import WebKit

// This swizzle allows JavaScript to set the focus on an input, not just when a user is interacting.
//
extension WKWebView {

  private typealias StartAssistingNodeMethodType = @convention(c) (Any, Selector, UnsafeRawPointer, Bool, Bool, Any) -> Void
  private typealias StartAssistingNodeClosureType = @convention(block) (Any, UnsafeRawPointer, Bool, Bool, Any) -> Void

  func focusInputsWithoutUserInteraction() {
    let selector: Selector = sel_getUid("_startAssistingNode:userIsInteracting:blurPreviousNode:userObject:")
    guard let wkContentViewClass: AnyClass = NSClassFromString("WKContentView") else { return }
    guard let method = class_getInstanceMethod(wkContentViewClass, selector) else { return }
    let original: StartAssistingNodeMethodType = unsafeBitCast(method_getImplementation(method), to: StartAssistingNodeMethodType.self)
    let replacement: StartAssistingNodeClosureType = { (me, arg0, arg1, arg2, arg3) in
      original(me, selector, arg0, true, arg2, arg3)
    }
    method_setImplementation(method, imp_implementationWithBlock(replacement))
  }

}