import 'package:flutter/material.dart';
import 'package:friendly_map/modules/app/app.dart';
import 'package:friendly_map/modules/storage/storage.dart';

import '../app_scope.dart';
import '../theme.dart';
import '../widgets/async_view.dart';
import '../widgets/common.dart';

class _ArchiveData {
  const _ArchiveData(this.span, this.advice);
  final (int, int)? span;
  final ArchiveAdvice advice;
}

/// 별도 저장: 지우지 않고 오래된 대화를 별도 저장으로 나눈다. 나눌 범위는 직접 고른다.
class ArchiveScreen extends StatefulWidget {
  const ArchiveScreen({super.key, required this.roomId});

  final String roomId;

  @override
  State<ArchiveScreen> createState() => _ArchiveScreenState();
}

class _ArchiveScreenState extends State<ArchiveScreen> {
  RangeValues? _range;

  Future<_ArchiveData> _load(FriendlyApp app) async =>
      _ArchiveData(await app.settings.selectableSpan(widget.roomId), await app.settings.adviseRoom(widget.roomId));

  Future<void> _archive(int from, int to) async {
    final ok = await askConfirm(context, '별도 저장으로 나눌까요?',
        '고른 기간의 대화가 별도 저장으로 옮겨져요. 지워지는 것은 아니고, 언제든 되돌릴 수 있어요.',
        ok: '나누기');
    if (!ok || !mounted) return;
    final n = await AppScope.of(context).app.settings.archiveRange(widget.roomId, from, to);
    if (!mounted) return;
    showNote(context, '$n건을 별도 저장으로 나눴어요.');
    setState(() => _range = null);
  }

  String _day(double v) {
    final d = DateTime.fromMillisecondsSinceEpoch(v.round() * 10);
    return '${d.year}.${d.month}.${d.day}';
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('별도 저장')),
      body: AsyncView<_ArchiveData>(
        load: _load,
        builder: (context, d) {
          final span = d.span;
          if (span == null) return const EmptyNote('나눌 대화가 없어요.');
          final lo = span.$1.toDouble(), hi = span.$2.toDouble();
          final r = _range ?? RangeValues(lo, hi);
          final kb = d.advice.textBytes ~/ 1024;
          return ListView(padding: const EdgeInsets.all(16), children: [
            Text('지금 이 방의 대화 크기: 약 $kb KB', style: const TextStyle(color: Pal.muted)),
            const SizedBox(height: 16),
            const Text('나눌 기간', style: TextStyle(fontWeight: FontWeight.w700)),
            RangeSlider(
              values: RangeValues(r.start.clamp(lo, hi), r.end.clamp(lo, hi)),
              min: lo,
              max: hi == lo ? lo + 1 : hi,
              onChanged: (v) => setState(() => _range = v),
            ),
            Row(mainAxisAlignment: MainAxisAlignment.spaceBetween, children: [Text(_day(r.start)), Text(_day(r.end))]),
            const SizedBox(height: 20),
            SizedBox(
              height: 52,
              child: FilledButton(onPressed: () => _archive(r.start.round(), r.end.round()), child: const Text('이 기간을 별도 저장으로 나누기')),
            ),
          ]);
        },
      ),
    );
  }
}