import 'dart:convert';
import 'dart:developer';

import 'package:flutter/foundation.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';

import 'push_actions.dart';
import 'push_target.dart';

/// Routes foreground notification interactions from the single
/// flutter_local_notifications response callback. Action responses (reply /
/// mark-read) are dispatched straight to [PushActions]; a plain tap publishes
/// its target via [pendingTarget] for [App] to navigate to.
class PushTapRouter {
  PushTapRouter._();

  /// Target of the most recently tapped notification, or null. [App] listens
  /// to this and navigates, then resets it to null.
  static final ValueNotifier<PushTarget?> pendingTarget = ValueNotifier(null);

  static void handleResponse(NotificationResponse response) {
    final actionId = response.actionId;
    if (actionId == kTalkReplyActionId || actionId == kTalkMarkReadActionId) {
      // Reuse the isolate-safe action dispatch for foreground actions too.
      PushActions.handleBackgroundResponse(response);
      return;
    }
    final map = _payloadMap(response.payload);
    if (map == null) return;
    final target = resolvePushTarget(map);
    if (target != null) pendingTarget.value = target;
  }

  static bool _launchHandled = false;

  /// Routes the tap that cold-started the app. The plugin reports such a tap
  /// only through its launch details, never through the response callback;
  /// the details stay set for the whole process, hence the one-shot guard.
  static Future<void> handleAppLaunch(
    FlutterLocalNotificationsPlugin plugin,
  ) async {
    if (_launchHandled) return;
    _launchHandled = true;
    try {
      final details = await plugin.getNotificationAppLaunchDetails();
      final response = details?.notificationResponse;
      if (details?.didNotificationLaunchApp != true || response == null) return;
      handleResponse(response);
    } on Object catch (e) {
      log('Reading the notification launch details failed: $e');
    }
  }

  static Map<String, dynamic>? _payloadMap(String? payload) {
    if (payload == null || payload.isEmpty) return null;
    try {
      return jsonDecode(payload) as Map<String, dynamic>;
    } on Object {
      return null;
    }
  }
}