import 'dart:async';

import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';
import 'package:url_launcher/url_launcher.dart';

import '../../../common/router/app_router.dart';
import '../data/ads_api_client.dart';
import 'ad_media.dart';

class HomeAdBanner extends ConsumerStatefulWidget {
  const HomeAdBanner({super.key});
  @override
  ConsumerState<HomeAdBanner> createState() => _HomeAdBannerState();
}

class _HomeAdBannerState extends ConsumerState<HomeAdBanner> {
  final pages = PageController();
  final impressed = <String>{};
  Timer? timer;
  int index = 0;
  int _length = 0;
  @override
  void dispose() {
    timer?.cancel();
    pages.dispose();
    super.dispose();
  }

  void _sync(List<AdCreative> ads) {
    if (_length == ads.length) return;
    _length = ads.length;
    timer?.cancel();
    if (ads.length > 1) {
      timer = Timer.periodic(const Duration(seconds: 4), (_) {
        if (pages.hasClients) {
          pages.nextPage(
            duration: const Duration(milliseconds: 320),
            curve: Curves.easeOut,
          );
        }
      });
    }
  }

  void _impression(AdCreative ad, String? id) {
    if (!impressed.add(ad.adId)) return;
    unawaited(
      ref
          .read(adsApiClientProvider)
          .report(ad, 'ad_impression', trackingId: id),
    );
  }

  Future<void> _open(AdCreative ad, String? tracking) async {
    final client = ref.read(adsApiClientProvider);
    final id = client.newClickId();
    final uri = ad.clickUri(id);
    if (uri == null) return;
    unawaited(client.report(ad, 'ad_click', clickId: id, trackingId: tracking));
    if (!mounted) return;
    if (ad.openMode == AdOpenMode.inApp) {
      context.push(
        '${AppRoutes.web}?url=${Uri.encodeComponent(uri.toString())}',
      );
    } else {
      await launchUrl(uri, mode: LaunchMode.externalApplication);
    }
  }

  @override
  Widget build(BuildContext context) {
    final async = ref.watch(featuredAdsProvider(homeBannerAdPlacement));
    return async.maybeWhen(
      data: (value) {
        if (!value.hasAds) return const SizedBox.shrink();
        final ads = value.ads;
        _sync(ads);
        WidgetsBinding.instance.addPostFrameCallback((_) {
          if (mounted) {
            _impression(ads[index.clamp(0, ads.length - 1)], value.trackingId);
          }
        });
        return Column(
          children: [
            AspectRatio(
              aspectRatio: 750 / 200,
              child: ClipRRect(
                borderRadius: BorderRadius.circular(12),
                child: PageView.builder(
                  controller: pages,
                  onPageChanged: (page) {
                    setState(() => index = page % ads.length);
                    _impression(ads[index], value.trackingId);
                  },
                  itemBuilder: (_, page) {
                    final ad = ads[page % ads.length];
                    return GestureDetector(
                      onTap: () => _open(ad, value.trackingId),
                      child: AdMedia(ad: ad),
                    );
                  },
                ),
              ),
            ),
            if (ads.length > 1)
              Padding(
                padding: const EdgeInsets.only(top: 8),
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: List.generate(
                    ads.length,
                    (i) => Container(
                      width: i == index ? 14 : 6,
                      height: 6,
                      margin: const EdgeInsets.symmetric(horizontal: 3),
                      decoration: BoxDecoration(
                        color: i == index
                            ? Theme.of(context).colorScheme.primary
                            : Theme.of(context).dividerColor,
                        borderRadius: BorderRadius.circular(3),
                      ),
                    ),
                  ),
                ),
              ),
          ],
        );
      },
      orElse: () => const SizedBox.shrink(),
    );
  }
}