Surface/lib/screens/post/post_publisher.dart

import 'dart:ui';

import 'package:easy_localization/easy_localization.dart';
import 'package:flutter/material.dart';
import 'package:gap/gap.dart';
import 'package:go_router/go_router.dart';
import 'package:material_symbols_icons/symbols.dart';
import 'package:provider/provider.dart';
import 'package:styled_widget/styled_widget.dart';
import 'package:surface/providers/post.dart';
import 'package:surface/providers/sn_network.dart';
import 'package:surface/providers/user_directory.dart';
import 'package:surface/types/account.dart';
import 'package:surface/types/post.dart';
import 'package:surface/widgets/account/account_image.dart';
import 'package:surface/widgets/dialog.dart';
import 'package:surface/widgets/post/post_item.dart';
import 'package:surface/widgets/universal_image.dart';
import 'package:very_good_infinite_list/very_good_infinite_list.dart';

class PostPublisherScreen extends StatefulWidget {
  final String name;
  const PostPublisherScreen({super.key, required this.name});

  @override
  State<PostPublisherScreen> createState() => _PostPublisherScreenState();
}

class _PostPublisherScreenState extends State<PostPublisherScreen> {
  late final ScrollController _scrollController = ScrollController();

  SnPublisher? _publisher;
  SnAccount? _account;

  Future<void> _fetchPublisher() async {
    try {
      final sn = context.read<SnNetworkProvider>();
      final ud = context.read<UserDirectoryProvider>();
      final resp = await sn.client.get('/cgi/co/publishers/${widget.name}');
      if (!mounted) return;
      _publisher = SnPublisher.fromJson(resp.data);
      _account = await ud.getAccount(_publisher?.accountId);
    } catch (err) {
      if (!mounted) return;
      context.showErrorDialog(err).then((_) {
        if (mounted) Navigator.pop(context);
      });
    } finally {
      setState(() {});
    }
  }

  double _appBarBlur = 0.0;

  late final _appBarWidth = MediaQuery.of(context).size.width;
  late final _appBarHeight =
      (_appBarWidth * kBannerAspectRatio).roundToDouble();

  void _updateAppBarBlur() {
    if (_scrollController.offset > _appBarHeight) return;
    setState(() {
      _appBarBlur =
          (_scrollController.offset / _appBarHeight * 10).clamp(0.0, 10.0);
    });
  }

  bool _isBusy = false;

  int? _postCount;
  final List<SnPost> _posts = List.empty(growable: true);

  Future<void> _fetchPosts() async {
    if (_isBusy) return;
    _isBusy = true;
    try {
      final pt = context.read<SnPostContentProvider>();
      final result = await pt.listPosts(
        offset: _posts.length,
        author: widget.name,
      );
      _postCount = result.$2;
      _posts.addAll(result.$1);
    } catch (err) {
      if (!mounted) return;
      context.showErrorDialog(err);
    } finally {
      _isBusy = false;
      setState(() {});
    }
  }

  @override
  void initState() {
    super.initState();
    _fetchPublisher().then((_) {
      _fetchPosts();
    });
    _scrollController.addListener(_updateAppBarBlur);
  }

  @override
  void dispose() {
    _scrollController.removeListener(_updateAppBarBlur);
    _scrollController.dispose();
    super.dispose();
  }

  static const kBannerAspectRatio = 7 / 16;

  @override
  Widget build(BuildContext context) {
    final imageHeight = _appBarHeight + kToolbarHeight + 8;

    final sn = context.read<SnNetworkProvider>();
    return Scaffold(
      body: CustomScrollView(
        controller: _scrollController,
        slivers: [
          SliverAppBar(
            expandedHeight: _appBarHeight,
            title: Text(_publisher?.nick ?? 'loading'.tr()),
            pinned: true,
            flexibleSpace: _publisher != null
                ? Stack(
                    fit: StackFit.expand,
                    children: [
                      UniversalImage(
                        sn.getAttachmentUrl(_publisher!.banner),
                        fit: BoxFit.cover,
                        height: imageHeight,
                        width: _appBarWidth,
                        cacheHeight: imageHeight,
                        cacheWidth: _appBarWidth,
                      ),
                      Positioned(
                        top: 0,
                        left: 0,
                        right: 0,
                        height: 56 + MediaQuery.of(context).padding.top,
                        child: ClipRect(
                          child: BackdropFilter(
                            filter: ImageFilter.blur(
                              sigmaX: _appBarBlur,
                              sigmaY: _appBarBlur,
                            ),
                            child: Container(
                              color: Colors.black.withOpacity(
                                clampDouble(_appBarBlur * 0.1, 0, 0.5),
                              ),
                            ),
                          ),
                        ),
                      ),
                    ],
                  )
                : null,
          ),
          if (_publisher != null)
            SliverToBoxAdapter(
              child: Container(
                constraints: const BoxConstraints(maxWidth: 640),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Row(
                      children: [
                        AccountImage(
                          content: _publisher!.avatar,
                          radius: 28,
                        ),
                        const Gap(16),
                        Expanded(
                          child: Column(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              Text(
                                _publisher!.nick,
                                style: Theme.of(context).textTheme.titleMedium,
                              ).bold(),
                              Text('@${_publisher!.name}').fontSize(13),
                            ],
                          ),
                        ),
                        ElevatedButton(
                          style:
                              ButtonStyle(elevation: WidgetStatePropertyAll(0)),
                          onPressed: () {},
                          child: Text('subscribe').tr(),
                        ),
                      ],
                    ).padding(right: 8),
                    const Gap(12),
                    Text(_publisher!.description).padding(horizontal: 8),
                    const Gap(12),
                    Column(
                      children: [
                        Row(
                          children: [
                            const Icon(Symbols.calendar_add_on),
                            const Gap(8),
                            Text('publisherJoinedAt').tr(args: [
                              DateFormat('y/M/d').format(_publisher!.createdAt)
                            ]),
                          ],
                        ),
                        Row(
                          children: [
                            const Icon(Symbols.trending_up),
                            const Gap(8),
                            Text('publisherSocialPointTotal').plural(
                              _publisher!.totalUpvote -
                                  _publisher!.totalDownvote,
                            ),
                          ],
                        ),
                        Row(
                          children: [
                            const Icon(Symbols.tools_wrench),
                            const Gap(8),
                            InkWell(
                              child: Text('publisherRunBy').tr(args: [
                                '@${_account?.name ?? 'unknown'}',
                              ]),
                              onTap: () {},
                            ),
                            const Gap(8),
                            AccountImage(content: _account?.avatar, radius: 8),
                          ],
                        ),
                      ],
                    ).padding(horizontal: 8),
                  ],
                ).padding(all: 16),
              ).center(),
            ),
          SliverToBoxAdapter(
            child: const Divider(height: 1),
          ),
          SliverInfiniteList(
            itemCount: _posts.length,
            isLoading: _isBusy,
            hasReachedMax: _postCount != null && _posts.length >= _postCount!,
            onFetchData: _fetchPosts,
            itemBuilder: (context, idx) {
              return GestureDetector(
                child: PostItem(
                  data: _posts[idx],
                  maxWidth: 640,
                  onChanged: (data) {
                    setState(() => _posts[idx] = data);
                  },
                  onDeleted: () {
                    _posts.clear();
                    _fetchPosts();
                  },
                ),
                onTap: () {
                  GoRouter.of(context).pushNamed(
                    'postDetail',
                    pathParameters: {'slug': _posts[idx].id.toString()},
                    extra: _posts[idx],
                  );
                },
              );
            },
            separatorBuilder: (context, index) => const Divider(height: 1),
          ),
        ],
      ),
    );
  }
}