import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';
import 'package:logging/logging.dart';
import 'package:photos/core/configuration.dart';
import 'package:photos/core/event_bus.dart';
import 'package:photos/db/collections_db.dart';
import 'package:photos/db/files_db.dart';
import 'package:photos/events/collection_updated_event.dart';
import 'package:photos/models/collection.dart';
import 'package:photos/models/collection_items.dart';
import 'package:photos/ui/collection_page.dart';
import 'package:photos/ui/collections_gallery_widget.dart';
import 'package:photos/ui/common_elements.dart';
import 'package:photos/ui/loading_widget.dart';
import 'package:photos/ui/shared_collection_page.dart';
import 'package:photos/ui/thumbnail_widget.dart';

class SharedCollectionGallery extends StatefulWidget {
  const SharedCollectionGallery({Key key}) : super(key: key);

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

class _SharedCollectionGalleryState extends State<SharedCollectionGallery>
    with AutomaticKeepAliveClientMixin {
  Logger _logger = Logger("SharedCollectionGallery");
  StreamSubscription<CollectionUpdatedEvent> _subscription;

  @override
  void initState() {
    _subscription = Bus.instance.on<CollectionUpdatedEvent>().listen((event) {
      setState(() {});
    });
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    super.build(context);
    return FutureBuilder<SharedCollections>(
      future:
          CollectionsDB.instance.getAllCollections().then((collections) async {
        final outgoing = List<CollectionWithThumbnail>();
        final incoming = List<CollectionWithThumbnail>();
        for (final collection in collections) {
          if (collection.owner.id == Configuration.instance.getUserID()) {
            if (collection.sharees.length > 0) {
              final withThumbnail =
                  await _getCollectionWithThumbnail(collection);
              if (withThumbnail.thumbnail != null) {
                outgoing.add(withThumbnail);
              }
            } else {
              continue;
            }
          } else {
            final withThumbnail = await _getCollectionWithThumbnail(collection);
            if (withThumbnail.thumbnail != null) {
              incoming.add(withThumbnail);
            }
          }
        }
        outgoing.sort((first, second) {
          return second.lastUpdatedFile.updationTime
              .compareTo(first.lastUpdatedFile.updationTime);
        });
        incoming.sort((first, second) {
          return second.lastUpdatedFile.updationTime
              .compareTo(first.lastUpdatedFile.updationTime);
        });
        return SharedCollections(outgoing, incoming);
      }),
      builder: (context, snapshot) {
        if (snapshot.hasData) {
          return _getSharedCollectionsGallery(snapshot.data);
        } else if (snapshot.hasError) {
          _logger.shout(snapshot.error);
          return Center(child: Text(snapshot.error.toString()));
        } else {
          return loadWidget;
        }
      },
    );
  }

  Widget _getSharedCollectionsGallery(SharedCollections collections) {
    return SingleChildScrollView(
      child: Column(
        children: [
          Padding(padding: EdgeInsets.all(6)),
          SectionTitle("incoming"),
          Padding(padding: EdgeInsets.all(16)),
          collections.incoming.length > 0
              ? GridView.builder(
                  shrinkWrap: true,
                  physics: NeverScrollableScrollPhysics(),
                  itemBuilder: (context, index) {
                    return _buildIncomingCollection(
                        context, collections.incoming[index]);
                  },
                  itemCount: collections.incoming.length,
                  gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                    crossAxisCount: 2,
                  ),
                )
              : nothingToSeeHere,
          Padding(padding: EdgeInsets.all(16)),
          Divider(height: 0),
          Padding(padding: EdgeInsets.all(14)),
          SectionTitle("outgoing"),
          Padding(padding: EdgeInsets.all(16)),
          collections.outgoing.length > 0
              ? Padding(
                  padding: const EdgeInsets.fromLTRB(12, 0, 0, 0),
                  child: ListView.builder(
                    shrinkWrap: true,
                    padding: EdgeInsets.only(bottom: 12),
                    physics: NeverScrollableScrollPhysics(),
                    itemBuilder: (context, index) {
                      return _buildOutgoingCollection(
                          context, collections.outgoing[index]);
                    },
                    itemCount: collections.outgoing.length,
                  ),
                )
              : nothingToSeeHere,
        ],
      ),
    );
  }

  Widget _buildOutgoingCollection(
      BuildContext context, CollectionWithThumbnail c) {
    final sharees = List<String>();
    for (int index = 0; index < c.collection.sharees.length; index++) {
      if (index < 2) {
        sharees.add(c.collection.sharees[index].name);
      } else {
        final remaining = c.collection.sharees.length - index;
        if (remaining == 1) {
          // If it's the last sharee
          sharees.add(c.collection.sharees[index].name);
        } else {
          sharees.add("and " +
              remaining.toString() +
              " other" +
              (remaining > 1 ? "s" : ""));
        }
        break;
      }
    }
    return GestureDetector(
      child: Container(
        margin: EdgeInsets.fromLTRB(16, 12, 8, 12),
        child: Row(
          children: <Widget>[
            ClipRRect(
              borderRadius: BorderRadius.circular(8.0),
              child: Container(
                child: Hero(
                    tag: "outgoing_collection" + c.thumbnail.tag(),
                    child: ThumbnailWidget(
                      c.thumbnail,
                    )),
                height: 60,
                width: 60,
              ),
            ),
            Padding(padding: EdgeInsets.all(8)),
            Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  c.collection.name,
                  style: TextStyle(
                    fontSize: 16,
                  ),
                ),
                Padding(
                  padding: EdgeInsets.fromLTRB(0, 4, 0, 0),
                  child: Text(
                    "Shared with " + sharees.join(", "),
                    style: TextStyle(
                      fontSize: 14,
                      color: Theme.of(context).primaryColorLight,
                    ),
                    textAlign: TextAlign.left,
                    overflow: TextOverflow.ellipsis,
                  ),
                ),
              ],
            ),
          ],
        ),
      ),
      onTap: () {
        final page = CollectionPage(
          c.collection,
          tagPrefix: "outgoing_collection",
        );
        Navigator.of(context).push(
          MaterialPageRoute(
            builder: (BuildContext context) {
              return page;
            },
          ),
        );
      },
    );
  }

  Widget _buildIncomingCollection(
      BuildContext context, CollectionWithThumbnail c) {
    return GestureDetector(
      child: Column(
        children: <Widget>[
          ClipRRect(
            borderRadius: BorderRadius.circular(18.0),
            child: Container(
              child: Stack(
                children: [
                  Hero(
                      tag: "shared_collection" + c.thumbnail.tag(),
                      child: ThumbnailWidget(c.thumbnail)),
                  Align(
                    alignment: Alignment.bottomRight,
                    child: Container(
                      child: Text(
                        c.collection.owner.name == null ||
                                c.collection.owner.name.isEmpty
                            ? c.collection.owner.email.substring(0, 1)
                            : c.collection.owner.name.substring(0, 1),
                        textAlign: TextAlign.center,
                      ),
                      padding: EdgeInsets.all(8),
                      margin: EdgeInsets.fromLTRB(0, 0, 4, 0),
                      decoration: BoxDecoration(
                        shape: BoxShape.circle,
                        color: Theme.of(context).accentColor,
                      ),
                    ),
                  ),
                ],
              ),
              height: 160,
              width: 160,
            ),
          ),
          Padding(padding: EdgeInsets.all(2)),
          Expanded(
            child: Padding(
              padding: const EdgeInsets.fromLTRB(8, 0, 8, 0),
              child: Text(
                c.collection.name,
                style: TextStyle(
                  fontSize: 16,
                ),
                overflow: TextOverflow.ellipsis,
              ),
            ),
          ),
        ],
      ),
      onTap: () {
        final page = SharedCollectionPage(c.collection);
        Navigator.of(context).push(
          MaterialPageRoute(
            builder: (BuildContext context) {
              return page;
            },
          ),
        );
      },
    );
  }

  Future<CollectionWithThumbnail> _getCollectionWithThumbnail(
      Collection collection) async {
    final thumbnail =
        await FilesDB.instance.getLatestFileInCollection(collection.id);
    final lastUpdatedFile =
        await FilesDB.instance.getLastModifiedFileInCollection(collection.id);
    return CollectionWithThumbnail(
      collection,
      thumbnail,
      lastUpdatedFile,
    );
  }

  @override
  void dispose() {
    _subscription.cancel();
    super.dispose();
  }

  @override
  bool get wantKeepAlive => true;
}