architect

name	architect
description	Design and plan software architecture for new features or refactoring. Use when asked to architect a solution, design a feature, create TDD, plan implementation, or make architectural decisions.
allowed-tools	Read, Grep, Glob, Task, Skill

Architect Skill

Design software architecture for the personal_assistant project following established patterns and principles. In PRD the user will add "!IMPORTANT!" for items you must address. Always evaluate this section and propose 1 to 2 solutions to the highlighted issue.

Architecture Principles

This project follows Domain Driven Design and Onion Architecture:

┌─────────────────────────────────────────────────────┐
│                   Controllers                       │
│              (Presentation Layer)                   │
│         HTTP handling, request validation           │
├─────────────────────────────────────────────────────┤
│                    Services                         │
│              (Business/Domain Layer)                │
│    Core business logic, domain rules, validation    │
├─────────────────────────────────────────────────────┤
│                  Repositories                       │
│              (Data Access Layer)                    │
│         Database operations, data mapping           │
├─────────────────────────────────────────────────────┤
│                    Database                         │
│                   (SQL Server)                      │
└─────────────────────────────────────────────────────┘

Database

The project uses SQL Server (not PostgreSQL). All raw SQL scripts in TDDs must use SQL Server syntax:

• INT IDENTITY(1,1) for auto-increment (not SERIAL)
• DATETIME2 for timestamps (not TIMESTAMPTZ)
• BIT for booleans (not BOOLEAN)
• UNIQUEIDENTIFIER for GUIDs (not UUID)
• NVARCHAR for Unicode strings
• Square brackets [TableName] for identifiers (not double quotes)
• CONSTRAINT [FK_Name] FOREIGN KEY syntax for foreign keys

Backwards Compatibility

All backend changes must be 100% backwards compatible for drops (memories) and access to drops (which users have access to drops they or others created).

Design Process

For every request, always create an md file and save it to directory docs/tdd. Most times you will be referrencing PRDs in docs/prd. You can ask /product-manager to create a prd if you don't have enough requirements to do a quality design.

1. Understand Requirements

• Clarify the feature/change scope
• Identify affected domains
• Determine integration points with existing code

2. Identify Components

For Backend Features:

• Which controllers need modification/creation?
• What services handle the business logic?
• What repositories are needed for data access?
• What domain models represent the data?
• What request/response models are needed?

For Frontend Features:

• !IMPORTANT! - use fyli-fe-v2 project. fyli-fe is deprecated and only used for reference.
• Which views/pages are affected?
• What components need creation/modification?
• What composables provide shared logic?
• What Pinia stores manage state?
• What service layer handles API calls?
• Use docs/FRONTEND_STYLE_GUIDE.md for all style decisions.
• Request the /designer to review proposed frontend changes.

3. Design Patterns to Apply

Factory Pattern - Use instead of if/else chains or switch statements:

// Good: Factory pattern via dictionary or DI registration
var handlerFactory = new Dictionary<string, INotificationHandler>
{
    ["email"] = new EmailHandler(),
    ["sms"] = new SmsHandler(),
    ["push"] = new PushHandler()
};
var handler = handlerFactory[type];

// Avoid: Switch statements
switch (type)
{
    case "email": ...
    case "sms": ...
}

Repository Pattern - Abstract database operations:

public interface IUserRepository
{
    Task<User?> FindByIdAsync(string id);
    Task<User> SaveAsync(User user);
}

Service Pattern - Encapsulate business logic:

public class AgendaService
{
    private readonly ICalendarRepository calendarRepo;
    private readonly ITodoRepository todoRepo;

    public AgendaService(ICalendarRepository calendarRepo, ITodoRepository todoRepo)
    {
        this.calendarRepo = calendarRepo;
        this.todoRepo = todoRepo;
    }

    public async Task<Agenda> GenerateDailyAgendaAsync(string userId, DateTime date)
    {
        // Business logic here
    }
}

Composable Pattern (Frontend) - Share reactive logic:

// useCalendar.ts
export function useCalendar() {
  const events = ref<CalendarEvent[]>([]);
  const loading = ref(false);

  async function fetchEvents(range: DateRange) { ... }

  return { events, loading, fetchEvents };
}

4. Data Flow Design

Request → Controller → Service → Repository → Database
                ↓
         Validation
                ↓
         Domain Logic
                ↓
Database → Repository → Service → Controller → Response

Model Transformations:

• Controller receives RequestDTO → transforms to DomainModel
• Service works with DomainModel
• Repository transforms DomainModel ↔ DatabaseEntity
• Controller transforms DomainModel → ResponseDTO

5. Error Handling Strategy

• Throw typed exceptions immediately when errors occur
• Let global error handler catch and format responses
• Define custom exception types for business errors:

public class NotFoundException : AppException { ... }
public class ValidationException : AppException { ... }
public class AuthorizationException : AppException { ... }

6. Testing Strategy

Following TDD approach:

1. Write failing tests first
2. Implement minimum code to pass
3. Refactor while keeping tests green

Test Boundaries:

• Unit tests: Services, Repositories, Utilities
• Integration tests: API endpoints
• Frontend: Component tests, Store tests, Composable tests, Service tests

Full testing standards: See docs/TESTING_BEST_PRACTICES.md for detailed backend and frontend testing patterns, examples, and checklists.

Architecture Output Format

When designing a feature, provide:

Overview

Brief description of the architectural approach

Component Diagram

Visual representation of component relationships

File Structure

cimplur-core/
├── Controllers/
│   └── [NewController]Controller.cs
├── Services/
│   └── [NewService]Service.cs
├── Repositories/
│   └── [NewRepo]Repository.cs
└── Models/
    └── [NewModel].cs

Interface Definitions

Key interfaces and types needed

Data Flow

Step-by-step flow through the system

Database Changes

This project uses EF Core Code-First migrations. Never write raw SQL for schema changes. To add/modify tables:

1. Create/update POCO entity class in cimplur-core/Memento/Domain/Entities/
2. Add FK and index configuration in StreamContext.cs → OnModelCreating
3. Add DbSet<T> property to StreamContext.cs
4. Generate migration: cd cimplur-core/Memento && dotnet ef migrations add <Name>

When documenting schema in TDDs, show the POCO entity, the OnModelCreating configuration, and the DbSet line.

Raw SQL MUST be included as a reference comment.

Always create the raw sql for each migration and save it in the TDD. That is the way the code gets to production (we don't use EF migrations in production).

Database Schema

Do not use jsonb fields if it can be avoided.

API Endpoints

New or modified endpoints

Frontend Components

Vue components and their responsibilities

Testing Plan

What tests are needed and at what level. Always add tests for both frontend and backend changes.

Implementation Order

Recommended sequence for building the feature

Review

After creating the TDD, use the Skill tool to invoke /code-review (e.g., Skill: code-review) to review the TDD and get feedback. Do NOT use the Task tool with subagent_type "code-review" — code-review is a skill, not a subagent type. Display feedback to the user to decide if to address.

Archiving

When a TDD is complete (all phases built and reviewed), move the corresponding PRD from docs/prd/ to docs/prd/archive/.

Project-Specific Considerations

• Calendar Integration: Consider Google Calendar and Outlook APIs
• Notes/Reminders: Auto-organization requires AI/categorization logic
• Daily Agenda: Combines calendar, todos, and priority algorithms
• Weekly Summary: Aggregation of completed items and accomplishments
• Focus Planning: AI-assisted priority recommendations

Remember: Keep methods under 100 lines, favor composability, and always consider testability in designs.