import 'package:cached_network_image/cached_network_image.dart';
import 'package:contacts_plus_plus/api_client.dart';
import 'package:contacts_plus_plus/apis/message_api.dart';
import 'package:contacts_plus_plus/auxiliary.dart';
import 'package:contacts_plus_plus/models/friend.dart';
import 'package:contacts_plus_plus/models/message.dart';
import 'package:contacts_plus_plus/models/session.dart';
import 'package:contacts_plus_plus/neos_hub.dart';
import 'package:contacts_plus_plus/widgets/generic_avatar.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:intl/intl.dart';

class Messages extends StatefulWidget {
  const Messages({required this.friend, super.key});

  final Friend friend;

  @override
  State<StatefulWidget> createState() => _MessagesState();
}

class _MessagesState extends State<Messages> {
  Future<Iterable<Message>>? _messagesFuture;
  final TextEditingController _messageTextController = TextEditingController();
  final ScrollController _sessionListScrollController = ScrollController();
  ClientHolder? _clientHolder;
  HubHolder? _cacheHolder;

  bool _isSendable = false;
  bool _showSessionListChevron = false;
  double get _shevronOpacity => _showSessionListChevron ? 1.0 : 0.0;

  void _loadMessages() {
    final cache = _cacheHolder?.hub.getCache(widget.friend.id);
    if (cache != null) {
      _messagesFuture = Future(() => cache.messages);
    } else {
      _messagesFuture = MessageApi.getUserMessages(
          _clientHolder!.client, userId: widget.friend.id)
        ..then((value) {
          final list = value.toList();
          list.sort();
          _cacheHolder?.hub.setCache(widget.friend.id, list);
          _cacheHolder?.hub.registerListener(
              widget.friend.id, () => setState(() {}));
          return list;
        });
    }
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    final clientHolder = ClientHolder.of(context);
    bool dirty = false;
    if (_clientHolder != clientHolder) {
      _clientHolder = clientHolder;
      dirty = true;
    }
    final cacheHolder = HubHolder.of(context);
    if (_cacheHolder != cacheHolder) {
      _cacheHolder = cacheHolder;
      dirty = true;
    }
    if (dirty) _loadMessages();
  }

  @override
  void dispose() {
    _cacheHolder?.hub.unregisterListener(widget.friend.id);
    _messageTextController.dispose();
    _sessionListScrollController.dispose();
    super.dispose();
  }

  @override
  void initState() {
    super.initState();
    _sessionListScrollController.addListener(() {
      if (_sessionListScrollController.position.maxScrollExtent > 0 && !_showSessionListChevron) {
        setState(() {
          _showSessionListChevron = true;
        });
      }
      if (_sessionListScrollController.position.atEdge && _sessionListScrollController.position.pixels > 0
          && _showSessionListChevron) {
        setState(() {
          _showSessionListChevron = false;
        });
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    final apiClient = ClientHolder
        .of(context)
        .client;
    var sessions = widget.friend.userStatus.activeSessions;
    final appBarColor = Theme
        .of(context)
        .colorScheme
        .surfaceVariant;
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.friend.username),
        scrolledUnderElevation: 0.0,
        backgroundColor: appBarColor,
        /*bottom: sessions.isEmpty ? null : PreferredSize(
          preferredSize: Size.fromHeight(_headerHeight),
          child: Column(
            children: sessions.getRange(0, _headerExpanded ? sessions.length : 1).map((e) => Row(
              mainAxisSize: MainAxisSize.max,
              mainAxisAlignment: MainAxisAlignment.start,
              children: [
                Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: GenericAvatar(imageUri: Aux.neosDbToHttp(e.thumbnail),),
                ),
                Expanded(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(e.name),
                      Text("${e.sessionUsers.length} users active"),
                    ],
                  ),
                ),
                const Spacer(),
                if (sessions.length > 1) TextButton(onPressed: (){
                  setState(() {
                    _headerExpanded = !_headerExpanded;
                  });
                }, child: Text("+${sessions.length-1}"),)
              ],
            )).toList(),
          ),
        ),*/
      ),
      body: Stack(
        children: [
          FutureBuilder(
            future: _messagesFuture,
            builder: (context, snapshot) {
              if (snapshot.hasData) {
                final data = _cacheHolder?.hub
                    .getCache(widget.friend.id)
                    ?.messages ?? [];
                return ListView.builder(
                  reverse: true,
                  itemCount: data.length,
                  itemBuilder: (context, index) {
                    final entry = data.elementAt(index);
                    return entry.senderId == apiClient.userId
                        ? MyMessageBubble(message: entry)
                        : OtherMessageBubble(message: entry);
                  },
                );
              } else if (snapshot.hasError) {
                return Padding(
                  padding: const EdgeInsets.symmetric(horizontal: 64, vertical: 128,),
                  child: Center(
                    child: Column(
                      mainAxisSize: MainAxisSize.max,
                      mainAxisAlignment: MainAxisAlignment.center,
                      crossAxisAlignment: CrossAxisAlignment.center,
                      children: [
                        Text("Failed to load messages:", style: Theme
                            .of(context)
                            .textTheme
                            .titleMedium,),
                        const SizedBox(height: 16,),
                        Text("${snapshot.error}"),
                        const Spacer(),
                        TextButton.icon(
                          onPressed: () {
                            setState(() {
                              _loadMessages();
                            });
                          },
                          style: TextButton.styleFrom(
                            backgroundColor: Theme
                                .of(context)
                                .colorScheme
                                .secondaryContainer,
                            padding: const EdgeInsets.symmetric(
                                vertical: 16, horizontal: 16),
                          ),
                          icon: const Icon(Icons.refresh),
                          label: const Text("Retry"),
                        ),
                      ],
                    ),
                  ),
                );
              } else {
                return Column(
                  mainAxisSize: MainAxisSize.max,
                  mainAxisAlignment: MainAxisAlignment.end,
                  children: const [
                    LinearProgressIndicator(),
                  ],
                );
              }
            },
          ),
          if (sessions.isNotEmpty) Positioned(
            top: 0.0,
            left: 0.0,
            right: 0.0,
            child: Container(
              constraints: const BoxConstraints(maxHeight: 64),
              decoration: BoxDecoration(
                color: appBarColor,
                border: const Border(top: BorderSide(width: 1, color: Colors.black26), )
              ),
              child: Stack(
                children: [
                  ListView.builder(
                    controller: _sessionListScrollController,
                    scrollDirection: Axis.horizontal,
                    itemCount: sessions.length,
                    itemBuilder: (context, index) => SessionTile(session: sessions[index]),
                  ),
                  AnimatedOpacity(
                    opacity: _shevronOpacity,
                    curve: Curves.easeOut,
                    duration: const Duration(milliseconds: 200),
                    child: Align(
                      alignment: Alignment.centerRight,
                      child: Container(
                        padding: const EdgeInsets.only(left: 16, right: 4, top: 1, bottom: 1),
                        decoration: BoxDecoration(
                          gradient: LinearGradient(
                            begin: Alignment.centerLeft,
                            end: Alignment.centerRight,
                            colors: [
                              appBarColor.withOpacity(0),
                              appBarColor,
                              appBarColor,
                            ],
                          ),
                        ),
                        height: double.infinity,
                        child: const Icon(Icons.chevron_right),
                      ),
                    ),
                  )
                ],
              ),
            ),
          ),
        ],
      ),
      bottomNavigationBar: Padding(
        padding: MediaQuery
            .of(context)
            .viewInsets,
        child: BottomAppBar(
          elevation: 0.0,
          padding: const EdgeInsets.symmetric(vertical: 0, horizontal: 6),
          child: Row(
            children: [
              Expanded(
                child: Padding(
                  padding: const EdgeInsets.all(8),
                  child: TextField(
                    autocorrect: true,
                    controller: _messageTextController,
                    maxLines: 4,
                    minLines: 1,
                    onChanged: (text) {
                      if (text.isNotEmpty && !_isSendable) {
                        setState(() {
                          _isSendable = true;
                        });
                      } else if (text.isEmpty && _isSendable) {
                        setState(() {
                          _isSendable = false;
                        });
                      }
                    },
                    decoration: InputDecoration(
                        isDense: true,
                        hintText: "Send a message to ${widget.friend
                            .username}...",
                        contentPadding: const EdgeInsets.all(16),
                        border: OutlineInputBorder(
                            borderRadius: BorderRadius.circular(24)
                        )
                    ),
                  ),
                ),
              ),
              Padding(
                padding: const EdgeInsets.only(left: 8, right: 4.0),
                child: IconButton(
                  splashRadius: 24,
                  onPressed: _isSendable ? () async {
                    setState(() {
                      _isSendable = false;
                    });
                    final message = Message(
                      id: Message.generateId(),
                      recipientId: widget.friend.id,
                      senderId: apiClient.userId,
                      type: MessageType.text,
                      content: _messageTextController.text,
                      sendTime: DateTime.now().toUtc(),
                    );
                    try {
                      if (_cacheHolder == null) {
                        throw "Hub not connected.";
                      }
                      _cacheHolder!.hub.sendMessage(message);
                      _messageTextController.clear();
                      setState(() {});
                    } catch (e) {
                      ScaffoldMessenger.of(context).showSnackBar(
                        SnackBar(
                          content: Text("Failed to send message\n$e",
                            maxLines: null,
                          ),
                        ),
                      );
                      setState(() {
                        _isSendable = true;
                      });
                    }
                  } : null,
                  iconSize: 28,
                  icon: const Icon(Icons.send),
                ),
              )
            ],
          ),
        ),
      ),
    );
  }
}

class MyMessageBubble extends StatelessWidget {
  MyMessageBubble({required this.message, super.key});

  final Message message;
  final DateFormat _dateFormat = DateFormat.Hm();

  @override
  Widget build(BuildContext context) {
    var content = message.content;
    if (message.type == MessageType.sessionInvite) {
      content = "<Session Invite>";
    } else if (message.type == MessageType.sound) {
      content = "<Voice Message>";
    } else if (message.type == MessageType.object) {
      content = "<Asset>";
    }
    return Row(
      mainAxisAlignment: MainAxisAlignment.end,
      mainAxisSize: MainAxisSize.min,
      children: [
        Flexible(
          child: Card(
            shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.circular(16),
            ),
            color: Theme.of(context).colorScheme.primaryContainer,
            margin: const EdgeInsets.only(left: 32, bottom: 16, right: 12),
            child: Padding(
              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.end,
                children: [
                  Text(
                    content,
                    softWrap: true,
                    maxLines: null,
                    style: Theme.of(context).textTheme.bodyLarge,
                  ),
                  const SizedBox(height: 6,),
                  Row(
                    mainAxisSize: MainAxisSize.min,
                    mainAxisAlignment: MainAxisAlignment.end,
                    children: [
                      Text(
                        _dateFormat.format(message.sendTime),
                        style: Theme.of(context).textTheme.labelMedium?.copyWith(color: Colors.white54),
                      ),
                      const SizedBox(width: 4,),
                      MessageStateIndicator(messageState: message.state),
                    ],
                  ),
                ],
              ),
            ),
          ),
        ),
      ],
    );
  }
}


class OtherMessageBubble extends StatelessWidget {
  OtherMessageBubble({required this.message, super.key});

  final Message message;
  final DateFormat _dateFormat = DateFormat.Hm();

  @override
  Widget build(BuildContext context) {
    var content = message.content;
    if (message.type == MessageType.sessionInvite) {
      content = "<Session Invite>";
    } else if (message.type == MessageType.sound) {
      content = "<Voice Message>";
    } else if (message.type == MessageType.object) {
      content = "<Asset>";
    }
    return Row(
      mainAxisSize: MainAxisSize.min,
      mainAxisAlignment: MainAxisAlignment.start,
      children: [
        Flexible(
          child: Card(
            shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.circular(16),
            ),
            color: Theme
                .of(context)
                .colorScheme
                .secondaryContainer,
            margin: const EdgeInsets.only(right: 32, bottom: 16, left: 12),
            child: Padding(
              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    content,
                    softWrap: true,
                    maxLines: null,
                    style: Theme.of(context).textTheme.bodyLarge,
                  ),
                  const SizedBox(height: 6,),
                  Text(
                    _dateFormat.format(message.sendTime),
                    style: Theme.of(context).textTheme.labelMedium?.copyWith(color: Colors.white54),
                  ),
                ],
              ),
            ),
          ),
        ),
      ],
    );
  }
}

class MessageStateIndicator extends StatelessWidget {
  const MessageStateIndicator({required this.messageState, super.key});

  final MessageState messageState;

  @override
  Widget build(BuildContext context) {
    late final IconData icon;
    switch (messageState) {
      case MessageState.local:
        icon = Icons.alarm;
        break;
      case MessageState.sent:
        icon = Icons.done;
        break;
      case MessageState.read:
        icon = Icons.done_all;
        break;
    }
    return Icon(
      icon,
      size: 12,
      color: messageState == MessageState.read ? Theme.of(context).colorScheme.primary : null,
    );
  }
}

class SessionTile extends StatelessWidget {
  const SessionTile({required this.session, super.key});
  final Session session;

  @override
  Widget build(BuildContext context) {
    return TextButton(
      onPressed: () {
        showDialog(context: context, builder: (context) {
          final ScrollController userListScrollController = ScrollController();
          final thumbnailUri = Aux.neosDbToHttp(session.thumbnail);
          return Dialog(
            insetPadding: const EdgeInsets.all(32),
            child: Container(
              constraints: const BoxConstraints(maxHeight: 400),
              padding: const EdgeInsets.all(24),
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  Expanded(
                    child: Row(
                      mainAxisSize: MainAxisSize.min,
                      crossAxisAlignment: CrossAxisAlignment.start,
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: [
                        Expanded(
                          child: ListView(
                            children: [
                              Text(session.name, style: Theme.of(context).textTheme.titleMedium),
                              Text(session.description.isEmpty ? "No description." : session.description, style: Theme.of(context).textTheme.labelMedium),
                              Text("Tags: ${session.tags.isEmpty ? "None" : session.tags.join(", ")}",
                                style: Theme.of(context).textTheme.labelMedium,
                                softWrap: true,
                              ),
                              Text("Users: ${session.sessionUsers.length}", style: Theme.of(context).textTheme.labelMedium),
                              Text("Maximum users: ${session.maxUsers}", style: Theme.of(context).textTheme.labelMedium),
                              Text("Headless: ${session.headlessHost ? "Yes" : "No"}", style: Theme.of(context).textTheme.labelMedium),
                            ],
                          ),
                        ),
                        if (session.sessionUsers.isNotEmpty) Expanded(
                          child: Scrollbar(
                            trackVisibility: true,
                            controller: userListScrollController,
                            thumbVisibility: true,
                            child: ListView.builder(
                              controller: userListScrollController,
                              shrinkWrap: true,
                              itemCount: session.sessionUsers.length,
                              itemBuilder: (context, index) {
                                final user = session.sessionUsers[index];
                                return ListTile(
                                  dense: true,
                                  title: Text(user.username, textAlign: TextAlign.end,),
                                  subtitle: Text(user.isPresent ? "Active" : "Inactive", textAlign: TextAlign.end,),
                                );
                              },
                            ),
                          ),
                        ) else Expanded(
                          child: Center(
                            child: Column(
                              mainAxisSize: MainAxisSize.min,
                              children: const [
                                Icon(Icons.person_remove_alt_1_rounded),
                                Padding(
                                  padding: EdgeInsets.all(16.0),
                                  child: Text("No one is currently playing.", textAlign: TextAlign.center,),
                                )
                              ],
                            ),
                          ),
                        ),
                      ],
                    ),
                  ),
                  Expanded(
                    child: Center(
                      child: thumbnailUri.isEmpty ? const Text("No Image") : CachedNetworkImage(
                        imageUrl: thumbnailUri,
                        placeholder: (context, url) {
                          return const CircularProgressIndicator();
                        },
                        errorWidget: (context, error, what) => Column(
                          mainAxisSize: MainAxisSize.max,
                          crossAxisAlignment: CrossAxisAlignment.center,
                          mainAxisAlignment: MainAxisAlignment.center,
                          children: const [
                            Icon(Icons.no_photography),
                            Padding(
                              padding: EdgeInsets.all(16.0),
                              child: Text("Failed to load Image"),
                            )
                          ],
                        ),
                      ),
                    ),
                  )
                ],
              ),
            ),
          );
        });
      },
      child: Row(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          GenericAvatar(imageUri: Aux.neosDbToHttp(session.thumbnail), placeholderIcon: Icons.no_photography),
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 12.0),
            child: Column(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(session.name),
                Text("${session.sessionUsers.length}/${session.maxUsers} active users")
              ],
            ),
          )
        ],
      ),
    );
  }
}