const fs = require('node:fs')
const path = require('node:path')
const {
  IOSConfig,
  withAppDelegate,
  withDangerousMod,
  withInfoPlist,
  withXcodeProject
} = require('expo/config-plugins')

// Why: UIKit stops an app built with the iOS 27 SDK at launch unless it adopts the UIScene
// lifecycle (TN3187), and Expo SDK 55's AppDelegate template still creates the window itself.
// The iOS 27 SDK is what lets the app resize on iPhone Duo, so the window moves into a scene
// delegate here. Drop this plugin once Expo's template adopts scenes (SDK 58).
const MARKER = 'orca: UIScene lifecycle'

const SCENE_MANIFEST = {
  UIApplicationSupportsMultipleScenes: false,
  UISceneConfigurations: {
    UIWindowSceneSessionRoleApplication: [
      {
        UISceneConfigurationName: 'Default Configuration',
        UISceneDelegateClassName: '$(PRODUCT_MODULE_NAME).SceneDelegate'
      }
    ]
  }
}

const FACTORY_PROPERTY = '  var reactNativeFactory: RCTReactNativeFactory?\n'
const WINDOW_BLOCK =
  /#if os\(iOS\) \|\| os\(tvOS\)\s*\n\s*window = UIWindow\(frame: UIScreen\.main\.bounds\)\s*\n\s*factory\.startReactNative\(\s*withModuleName: "main",\s*in: window,\s*launchOptions: launchOptions\)\s*\n#endif\n/

function patchAppDelegate(contents) {
  if (contents.includes(MARKER)) {
    return contents
  }
  // A changed template must fail prebuild rather than ship an app that cannot launch.
  if (!contents.includes(FACTORY_PROPERTY) || !WINDOW_BLOCK.test(contents)) {
    throw new Error(
      "ios-scene-lifecycle: Expo's AppDelegate template changed; update the plugin before building."
    )
  }
  return contents
    .replace(
      FACTORY_PROPERTY,
      `${FACTORY_PROPERTY}  // ${MARKER}: SceneDelegate starts React Native with these.\n  var launchOptions: [UIApplication.LaunchOptionsKey: Any]?\n`
    )
    .replace(
      WINDOW_BLOCK,
      `    // ${MARKER}: SceneDelegate creates the window.\n    self.launchOptions = launchOptions\n`
    )
}

const SCENE_DELEGATE_SWIFT = `import React
import UIKit

// ${MARKER}, generated by plugins/ios-scene-lifecycle.js.
// Under scenes UIKit stops calling the AppDelegate URL callbacks, where RCTLinkingManager and
// Expo's subscribers listen, so every URL and user activity is forwarded to them.
class SceneDelegate: UIResponder, UIWindowSceneDelegate {
  var window: UIWindow?

  private var appDelegate: AppDelegate? {
    UIApplication.shared.delegate as? AppDelegate
  }

  func scene(
    _ scene: UIScene,
    willConnectTo session: UISceneSession,
    options connectionOptions: UIScene.ConnectionOptions
  ) {
    guard let windowScene = scene as? UIWindowScene, let appDelegate,
      let factory = appDelegate.reactNativeFactory
    else { return }

    let window = UIWindow(windowScene: windowScene)
    self.window = window
    // A scene iOS dropped in the background and reconnects keeps the running app, not a fresh one.
    let runningRoot = appDelegate.window?.rootViewController
    appDelegate.window = window

    let launchURL = connectionOptions.urlContexts.first
    // Universal links are the only activity the app handles.
    let launchActivity = connectionOptions.userActivities.first {
      $0.activityType == NSUserActivityTypeBrowsingWeb
    }

    if let runningRoot {
      window.rootViewController = runningRoot
      window.makeKeyAndVisible()
    } else {
      // A cold-start URL arrives here rather than in the launch options getInitialURL reads.
      var launchOptions = appDelegate.launchOptions ?? [:]
      if let launchURL {
        launchOptions[.url] = launchURL.url
        if let source = launchURL.options.sourceApplication {
          launchOptions[.sourceApplication] = source
        }
      }
      if let launchActivity {
        launchOptions[.userActivityDictionary] = [
          UIApplication.LaunchOptionsKey.userActivityType.rawValue: launchActivity.activityType,
          "UIApplicationLaunchOptionsUserActivityKey": launchActivity,
        ]
      }
      factory.startReactNative(withModuleName: "main", in: window, launchOptions: launchOptions)
    }

    if let launchURL {
      forward(launchURL)
    }
    if let launchActivity {
      _ = appDelegate.application(UIApplication.shared, continue: launchActivity) { _ in }
    }
  }

  func scene(_ scene: UIScene, openURLContexts URLContexts: Set<UIOpenURLContext>) {
    for context in URLContexts {
      forward(context)
    }
  }

  func scene(_ scene: UIScene, continue userActivity: NSUserActivity) {
    _ = appDelegate?.application(UIApplication.shared, continue: userActivity) { _ in }
  }

  private func forward(_ context: UIOpenURLContext) {
    var options: [UIApplication.OpenURLOptionsKey: Any] = [
      .openInPlace: context.options.openInPlace
    ]
    if let source = context.options.sourceApplication {
      options[.sourceApplication] = source
    }
    if let annotation = context.options.annotation {
      options[.annotation] = annotation
    }
    _ = appDelegate?.application(UIApplication.shared, open: context.url, options: options)
  }
}
`

module.exports = function withIosSceneLifecycle(config) {
  config = withInfoPlist(config, (cfg) => {
    cfg.modResults.UIApplicationSceneManifest = SCENE_MANIFEST
    return cfg
  })

  config = withAppDelegate(config, (cfg) => {
    if (cfg.modResults.language !== 'swift') {
      throw new Error(
        `ios-scene-lifecycle: expected a Swift AppDelegate, got ${cfg.modResults.language}`
      )
    }
    cfg.modResults.contents = patchAppDelegate(cfg.modResults.contents)
    return cfg
  })

  config = withDangerousMod(config, [
    'ios',
    (cfg) => {
      const { platformProjectRoot, projectName } = cfg.modRequest
      fs.writeFileSync(
        path.join(platformProjectRoot, projectName, 'SceneDelegate.swift'),
        SCENE_DELEGATE_SWIFT
      )
      return cfg
    }
  ])

  return withXcodeProject(config, (cfg) => {
    const filepath = `${cfg.modRequest.projectName}/SceneDelegate.swift`
    if (!cfg.modResults.hasFile(filepath)) {
      IOSConfig.XcodeUtils.addBuildSourceFileToGroup({
        filepath,
        groupName: cfg.modRequest.projectName,
        project: cfg.modResults
      })
    }
    return cfg
  })
}