import Flutter
import UIKit

@main
@objc class AppDelegate: FlutterAppDelegate, FlutterImplicitEngineDelegate {
  private var mediaUploadChannel: FlutterMethodChannel?

  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }

  func didInitializeImplicitFlutterEngine(_ engineBridge: FlutterImplicitEngineBridge) {
    GeneratedPluginRegistrant.register(with: engineBridge.pluginRegistry)
    mediaUploadChannel = FlutterMethodChannel(
      name: "sprout/media_upload",
      binaryMessenger: engineBridge.applicationRegistrar.messenger()
    )
    mediaUploadChannel?.setMethodCallHandler { [weak self] call, result in
      self?.handleMediaUploadMethodCall(call, result: result)
    }
  }

  private func handleMediaUploadMethodCall(
    _ call: FlutterMethodCall,
    result: @escaping FlutterResult
  ) {
    switch call.method {
    case "sanitizeImageForUpload":
      guard
        let arguments = call.arguments as? [String: Any],
        let typedData = arguments["bytes"] as? FlutterStandardTypedData,
        let mimeType = arguments["mimeType"] as? String
      else {
        result(
          FlutterError(
            code: "invalid_arguments",
            message: "Expected image bytes and mime type.",
            details: nil
          )
        )
        return
      }

      guard let image = UIImage(data: typedData.data) else {
        result(
          FlutterError(
            code: "sanitize_failed",
            message: "Unable to decode picked image.",
            details: nil
          )
        )
        return
      }

      let sanitizedData: Data?
      switch mimeType {
      case "image/png":
        sanitizedData = image.pngData()
      case "image/jpeg":
        sanitizedData = image.jpegData(compressionQuality: 1.0)
      default:
        sanitizedData = nil
      }

      guard let sanitizedData else {
        result(
          FlutterError(
            code: "sanitize_failed",
            message: "Unable to sanitize picked image.",
            details: mimeType
          )
        )
        return
      }

      result(FlutterStandardTypedData(bytes: sanitizedData))
    case "transcodeImageToJpeg":
      guard let typedData = call.arguments as? FlutterStandardTypedData else {
        result(
          FlutterError(
            code: "invalid_arguments",
            message: "Expected raw image bytes.",
            details: nil
          )
        )
        return
      }

      guard let image = UIImage(data: typedData.data),
        let jpegData = image.jpegData(compressionQuality: 1.0)
      else {
        result(
          FlutterError(
            code: "transcode_failed",
            message: "Unable to convert picked image to JPEG.",
            details: nil
          )
        )
        return
      }

      result(FlutterStandardTypedData(bytes: jpegData))
    default:
      result(FlutterMethodNotImplemented)
    }
  }
}