A2UI Rails

gem 'dspy', '~> 0.34'
gem 'sorbet-runtime'

# Choose your LLM provider:
gem 'dspy-openai'    # OpenAI, OpenRouter, Ollama
# gem 'dspy-anthropic' # Claude
# gem 'dspy-gemini'    # Gemini

# config/initializers/dspy.rb
DSPy.configure do |c|
  c.lm = DSPy::LM.new('openai/gpt-4o-mini', api_key: ENV['OPENAI_API_KEY'])
end

# config/initializers/a2ui.rb
A2UI.configure do |config|
  config.default_model = 'anthropic/claude-sonnet-4-20250514'
  config.debug = Rails.env.development?
end

# Define typed data models
class BookingData < T::Struct
  const :guests, Integer, default: 2
  const :date, T.nilable(String)
  const :email, T.nilable(String)
end

manager = A2UI::SurfaceManager.new

# Create a surface with typed data
surface = manager.create(
  surface_id: 'booking-form',
  request: 'Create a booking form with guest count, date picker, and submit button',
  data: BookingData.new(guests: 2)
)

# For surfaces without initial data
surface = manager.create(
  surface_id: 'welcome',
  request: 'Create a welcome message',
  data: A2UI::EmptyData.new
)

# Render in your view
render partial: 'a2ui/surface', locals: { surface: surface }

# Define typed context for the action
class SubmitBookingContext < T::Struct
  const :guests, Integer
  const :date, String
end

action = A2UI::UserAction.new(
  name: 'submit_booking',
  surface_id: 'booking-form',
  source_id: 'submit-btn',
  context: SubmitBookingContext.new(guests: 3, date: '2025-01-15')
)

result = manager.handle_action(
  action: action,
  business_rules: 'Maximum 10 guests per booking'
)

# result.response_type => A2UI::ActionResponseType::UpdateUI
# result.streams => [A2UI::StreamOp, ...]
# result.components => [A2UI::Component, ...]

result = manager.update(
  surface_id: 'booking-form',
  request: 'Add a phone number field after the email'
)

# Returns Turbo Stream operations to apply

class A2UI::GenerateUI < DSPy::Signature
  description 'Generate UI components from natural language.'

  input do
    const :request, String
    const :surface_id, String
    const :available_data, String, default: '{}'
  end

  output do
    const :root_id, String
    const :components, T::Array[Component]  # Union type
    const :initial_data, T::Array[DataUpdate], default: []
  end
end

# Value is either literal or a path reference
A2UI::Value = T.any(A2UI::LiteralValue, A2UI::PathReference)

# Children are either explicit IDs or data-driven
A2UI::Children = T.any(A2UI::ExplicitChildren, A2UI::DataDrivenChildren)

# Component is a union of all component types
A2UI::Component = T.any(
  A2UI::TextComponent,
  A2UI::ButtonComponent,
  A2UI::TextFieldComponent,
  A2UI::RowComponent,
  A2UI::ColumnComponent,
  # ... 13 total
)

class BookingData < T::Struct
  const :guests, Integer, default: 2
  const :date, T.nilable(String)
end

manager.create(
  surface_id: 'booking',
  request: 'Create a booking form',
  data: BookingData.new(guests: 4)
)

# For surfaces without data
manager.create(
  surface_id: 'welcome',
  request: 'Create a welcome message',
  data: A2UI::EmptyData.new
)

# Define context types
class SubmitContext < T::Struct
  const :guests, Integer
  const :date, String
end

class CancelContext < T::Struct
  const :reason, T.nilable(String)
end

# Register when creating surface
manager.create(
  surface_id: 'booking',
  request: 'Create a booking form',
  data: BookingData.new,
  actions: {
    submit: SubmitContext,
    cancel: CancelContext
  }
)

# Client sends raw JSON, server coerces automatically
action = A2UI::UserAction.new(
  name: 'submit',
  surface_id: 'booking',
  source_id: 'btn',
  context: { 'guests' => '3', 'date' => '2025-01-15' }
)

result = manager.handle_action(action: action)
# Context coerced to SubmitContext.new(guests: 3, date: "2025-01-15")

context = A2UI::TypeCoercion.coerce(
  { 'guests' => '3', 'date' => '2025-01-15' },
  SubmitContext
)
# => SubmitContext.new(guests: 3, date: "2025-01-15")

# Component definition
A2UI::TextFieldComponent.new(
  id: 'guest-count',
  value: A2UI::PathReference.new(path: '/booking/guests'),
  input_type: A2UI::InputType::Number
)

# Renders with Stimulus binding
# <input data-controller="a2ui-binding"
#        data-a2ui-binding-path-value="/booking/guests" ...>

A2UI::ButtonComponent.new(
  id: 'submit',
  label: A2UI::LiteralValue.new(value: 'Book Now'),
  action: A2UI::Action.new(
    name: 'submit_booking',
    context: [
      A2UI::ContextBinding.new(key: 'booking', path: '/booking')
    ]
  )
)

namespace :a2ui do
  resources :surfaces, only: [:create, :show, :update, :destroy]
  resources :actions, only: [:create]
end

RSpec.describe A2UI::GenerateUI, :vcr do
  it 'generates a booking form' do
    generator = A2UI::UIGenerator.new
    result = generator.call(
      request: 'Create a booking form',
      surface_id: 'booking'
    )

    expect(result.components).not_to be_empty
  end
end