ios-sdk-code-review

# iOS SDK Code Review

Perform comprehensive code reviews for Payoo iOS Frameworks following Clean Architecture, MVVM, and iOS SDK best practices.

## When to Activate

- "review code", "code review", "check this code"
- "review PR", "review pull request", "review MR"
- "check iOS code", "review Swift code"
- User asks about code quality or best practices
- Reviewing ViewModels, ViewControllers, UseCases, or DataSources

## Review Process

### 1. Identify Code Context

Determine what's being reviewed:
- **File type**: ViewModel, ViewController, UseCase, DataSource, Model, Service
- **Framework**: PayooCore, PayooEwallet, PayooPayment, etc.
- **Layer**: Presentation (Scenes), Domain (UseCase), Data (DataSources/Services)

### 2. Architecture Review

**Clean Architecture Compliance:**
- ✓ Proper layer separation (Presentation/Domain/Data)
- ✓ Dependencies point inward (Presentation → Domain → Data)
- ✓ ViewModels don't directly access Services (must use UseCases)
- ✓ Models in correct layer (Domain models vs Data models)

**MVVM Pattern:**
- ✓ ViewModel has protocol definition (`{Feature}ViewModelType`)
- ✓ Delegate protocol exists (`{Feature}ViewModelDelegate`)
- ✓ ViewController implements delegate
- ✓ ViewModel is testable (no UIKit dependencies)
- ✓ View state managed through delegate callbacks

**UseCase Pattern:**
- ✓ Business logic in UseCases, not ViewModels
- ✓ Single responsibility per UseCase
- ✓ UseCases injected into ViewModels
- ✓ UseCases coordinate repositories/services

### 3. Memory Management Review

**Retain Cycles:**
- ✓ Delegates marked `weak`
- ✓ Closures use `[weak self]` or `[unowned self]` appropriately
- ✓ No strong reference cycles in ViewModels
- ✓ Timer/observer cleanup in `deinit`

**Example issues:**
```swift
// ❌ BAD: Strong delegate reference
var delegate: SomeDelegate?

// ✅ GOOD: Weak delegate reference
weak var delegate: SomeDelegate?

// ❌ BAD: Strong self in closure
viewModel.loadData { data in
    self.updateUI(data)
}

// ✅ GOO