// Version: 1.0.0 | Created: 2026-04-01
// Full chat screen — timeline + message input.

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

import '../../../core/network/matrix_client.dart';
import 'chat_controller.dart';
import 'message_bubble.dart';
import 'message_input.dart';

class ChatScreen extends ConsumerWidget {
  const ChatScreen({super.key, required this.roomId});

  final String roomId;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    // Decode the roomId — GoRouter encodes ! as %21 etc.
    final decodedRoomId = Uri.decodeComponent(roomId);

    final client = ref.watch(matrixClientProvider);
    final room = client.getRoomById(decodedRoomId);
    final roomName = room?.getLocalizedDisplayname() ?? 'Chat';
    final roomAvatar = room?.avatar?.toString();

    return Scaffold(
      appBar: AppBar(
        titleSpacing: 0,
        title: Row(
          children: [
            _RoomAvatarSmall(name: roomName, avatarUrl: roomAvatar),
            const SizedBox(width: 10),
            Flexible(child: Text(roomName, overflow: TextOverflow.ellipsis)),
          ],
        ),
        actions: [
          IconButton(
            icon: const Icon(Icons.call),
            tooltip: 'Start call (Phase 2)',
            onPressed: null, // Phase 2
          ),
          IconButton(
            icon: const Icon(Icons.more_vert),
            tooltip: 'Room options',
            onPressed: () {
              // Phase 2: room settings sheet
            },
          ),
        ],
      ),
      body: Column(
        children: [
          Expanded(child: _Timeline(roomId: decodedRoomId)),
          _Input(roomId: decodedRoomId),
        ],
      ),
    );
  }
}

class _RoomAvatarSmall extends StatelessWidget {
  const _RoomAvatarSmall({required this.name, this.avatarUrl});

  final String name;
  final String? avatarUrl;

  @override
  Widget build(BuildContext context) {
    final initials = name.isNotEmpty ? name[0].toUpperCase() : '?';
    if (avatarUrl != null) {
      return CircleAvatar(
        radius: 18,
        backgroundImage: NetworkImage(avatarUrl!),
      );
    }
    return CircleAvatar(
      radius: 18,
      backgroundColor: Theme.of(context).colorScheme.primary.withAlpha(51),
      child: Text(
        initials,
        style: TextStyle(
          fontSize: 14,
          fontWeight: FontWeight.bold,
          color: Theme.of(context).colorScheme.primary,
        ),
      ),
    );
  }
}

class _Timeline extends ConsumerWidget {
  const _Timeline({required this.roomId});

  final String roomId;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final timelineAsync = ref.watch(chatTimelineProvider(roomId));

    return timelineAsync.when(
      loading: () => const Center(child: CircularProgressIndicator()),
      error: (error, _) => Center(
        child: Padding(
          padding: const EdgeInsets.all(24),
          child: Text('Could not load messages: $error'),
        ),
      ),
      data: (messages) {
        if (messages.isEmpty) {
          return Center(
            child: Text(
              'No messages yet. Say hello!',
              style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                color: Theme.of(context).colorScheme.onSurface.withAlpha(102),
              ),
            ),
          );
        }

        return ListView.builder(
          reverse: true,
          padding: const EdgeInsets.symmetric(vertical: 8),
          itemCount: messages.length,
          itemBuilder: (context, index) {
            return MessageBubble(message: messages[index]);
          },
        );
      },
    );
  }
}

class _Input extends ConsumerWidget {
  const _Input({required this.roomId});

  final String roomId;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final isSending = ref.watch(sendMessageProvider);

    return MessageInput(
      isSending: isSending,
      onSend: (text) async {
        final error = await ref
            .read(sendMessageProvider.notifier)
            .send(roomId, text);

        if (error != null && context.mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            SnackBar(
              content: Text('Failed to send message: $error'),
              backgroundColor: Theme.of(context).colorScheme.error,
            ),
          );
        }
      },
    );
  }
}