[Backend] Implement Image and Video Processing BullMQ Processors

[llinsss]

⚠️ This is a backend issue — work is done inside the backend/ folder

Description

backend/src/modules/processing/ has a ProcessingService that enqueues jobs into image-processing and video-processing BullMQ queues, and the processor files exist at processors/image.processor.ts and processors/video.processor.ts. However, both processor files are stubs — they contain no actual processing logic. Uploaded pet photos and documents are queued but never processed.

Current State

• backend/src/modules/processing/processing.service.ts — enqueues jobs correctly
• backend/src/modules/processing/processors/image.processor.ts — stub
• backend/src/modules/processing/processors/video.processor.ts — stub
• ProcessingOptions interface defines: generateThumbnail, compress, convertToWebP, addWatermark, stripMetadata

What Needs to Be Built

1. Image Processor (processors/image.processor.ts)

@Processor('image-processing')
export class ImageProcessor {
  @Process('process')
  async handle(job: Job<{ fileId: string; options: ProcessingOptions }>) { ... }
}

Use sharp (already a common NestJS dependency) to:

• Generate thumbnail (300×300, WebP)
• Compress original (quality 80)
• Convert to WebP if convertToWebP is set
• Strip EXIF metadata if stripMetadata is set
• Upload processed variants to S3 via StorageModule
• Update FileMetadata entity with thumbnail URL and processed status

2. Video Processor (processors/video.processor.ts)

• Generate a preview thumbnail from frame at 1 second using ffmpeg
• Update FileMetadata with preview URL and status: 'processed'

3. Error Handling

• On failure: update ProcessingJob.status to FAILED with error message
• Emit real-time status update via RealtimeGateway
• Retry up to 2 times before marking failed

4. Unit Tests

• Mock sharp and StorageModule
• Test each processing option independently

Acceptance Criteria

• Uploaded images are thumbnailed, compressed, and stripped of metadata
• FileMetadata.thumbnailUrl is populated after processing
• ProcessingJob.status transitions: PENDING → PROCESSING → COMPLETED / FAILED
• Real-time status updates are emitted via WebSocket
• Failed jobs retry twice before marking FAILED
• Unit tests cover all ProcessingOptions flags

Files to Implement

• backend/src/modules/processing/processors/image.processor.ts
• backend/src/modules/processing/processors/video.processor.ts
• backend/src/modules/processing/processors/image.processor.spec.ts (new)

Priority

High — pet photos are uploaded but never processed or thumbnailed

Estimated Effort

2–3 days

[Opeyemi01-del]

@Opeyemi01-del has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

I would love to work on this issue boss

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[yosemite01]

@yosemite01 has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Hello Maintainer
I'll like to work on this Issue

ℹ️ Repo Maintainers: To accept this application, review their application or assign @yosemite01 to this issue.

[drips-wave]

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