refactor: Modernize Project Structure and Refine Codebase

[peterfriese]

This pull request modernizes the iOS quickstart project, building upon the significant restructuring work initiated by Young Hypo. The primary goal is to create a more modular, scalable, and maintainable codebase that aligns with modern Swift and SwiftUI best practices.

Initial Refactoring (by Young Hypo):

• A major effort was undertaken to deconstruct the monolithic project into a more organized and modular structure.

Refinements and Additions in this PR:

• Logical Folder Structure: The folder organization was further refined to logically group files by feature (Features) and shared components (Shared), improving clarity and navigation.
• Code Cleanup & Best Practices:
  • Addressed security concerns by removing hardcoded API key initialization and adopting the recommended FirebaseAI.firebaseAI(backend:) factory method.
  • Centralized shared models (like BackendOption) and UI components (ProgressOverlay, ErrorDetailsView) to eliminate redundancy and fix compilation errors.
• New 'Hello World (with template)' Sample:
  • Added a new, simple example (GenerateContentFromTemplateScreen) to demonstrate server-side template functionality with the apple-qs-greeting template. This provides a clear and minimal entry point for users.

Overall, these changes make the project easier to understand, maintain, and extend, providing a better foundation for developers exploring Firebase AI features.

[gemini-code-assist]

Summary of Changes

Hello @peterfriese, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request undertakes a comprehensive refactoring of the iOS project, aiming to enhance its modularity, maintainability, and scalability. The changes involve a complete overhaul of the project's directory structure, the introduction of a new templated content generation feature, and a significant upgrade to the user interface by adopting the ConversationKit framework. These improvements streamline development, centralize common components, and lay a robust foundation for future feature expansion.

Highlights

• Project Structure Reorganization: The project codebase has been significantly refactored into Features (for feature-specific modules) and Shared (for common models, views, and utilities) directories, improving modularity and maintainability.
• New 'Hello world (with template)' Feature: A new feature demonstrating server-side template generation using apple-qs-greeting has been added under Features/GenerativeAIText.
• Enhanced UI/UX with ConversationKit: The UI components for chat and multimodal interactions have been migrated to use the ConversationKit framework, providing a more streamlined and feature-rich conversational interface.
• Security and Best Practices: Insecure API key initialization has been replaced with a secure factory method, and shared UI components were moved to a centralized location to resolve compile errors and improve accessibility.
• Centralized Backend Configuration: The BackendOption enum has been extracted into its own file for better organization and reusability across the application.
• Updated Xcode Project Settings: The project's deployment target has been updated, and Swift Package Manager dependencies have been revised to align with the new modular structure and introduced frameworks.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This is a significant and well-executed refactoring of the iOS project. The move to a feature-based architecture, centralization of shared components, and adoption of ConversationKit greatly improve the project's structure, maintainability, and scalability. The new Sample-driven approach for showcasing examples is also a fantastic improvement.

I've identified a couple of critical issues, primarily a merge conflict in a script and an invalid build setting, that must be addressed. I also have a high-severity suggestion regarding dependency pinning for better build stability and a medium-severity suggestion to improve the new navigation routing logic. Overall, this is excellent work.

[gemini-code-assist]

The ConversationKit dependency is pinned to the main branch. This can lead to non-reproducible builds as the main branch can change at any time. It's recommended to pin dependencies to a specific version tag or commit hash to ensure build stability.

-            requirement = {
-                branch = main;
-                kind = branch;
-            };

[gemini-code-assist]

The navigation logic in destinationView(for:) relies on string matching for sample.navRoute. This is fragile and prone to typos. Consider using an enum for the navigation routes to make this more robust and type-safe.

For example:

// In Sample.swift
enum NavRoute {
    case chatScreen
    case imagenScreen
    // ... other cases
}

// In ContentView.swift
@ViewBuilder
private func destinationView(for sample: Sample) -> some View {
  switch sample.navRoute {
  case .chatScreen:
    ChatScreen(backendType: selectedBackend, sample: sample)
  // ... other cases
  }
}