PiliPlus/lib/pages/search_trending/view.dart

import 'package:PiliPlus/common/widgets/http_error.dart';
import 'package:PiliPlus/common/widgets/refresh_indicator.dart';
import 'package:PiliPlus/http/loading_state.dart';
import 'package:PiliPlus/models/search/search_trending/trending_list.dart';
import 'package:PiliPlus/pages/search_trending/controller.dart';
import 'package:PiliPlus/utils/extension.dart';
import 'package:cached_network_image/cached_network_image.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:get/get.dart';

class SearchTrendingPage extends StatefulWidget {
  const SearchTrendingPage({super.key});

  @override
  State<SearchTrendingPage> createState() => _SearchTrendingPageState();
}

class _SearchTrendingPageState extends State<SearchTrendingPage> {
  final _controller = Get.put(
    SearchTrendingController(),
    tag: Get.parameters['tag'],
  );

  late double _offset;
  final RxDouble _scrollRatio = 0.0.obs;

  @override
  void initState() {
    super.initState();
    _controller.scrollController.addListener(listener);
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    _offset = Get.width * 528 / 1125 - 56 - Get.mediaQuery.padding.top;
    listener();
  }

  @override
  void dispose() {
    _controller.scrollController.removeListener(listener);
    super.dispose();
  }

  void listener() {
    if (_controller.scrollController.hasClients) {
      _scrollRatio.value = clampDouble(
        _controller.scrollController.position.pixels / _offset,
        0.0,
        1.0,
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    final removePadding = context.width > 640;
    return Scaffold(
      extendBody: true,
      extendBodyBehindAppBar: true,
      appBar: PreferredSize(
        preferredSize: Size.fromHeight(56),
        child: Obx(
          () {
            final half = _scrollRatio.value >= 0.5;
            return AppBar(
              title: Opacity(
                opacity: _scrollRatio.value,
                child: Text(
                  'B站热搜',
                  style: TextStyle(
                    color: half ? null : Colors.white,
                  ),
                ),
              ),
              backgroundColor: Theme.of(context)
                  .colorScheme
                  .surface
                  .withOpacity(_scrollRatio.value),
              foregroundColor: half ? null : Colors.white,
              systemOverlayStyle: half
                  ? null
                  : SystemUiOverlayStyle(
                      statusBarBrightness: Brightness.dark,
                      statusBarIconBrightness: Brightness.light,
                    ),
              bottom: _scrollRatio.value == 1
                  ? PreferredSize(
                      preferredSize: Size.fromHeight(1),
                      child: Divider(
                        height: 1,
                        color: Theme.of(context)
                            .colorScheme
                            .outline
                            .withOpacity(0.1),
                      ),
                    )
                  : null,
            );
          },
        ),
      ),
      body: MediaQuery.removePadding(
        context: context,
        removeLeft: removePadding,
        removeRight: removePadding,
        child: Center(
          child: ConstrainedBox(
            constraints: BoxConstraints(maxWidth: 640),
            child: refreshIndicator(
              onRefresh: () async {
                await _controller.onRefresh();
              },
              child: CustomScrollView(
                controller: _controller.scrollController,
                slivers: [
                  SliverToBoxAdapter(
                    child: CachedNetworkImage(
                      fit: BoxFit.fitWidth,
                      fadeInDuration: const Duration(milliseconds: 120),
                      fadeOutDuration: const Duration(milliseconds: 120),
                      imageUrl:
                          'https://activity.hdslb.com/blackboard/activity59158/img/hot_banner.fbb081df.png',
                      placeholder: (context, url) {
                        return AspectRatio(
                          aspectRatio: 1125 / 528,
                          child: Image.asset('assets/images/loading.png'),
                        );
                      },
                    ),
                  ),
                  Obx(() => _buildBody(_controller.loadingState.value)),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }

  Widget _buildBody(LoadingState<List<SearchKeywordList>?> loadingState) {
    return switch (loadingState) {
      Loading() => SliverToBoxAdapter(child: LinearProgressIndicator()),
      Success() => loadingState.response?.isNotEmpty == true
          ? SliverPadding(
              padding: EdgeInsets.only(
                  bottom: MediaQuery.paddingOf(context).bottom + 100),
              sliver: SliverList.separated(
                itemCount: loadingState.response!.length,
                itemBuilder: (context, index) {
                  final item = loadingState.response![index];
                  return ListTile(
                    dense: true,
                    onTap: () {
                      Get.toNamed(
                        '/searchResult',
                        parameters: {
                          'keyword': item.keyword!,
                        },
                      );
                    },
                    leading: index < _controller.topCount
                        ? Icon(
                            size: 17,
                            Icons.vertical_align_top_outlined,
                            color: const Color(0xFFd1403e),
                          )
                        : Text(
                            '${index + 1 - _controller.topCount}',
                            style: TextStyle(
                              fontWeight: FontWeight.bold,
                              color: switch (index - _controller.topCount) {
                                0 => const Color(0xFFfdad13),
                                1 => const Color(0xFF8aace1),
                                2 => const Color(0xFFdfa777),
                                _ => Theme.of(context).colorScheme.outline,
                              },
                              fontSize: 17,
                              fontStyle: FontStyle.italic,
                            ),
                          ),
                    title: Row(
                      children: [
                        Flexible(
                          child: Text(
                            item.keyword!,
                            maxLines: 1,
                            overflow: TextOverflow.ellipsis,
                            strutStyle: StrutStyle(height: 1, leading: 0),
                            style: TextStyle(height: 1, fontSize: 15),
                          ),
                        ),
                        if (item.icon?.isNotEmpty == true) ...[
                          const SizedBox(width: 4),
                          CachedNetworkImage(
                            imageUrl: item.icon!.http2https,
                            height: 16,
                          ),
                        ] else if (item.showLiveIcon == true) ...[
                          const SizedBox(width: 4),
                          Image.asset(
                            'assets/images/live/live.gif',
                            width: 51,
                            height: 16,
                          ),
                        ],
                      ],
                    ),
                  );
                },
                separatorBuilder: (context, index) => Divider(
                  height: 1,
                  indent: 48,
                  color: Theme.of(context).colorScheme.outline.withOpacity(0.1),
                ),
              ),
            )
          : HttpError(
              callback: _controller.onReload,
            ),
      Error() => HttpError(
          errMsg: loadingState.errMsg,
          callback: _controller.onReload,
        ),
      _ => throw UnimplementedError(),
    };
  }
}