class RubyNative::Screenshots::SessionsController

fallback is the primary path used by Ruby Native’s screenshot pipeline.
headers across redirect chains in some iOS versions, so the URL-param
`?ruby_native_screenshot_key=‘ URL parameter. WKWebView drops custom
The key is accepted via the `X-RubyNative-Screenshot-Key` header or the
render deterministically (freeze timestamps, hide notifications, etc.).
user, and sets a session-scoped cookie that the host app can use to
Validates the per-app screenshot key, signs in the configured screenshot

def safe_return_to 

def safe_return_to
  target = params[:return_to].to_s
  return "/" if target.empty?
  # Reject anything that isn't a single-leading-slash same-host path.
  # `//evil.com` and `/\evil.com` would be treated as protocol-relative
  # or backslash-confusing inputs by some browsers.
  return "/" if target.start_with?("//", "/\\")
  return "/" unless target.start_with?("/")
  target
end

def show 

def show
  # Defense in depth: prevent the URL (which carries the key as a query
  # param on the way in) from leaking via the Referer header to anything
  # the redirect target loads.
  response.headers["Referrer-Policy"] = "no-referrer"
  unless RubyNative.screenshot_key.present? && RubyNative.screenshot_sign_in.present?
    Rails.logger.info { "[RubyNative] /native/screenshots/session called but screenshot config is not set" }
    head :not_found
    return
  end
  unless valid_key?
    Rails.logger.info { "[RubyNative] /native/screenshots/session rejected: invalid key" }
    head :unauthorized
    return
  end
  RubyNative.screenshot_sign_in.call(SignInHelper.new(self))
  cookies[:_ruby_native_screenshot_session] = {
    value: "1",
    httponly: true,
    secure: request.ssl?,
    same_site: :lax
  }
  redirect_to safe_return_to, allow_other_host: false
end

def valid_key? 

def valid_key?
  provided = request.headers["X-RubyNative-Screenshot-Key"].presence || params[:ruby_native_screenshot_key].presence
  return false unless provided
  ActiveSupport::SecurityUtils.secure_compare(provided.to_s, RubyNative.screenshot_key.to_s)
end