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

import '../i18n/strings.g.dart';
import '../services/social_service.dart';
import '../services/social_settings.dart';
import '../state/messages_cubit.dart';
import 'theme.dart';

/// A 1:1 encrypted chat with one peer (redesign screen 10). Private and
/// metadata-hiding (NIP-17) under the hood; local-first, so it degrades to a
/// "set up sharing" note when there's no relay.
class ChatScreen extends StatefulWidget {
  const ChatScreen({
    required this.social,
    required this.settings,
    required this.peerPubkey,
    super.key,
  });

  final SocialService social;
  final SocialSettings settings;
  final String peerPubkey;

  @override
  State<ChatScreen> createState() => _ChatScreenState();
}

class _ChatScreenState extends State<ChatScreen> {
  MessagesCubit? _cubit;
  bool _loading = true;
  final _input = TextEditingController();

  @override
  void initState() {
    super.initState();
    _init();
  }

  Future<void> _init() async {
    final cubit = await createMessagesCubit(
      widget.social,
      widget.settings,
      peerPubkey: widget.peerPubkey,
    );
    if (!mounted) {
      await cubit.close();
      return;
    }
    cubit.start();
    setState(() {
      _cubit = cubit;
      _loading = false;
    });
  }

  Future<void> _send() async {
    final cubit = _cubit;
    if (cubit == null || _input.text.trim().isEmpty) return;
    final text = _input.text;
    _input.clear();
    await cubit.send(text);
  }

  @override
  void dispose() {
    _cubit?.close();
    _input.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final t = context.t;
    final cubit = _cubit;
    return Scaffold(
      appBar: AppBar(title: Text(t.chat.title)),
      body: _loading || cubit == null
          ? const Center(child: CircularProgressIndicator())
          : BlocProvider.value(
              value: cubit,
              child: _ChatBody(controller: _input, onSend: _send),
            ),
    );
  }
}

class _ChatBody extends StatelessWidget {
  const _ChatBody({required this.controller, required this.onSend});

  final TextEditingController controller;
  final Future<void> Function() onSend;

  @override
  Widget build(BuildContext context) {
    final t = context.t;
    final cubit = context.read<MessagesCubit>();
    if (!cubit.isOnline) {
      return Center(
        child: Padding(
          padding: const EdgeInsets.all(32),
          child: Text(
            t.chat.offline,
            textAlign: TextAlign.center,
            style: const TextStyle(color: seedMuted, fontSize: 15),
          ),
        ),
      );
    }
    return Column(
      children: [
        Expanded(
          child: BlocBuilder<MessagesCubit, ChatState>(
            builder: (context, state) {
              if (state.messages.isEmpty) {
                return Center(
                  child: Text(t.chat.empty,
                      style: const TextStyle(color: seedMuted)),
                );
              }
              return ListView.builder(
                padding: const EdgeInsets.all(12),
                itemCount: state.messages.length,
                itemBuilder: (context, i) {
                  final m = state.messages[i];
                  return _Bubble(text: m.text, mine: cubit.isMine(m));
                },
              );
            },
          ),
        ),
        _Composer(controller: controller, onSend: onSend),
      ],
    );
  }
}

class _Bubble extends StatelessWidget {
  const _Bubble({required this.text, required this.mine});

  final String text;
  final bool mine;

  @override
  Widget build(BuildContext context) {
    return Align(
      alignment: mine ? AlignmentDirectional.centerEnd : AlignmentDirectional.centerStart,
      child: Container(
        margin: const EdgeInsets.symmetric(vertical: 4),
        padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 10),
        constraints: BoxConstraints(
          maxWidth: MediaQuery.of(context).size.width * 0.75,
        ),
        decoration: BoxDecoration(
          color: mine ? seedGreen : seedPrimaryContainer,
          borderRadius: BorderRadius.circular(16),
        ),
        child: Text(
          text,
          style: TextStyle(
            color: mine ? Colors.white : seedOnSurface,
            fontSize: 15,
          ),
        ),
      ),
    );
  }
}

class _Composer extends StatelessWidget {
  const _Composer({required this.controller, required this.onSend});

  final TextEditingController controller;
  final Future<void> Function() onSend;

  @override
  Widget build(BuildContext context) {
    final t = context.t;
    return SafeArea(
      top: false,
      child: Padding(
        padding: const EdgeInsets.fromLTRB(12, 6, 12, 12),
        child: Row(
          children: [
            Expanded(
              child: TextField(
                key: const Key('chat.input'),
                controller: controller,
                textInputAction: TextInputAction.send,
                onSubmitted: (_) => onSend(),
                decoration: InputDecoration(
                  hintText: t.chat.hint,
                  filled: true,
                  fillColor: seedField,
                  border: OutlineInputBorder(
                    borderRadius: BorderRadius.circular(24),
                    borderSide: BorderSide.none,
                  ),
                  contentPadding:
                      const EdgeInsets.symmetric(horizontal: 18, vertical: 10),
                ),
              ),
            ),
            const SizedBox(width: 8),
            IconButton.filled(
              key: const Key('chat.send'),
              icon: const Icon(Icons.send),
              tooltip: t.chat.send,
              onPressed: onSend,
            ),
          ],
        ),
      ),
    );
  }
}