- **Schemas Layer:** Defines Pydantic models for request validation and API responses.
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- **Service Layer:** Implements business logic (NLP, chat assistant).
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- **Routes Layer:** Defines API endpoints exposed via FastAPI.
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- **Utility Layer:** Includes reusable components like embedding generation, configuration, logging, and security helpers.
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- **Worker Layer:** Handles background jobs such as scheduled chat message fetching and NLP processing.
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This modular layout ensures that each component can evolve independently — for example, NLP services or integrations can scale separately from the main API.
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The **frontend** is built using **React** and consumes REST APIs exposed by the FastAPI backend. It serves as the user interface for screens, chatbot interactions, and employee views.
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### 📁 Repository Structure
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```bash
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/repo
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├─ /api # FastAPI app
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│ ├─ main.py
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│ ├─ routers/
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│ │ ├─ auth.py
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│ │ ├─ chat.py
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│ │ ├─ employees.py
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│ ├─ models/ # ORM classes
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│ └─ services/ # Business logic (NLP invocations, DB helpers)
The database schema defines all core entities and their relationships for the MVP.
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It is implemented in **PostgreSQL** and **pgvector** for storing text embeddings used in semantic search.
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The schema captures four main domains:
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### **Employee Domain**
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- **Tables:** `employees`, `employee_tag`
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- Manages employee profiles, departmental details, and tag associations.
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- Defines users of the system (employees and admins) and establishes relationships between employees and tags for access control and contextual filtering.
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### **Message Domain**
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- **Tables:** `messages`
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- Stores sanitized chat messages fetched from configured data sources.
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- Each message is tied to an employee (sender) and a data source (Telegram or Google Chat), and includes an embedding vector for semantic search.
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### **Tag Domain**
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- **Tables:** `tags`
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- Defines organizational tags or categories such as projects, teams, or topics.
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- Tags serve as contextual identifiers used to categorize employees, data sources, and messages.
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### **Data Source Domain**
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- **Tables:** `data_sources`
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- Represents external chat integrations (Google Chat or Telegram groups).
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- Each data source is linked to a specific tag and acts as an entry point for message ingestion.
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- Foreign key relationships use `ON DELETE CASCADE` for integrity.
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> Example: Deleting a project automatically removes related skills or employees linked via `projects_employee`.
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---
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### 🧑💼 **employees**
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```sql
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CREATE TABLE employees (
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id SERIAL PRIMARY KEY,
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external_id JSONB,
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name VARCHAR(150) NOT NULL,
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role VARCHAR(50) NOT NULL, -- e.g., 'Java Developer'