import 'package:flutter/material.dart';
import 'package:matrix/matrix.dart';

import '../matrix/client.dart';
import '../theme.dart';
import 'avatar.dart';

const _i18n = MatrixDefaultLocalizations();

/// The reactions offered with one tap.
const quickReactions = ['👍', '❤️', '😂', '😮', '😢', '🙏'];

/// The key of a reaction event: the emoji (or text) it reacts with.
String? reactionKey(Event reaction) => reaction.content
    .tryGetMap<String, Object?>('m.relates_to')
    ?.tryGet<String>('key');

/// The user's own reaction with [key] to [event], if any.
Event? myReaction(Event event, Timeline timeline, String key) => event
    .aggregatedEvents(timeline, RelationshipTypes.reaction)
    .where(
      (r) =>
          r.senderId == event.room.client.userID &&
          !r.redacted &&
          reactionKey(r) == key,
    )
    .firstOrNull;

/// Reacts to [event] with [key], or takes the reaction back if it's there.
Future<void> toggleReaction(Event event, Timeline timeline, String key) async {
  final mine = myReaction(event, timeline, key);
  if (mine != null) {
    await mine.redactEvent();
  } else {
    await event.room.sendReaction(event.eventId, key);
  }
}

Future<String?> askReaction(BuildContext context) {
  final controller = TextEditingController();
  return showDialog<String>(
    context: context,
    builder: (dialog) => AlertDialog(
      title: const Text('React with'),
      content: TextField(
        controller: controller,
        autofocus: true,
        maxLength: 16,
        decoration: const InputDecoration(hintText: 'An emoji, or a word'),
        onSubmitted: (v) =>
            Navigator.pop(dialog, v.trim().isEmpty ? null : v.trim()),
      ),
      actions: [
        TextButton(
          onPressed: () => Navigator.pop(dialog),
          child: const Text('Cancel'),
        ),
        FilledButton(
          onPressed: () {
            final v = controller.text.trim();
            Navigator.pop(dialog, v.isEmpty ? null : v);
          },
          child: const Text('React'),
        ),
      ],
    ),
  );
}

class ReactionButton extends StatelessWidget {
  const ReactionButton({
    super.key,
    required this.emoji,
    required this.selected,
    required this.onTap,
  });
  final String emoji;
  final bool selected;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    final c = context.warp;
    return InkWell(
      onTap: onTap,
      customBorder: const CircleBorder(),
      child: Container(
        width: 44,
        height: 44,
        alignment: Alignment.center,
        decoration: BoxDecoration(
          shape: BoxShape.circle,
          color: selected ? c.tealSoft : c.surfaceSunken,
        ),
        child: Text(emoji, style: const TextStyle(fontSize: 22)),
      ),
    );
  }
}

/// The reactions under a message, one chip per key with its count. Tapping
/// one adds or takes back the user's own; a long press says who reacted.
class Reactions extends StatelessWidget {
  const Reactions({super.key, required this.event, required this.timeline});
  final Event event;
  final Timeline timeline;

  @override
  Widget build(BuildContext context) {
    final reactions = event
        .aggregatedEvents(timeline, RelationshipTypes.reaction)
        .where((r) => !r.redacted && reactionKey(r) != null)
        .toList();
    if (reactions.isEmpty) return const SizedBox.shrink();
    final me = event.room.client.userID;
    final byKey = <String, List<Event>>{};
    for (final r in reactions) {
      byKey.putIfAbsent(reactionKey(r)!, () => []).add(r);
    }
    final keys = byKey.keys.toList()
      ..sort((a, b) => byKey[b]!.length.compareTo(byKey[a]!.length));
    final c = context.warp;
    final text = Theme.of(context).textTheme;
    final canReact =
        event.status.isSent && event.room.canSendEvent(EventTypes.Reaction);

    return Padding(
      padding: const EdgeInsets.only(top: 4),
      child: Wrap(
        spacing: 4,
        runSpacing: 4,
        children: [
          for (final key in keys)
            _ReactionChip(
              label: '$key ${byKey[key]!.length}',
              mine: byKey[key]!.any((r) => r.senderId == me),
              colours: c,
              style: text.labelMedium,
              onTap: !canReact
                  ? null
                  : () => toggleReaction(event, timeline, key).catchError((
                      Object e,
                    ) {
                      if (context.mounted) {
                        ScaffoldMessenger.of(context).showSnackBar(
                          SnackBar(content: Text(describeError(e))),
                        );
                      }
                    }),
              onLongPress: () => _showReactors(context, key, byKey[key]!),
            ),
        ],
      ),
    );
  }

  void _showReactors(BuildContext context, String key, List<Event> list) {
    showModalBottomSheet<void>(
      context: context,
      builder: (sheet) => SafeArea(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Text(key, style: const TextStyle(fontSize: 32)),
            for (final r in list)
              ListTile(
                leading: Avatar(
                  name: r.senderFromMemoryOrFallback.calcDisplayname(),
                  seed: r.senderId,
                  mxc: r.senderFromMemoryOrFallback.avatarUrl,
                  size: 32,
                ),
                title: Text(r.senderFromMemoryOrFallback.calcDisplayname()),
              ),
            const SizedBox(height: 8),
          ],
        ),
      ),
    );
  }
}

class _ReactionChip extends StatelessWidget {
  const _ReactionChip({
    required this.label,
    required this.mine,
    required this.colours,
    required this.style,
    required this.onTap,
    required this.onLongPress,
  });
  final String label;
  final bool mine;
  final WarpColors colours;
  final TextStyle? style;
  final VoidCallback? onTap;
  final VoidCallback onLongPress;

  @override
  Widget build(BuildContext context) {
    final c = colours;
    return Material(
      color: mine ? c.tealSoft : c.surfaceSunken,
      shape: StadiumBorder(
        side: BorderSide(color: mine ? c.tealStrong : c.line),
      ),
      child: InkWell(
        customBorder: const StadiumBorder(),
        onTap: onTap,
        onLongPress: onLongPress,
        child: Padding(
          padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 3),
          child: Text(
            label,
            style: style?.copyWith(color: mine ? c.tealText : c.ink),
          ),
        ),
      ),
    );
  }
}

/// The message a reply answers, quoted above the reply: who wrote it and
/// its first line.
class ReplyPreview extends StatelessWidget {
  const ReplyPreview({super.key, required this.event, required this.timeline});
  final Event event;
  final Timeline timeline;

  @override
  Widget build(BuildContext context) {
    return FutureBuilder<Event?>(
      future: event.getReplyEvent(timeline),
      builder: (context, snapshot) {
        final original = snapshot.data;
        return QuoteBlock(
          sender: original?.senderFromMemoryOrFallback.calcDisplayname(),
          text: original == null
              ? (snapshot.connectionState == ConnectionState.done
                    ? 'Message not available'
                    : '…')
              : quoteText(original.getDisplayEvent(timeline)),
        );
      },
    );
  }
}

/// One line describing a message, for a quote or the reply bar.
String quoteText(Event event) {
  if (event.redacted) return 'Message deleted';
  if (event.type == EventTypes.Encrypted) return 'Encrypted message';
  return switch (event.messageType) {
    MessageTypes.Image => '🖼 Image',
    MessageTypes.Sticker => 'Sticker',
    MessageTypes.Video => '🎬 Video',
    MessageTypes.Audio => '🎵 Audio',
    MessageTypes.File => '📄 ${event.body}',
    _ =>
      event.calcLocalizedBodyFallback(_i18n, hideReply: true).split('\n').first,
  };
}

/// A quoted message: a teal bar, the sender, a line of text.
class QuoteBlock extends StatelessWidget {
  const QuoteBlock({super.key, required this.sender, required this.text});
  final String? sender;
  final String text;

  @override
  Widget build(BuildContext context) {
    final c = context.warp;
    final style = Theme.of(context).textTheme;
    return Container(
      padding: const EdgeInsets.fromLTRB(10, 4, 10, 4),
      decoration: BoxDecoration(
        color: c.surface.withValues(alpha: 0.6),
        border: Border(left: BorderSide(color: c.tealStrong, width: 3)),
        borderRadius: BorderRadius.circular(6),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        mainAxisSize: MainAxisSize.min,
        children: [
          if (sender != null)
            Text(
              sender!,
              maxLines: 1,
              overflow: TextOverflow.ellipsis,
              style: style.labelMedium?.copyWith(
                color: c.tealText,
                fontWeight: FontWeight.w600,
              ),
            ),
          Text(
            text,
            maxLines: 2,
            overflow: TextOverflow.ellipsis,
            style: style.bodySmall?.copyWith(color: c.inkMuted),
          ),
        ],
      ),
    );
  }
}

/// Under a message that starts a thread: how many replies, opening it.
class ThreadSummary extends StatelessWidget {
  const ThreadSummary({
    super.key,
    required this.event,
    required this.timeline,
    required this.onTap,
  });
  final Event event;
  final Timeline timeline;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    final count = threadReplyCount(event, timeline);
    if (count == 0) return const SizedBox.shrink();
    final c = context.warp;
    return Padding(
      padding: const EdgeInsets.only(top: 4),
      child: InkWell(
        onTap: onTap,
        borderRadius: BorderRadius.circular(12),
        child: Padding(
          padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
          child: Row(
            mainAxisSize: MainAxisSize.min,
            children: [
              Icon(Icons.forum_outlined, size: 16, color: c.tealText),
              const SizedBox(width: 4),
              Text(
                count == 1 ? '1 reply' : '$count replies',
                style: Theme.of(context).textTheme.labelMedium?.copyWith(
                  color: c.tealText,
                  fontWeight: FontWeight.w600,
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

/// How many replies a thread root has: the server's count from the event's
/// bundled relations, or the replies loaded here if that is more (some came
/// in since the root was fetched).
int threadReplyCount(Event root, Timeline timeline) {
  final bundled =
      root.unsigned
          ?.tryGetMap<String, Object?>('m.relations')
          ?.tryGetMap<String, Object?>(RelationshipTypes.thread)
          ?.tryGet<int>('count') ??
      0;
  final loaded = root
      .aggregatedEvents(timeline, RelationshipTypes.thread)
      .length;
  return bundled > loaded ? bundled : loaded;
}