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[Cuneyt-Sahin]

No description provided.

[Copilot]

Pull request overview

This PR refactors the embedding service architecture to consolidate embedding operations in the LLM backend and improves error handling and null safety across the codebase. The minimal title "." does not adequately describe the changes made.

Changes:

• Refactored embedding service to call LLM backend's /rag/embeddings endpoint instead of directly calling Ollama from the backend
• Removed duplicate exception handler in Python chat endpoint
• Improved null safety in Dart models with defensive parsing and default values
• Increased API timeout values and added sendTimeout configuration
• Removed unused content_text database column updates and cleaned up environment variables

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
backend/src/services/llm_backend.service.ts	Refactored embedTexts() to call LLM backend instead of Ollama directly, simplified retry logic
backend/src/services/document_rag.service.ts	Removed content_text column from database UPDATE queries
backend/src/config/env.ts	Removed OLLAMA_EMBEDDINGS_URL configuration (no longer needed)
scripts/dev_start.sh	Removed OLLAMA_EMBEDDINGS_URL and EMBEDDING_MODEL environment variable exports
llm_backend/app/api/chat.py	Removed duplicate exception handler block
lib/shared/services/api_service.dart	Increased timeout values (connect: 15→30s, receive: 15→60s, added send: 60s)
lib/shared/models/models.dart	Added null-safe parsing for Document fields (title, summary, uploaded_at)
lib/features/auth/data/api_auth_repository.dart	Added null-safe parsing for AuthUser fields
lib/shared/data/api_document_repository.dart	Added debug print statements for API responses and errors
lib/features/home/presentation/widgets/procedural_tree.dart	Removed unused constant variable branches

Comments suppressed due to low confidence (2)

lib/shared/models/models.dart:164

• The handling of null uploaded_at values could mask backend data issues. Since the database schema has uploaded_at as NOT NULL with a default value, it should always be present. Consider logging a warning or throwing an error when uploadedAtRaw is not a valid string to make debugging easier. The current implementation silently falls back to DateTime.now() which could lead to incorrect timestamps if the backend has issues.

    DateTime? uploadedAt;
    final uploadedAtRaw = json['uploaded_at'];
    if (uploadedAtRaw is String) {
      uploadedAt = DateTime.tryParse(uploadedAtRaw);
    }

    return Document(
      id: json['id'] as String?,
      title: (json['title'] as String?) ?? 'Untitled',
      summary: (json['summary'] as String?) ?? '',
      status: status,
      uploadedAt: uploadedAt,

backend/src/config/env.ts:36

• The EMBEDDING_MODEL configuration field is defined in the interface and exported but is not used anywhere in the backend service since embeddings are now handled by the LLM backend. Consider removing this unused configuration field from both the interface (line 11) and the config object (line 36) to keep the codebase clean and reduce confusion, or add a comment explaining why it's kept.

    EMBEDDING_MODEL: string;
}

function validateEnv(): EnvConfig {
    const nodeEnv = process.env.NODE_ENV || 'development';
    const port = parseInt(process.env.PORT || '3000', 10);

    // DATABASE_URL priority: use it if exists, otherwise construct from PG* vars
    let databaseUrl = process.env.DATABASE_URL;

    if (!databaseUrl) {
        const host = process.env.PGHOST || 'localhost';
        const pgPort = process.env.PGPORT || '5432';
        const database = process.env.PGDATABASE || 'learning_coach_dev';
        const user = process.env.PGUSER || 'postgres';
        const password = process.env.PGPASSWORD || 'postgres';

        databaseUrl = `postgres://${user}:${password}@${host}:${pgPort}/${database}?sslmode=disable`;
    }

    return {
        NODE_ENV: nodeEnv,
        PORT: port,
        DATABASE_URL: databaseUrl,
        LLM_BACKEND_URL: process.env.LLM_BACKEND_URL || 'http://localhost:8000',
        EMBEDDING_MODEL: process.env.EMBEDDING_MODEL || 'nomic-embed-text',

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