import ExpoModulesCore
import QuickLook
import UIKit

public class OrcaMobileWebShellModule: Module {
  private var pdfPreview: MobileWebShellPdfPreview?
  private var memoryWarningObserver: NSObjectProtocol?

  public func definition() -> ModuleDefinition {
    Name("OrcaMobileWebShell")

    OnCreate {
      memoryWarningObserver = NotificationCenter.default.addObserver(
        forName: UIApplication.didReceiveMemoryWarningNotification,
        object: nil,
        queue: .main
      ) { _ in
        MobileWebShellSparePool.shared.didReceiveMemoryWarning()
      }
    }

    OnDestroy {
      if let memoryWarningObserver {
        NotificationCenter.default.removeObserver(memoryWarningObserver)
      }
      DispatchQueue.main.async {
        MobileWebShellSparePool.shared.discardAll()
      }
    }

    // Home boots the next one after its next foreground idle.
    OnAppEntersBackground {
      DispatchQueue.main.async {
        MobileWebShellSparePool.shared.discardAll()
      }
    }

    AsyncFunction("prepareSpareDocument") { (directory: String, sessionId: String) -> Bool in
      MobileWebShellSparePool.shared.prepare(directory: directory, sessionId: sessionId)
    }.runOnQueue(.main)

    AsyncFunction("claimSpareDocument") { (directory: String) -> String? in
      MobileWebShellSparePool.shared.claim(directory: directory)
    }.runOnQueue(.main)

    AsyncFunction("discardSpareDocument") {
      MobileWebShellSparePool.shared.discardAll()
    }.runOnQueue(.main)

    // Home calls this once it has a paired host, so a user with nothing to open pays nothing.
    Function("warmUp") {
      // A second's delay keeps the warm-up off the launch's first frames.
      DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
        MobileWebShellWarmUp.start()
      }
    }

    AsyncFunction("presentPdf") { (url: URL) in
      guard let presenter = self.appContext?.utilities?.currentViewController() else {
        throw PdfPresenterUnavailableException()
      }
      let preview = MobileWebShellPdfPreview(url: url)
      let controller = QLPreviewController()
      controller.dataSource = preview
      self.pdfPreview = preview
      presenter.present(controller, animated: true)
    }.runOnQueue(.main)

    AsyncFunction("shareImage") { (url: URL, _: String) in
      guard let presenter = self.appContext?.utilities?.currentViewController() else {
        throw ImagePresenterUnavailableException()
      }
      presentImageShareSheet(url: url, from: presenter)
    }.runOnQueue(.main)

    AsyncFunction("saveImageToPhotos") { (url: URL, _: String, promise: Promise) in
      saveImageToPhotoLibrary(url: url, promise: promise)
    }

    View(OrcaMobileWebShellView.self) {
      Events("onLoadState", "onBridgeMessage", "onExternalNavigation", "onBackEdgeSwipe")

      Prop("generationDirectory") { (view: OrcaMobileWebShellView, value: String) in
        view.setGenerationDirectory(value)
      }

      Prop("sessionId") { (view: OrcaMobileWebShellView, value: String) in
        view.setSessionId(value)
      }

      Prop("bridgeEnabled") { (view: OrcaMobileWebShellView, value: Bool) in
        view.setBridgeEnabled(value)
      }

      Prop("backEdgeSwipe") { (view: OrcaMobileWebShellView, value: Bool) in
        view.setBackEdgeSwipe(value)
      }

      AsyncFunction("postBridgeMessage") {
        (view: OrcaMobileWebShellView, json: String, promise: Promise) in
        try view.postBridgeMessage(json, promise: promise)
      }

      OnViewDidUpdateProps { (view: OrcaMobileWebShellView) in
        view.propsDidUpdate()
      }
    }
  }
}