import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:freezer/api/deezer.dart';
import 'package:freezer/api/definitions.dart';
import 'package:freezer/api/player/audio_handler.dart';
import 'package:freezer/main.dart';
import 'package:freezer/ui/error.dart';
import 'package:freezer/ui/external_link_route.dart';
import 'package:freezer/ui/menu.dart';
import 'package:freezer/translations.i18n.dart';
import 'tiles.dart';
import 'details_screens.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 {
  const HomeScreen({super.key});

  @override
  Widget build(BuildContext context) {
    final actualScrollConfiguration = ScrollConfiguration.of(context);
    return ScrollConfiguration(
      behavior: actualScrollConfiguration.copyWith(
        dragDevices: {
          PointerDeviceKind.mouse,
          PointerDeviceKind.stylus,
          PointerDeviceKind.touch,
          PointerDeviceKind.trackpad
        },
      ),
      child: AnnotatedRegion<SystemUiOverlayStyle>(
        value: Theme.of(context).appBarTheme.systemOverlayStyle ??
            const SystemUiOverlayStyle(),
        child: SafeArea(
          child: Scaffold(
            body: NestedScrollView(
              floatHeaderSlivers: true,
              headerSliverBuilder: (context, _) => [
                SliverPersistentHeader(
                    delegate: _SearchHeaderDelegate(), floating: true)
              ],
              body: const HomePageWidget(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),
            const Text(
              'freezer',
              style: TextStyle(fontSize: 56, fontWeight: FontWeight.w900),
            )
          ],
        );
      }),
    );
  }
}

class HomePageScreen extends StatelessWidget {
  final String title;
  final HomePage? homePage;
  final bool cacheable;
  final DeezerChannel channel;

  const HomePageScreen({
    super.key,
    required this.title,
    required this.channel,
    this.homePage,
    this.cacheable = false,
  });

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text(title)),
      body: HomePageWidget(
        homePage: homePage,
        channel: channel,
        cacheable: cacheable,
      ),
    );
  }
}

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

  @override
  State<HomePageWidget> createState() => _HomePageWidgetState();
}

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

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

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

  Future<void> _load() async {
    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();
    });
  }

  Widget getSectionChild(HomePageSection section) {
    switch (section.layout) {
      case HomePageSectionLayout.grid:
        return HomePageGridSection(section);
      case HomePageSectionLayout.slideshow:
      case HomePageSectionLayout.row:
      default:
        return HomepageRowSection(section);
    }
  }

  @override
  Widget build(BuildContext context) {
    if (_error) return const 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) {
                return Padding(
                    padding: index == 0
                        ? EdgeInsets.zero
                        : const EdgeInsets.only(top: 16.0),
                    child: getSectionChild(sections![index]));
              },
              itemCount: sections!.length,
              padding: const EdgeInsets.symmetric(horizontal: 8.0),
            ),
    );
  }
}

class HomepageRowSection extends StatefulWidget {
  final HomePageSection section;
  const HomepageRowSection(this.section, {super.key});

  @override
  State<HomepageRowSection> createState() => _HomepageRowSectionState();
}

class _HomepageRowSectionState extends State<HomepageRowSection> {
  final _controller = ScrollController();

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

  @override
  Widget build(BuildContext context) {
    return ListTile(
        title: Text(
          widget.section.title ?? '',
          textAlign: TextAlign.left,
          maxLines: 2,
          overflow: TextOverflow.ellipsis,
          style: const TextStyle(fontSize: 20.0, fontWeight: FontWeight.w900),
        ),
        subtitle: Scrollbar(
          controller: _controller,
          thickness: MainScreen.of(context).isDesktop ? null : 1.0,
          child: SingleChildScrollView(
            controller: _controller,
            scrollDirection: Axis.horizontal,
            child: Row(
              children: List.generate(widget.section.items!.length + 1, (j) {
                //Has more items
                if (j == widget.section.items!.length) {
                  if (widget.section.hasMore ?? false) {
                    return TextButton(
                      child: Text(
                        'Show more'.i18n,
                        textAlign: TextAlign.center,
                        style: const TextStyle(fontSize: 20.0),
                      ),
                      onPressed: () => Navigator.of(context).pushRoute(
                        builder: (context) => HomePageScreen(
                          title: widget.section.title!,
                          channel:
                              DeezerChannel(target: widget.section.pagePath),
                        ),
                      ),
                    );
                  }
                  return const SizedBox();
                }

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

class HomePageGridSection extends StatelessWidget {
  final HomePageSection section;
  final double horizontalSpacing;
  final double verticalSpacing;
  const HomePageGridSection(
    this.section, {
    this.horizontalSpacing = 6.0,
    this.verticalSpacing = 6.0,
    super.key,
  });

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        if (section.title != null)
          Padding(
            padding: const EdgeInsets.symmetric(vertical: 4.0, horizontal: 6.0),
            child: Text(
              section.title!,
              textAlign: TextAlign.left,
              maxLines: 2,
              overflow: TextOverflow.ellipsis,
              style:
                  const TextStyle(fontSize: 20.0, fontWeight: FontWeight.w900),
            ),
          ),
        LayoutBuilder(builder: (context, constraints) {
          final amountThatCanFit =
              constraints.maxWidth ~/ (150.0 + horizontalSpacing);
          final widthOfEach =
              constraints.maxWidth / amountThatCanFit - horizontalSpacing;
          return Wrap(
              spacing: horizontalSpacing,
              runSpacing: verticalSpacing,
              alignment: WrapAlignment.start,
              children: section.items!
                  .map((e) => SizedBox(
                        width: widthOfEach,
                        child: HomePageItemWidget(e),
                      ))
                  .toList(growable: false));
        }),
      ],
    );
  }
}

class HomePageItemWidget extends StatelessWidget {
  final HomePageItem item;
  final Size? itemSize;
  const HomePageItemWidget(this.item, {super.key, this.itemSize});

  @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));
          },
          onSecondary: (details) {
            MenuSheet m = MenuSheet(context);
            m.defaultAlbumMenu(item.value, details: details);
          },
        );
      case HomePageItemType.ARTIST:
        return ArtistTile(
          item.value,
          onTap: () {
            Navigator.of(context)
                .pushRoute(builder: (context) => ArtistDetails(item.value));
          },
          onSecondary: (details) {
            MenuSheet m = MenuSheet(context);
            m.defaultArtistMenu(item.value, details: details);
          },
        );
      case HomePageItemType.PLAYLIST:
        return PlaylistCardTile(
          item.value,
          onTap: () {
            Navigator.of(context)
                .pushRoute(builder: (context) => PlaylistDetails(item.value));
          },
          onSecondary: (details) {
            MenuSheet m = MenuSheet(context);
            m.defaultPlaylistMenu(item.value, details: details);
          },
        );
      case HomePageItemType.CHANNEL:
        return ChannelTile(
          item.value,
          onTap: () {
            Navigator.of(context).pushRoute(
              builder: (context) => HomePageScreen(
                channel: item.value,
                title: item.value.title.toString(),
              ),
            );
          },
        );
      case HomePageItemType.EXTERNAL_LINK:
        return ChannelTile(
          item.value,
          onTap: () {
            final channel = item.value as DeezerChannel;
            Navigator.of(context).pushRoute(
              builder: (context) => ExternalLinkRoute(
                target: channel.target!,
                title: channel.title ?? '',
              ),
            );
          },
        );
      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);
    }
  }
}