import 'package:flutter/material.dart';

import '../../core/data/backend.dart';
import '../../core/data/server_clock.dart';
import '../../core/theme/tokens.dart';
import '../home/home_screen.dart' show formatPop;
import 'place_picker_screen.dart';
import 'quest_data.dart';
import 'widgets/quest_card_tile.dart';
import '../../core/i18n/app_locale.dart';

/// 퀘스트 생성 — 화면 대조 원장 F4 · Figma `254:164081`.
///
/// 명세 `523:18152` — *완료 버튼 디폴트 비활성화. 입력 항목이 모두 선택될 경우 활성화 ·*
/// *클릭 시 생성 안내 모달 노출*
/// 명세 `523:18163` — *퀘스트 미리보기 카드 · 입력 상태에 따라 실시간 반영*
/// 명세 `523:18173` — *디폴트 카테고리 항목 미선택 · 단일 선택 가능 ·*
/// *선택한 카테고리에 해당하는 입력필드 노출*
class QuestCreateScreen extends StatefulWidget {
  const QuestCreateScreen({super.key, required this.repository});

  /// 저장소는 호출부가 준다 — 화면이 표본을 기본값으로 만들지 않는다.
  final QuestRepository repository;

  @override
  State<QuestCreateScreen> createState() => _QuestCreateScreenState();
}

class _QuestCreateScreenState extends State<QuestCreateScreen> {
  final _title = TextEditingController();
  final _description = TextEditingController();
  final _url = TextEditingController();
  final _manualTitle = TextEditingController();
  final _reward = TextEditingController();
  final _participants = TextEditingController();

  /// 이 화면 한 번의 생성 요청 키 — 응답 유실 뒤 다시 눌러도 서버가 한 건으로 묶는다.
  final _clientSeq = DateTime.now().microsecondsSinceEpoch.toString();

  QuestCatalog? _catalog;
  QuestCategory? _category;
  QuestActivity? _activity;
  List<QuestPlace> _places = const [];
  QuestPlace? _place;
  DateTime? _endDate;
  QuestLink? _link;
  bool _checkingLink = false;
  bool _saving = false;

  @override
  void initState() {
    super.initState();
    for (final c in [_title, _description, _manualTitle, _reward, _participants]) {
      // 입력이 바뀔 때마다 미리보기와 완료 버튼 활성화가 함께 움직여야 한다.
      c.addListener(() => setState(() {}));
    }
    // 주소가 바뀌면 이전 미리보기는 더 이상 이 주소의 것이 아니다.
    _url.addListener(() {
      if (_link != null && _link!.url != _url.text.trim()) setState(() => _link = null);
    });
    _load();
  }

  @override
  void dispose() {
    for (final c in [_title, _description, _url, _manualTitle, _reward, _participants]) {
      c.dispose();
    }
    super.dispose();
  }

  Future<void> _load() async {
    final catalog = await widget.repository.catalog();
    if (mounted) setState(() => _catalog = catalog);
  }

  int _intOf(TextEditingController c) => int.tryParse(c.text.trim()) ?? 0;

  bool _needs(String field) => _activity?.fields.contains(field) ?? false;

  bool get _paid => !(_activity?.noReward ?? true);

  int get _pool => _intOf(_reward) * _intOf(_participants);

  /// 완료 버튼 활성화 조건 — 선택한 활동에 필요한 입력만 본다(C-01).
  bool get _ready {
    if (_activity == null || _title.text.trim().isEmpty) return false;
    if (_needs('place') && _place == null) return false;
    if (_needs('link')) {
      final link = _link;
      if (link == null || !(link.ok || (link.failed && _manualTitle.text.trim().isNotEmpty))) {
        return false;
      }
    }
    return !_paid || (_intOf(_reward) > 0 && _intOf(_participants) > 0);
  }

  QuestCard get _preview => QuestCard(
    id: 'preview',
    title: _title.text.trim().isEmpty
        ? context.l10n.questPreviewHint
        : _title.text.trim(),
    categoryName: _activity?.name ?? _category?.name ?? context.l10n.questNoCategory,
    author: QuestAuthor.user,
    stage: QuestStage.mine,
    goal: 1,
    progress: 0,
    rewardPop: _intOf(_reward),
    // 시안 — *참여 인원 : 0 / 0*. 분모가 모집 인원이다.
    participants: 0,
    capacity: _intOf(_participants),
  );

  /// 카테고리 칩 아이콘 — 시안 `254:164081`. 분류 키(`config/questCatalog`)로 고른다.
  static String? _chipIcon(String key) => switch (key) {
    'health' => 'assets/figma/quest-pulse.png',
    'planet' => 'assets/figma/quest-globe.png',
    'community' => 'assets/figma/quest-people.png',
    'location' => 'assets/figma/quest-pin.png',
    _ => null,
  };

  static const _fieldBorder = OutlineInputBorder(
    borderRadius: BorderRadius.all(Radius.circular(AppRadius.sm)),
    borderSide: BorderSide(color: Color(0xFF333333)),
  );

  InputDecoration _field(String label, {String? helper, String? error, Widget? suffix}) =>
      InputDecoration(
        labelText: label,
        helperText: helper,
        errorText: error,
        suffixIcon: suffix,
        border: _fieldBorder,
        enabledBorder: _fieldBorder,
      );

  static const _sectionStyle = TextStyle(
    fontSize: 20,
    fontWeight: FontWeight.w500,
    height: 28 / 20,
    letterSpacing: -0.5,
    color: AppColors.onCosmic,
  );

  @override
  Widget build(BuildContext context) {
    final catalog = _catalog;
    final category = _category;
    final activity = _activity;
    final link = _link;
    return Scaffold(
      appBar: AppBar(
        leading: const CloseButton(),
        title: Text(context.l10n.questNew),
        actions: [
          TextButton(
            onPressed: _ready && !_saving ? _confirm : null,
            style: TextButton.styleFrom(
              foregroundColor: AppColors.onCosmic,
              disabledForegroundColor: const Color(0xFF474747),
              padding: const EdgeInsets.symmetric(horizontal: 16),
              textStyle: const TextStyle(
                fontFamily: AppFonts.body,
                fontSize: 14,
                fontWeight: FontWeight.w600,
                height: 1,
                letterSpacing: -0.35,
              ),
            ),
            child: Text(context.l10n.commonDone),
          ),
        ],
      ),
      body: ListView(
        padding: const EdgeInsets.all(AppSpace.s4),
        children: [
          // 명세 — 입력 상태에 따라 실시간 반영.
          QuestCardTile.preview(card: _preview),
          const SizedBox(height: 24),
          const Divider(height: 1, thickness: 1, color: Color(0xFF242424)),
          const SizedBox(height: 24),

          Text(context.l10n.questCategory, style: _sectionStyle),
          const SizedBox(height: 20),
          if (catalog != null && catalog.categories.isEmpty)
            Text(
              context.l10n.questNoCreatable,
              style: const TextStyle(color: AppColors.onCosmicVariant),
            ),
          Wrap(
            spacing: 8,
            runSpacing: 8,
            children: [
              for (final c in catalog?.categories ?? const <QuestCategory>[])
                _CategoryChip(
                  label: c.name,
                  icon: _chipIcon(c.id),
                  selected: category?.id == c.id,
                  onTap: () => setState(() {
                    _category = c;
                    // 분류를 바꾸면 활동과 그 활동의 입력을 다시 고른다.
                    _activity = c.activities.length == 1 ? c.activities.first : null;
                    _place = null;
                    _link = null;
                  }),
                ),
            ],
          ),

          // 명세 `523:18182` — *액션 종류(어드민에서 등록된 데이터) · 선택한 카테고리에 따라 노출*.
          if (category != null) ...[
            const SizedBox(height: 36),
            Text(context.l10n.questActivity, style: _sectionStyle),
            const SizedBox(height: 20),
            Wrap(
              spacing: 8,
              runSpacing: 8,
              children: [
                for (final a in category.activities)
                  _CategoryChip(
                    label: a.name,
                    icon: null,
                    selected: activity?.key == a.key,
                    onTap: () => setState(() {
                      _activity = a;
                      _place = null;
                      _link = null;
                    }),
                  ),
              ],
            ),
          ],

          // 선택한 활동에 필요한 입력만(C-01).
          if (activity != null) ...[
            const SizedBox(height: 36),
            TextField(controller: _title, decoration: _field(context.l10n.questName)),
            const SizedBox(height: AppSpace.s3),
            TextField(
              controller: _description,
              maxLines: 3,
              minLines: 1,
              decoration: _field(context.l10n.questDescriptionOptional),
            ),
            const SizedBox(height: AppSpace.s3),

            if (_needs('link')) ...[
              TextField(
                controller: _url,
                keyboardType: TextInputType.url,
                decoration: _field(
                  context.l10n.questLinkUrl,
                  error: link?.status == 'invalid' ? context.l10n.questLinkInvalid : null,
                  suffix: IconButton(
                    tooltip: context.l10n.questLinkCheck,
                    icon: _checkingLink
                        ? const SizedBox.square(
                            dimension: 18,
                            child: CircularProgressIndicator(strokeWidth: 2),
                          )
                        : const Icon(Icons.search),
                    onPressed: _checkingLink ? null : _checkLink,
                  ),
                ),
                onSubmitted: (_) => _checkLink(),
              ),
              if (link != null && link.ok) ...[
                const SizedBox(height: AppSpace.s3),
                QuestLinkCard(link: link),
              ],
              if (link != null && link.failed) ...[
                const SizedBox(height: AppSpace.s3),
                TextField(
                  controller: _manualTitle,
                  decoration: _field(
                    context.l10n.questLinkTitle,
                    helper: context.l10n.questLinkPreviewFailed,
                  ),
                ),
              ],
              const SizedBox(height: AppSpace.s3),
            ],

            if (_needs('place')) ...[
              ListTile(
                contentPadding: EdgeInsets.zero,
                leading: const Icon(Icons.place_outlined),
                title: Text(_place?.name ?? context.l10n.questPickPlace),
                trailing: const Icon(Icons.chevron_right),
                onTap: _pickPlace,
              ),
              const SizedBox(height: AppSpace.s3),
            ],

            // 기간 — 기본 공개 + 24h, 종료일은 생성자 시간대의 23:59:59(C-06).
            ListTile(
              contentPadding: EdgeInsets.zero,
              leading: const Icon(Icons.event_outlined),
              title: Text(context.l10n.questEndDate),
              subtitle: Text(
                _endDate == null
                    ? context.l10n.questEndDefault
                    : context.l10n.questEndDateValue(_dateLabel(_endDate!)),
              ),
              trailing: const Icon(Icons.chevron_right),
              onTap: _pickEndDate,
            ),
            const SizedBox(height: AppSpace.s3),

            if (_paid) ...[
              Row(
                children: [
                  Expanded(
                    child: TextField(
                      controller: _participants,
                      keyboardType: TextInputType.number,
                      decoration: _field(context.l10n.questParticipants),
                    ),
                  ),
                  const SizedBox(width: AppSpace.s3),
                  Expanded(
                    child: TextField(
                      controller: _reward,
                      keyboardType: TextInputType.number,
                      decoration: _field(context.l10n.questRewardPop),
                    ),
                  ),
                ],
              ),
              const SizedBox(height: AppSpace.s2),
              // 명세 `523:18194` — *참여 인원 및 완료 보상 POP 기준 계산* · B-30 수수료.
              Text(
                context.l10n.questPoolHelper(
                  formatPop(_pool),
                  formatPop(catalog?.feeOf(_pool) ?? 0),
                ),
                style: const TextStyle(fontSize: 13, color: AppColors.onCosmicVariant),
              ),
            ] else
              Text(
                context.l10n.questNoReward,
                style: const TextStyle(fontSize: 13, color: AppColors.onCosmicVariant),
              ),
          ],
        ],
      ),
    );
  }

  static String _dateLabel(DateTime d) =>
      '${d.year}.${d.month.toString().padLeft(2, '0')}.${d.day.toString().padLeft(2, '0')}';

  Future<void> _checkLink() async {
    final url = _url.text.trim();
    if (url.isEmpty || _checkingLink) return;
    setState(() => _checkingLink = true);
    QuestLink link;
    try {
      link = await widget.repository.previewLink(url);
    } on BackendException {
      // 조회 호출 자체가 실패해도 주소가 틀렸다는 뜻은 아니다 — 기본 카드 경로(C-05).
      link = QuestLink(url: url, status: 'preview_failed');
    }
    if (!mounted) return;
    setState(() {
      _checkingLink = false;
      _link = _url.text.trim() == url ? link : null;
    });
  }

  Future<void> _pickPlace() async {
    if (_places.isEmpty) {
      final places = await widget.repository.places();
      if (!mounted) return;
      _places = places;
    }
    final name = await Navigator.of(context, rootNavigator: true).push<String>(
      MaterialPageRoute(
        builder: (_) => PlacePickerScreen(places: [for (final p in _places) p.name]),
      ),
    );
    if (name == null || !mounted) return;
    setState(() => _place = _places.firstWhere((p) => p.name == name));
  }

  /// 공개일을 1일째로 최대 [QuestCatalog.maxDays] 일째까지. 남은 1시간 미만 판정은 서버가 한다.
  Future<void> _pickEndDate() async {
    // 오늘은 서버 시각의 현지 날짜 — 단말 시계를 돌려도 선택 범위가 늘지 않는다(G-04).
    final today = DateUtils.dateOnly(ServerClock.now());
    final picked = await showDatePicker(
      context: context,
      initialDate: _endDate ?? today,
      firstDate: today,
      lastDate: today.add(Duration(days: (_catalog?.maxDays ?? 30) - 1)),
    );
    if (picked != null && mounted) setState(() => _endDate = picked);
  }

  /// 명세 — *완료 버튼 클릭 시, 생성 안내 모달 노출*.
  Future<void> _confirm() async {
    final pool = _paid ? _pool : 0;
    final fee = _catalog?.feeOf(pool) ?? 0;
    final go = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: Text(context.l10n.questCreateConfirm),
        content: Text(
          context.l10n.questCreateCost(
            _preview.title,
            formatPop(_intOf(_reward)),
            formatPop(_intOf(_participants)),
            formatPop(pool),
            formatPop(fee),
            formatPop(pool + fee),
          ),
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(context).pop(false),
            child: Text(context.l10n.commonKeepEditing),
          ),
          FilledButton(
            onPressed: () => Navigator.of(context).pop(true),
            child: Text(context.l10n.questCreate),
          ),
        ],
      ),
    );
    if (go != true || !mounted) return;

    setState(() => _saving = true);
    final String id;
    try {
      id = await widget.repository.create(
        QuestDraft(
          clientSeq: _clientSeq,
          activityKey: _activity!.key,
          title: _title.text.trim(),
          description: _description.text.trim(),
          rewardPop: _paid ? _intOf(_reward) : 0,
          participants: _paid ? _intOf(_participants) : 0,
          endDate: _endDate,
          url: _needs('link') ? _link?.url : null,
          manualTitle: _needs('link') && (_link?.failed ?? false) ? _manualTitle.text.trim() : null,
          placeId: _needs('place') ? _place?.id : null,
        ),
      );
    } on BackendException catch (error) {
      // 잔액 부족 · 자격 · 기간 거부는 서버 문구를 그대로 띄운다. 삼키면 「아무 일도 없다」로 보인다.
      if (!mounted) return;
      setState(() => _saving = false);
      ScaffoldMessenger.of(context)
        ..hideCurrentSnackBar()
        ..showSnackBar(SnackBar(
          content: Text(error.message),
          behavior: SnackBarBehavior.floating,
        ));
      return;
    }
    if (mounted) Navigator.of(context).pop(id);
  }
}

/// 링크 카드 — 서버가 조회한 **원본** 제목 · 썸네일 · 서비스명(C-05 · R10). 작성자 설명과 섞지 않는다.
class QuestLinkCard extends StatelessWidget {
  const QuestLinkCard({super.key, required this.link});

  final QuestLink link;

  @override
  Widget build(BuildContext context) {
    final thumb = link.thumbnail;
    return Container(
      padding: const EdgeInsets.all(12),
      decoration: BoxDecoration(
        color: AppColors.cosmicSurfaceContainer,
        borderRadius: BorderRadius.circular(AppRadius.sm),
      ),
      child: Row(
        children: [
          if (thumb != null) ...[
            ClipRRect(
              borderRadius: BorderRadius.circular(8),
              child: Image.network(
                thumb,
                width: 96,
                height: 54,
                fit: BoxFit.cover,
                errorBuilder: (_, _, _) => const SizedBox(width: 96, height: 54),
              ),
            ),
            const SizedBox(width: 12),
          ],
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                if (link.provider != null)
                  Text(
                    link.provider!,
                    style: const TextStyle(fontSize: 12, color: AppColors.onCosmicVariant),
                  ),
                Text(
                  link.title.isEmpty ? link.url : link.title,
                  maxLines: 2,
                  overflow: TextOverflow.ellipsis,
                  style: const TextStyle(
                    fontSize: 14,
                    fontWeight: FontWeight.w600,
                    color: AppColors.onCosmic,
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}

/// 카테고리 칩 — #1a1a1a · #232324 테두리 · 높이 42 알약. 고르면 흰 바탕 검은 글자.
class _CategoryChip extends StatelessWidget {
  const _CategoryChip({
    required this.label,
    required this.icon,
    required this.selected,
    required this.onTap,
  });

  final String label;
  final String? icon;
  final bool selected;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    final fg = selected ? Colors.black : AppColors.onCosmic;
    return Semantics(
      button: true,
      selected: selected,
      child: InkWell(
        onTap: onTap,
        borderRadius: BorderRadius.circular(AppRadius.full),
        child: Container(
          padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 10),
          decoration: BoxDecoration(
            color: selected ? AppColors.onCosmic : const Color(0xFF1A1A1A),
            border: Border.all(color: const Color(0xFF232324)),
            borderRadius: BorderRadius.circular(AppRadius.full),
          ),
          child: Row(
            mainAxisSize: MainAxisSize.min,
            children: [
              if (icon != null) ...[
                ImageIcon(AssetImage(icon!), size: 20, color: fg),
                const SizedBox(width: 4),
              ],
              Text(
                label,
                style: TextStyle(
                  fontSize: 14,
                  fontWeight: FontWeight.w500,
                  height: 20 / 14,
                  letterSpacing: -0.5,
                  color: fg,
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}