module SvelteOnRails::Installer::HelloWorld

def self.install_hello_world
  utils_i = SvelteOnRails::Installer::Utils
  # write templates
  templates = %w[
    app/controllers/svelte_on_rails_hello_world_controller.rb
    app/views/svelte_on_rails_hello_world/index.haml
    app/frontend/javascript/components/SvelteOnRailsHelloWorld.svelte
  ]
  utils_i.write_templates(templates)
  # route
  route = 'svelte_on_rails_hello_world#index'
  rr = utils_i.which_root_route
  root_url = "/"
  url = root_url + route.sub('#', '/')
  if rr && rr == route
    puts "Root route «#{route}» already exists, skipping."
    root_url
  elsif rr && utils_i.route_exists?(route.sub('#', '/'))
    puts "route «#{route}» already exists, skipping."
    url
  elsif rr
    utils_i.add_route("  get \"#{route.sub('#', '/')}\"")
    url
  else
    utils_i.add_route('  root "svelte_on_rails_hello_world#index"')
    root_url
  end
end