import Flutter
import UIKit

private enum NexoMessagingChannels {
  static let legacy = "nexo_messaging"
  static let events = "com.tokilabs.nexo.messaging/notifications"
  static let actions = "com.tokilabs.nexo.messaging/notification_actions"
}

private enum NexoMessagingKeys {
  static let deviceToken = "nexo.messaging.deviceToken"
}

public class NexoMessagingPlugin: NSObject, FlutterPlugin, FlutterStreamHandler {
  private var eventSink: FlutterEventSink?

  public static func register(with registrar: FlutterPluginRegistrar) {
    let instance = NexoMessagingPlugin()
    let messenger = registrar.messenger()

    let legacyChannel = FlutterMethodChannel(
      name: NexoMessagingChannels.legacy,
      binaryMessenger: messenger
    )
    registrar.addMethodCallDelegate(instance, channel: legacyChannel)

    let actionChannel = FlutterMethodChannel(
      name: NexoMessagingChannels.actions,
      binaryMessenger: messenger
    )
    registrar.addMethodCallDelegate(instance, channel: actionChannel)

    let eventChannel = FlutterEventChannel(
      name: NexoMessagingChannels.events,
      binaryMessenger: messenger
    )
    eventChannel.setStreamHandler(instance)
  }

  public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
    switch call.method {
    case "debugSendNativeEvent":
      guard let payload = call.arguments as? [String: Any] else {
        result(FlutterError(code: "INVALID_ARG", message: "event payload is null", details: nil))
        return
      }
      eventSink?(payload)
      result(nil)
    case "saveDeviceToken":
      guard let token = argument("token", from: call) else {
        result(FlutterError(code: "INVALID_ARG", message: "token is null", details: nil))
        return
      }
      UserDefaults.standard.set(token, forKey: NexoMessagingKeys.deviceToken)
      result(nil)
    case "getDeviceToken":
      result(UserDefaults.standard.string(forKey: NexoMessagingKeys.deviceToken))
    case "setAuthToken":
      guard argument("serverUrl", from: call) != nil, argument("token", from: call) != nil else {
        result(FlutterError(code: "INVALID_ARG", message: "serverUrl or token is null", details: nil))
        return
      }
      result(nil)
    case "setSigningKey":
      guard argument("serverUrl", from: call) != nil, argument("signingKey", from: call) != nil else {
        result(FlutterError(code: "INVALID_ARG", message: "serverUrl or signingKey is null", details: nil))
        return
      }
      result(nil)
    case "clearAuthToken":
      guard argument("serverUrl", from: call) != nil else {
        result(FlutterError(code: "INVALID_ARG", message: "serverUrl is null", details: nil))
        return
      }
      result(nil)
    case "getPlatformVersion":
      result("iOS " + UIDevice.current.systemVersion)
    default:
      result(FlutterMethodNotImplemented)
    }
  }

  public func onListen(withArguments arguments: Any?, eventSink events: @escaping FlutterEventSink) -> FlutterError? {
    eventSink = events
    return nil
  }

  public func onCancel(withArguments arguments: Any?) -> FlutterError? {
    eventSink = nil
    return nil
  }

  private func argument(_ name: String, from call: FlutterMethodCall) -> String? {
    guard let arguments = call.arguments as? [String: Any] else { return nil }
    return arguments[name] as? String
  }
}