastError: Error;

    for (let attempt = 1; attempt <= maxRetries; attempt++) {
      try {
        return await this.storageProvider.uploadChunk(
          uploadId,
          chunkNumber,
          chunkData
        );
      } catch (error) {
        lastError = error;

        if (attempt < maxRetries) {
          const delay = Math.min(1000 * Math.pow(2, attempt), 10000); // Exponential backoff
          console.log(
            `Chunk upload failed (attempt ${attempt}), retrying in ${delay}ms`
          );
          await new Promise((resolve) => setTimeout(resolve, delay));
        }
      }
    }

    throw new FileUploadError(
      `Chunk upload failed after ${maxRetries} attempts`,
      "CHUNK_UPLOAD_FAILED",
      500,
      { chunkNumber, originalError: lastError }
    );
  }

  // File validation implementations
  private getMaxFileSize(fileType: string): number {
    const limits: Record<string, number> = {
      image: 10 * 1024 * 1024, // 10MB for images
      video: 500 * 1024 * 1024, // 500MB for videos
      audio: 50 * 1024 * 1024, // 50MB for audio
      document: 25 * 1024 * 1024, // 25MB for documents
      archive: 100 * 1024 * 1024, // 100MB for archives
    };

    return limits[fileType] || 10 * 1024 * 1024; // Default 10MB
  }

  private isAllowedFileType(mimeType: string, category: string): boolean {
    const allowedTypes: Record<string, string[]> = {
      image: [
        "image/jpeg",
        "image/png",
        "image/gif",
        "image/webp",
        "image/svg+xml",
        "image/bmp",
        "image/tiff",
      ],
      video: [
        "video/mp4",
        "video/webm",
        "video/ogg",
        "video/avi",
        "video/mov",
        "video/wmv",
        "video/flv",
        "video/mkv",
      ],
      audio: [
        "audio/mpeg",
        "audio/wav",
        "audio/ogg",
        "audio/aac",
        "audio/flac",
        "audio/m4a",
      ],
      document: [
        "application/pdf",
        "text/plain",
        "text/csv",
        "application/msword",
        "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
        "application/vnd.ms-excel",
        "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
      ],
    };

    return allowedTypes[category]?.includes(mimeType) || false;
  }

  private getAllowedTypes(category: string): string[] {
    const allowedTypes: Record<string, string[]> = {
      image: ["JPEG", "PNG", "GIF", "WebP", "SVG"],
      video: ["MP4", "WebM", "OGG", "AVI", "MOV"],
      audio: ["MP3", "WAV", "OGG", "AAC", "FLAC"],
      document: ["PDF", "TXT", "DOC", "DOCX", "XLS", "XLSX"],
    };

    return allowedTypes[category] || [];
  }

  private sanitizeFilename(filename: string): string {
    // Remove dangerous characters and normalize
    return filename
      .replace(/[^\w\s.-]/g, "") // Remove special characters
      .replace(/\s+/g, "_") // Replace spaces with underscores
      .toLowerCase()
      .substring(0, 100); // Limit length
  }

  private generateStorageKey(
    metadata: FileMetadata,
    options?: UploadOptions
  ): string {
    const date = new Date();
    const year = date.getFullYear();
    const month = String(date.getMonth() + 1).padStart(2, "0");
    const day = String(date.getDate()).padStart(2, "0");

    const extension = this.getFileExtension(metadata.originalName);

    return `uploads/${year}/${month}/${day}/${metadata.fileId}${extension}`;
  }

  private getFileExtension(filename: string): string {
    const match = filename.match(/\.[^.]*$/);
    return match ? match[0] : "";
  }

  private generateUploadId(): string {
    return `upload_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`;
  }

  private generateFileId(): string {
    return `file_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`;
  }

  private generateBatchId(): string {
    return `batch_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`;
  }

  // Cleanup and monitoring
  private setupCleanupTasks(): void {
    // Clean up temporary files every hour
    setInterval(async () => {
      try {
        await this.cleanupExpiredTemporaryFiles();
      } catch (error) {
        console.error("Temporary file cleanup failed:", error);
      }
    }, 3600000); // 1 hour
  }

  private setupMonitoring(): void {
    // Monitor upload metrics
    setInterval(async () => {
      try {
        const metrics = await this.uploadMetrics.getRecentMetrics();
        console.log("Upload metrics:", metrics);
      } catch (error) {
        console.error("Failed to collect upload metrics:", error);
      }
    }, 300000); // 5 minutes
  }

  // Utility methods would be implemented based on your specific requirements
  private async createTemporaryFile(
    request: FileUploadRequest,
    uploadId: string
  ): Promise<TemporaryFile> {
    // Implementation depends on your temporary storage solution
    throw new Error("createTemporaryFile implementation needed");
  }

  private async cleanupTemporaryFile(tempFile: TemporaryFile): Promise<void> {
    // Implementation for cleaning up temporary files
  }

  private async getBasicFileMetadata(
    tempFile: TemporaryFile
  ): Promise<BasicFileMetadata> {
    // Implementation for extracting basic metadata
    throw new Error("getBasicFileMetadata implementation needed");
  }

  private requiresProcessing(metadata: FileMetadata): boolean {
    // Determine if file needs async processing (thumbnails, transcoding, etc.)
    const processingRequired = ["image/", "video/", "audio/"];
    return processingRequired.some((type) =>
      metadata.mimeType.startsWith(type)
    );
  }

  private async queueForProcessing(
    storageResult: StorageResult,
    metadata: FileMetadata,
    options: UploadOptions
  ): Promise<void> {
    await this.processingQueue.enqueue({
      fileId: metadata.fileId,
      storageKey: storageResult.storageKey,
      mimeType: metadata.mimeType,
      processingOptions: options.processing || {},
    });
  }
}

// File validator implementations
class MimeTypeValidator implements FileValidator {
  name = "mime_type";

  async shouldValidate(
    file: TemporaryFile,
    request: FileUploadRequest
  ): Promise<boolean> {
    return true; // Always validate MIME type
  }

  async validate(
    file: TemporaryFile,
    request: FileUploadRequest
  ): Promise<ValidationStepResult> {
    // Use file-type library or similar to detect actual MIME type
    const detectedType = await this.detectMimeType(file.path);
    const declaredType = request.mimeType;

    if (detectedType !== declaredType) {
      return {
        validatorName: this.name,
        isValid: false,
        severity: "critical",
        errors: [
          `MIME type mismatch: declared ${declaredType}, detected ${detectedType}`,
        ],
      };
    }

    return {
      validatorName: this.name,
      isValid: true,
      severity: "info",
      errors: [],
    };
  }

  private async detectMimeType(filePath: string): Promise<string> {
    // Implementation would use a library like file-type
    return "application/octet-stream"; // Placeholder
  }
}

class ImageValidator implements FileValidator {
  name = "image";

  async shouldValidate(
    file: TemporaryFile,
    request: FileUploadRequest
  ): Promise<boolean> {
    return request.mimeType.startsWith("image/");
  }

  async validate(
    file: TemporaryFile,
    request: FileUploadRequest
  ): Promise<ValidationStepResult> {
    try {
      // Use sharp or similar library to validate image
      const imageInfo = await this.getImageInfo(file.path);

      // Check for reasonable dimensions
      if (imageInfo.width > 50000 || imageInfo.height > 50000) {
        return {
          validatorName: this.name,
          isValid: false,
          severity: "critical",
          errors: ["Image dimensions too large"],
        };
      }

      // Check for corrupted image
      if (!imageInfo.valid) {
        return {
          validatorName: this.name,
          isValid: false,
          severity: "critical",
          errors: ["Corrupted image file"],
        };
      }

      return {
        validatorName: this.name,
        isValid: true,
        severity: "info",
        errors: [],
      };
    } catch (error) {
      return {
        validatorName: this.name,
        isValid: false,
        severity: "critical",
        errors: [`Image validation failed: ${error.message}`],
      };
    }
  }

  private async getImageInfo(filePath: string): Promise<any> {
    // Implementation would use sharp or similar
    return { width: 0, height: 0, valid: true };
  }
}

// Supporting interfaces and types
interface FileUploadRequest {
  filename: string;
  mimeType: string;
  size: number;
  userId: string;
  fileType: string;
  data?: Buffer | ReadableStream;
}

interface UploadOptions {
  ttl?: number;
  encrypt?: boolean;
  redundancy?: "standard" | "high";
  processing?: ProcessingOptions;
  batchId?: string;
  batchIndex?: number;
}

interface ProcessingOptions {
  generateThumbnails?: boolean;
  optimizeImages?: boolean;
  transcodeVideo?: boolean;
  extractMetadata?: boolean;
}

interface FileUploadResult {
  uploadId: string;
  fileId: string;
  filename: string;
  mimeType: string;
  size: number;
  url: string;
  thumbnailUrl?: string | null;
  metadata: any;
  processingStatus: "queued" | "processing" | "completed" | "failed";
  uploadedAt: number;
  expiresAt?: number | null;
}

interface ValidationResult {
  isValid: boolean;
  errors: string[];
  warnings: string[];
  validationSteps: ValidationStepResult[];
}

interface ValidationStepResult {
  validatorName: string;
  isValid: boolean;
  severity: "info" | "warning" | "critical";
  errors: string[];
}

interface FileValidator {
  name: string;
  shouldValidate(
    file: TemporaryFile,
    request: FileUploadRequest
  ): Promise<boolean>;
  validate(
    file: TemporaryFile,
    request: FileUploadRequest
  ): Promise<ValidationStepResult>;
}

interface TemporaryFile {
  path: string;
  size: number;
  mimeType: string;
  createdAt: number;
}

interface FileMetadata {
  fileId: string;
  originalName: string;
  sanitizedName: string;
  mimeType: string;
  size: number;
  checksum: string;
  uploadedBy: string;
  uploadedAt: number;
  scanResults: any[];
  riskLevel: string;
  [key: string]: any; // Extended metadata
}

interface BasicFileMetadata {
  mimeType: string;
  size: number;
  checksum: string;
}

interface StorageResult {
  fileId: string;
  storageKey: string;
  url: string;
  thumbnailUrl?: string | null;
  size: number;
  etag: string;
}

interface BatchUploadOptions extends UploadOptions {
  concurrency?: number;
  failFast?: boolean;
}

interface BatchUploadResult {
  batchId: string;
  totalFiles: number;
  successfulUploads: number;
  failedUploads: number;
  results: FileUploadResult[];
  errors: BatchUploadError[];
  completedAt: number;
}

interface BatchUploadError {
  index: number;
  filename: string;
  error: string;
  code: string;
}

interface LargeFileUploadRequest {
  filename: string;
  mimeType: string;
  totalSize: number;
  getChunk: (start: number, end: number) => Buffer;
}

interface LargeFileUploadOptions extends UploadOptions {
  chunkSize?: number;
  maxRetries?: number;
  onProgress?: (progress: UploadProgress) => void;
}

interface UploadProgress {
  uploadId: string;
  totalChunks: number;
  completedChunks: number;
  uploadedBytes: number;
  startTime: number;
}

interface ChunkUploadResult {
  chunkNumber: number;
  etag: string;
}

class FileUploadError extends Error {
  constructor(
    message: string,
    public code: string,
    public status: number,
    public metadata?: any
  ) {
    super(message);
    this.name = "FileUploadError";
  }
}

// Placeholder classes that would need full implementation
interface FileUploadConfig {
  storage: any;
  validation: any;
  processing: any;
  security: any;
  virusScanning: any;
}

interface StorageProvider {
  upload(filePath: string, key: string, options: any): Promise<any>;
  createMultipartUpload(options: any): Promise<any>;
  uploadChunk(
    uploadId: string,
    chunkNumber: number,
    data: Buffer
  ): Promise<ChunkUploadResult>;
  completeMultipartUpload(
    uploadId: string,
    parts: ChunkUploadResult[]
  ): Promise<any>;
  abortMultipartUpload(uploadId: string): Promise<void>;
}

class FileValidationEngine {
  constructor(config: any) {}
}

class MediaProcessingQueue {
  constructor(config: any) {}
  async enqueue(job: any): Promise<void> {}
}

class FileSecurityScanner {
  constructor(config: any) {}
  async verifyFileSignature(path: string, mimeType: string): Promise<boolean> {
    return true;
  }
  async containsExecutableContent(path: string): Promise<boolean> {
    return false;
  }
}

class FileMetadataExtractor {
  async extract(path: string, mimeType: string): Promise<any> {
    return {};
  }
}

class UploadMetrics {
  async getRecentMetrics(): Promise<any> {
    return {};
  }
}

class VirusScanner {
  constructor(config: any) {}
  async scan(
    path: string
  ): Promise<{ infected: boolean; clean: boolean; threats?: string[] }> {
    return { infected: false, clean: true };
  }
}

// Comprehensive image processing system with optimization and format conversion
class ImageProcessingEngine {
  private processingQueue: Queue<ImageJob>;
  private storageProvider: StorageProvider;
  private cdn: CDNProvider;
  private cache: ProcessingCache;
  private optimizer: ImageOptimizer;
  private transformer: ImageTransformer;

  constructor(config: ImageProcessingConfig) {
    this.processingQueue = new Queue("image-processing", config.queueConfig);
    this.storageProvider = new StorageProvider(config.storage);
    this.cdn = new CDNProvider(config.cdn);
    this.cache = new ProcessingCache(config.cache);
    this.optimizer = new ImageOptimizer(config.optimization);
    this.transformer = new ImageTransformer(config.transformation);

    this.setupProcessingWorkers(config.workerCount || 4);
  }

  // Process uploaded image with multiple optimizations
  async processImage(
    imageJob: ImageProcessingJob
  ): Promise<ImageProcessingResult> {
    const jobId = this.generateJobId();
    const startTime = Date.now();

    try {
      console.log(`Starting image processing: ${jobId}`);

      // Download source image
      const sourceImage = await this.downloadImage(imageJob.sourceUrl);

      // Extract image metadata
      const metadata = await this.extractImageMetadata(sourceImage);

      // Generate multiple variants
      const variants = await this.generateImageVariants(
        sourceImage,
        metadata,
        imageJob.variants
      );

      // Optimize each variant
      const optimizedVariants = await Promise.all(
        variants.map((variant) =>
          this.optimizeImageVariant(variant, imageJob.optimization)
        )
      );

      // Upload variants to storage
      const uploadResults = await this.uploadImageVariants(
        optimizedVariants,
        imageJob.destinationPath
      );

      // Update CDN cache
      await this.updateCDNCache(uploadResults);

      const result: ImageProcessingResult = {
        jobId,
        originalUrl: imageJob.sourceUrl,
        variants: uploadResults.map((upload) => ({
          size: upload.variant.size,
          url: upload.url,
          width: upload.variant.width,
          height: upload.variant.height,
          format: upload.variant.format,
          fileSize: upload.fileSize,
          optimizationSavings: upload.optimizationSavings,
        })),
        metadata,
        processingTime: Date.now() - startTime,
        processedAt: Date.now(),
      };

      console.log(`Image processing completed: ${jobId}`);
      return result;
    } catch (error) {
      console.error(`Image processing failed: ${jobId}`, error);
      throw new ImageProcessingError(
        "Image processing failed",
        "PROCESSING_FAILED",
        500,
        { jobId, originalError: error }
      );
    }
  }

  private async generateImageVariants(
    sourceImage: ProcessedImage,
    metadata: ImageMetadata,
    variantSpecs: ImageVariantSpec[]
  ): Promise<ProcessedImage[]> {
    const variants: ProcessedImage[] = [];

    for (const spec of variantSpecs) {
      try {
        console.log(`Generating variant: ${spec.name}`);

        let variant = sourceImage;

        // Resize if needed
        if (spec.width || spec.height) {
          variant = await this.transformer.resize(variant, {
            width: spec.width,
            height: spec.height,
            fit: spec.fit || "cover",
            position: spec.position || "center",
            withoutEnlargement: spec.withoutEnlargement !== false,
          });
        }

        // Apply transformations
        if (spec.transformations) {
          for (const transform of spec.transformations) {
            switch (transform.type) {
              case "crop":
                variant = await this.transformer.crop(
                  variant,
                  transform.options
                );
                break;
              case "rotate":
                variant = await this.transformer.rotate(
                  variant,
                  transform.options
                );
                break;
              case "blur":
                variant = await this.transformer.blur(
                  variant,
                  transform.options
                );
                break;
              case "sharpen":
                variant = await this.transformer.sharpen(
                  variant,
                  transform.options
                );
                break;
              case "grayscale":
                variant = await this.transformer.grayscale(variant);
                break;
              case "sepia":
                variant = await this.transformer.sepia(variant);
                break;
              case "watermark":
                variant = await this.transformer.addWatermark(
                  variant,
                  transform.options
                );
                break;
            }
          }
        }

        // Convert format if needed
        if (spec.format && spec.format !== metadata.format) {
          variant = await this.transformer.convertFormat(variant, spec.format, {
            quality: spec.quality,
            progressive: spec.progressive,
          });
        }

        // Update variant metadata
        variant.spec = spec;
        variant.name = spec.name;

        variants.push(variant);
      } catch (error) {
        console.error(`Failed to generate variant ${spec.name}:`, error);

        if (spec.required) {
          throw new ImageProcessingError(
            `Failed to generate required variant: ${spec.name}`,
            "VARIANT_GENERATION_FAILED",
            500,
            { variant: spec.name, originalError: error }
          );
        }
      }
    }

    return variants;
  }

  private async optimizeImageVariant(
    variant: ProcessedImage,
    optimization: OptimizationOptions
  ): Promise<OptimizedImage> {
    console.log(`Optimizing variant: ${variant.name}`);

    const originalSize = variant.buffer.length;
    let optimizedBuffer = variant.buffer;
    let optimizationSavings = 0;

    try {
      switch (variant.format) {
        case "jpeg":
          optimizedBuffer = await this.optimizer.optimizeJPEG(variant.buffer, {
            quality: optimization.jpegQuality || 85,
            progressive: optimization.progressive !== false,
            mozjpeg: optimization.mozjpeg !== false,
          });
          break;

        case "png":
          optimizedBuffer = await this.optimizer.optimizePNG(variant.buffer, {
            compressionLevel: optimization.pngCompressionLevel || 6,
            palette: optimization.pngPalette,
            colors: optimization.pngColors,
          });
          break;

        case "webp":
          optimizedBuffer = await this.optimizer.optimizeWebP(variant.buffer, {
            quality: optimization.webpQuality || 80,
            lossless: optimization.webpLossless,
            effort: optimization.webpEffort || 4,
          });
          break;

        case "avif":
          optimizedBuffer = await this.optimizer.optimizeAVIF(variant.buffer, {
            quality: optimization.avifQuality || 75,
            effort: optimization.avifEffort || 4,
          });
          break;
      }

      optimizationSavings =
        ((originalSize - optimizedBuffer.length) / originalSize) * 100;

      console.log(
        `Optimization complete: ${variant.name} - ${optimizationSavings.toFixed(
          1
        )}% savings`
      );
    } catch (error) {
      console.warn(
        `Optimization failed for ${variant.name}, using original:`,
        error
      );
      optimizedBuffer = variant.buffer;
    }

    return {
      ...variant,
      buffer: optimizedBuffer,
      originalSize,
      optimizedSize: optimizedBuffer.length,
      optimizationSavings,
    };
  }

  private async uploadImageVariants(
    variants: OptimizedImage[],
    basePath: string
  ): Promise<VariantUploadResult[]> {
    const uploadPromises = variants.map(async (variant) => {
      const filename = this.generateVariantFilename(basePath, variant);

      const uploadResult = await this.storageProvider.upload(
        variant.buffer,
        filename,
        {
          mimeType: `image/${variant.format}`,
          metadata: {
            width: variant.width,
            height: variant.height,
            originalSize: variant.originalSize,
            optimizedSize: variant.optimizedSize,
            optimizationSavings: variant.optimizationSavings,
          },
          cacheControl: "public, max-age=31536000", // 1 year cache
        }
      );

      return {
        variant,
        url: uploadResult.url,
        fileSize: variant.optimizedSize,
        optimizationSavings: variant.optimizationSavings,
      };
    });

    return await Promise.all(uploadPromises);
  }

  // Smart format selection based on browser support and content
  async selectOptimalFormat(
    sourceImage: ProcessedImage,
    userAgent?: string,
    acceptHeader?: string
  ): Promise<string> {
    const supportedFormats = this.getSupportedFormats(userAgent, acceptHeader);

    // Analyze image content
    const analysis = await this.analyzeImageContent(sourceImage);

    // Decision matrix for format selection
    if (supportedFormats.includes("avif") && analysis.complexity === "high") {
      return "avif"; // Best compression for complex images
    }

    if (supportedFormats.includes("webp")) {
      if (analysis.hasTransparency) {
        return "webp"; // WebP handles transparency better than JPEG
      }
      if (analysis.isPhotographic) {
        return "webp"; // Good balance for photos
      }
    }

    if (analysis.hasTransparency) {
      return "png"; // Fallback for transparency
    }

    if (analysis.isPhotographic) {
      return "jpeg"; // Traditional choice for photos
    }

    return "png"; // Safe fallback
  }

  private getSupportedFormats(
    userAgent?: string,
    acceptHeader?: string
  ): string[] {
    const formats = ["jpeg", "png"]; // Base support

    if (!userAgent && !acceptHeader) {
      return formats;
    }

    // Check Accept header first (most reliable)
    if (acceptHeader) {
      if (acceptHeader.includes("image/avif")) {
        formats.push("avif");
      }
      if (acceptHeader.includes("image/webp")) {
        formats.push("webp");
      }
    }

    // Fallback to User-Agent parsing
    if (userAgent) {
      // Chrome supports WebP and AVIF
      if (userAgent.includes("Chrome/")) {
        const chromeVersion = this.extractChromeVersion(userAgent);
        if (chromeVersion >= 85) formats.push("avif");
        if (chromeVersion >= 23) formats.push("webp");
      }

      // Firefox supports WebP and AVIF
      if (userAgent.includes("Firefox/")) {
        const firefoxVersion = this.extractFirefoxVersion(userAgent);
        if (firefoxVersion >= 93) formats.push("avif");
        if (firefoxVersion >= 65) formats.push("webp");
      }

      // Safari supports WebP in newer versions
      if (userAgent.includes("Safari/")) {
        const safariVersion = this.extractSafariVersion(userAgent);
        if (safariVersion >= 14) formats.push("webp");
      }
    }

    return formats;
  }

  private async analyzeImageContent(
    image: ProcessedImage
  ): Promise<ImageAnalysis> {
    // Use image processing library to analyze content
    const analysis = await this.transformer.analyze(image.buffer);

    return {
      isPhotographic: analysis.entropy > 7, // High entropy suggests photographic content
      hasTransparency: analysis.channels > 3,
      complexity:
        analysis.edges > 1000
          ? "high"
          : analysis.edges > 300
          ? "medium"
          : "low",
      dominantColors: analysis.dominantColors,
      averageColor: analysis.averageColor,
    };
  }

  // Responsive image generation with srcset
  async generateResponsiveImages(
    sourceUrl: string,
    breakpoints: ResponsiveBreakpoint[]
  ): Promise<ResponsiveImageSet> {
    const sourceImage = await this.downloadImage(sourceUrl);
    const metadata = await this.extractImageMetadata(sourceImage);

    // Generate variants for each breakpoint
    const variants: ResponsiveVariant[] = [];

    for (const breakpoint of breakpoints) {
      for (const density of breakpoint.densities || [1, 2]) {
        const width = Math.round(breakpoint.width * density);
        const height = breakpoint.height
          ? Math.round(breakpoint.height * density)
          : undefined;

        // Don't upscale beyond original dimensions
        if (width > metadata.width || (height && height > metadata.height)) {
          continue;
        }

        const variant = await this.transformer.resize(sourceImage, {
          width,
          height,
          fit: breakpoint.fit || "cover",
          withoutEnlargement: true,
        });

        const optimized = await this.optimizeImageVariant(variant, {
          jpegQuality: breakpoint.quality || 85,
          webpQuality: (breakpoint.quality || 85) - 5,
        });

        const filename = this.generateResponsiveFilename(
          sourceUrl,
          width,
          height,
          density,
          optimized.format
        );

        const uploadResult = await this.storageProvider.upload(
          optimized.buffer,
          filename,
          {
            mimeType: `image/${optimized.format}`,
            cacheControl: "public, max-age=31536000",
          }
        );

        variants.push({
          url: uploadResult.url,
          width,
          height: optimized.height,
          density,
          fileSize: optimized.optimizedSize,
          format: optimized.format,
        });
      }
    }

    // Generate srcset string
    const srcset = variants.map((v) => `${v.url} ${v.width}w`).join(", ");

    // Generate sizes string
    const sizes = breakpoints
      .map((bp) =>
        bp.mediaQuery ? `${bp.mediaQuery} ${bp.width}px` : `${bp.width}px`
      )
      .join(", ");

    return {
      srcset,
      sizes,
      variants,
      fallbackUrl: variants[0]?.url,
    };
  }

  // Background processing for bulk image optimization
  async processBulkImages(
    imageJobs: ImageProcessingJob[],
    options: BulkProcessingOptions = {}
  ): Promise<BulkProcessingResult> {
    const batchId = this.generateBatchId();
    const concurrency = options.concurrency || 3;

    console.log(
      `Starting bulk image processing: ${batchId} (${imageJobs.length} images)`
    );

    const results: ImageProcessingResult[] = [];
    const errors: BulkProcessingError[] = [];
    const executing: Promise<any>[] = [];

    for (let i = 0; i < imageJobs.length; i++) {
      const job = { ...imageJobs[i], batchId, batchIndex: i };

      const promise = this.processImage(job).then(
        (result) => {
          results.push(result);
          if (options.onProgress) {
            options.onProgress({
              completed: results.length + errors.length,
              total: imageJobs.length,
              batchId,
            });
          }
          return result;
        },
        (error) => {
          const bulkError: BulkProcessingError = {
            index: i,
            sourceUrl: job.sourceUrl,
            error: error.message,
            code: error.code,
          };
          errors.push(bulkError);
          if (options.onProgress) {
            options.onProgress({
              completed: results.length + errors.length,
              total: imageJobs.length,
              batchId,
            });
          }
          return bulkError;
        }
      );

      executing.push(promise);

      // Control concurrency
      if (executing.length >= concurrency) {
        await Promise.race(executing);
        const completedIndex = executing.findIndex((p) => p === promise);
        if (completedIndex !== -1) {
          executing.splice(completedIndex, 1);
        }
      }
    }

    // Wait for all remaining processing
    await Promise.allSettled(executing);

    return {
      batchId,
      totalImages: imageJobs.length,
      successfulProcessing: results.length,
      failedProcessing: errors.length,
      results,
      errors,
      totalSavings: results.reduce((sum, r) => {
        return (
          sum +
          r.variants.reduce(
            (variantSum, v) => variantSum + v.optimizationSavings,
            0
          )
        );
      }, 0),
      completedAt: Date.now(),
    };
  }

  private generateJobId(): string {
    return `img_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`;
  }

  private generateBatchId(): string {
    return `batch_img_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`;
  }

  private generateVariantFilename(
    basePath: string,
    variant: OptimizedImage
  ): string {
    const extension = variant.format;
    const size = variant.spec?.name || `${variant.width}x${variant.height}`;

    return `${basePath}_${size}.${extension}`;
  }

  private generateResponsiveFilename(
    sourceUrl: string,
    width: number,
    height?: number,
    density?: number,
    format?: string
  ): string {
    const basename =
      sourceUrl
        .split("/")
        .pop()
        ?.replace(/\.[^.]*$/, "") || "image";
    const densityStr = density && density > 1 ? `@${density}x` : "";
    const sizeStr = height ? `${width}x${height}` : `${width}w`;

    return `responsive/${basename}_${sizeStr}${densityStr}.${format || "jpg"}`;
  }

  // Utility methods
  private extractChromeVersion(userAgent: string): number {
    const match = userAgent.match(/Chrome\/(\d+)/);
    return match ? parseInt(match[1]) : 0;
  }

  private extractFirefoxVersion(userAgent: string): number {
    const match = userAgent.match(/Firefox\/(\d+)/);
    return match ? parseInt(match[1]) : 0;
  }

  private extractSafariVersion(userAgent: string): number {
    const match = userAgent.match(/Version\/(\d+)/);
    return match ? parseInt(match[1]) : 0;
  }

  // Placeholder implementations
  private async downloadImage(url: string): Promise<ProcessedImage> {
    // Implementation would download and load image
    throw new Error("downloadImage implementation needed");
  }

  private async extractImageMetadata(
    image: ProcessedImage
  ): Promise<ImageMetadata> {
    // Implementation would extract EXIF and other metadata
    throw new Error("extractImageMetadata implementation needed");
  }

  private async updateCDNCache(results: VariantUploadResult[]): Promise<void> {
    // Implementation would invalidate CDN cache
  }

  private setupProcessingWorkers(workerCount: number): void {
    // Implementation would set up background workers
  }
}

// Supporting classes and interfaces
interface ImageProcessingJob {
  sourceUrl: string;
  destinationPath: string;
  variants: ImageVariantSpec[];
  optimization: OptimizationOptions;
  batchId?: string;
  batchIndex?: number;
}

interface ImageVariantSpec {
  name: string;
  width?: number;
  height?: number;
  format?: string;
  quality?: number;
  fit?: "cover" | "contain" | "fill" | "inside" | "outside";
  position?: string;
  withoutEnlargement?: boolean;
  progressive?: boolean;
  required?: boolean;
  transformations?: ImageTransformation[];
}

interface ImageTransformation {
  type:
    | "crop"
    | "rotate"
    | "blur"
    | "sharpen"
    | "grayscale"
    | "sepia"
    | "watermark";
  options: any;
}

interface OptimizationOptions {
  jpegQuality?: number;
  webpQuality?: number;
  avifQuality?: number;
  pngCompressionLevel?: number;
  pngPalette?: boolean;
  pngColors?: number;
  progressive?: boolean;
  mozjpeg?: boolean;
  webpLossless?: boolean;
  webpEffort?: number;
  avifEffort?: number;
}

interface ProcessedImage {
  buffer: Buffer;
  width: number;
  height: number;
  format: string;
  channels: number;
  name?: string;
  spec?: ImageVariantSpec;
}

interface OptimizedImage extends ProcessedImage {
  originalSize: number;
  optimizedSize: number;
  optimizationSavings: number;
}

interface ImageMetadata {
  width: number;
  height: number;
  format: string;
  channels: number;
  density: number;
  hasAlpha: boolean;
  exif?: any;
  icc?: any;
}

interface ImageProcessingResult {
  jobId: string;
  originalUrl: string;
  variants: ProcessingVariant[];
  metadata: ImageMetadata;
  processingTime: number;
  processedAt: number;
}

interface ProcessingVariant {
  size: string;
  url: string;
  width: number;
  height: number;
  format: string;
  fileSize: number;
  optimizationSavings: number;
}

interface VariantUploadResult {
  variant: OptimizedImage;
  url: string;
  fileSize: number;
  optimizationSavings: number;
}

interface ImageAnalysis {
  isPhotographic: boolean;
  hasTransparency: boolean;
  complexity: "low" | "medium" | "high";
  dominantColors: string[];
  averageColor: string;
}

interface ResponsiveBreakpoint {
  width: number;
  height?: number;
  densities?: number[];
  quality?: number;
  fit?: "cover" | "contain";
  mediaQuery?: string;
}

interface ResponsiveVariant {
  url: string;
  width: number;
  height: number;
  density: number;
  fileSize: number;
  format: string;
}

interface ResponsiveImageSet {
  srcset: string;
  sizes: string;
  variants: ResponsiveVariant[];
  fallbackUrl: string;
}

interface BulkProcessingOptions {
  concurrency?: number;
  onProgress?: (progress: {
    completed: number;
    total: number;
    batchId: string;
  }) => void;
}

interface BulkProcessingResult {
  batchId: string;
  totalImages: number;
  successfulProcessing: number;
  failedProcessing: number;
  results: ImageProcessingResult[];
  errors: BulkProcessingError[];
  totalSavings: number;
  completedAt: number;
}

interface BulkProcessingError {
  index: number;
  sourceUrl: string;
  error: string;
  code: string;
}

class ImageProcessingError extends Error {
  constructor(
    message: string,
    public code: string,
    public status: number,
    public metadata?: any
  ) {
    super(message);
    this.name = "ImageProcessingError";
  }
}

// Placeholder classes
interface ImageProcessingConfig {
  queueConfig: any;
  storage: any;
  cdn: any;
  cache: any;
  optimization: any;
  transformation: any;
  workerCount?: number;
}

class Queue<T> {
  constructor(name: string, config: any) {}
}

class StorageProvider {
  constructor(config: any) {}
  async upload(data: Buffer, filename: string, options: any): Promise<any> {
    return { url: `https://example.com/${filename}` };
  }
}

class CDNProvider {
  constructor(config: any) {}
}

class ProcessingCache {
  constructor(config: any) {}
}

class ImageOptimizer {
  constructor(config: any) {}

  async optimizeJPEG(buffer: Buffer, options: any): Promise<Buffer> {
    return buffer; // Placeholder
  }

  async optimizePNG(buffer: Buffer, options: any): Promise<Buffer> {
    return buffer; // Placeholder
  }

  async optimizeWebP(buffer: Buffer, options: any): Promise<Buffer> {
    return buffer; // Placeholder
  }

  async optimizeAVIF(buffer: Buffer, options: any): Promise<Buffer> {
    return buffer; // Placeholder
  }
}

class ImageTransformer {
  constructor(config: any) {}

  async resize(image: ProcessedImage, options: any): Promise<ProcessedImage> {
    return image; // Placeholder
  }

  async crop(image: ProcessedImage, options: any): Promise<ProcessedImage> {
    return image; // Placeholder
  }

  async rotate(image: ProcessedImage, options: any): Promise<ProcessedImage> {
    return image; // Placeholder
  }

  async blur(image: ProcessedImage, options: any): Promise<ProcessedImage> {
    return image; // Placeholder
  }

  async sharpen(image: ProcessedImage, options: any): Promise<ProcessedImage> {
    return image; // Placeholder
  }

  async grayscale(image: ProcessedImage): Promise<ProcessedImage> {
    return image; // Placeholder
  }

  async sepia(image: ProcessedImage): Promise<ProcessedImage> {
    return image; // Placeholder
  }

  async addWatermark(
    image: ProcessedImage,
    options: any
  ): Promise<ProcessedImage> {
    return image; // Placeholder
  }

  async convertFormat(
    image: ProcessedImage,
    format: string,
    options: any
  ): Promise<ProcessedImage> {
    return { ...image, format }; // Placeholder
  }

  async analyze(buffer: Buffer): Promise<any> {
    return {}; // Placeholder
  }
}