User Profile Sync & Reaction Anonymization

TIP

Interactive Architecture Tour: Open Live Tour (User Profile & Settings)

This document details the propagation of profile modifications (nickname, avatar URL) to active group feeds and the privacy anonymization protocol executed upon account deletion in Scripture Habit.

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1. Architecture Overview (ProfileService)

The serverless ProfileService (api_internal/services/profile-service.ts) coordinates identity propagation and social data anonymization:

Synchronization Sequence Breakdown

1. Profile Modification Sync
   Updates the user's root document and propagates altered nicknames and avatars across joined group parent cards and recent message cache documents.

2. Account Deletion & Identity Scrubbing
   Clears private records and traverses active group logs to anonymize reaction author descriptors without disrupting conversation flow.

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2. Profile Propagation to Group Feeds

Updating every historical message across all groups would incur prohibitive write costs. The sync engine balances consistency with performance:

1. Targeted Scan Horizon: Scans recent active messages (up to 500 documents per joined group).
2. Reaction Preview Invalidation: Updates cached author nicknames and avatars within reactionPreviews.
3. Batch Partitioning: Commits Firestore operations in chunks of 450 (within Firestore's 500-write transactional limit).

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3. Account Deletion & Social Identity Anonymization

When an account is deleted, personal identifiable data is removed while preserving chat stream continuity:

[Before Account Deletion]
  Reaction: { uid: "user_123", nickname: "Jane Doe", photoURL: "https://..." }
        │
        ▼ (Account Deletion Triggered)
[After Account Deletion]
  Reaction: { uid: "user_123", nickname: "...", photoURL: "" }

• Identity Scrubbing: Display nicknames are replaced with "..." and avatar URLs are cleared.
• Feed Integrity: Reaction counts and discussion threads remain intact without rendering broken image placeholders.

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4. Related Documentation

• Group Chat Architecture & Implementation
• Database & Security Architecture