import 'package:flutter/material.dart';
import 'package:freezer/api/deezer.dart';
import 'package:freezer/api/definitions.dart';
import 'package:freezer/api/player.dart';
import 'package:freezer/ui/error.dart';
import 'package:freezer/ui/menu.dart';
import 'package:freezer/translations.i18n.dart';
import 'tiles.dart';
import 'details_screens.dart';
import '../settings.dart';

class _SearchHeaderDelegate extends SliverPersistentHeaderDelegate {
  @override
  double get maxExtent => 76.0;

  @override
  double get minExtent => 76.0;

  @override
  bool shouldRebuild(covariant SliverPersistentHeaderDelegate oldDelegate) =>
      false;

  @override
  Widget build(
      BuildContext context, double shrinkOffset, bool overlapsContent) {
    return Padding(
        padding: const EdgeInsets.all(8.0),
        child: Card(
            clipBehavior: Clip.antiAlias,
            shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(56.0)),
            child: ListTile(
                mouseCursor: MaterialStateMouseCursor.textable,
                leading: const Icon(Icons.search),
                title: Text('Search or paste URL'.i18n),
                onTap: () => Navigator.of(context).pushNamed('/search'))));
  }
}

class HomeScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: Scaffold(
        body: NestedScrollView(
          floatHeaderSlivers: true,
          headerSliverBuilder: (context, _) => [
            SliverPersistentHeader(
                delegate: _SearchHeaderDelegate(), floating: true)
          ],
          body: HomePageScreen(cacheable: true),
        ),
      ),
    );
  }
}

class FreezerTitle extends StatelessWidget {
  const FreezerTitle({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.fromLTRB(0, 24, 0, 8),
      child: LayoutBuilder(builder: (context, constraints) {
        return Row(
          mainAxisSize: MainAxisSize.max,
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Image.asset('assets/icon.png', width: 64, height: 64),
            Text(
              'freezer',
              style: TextStyle(fontSize: 56, fontWeight: FontWeight.w900),
            )
          ],
        );
      }),
    );
  }
}

class HomePageScreen extends StatefulWidget {
  final HomePage? homePage;
  final bool cacheable;
  final DeezerChannel? channel;
  HomePageScreen(
      {this.homePage, this.channel, this.cacheable = false, Key? key})
      : super(key: key);

  @override
  _HomePageScreenState createState() => _HomePageScreenState();
}

class _HomePageScreenState extends State<HomePageScreen> {
  HomePage? _homePage;
  bool _error = false;
  bool _loadExplicitlyRequested = false;
  final _indicatorKey = GlobalKey<RefreshIndicatorState>();

  Future<void> _loadChannel() async {
    HomePage? _hp;
    //Fetch channel from api
    try {
      if (widget.channel == null)
        _hp = await deezerAPI.homePage();
      else
        _hp = await deezerAPI.getChannel(widget.channel!.target);
    } catch (e) {
      _hp = null;
      print(e);
    }
    if (!mounted) return;
    if (_hp == null) {
      //On error
      setState(() => _error = true);
      return;
    }
    if (_hp!.sections.isEmpty) return;
    if (widget.cacheable) _hp.save(widget.channel?.target ?? '');
    setState(() => _homePage = _hp!);
  }

  Future<void> _loadLocalChannel() async {
    HomePage? _hp = await HomePage.local(widget.channel?.target ?? '');
    //print('LOCAL: ${_hp.sections}');
    setState(() => _homePage = _hp);
  }

  Future<void> _load() async {
    print("channel: " + (widget.channel?.target ?? "null"));
    if (widget.homePage != null && widget.homePage!.sections.isNotEmpty) {
      setState(() => _homePage = widget.homePage);
      return;
    }

    if (!_loadExplicitlyRequested) {
      if (_homePage == null && widget.cacheable) await _loadLocalChannel();
      if (_homePage == null ||
          DateTime.now().difference(_homePage!.lastUpdated) >
              HomePage.cacheDuration) await _loadChannel();

      _loadExplicitlyRequested = true;

      return;
    }

    await _loadChannel();
  }

  @override
  void initState() {
    super.initState();

    WidgetsBinding.instance.addPostFrameCallback((_) {
      _indicatorKey.currentState!.show();
    });
  }

  @override
  Widget build(BuildContext context) {
    if (_error) return ErrorScreen();
    List<HomePageSection>? sections;
    if (_homePage != null) {
      sections = _homePage!.sections!;
    }
    return RefreshIndicator(
      key: _indicatorKey,
      onRefresh: _load,
      child: _homePage == null
          ? const SizedBox.expand(child: SingleChildScrollView())
          : ListView.builder(
              itemBuilder: (context, index) {
                final section = sections![index];
                switch (section.layout) {
                  case HomePageSectionLayout.GRID:
                    return HomePageGridSection(section);
                  case HomePageSectionLayout.ROW:
                  default:
                    return HomepageRowSection(section);
                }
              },
              itemCount: sections!.length,
              padding: EdgeInsets.symmetric(horizontal: 8.0),
            ),
    );
  }
}

class HomepageRowSection extends StatelessWidget {
  final HomePageSection section;
  HomepageRowSection(this.section);

  @override
  Widget build(BuildContext context) {
    return ListTile(
        title: Text(
          section.title ?? '',
          textAlign: TextAlign.left,
          maxLines: 2,
          overflow: TextOverflow.ellipsis,
          style: TextStyle(fontSize: 20.0, fontWeight: FontWeight.w900),
        ),
        subtitle: SingleChildScrollView(
          scrollDirection: Axis.horizontal,
          child: Row(
            children: List.generate(section.items!.length + 1, (j) {
              //Has more items
              if (j == section.items!.length) {
                if (section.hasMore ?? false) {
                  return TextButton(
                    child: Text(
                      'Show more'.i18n,
                      textAlign: TextAlign.center,
                      style: TextStyle(fontSize: 20.0),
                    ),
                    onPressed: () => Navigator.of(context).pushRoute(
                        builder: (context) => Scaffold(
                              appBar: AppBar(title: Text(section.title!)),
                              body: HomePageScreen(
                                channel:
                                    DeezerChannel(target: section.pagePath),
                              ),
                            )),
                  );
                }
                return const SizedBox();
              }

              //Show item
              HomePageItem item = section.items![j];
              return Padding(
                padding: const EdgeInsets.symmetric(horizontal: 6.0),
                child: HomePageItemWidget(item),
              );
            }),
          ),
        ));
  }
}

class HomePageGridSection extends StatelessWidget {
  final HomePageSection section;
  HomePageGridSection(this.section);

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        if (section.title != null)
          Padding(
            padding: EdgeInsets.symmetric(vertical: 4.0, horizontal: 6.0),
            child: Text(
              section.title!,
              textAlign: TextAlign.left,
              maxLines: 2,
              overflow: TextOverflow.ellipsis,
              style: TextStyle(fontSize: 20.0, fontWeight: FontWeight.w900),
            ),
          ),
        Wrap(
            spacing: 4.0,
            runSpacing: 4.0,
            alignment: WrapAlignment.spaceEvenly,
            children: section.items!
                .map((e) => HomePageItemWidget(e))
                .toList(growable: false)),
      ],
    );
  }
}

class HomePageItemWidget extends StatelessWidget {
  final HomePageItem item;
  HomePageItemWidget(this.item);

  @override
  Widget build(BuildContext context) {
    switch (item.type) {
      case HomePageItemType.SMARTTRACKLIST:
        return SmartTrackListTile(
          item.value,
          size: (item.value as SmartTrackList).id == 'flow' ? 96.0 : 128.0,
          onTap: () => playerHelper.playFromSmartTrackList(item.value),
        );
      case HomePageItemType.ALBUM:
        return AlbumCard(
          item.value,
          onTap: () {
            Navigator.of(context)
                .pushRoute(builder: (context) => AlbumDetails(item.value));
          },
          onHold: () {
            MenuSheet m = MenuSheet(context);
            m.defaultAlbumMenu(item.value);
          },
        );
      case HomePageItemType.ARTIST:
        return ArtistTile(
          item.value,
          onTap: () {
            Navigator.of(context)
                .pushRoute(builder: (context) => ArtistDetails(item.value));
          },
          onHold: () {
            MenuSheet m = MenuSheet(context);
            m.defaultArtistMenu(item.value);
          },
        );
      case HomePageItemType.PLAYLIST:
        return PlaylistCardTile(
          item.value,
          onTap: () {
            Navigator.of(context)
                .pushRoute(builder: (context) => PlaylistDetails(item.value));
          },
          onHold: () {
            MenuSheet m = MenuSheet(context);
            m.defaultPlaylistMenu(item.value);
          },
        );
      case HomePageItemType.CHANNEL:
        return ChannelTile(
          item.value,
          onTap: () {
            Navigator.of(context).pushRoute(
                builder: (context) => Scaffold(
                      appBar: AppBar(title: Text(item.value.title.toString())),
                      body: HomePageScreen(channel: item.value),
                    ));
          },
        );
      case HomePageItemType.SHOW:
        return ShowCard(
          item.value,
          onTap: () {
            Navigator.of(context)
                .pushRoute(builder: (context) => ShowScreen(item.value));
          },
        );
      default:
        return const SizedBox(height: 0, width: 0);
    }
  }
}