import 'package:firebase_core/firebase_core.dart' show FirebaseException;
import 'package:flutter/material.dart';
import 'package:share_plus/share_plus.dart';

import '../../core/data/backend.dart' show BackendException;
import '../../core/theme/tokens.dart';
import '../../core/ui/app_icons.dart';
import '../../core/ui/relative_time.dart';
import '../campaign/campaign_share.dart' show campaignShareText;
import '../my/my_data.dart' show PickedPhoto, PhotoRejected;
import '../my/photo_picker.dart';
import '../translation/translation_comments.dart';
import '../translation/translation_data.dart';
import 'moderation.dart';
import 'planet_data.dart';
import '../../core/i18n/app_locale.dart';

/// 글 상세 · 글 쓰기 — 화면 대조 원장 F3.
///
/// Figma 노드
/// - `244:22509` Galaxy/행성 상세/글 상세 · `373:439127` 홈/…/글 상세
/// - `244:21746` Galaxy/행성 상세_팬덤 라운지/글 쓰기 · `373:437905` 홈/…/글 쓰기
/// - 신고·차단(`252:162674` · `252:163306` · `251:51469`)은 [ReportScreen] 공용

/// 글 쓰기가 돌려주는 값.
class PostDraft {
  const PostDraft({
    required this.title,
    required this.body,
    this.photos = const [],
  });
  final String title;
  final String body;

  /// 첨부 사진. 1차 검증([checkLoungePhotos])을 지난 것만 담긴다.
  final List<PickedPhoto> photos;
}

/// 라운지 쓰기 실패를 사용자 문구로. 사유가 있는 실패는 그 문구를, 규칙 거부는
/// 권한 안내를, 나머지는 재시도 안내를 띄운다.
String loungeError(Object error) => switch (error) {
  PhotoRejected(:final message) => message,
  BackendException(:final message) => message,
  FirebaseException(code: 'permission-denied') => appL10n.loungeMembersOnly,
  _ => appL10n.loungeFailed,
};

/// 라운지 글 공유 — 시스템 공유 시트로 본문 문구를 보낸다.
Future<void> shareLoungePost(LoungePost post) => SharePlus.instance.share(
  ShareParams(
    text: campaignShareText(
      title: loungePostText(post),
      topic: appL10n.loungeTitle,
    ),
  ),
);

void _toast(BuildContext context, String message) =>
    ScaffoldMessenger.of(context)
      ..hideCurrentSnackBar()
      ..showSnackBar(SnackBar(content: Text(message)));

/// 글 한 편의 본문. 설계서 §2.6 `posts` 에는 제목이 없어(서버 글은 [LoungePost.title]
/// 이 빈 값) Figma 도 본문 한 덩어리만 둔다. 표본 글처럼 제목이 있으면 첫 줄로 붙인다.
String loungePostText(LoungePost p) =>
    [p.title, p.body].where((s) => s.isNotEmpty).join('\n');

/// Figma 글 문구 공통 — 42dot Sans 500 · 행간 130% · 자간 -2.5%.
TextStyle loungeText(double size, Color color) => TextStyle(
  fontFamily: AppFonts.body,
  fontSize: size,
  fontWeight: FontWeight.w500,
  height: 1.3,
  letterSpacing: size * -0.025,
  color: color,
);

/// 에셋 경로 또는 URL.
ImageProvider loungeImage(String src) =>
    src.startsWith('http') ? NetworkImage(src) : AssetImage(src);

/// 작성자 줄 — 아바타 26 · 간격 9 · 닉네임 ABeeZee 12 / 시각 10 #767676.
class LoungeAuthorRow extends StatelessWidget {
  const LoungeAuthorRow({super.key, required this.post, this.trailing});

  final LoungePost post;
  final Widget? trailing;

  @override
  Widget build(BuildContext context) => Row(
    children: [
      CircleAvatar(
        radius: 13,
        backgroundColor: const Color(0xFFD9D9D9),
        backgroundImage: switch (post.authorPhoto) {
          final p? => loungeImage(p),
          null => null,
        },
      ),
      const SizedBox(width: 9),
      Expanded(
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              post.authorName,
              style: loungeText(12, AppColors.onCosmic).copyWith(
                fontFamily: AppFonts.display,
                fontWeight: FontWeight.w400,
              ),
            ),
            Text(
              relativeTime(post.createdAt),
              style: loungeText(10, AppColors.onCosmicMuted),
            ),
          ],
        ),
      ),
      ?trailing,
    ],
  );
}

/// 좋아요 · 댓글 수. 수가 0 이면 아이콘만 둔다(Figma 글 상세 첫 화면 `244:22509`).
class LoungeCounts extends StatelessWidget {
  const LoungeCounts({
    super.key,
    required this.post,
    required this.icon,
    required this.color,
    this.onLike,
  });

  final LoungePost post;
  final double icon;
  final Color color;

  /// 하트를 누르면 좋아요를 켜고 끈다. null 이면 수만 보인다.
  final VoidCallback? onLike;

  @override
  Widget build(BuildContext context) {
    Widget item(String asset, int n, [Color? tint]) => Row(
      mainAxisSize: MainAxisSize.min,
      children: [
        Image.asset(asset, width: icon, height: icon, color: tint ?? color),
        if (n > 0) ...[
          const SizedBox(width: 4),
          Text(
            '$n',
            style: loungeText(icon <= 14 ? 12 : 14, color).copyWith(height: 1),
          ),
        ],
      ],
    );
    final heart = item(
      'assets/figma/icon-heart.png',
      post.likes,
      post.liked ? AppColors.cosmicAccent : null,
    );
    return Row(
      children: [
        if (onLike == null)
          heart
        else
          Semantics(
            button: true,
            label: post.liked ? context.l10n.likeCancel : context.l10n.like,
            child: InkResponse(onTap: onLike, radius: 18, child: heart),
          ),
        const SizedBox(width: 12),
        item('assets/figma/icon-message-circle.png', post.comments),
      ],
    );
  }
}

/// 글 상세. 좋아요 · 댓글 · 공유 · 신고 · 차단 · 내 글 수정 · 삭제가 여기서 일어난다.
///
/// 바뀐 글은 [onChanged] 로 목록에 알린다 — 목록이 같은 글을 다시 읽지 않아도
/// 수가 맞는다. `null` 을 보내면 글이 목록에서 빠진다(삭제 · 차단).
class LoungePostScreen extends StatefulWidget {
  const LoungePostScreen({
    super.key,
    required this.post,
    this.repository = const SamplePlanetRepository(),
    this.onChanged,
    this.translation,
  });

  final LoungePost post;
  final PlanetRepository repository;
  final ValueChanged<LoungePost?>? onChanged;

  /// 참여형 번역 — 없으면 앱 루트의 [TranslationScope] 를 쓴다.
  final TranslationRepository? translation;

  @override
  State<LoungePostScreen> createState() => _LoungePostScreenState();
}

class _LoungePostScreenState extends State<LoungePostScreen> {
  late LoungePost _post = widget.post;
  List<LoungeComment>? _comments;

  /// 번역할 댓글. 없으면 번역 댓글은 글 본문의 번역이다(🟡 Q-TR-07 권고 A안).
  TranslationReplyTarget? _replyTo;

  TranslationRepository? get _translation =>
      translationSurfaces.contains(TranslationSurface.lounge)
      ? widget.translation ?? TranslationScope.maybeOf(context)
      : null;

  String get _root => 'posts/${_post.id}';

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

  Future<void> _loadComments() async {
    try {
      final list = await widget.repository.comments(_post.id);
      if (mounted) setState(() => _comments = list);
    } catch (e) {
      if (mounted) {
        setState(() => _comments = const []);
        _toast(context, loungeError(e));
      }
    }
  }

  void _update(LoungePost post) {
    setState(() => _post = post);
    widget.onChanged?.call(post);
  }

  Future<void> _run(Future<void> Function() action) async {
    try {
      await action();
    } catch (e) {
      if (mounted) _toast(context, loungeError(e));
    }
  }

  Future<void> _like() =>
      _run(() async => _update(await widget.repository.toggleLike(_post)));

  Future<bool> _send(String body) async {
    try {
      final c = await widget.repository.addComment(_post.id, body);
      if (!mounted) return true;
      setState(() => _comments = [...?_comments, c]);
      _update(_post.copyWith(comments: _post.comments + 1));
      return true;
    } catch (e) {
      if (mounted) _toast(context, loungeError(e));
      return false;
    }
  }

  Future<void> _deleteComment(LoungeComment c) async {
    if (!await confirmOverlay(context, context.l10n.commentDeleteConfirm))
      return;
    await _run(() async {
      await widget.repository.deleteComment(_post.id, c.id);
      setState(() => _comments = [...?_comments]..remove(c));
      _update(
        _post.copyWith(comments: _post.comments > 0 ? _post.comments - 1 : 0),
      );
    });
  }

  @override
  Widget build(BuildContext context) {
    final post = _post;
    final comments = _comments;
    final translation = _translation;
    return Scaffold(
      appBar: AppBar(
        actions: [
          IconButton(
            tooltip: context.l10n.commonShare,
            onPressed: () => _run(() => shareLoungePost(post)),
            icon: const ImageIcon(AppIcons.share, size: 24),
          ),
          PopupMenuButton<String>(
            tooltip: context.l10n.commonMore,
            icon: const ImageIcon(AppIcons.ellipsisVertical, size: 24),
            onSelected: (v) => _moderate(context, v),
            itemBuilder: (_) => post.isMine
                ? [
                    PopupMenuItem(
                      value: 'edit',
                      child: Text(context.l10n.commonEditAction),
                    ),
                    PopupMenuItem(
                      value: 'delete',
                      child: Text(context.l10n.commonDeleteAction),
                    ),
                  ]
                : [
                    PopupMenuItem(
                      value: 'report',
                      child: Text(context.l10n.reportTitle),
                    ),
                    PopupMenuItem(
                      value: 'block',
                      child: Text(context.l10n.commonBlockAction),
                    ),
                  ],
          ),
        ],
      ),
      body: Column(
        children: [
          Expanded(
            // 시안 `Frame 4241` — 검정 바탕 위에 글 · 댓글 두 판을 8 간격으로 쌓는다.
            child: ColoredBox(
              color: Colors.black,
              child: ListView(
                padding: EdgeInsets.zero,
                children: [
                  ColoredBox(
                    color: AppColors.cosmicVoid,
                    child: Padding(
                      padding: const EdgeInsets.all(AppSpace.s4),
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          LoungeAuthorRow(post: post),
                          const SizedBox(height: 24),
                          Text(
                            loungePostText(post),
                            style: loungeText(16, AppColors.onCosmic),
                          ),
                          for (final (i, src) in post.images.indexed) ...[
                            const SizedBox(height: 12),
                            AspectRatio(
                              aspectRatio: 1,
                              child: ClipRRect(
                                borderRadius: BorderRadius.circular(6),
                                child: Stack(
                                  fit: StackFit.expand,
                                  children: [
                                    Image(
                                      image: loungeImage(src),
                                      fit: BoxFit.cover,
                                    ),
                                    // 시안 `244:22509` — 영상 길이 「00:36」 15/500 흰색, 오른쪽 아래 10.
                                    if (i == 0 && post.videoDuration != null)
                                      Positioned(
                                        right: 10,
                                        bottom: 10,
                                        child: Text(
                                          _mmss(post.videoDuration!),
                                          style: loungeText(
                                            15,
                                            AppColors.onCosmic,
                                          ).copyWith(height: 1),
                                        ),
                                      ),
                                  ],
                                ),
                              ),
                            ),
                          ],
                          const SizedBox(height: AppSpace.s4),
                          LoungeCounts(
                            post: post,
                            icon: 18,
                            color: const Color(0xFFD5D7D9),
                            onLike: _like,
                          ),
                        ],
                      ),
                    ),
                  ),
                  const SizedBox(height: 8),
                  if (comments != null)
                    switch (translation) {
                      final t? => TranslationThreads(
                        repository: t,
                        rootPath: _root,
                        builder: (_, byTarget) =>
                            _commentList(comments, t, byTarget),
                      ),
                      null => _commentList(comments, null, const {}),
                    },
                ],
              ),
            ),
          ),
          CommentInputBar(
            hint: context.l10n.commentHint,
            onComment: _send,
            // 규칙의 댓글 상한과 같은 수.
            maxLength: 1000,
            translation: translation,
            rootPath: _root,
            replyTo: _replyTo,
            onClearReply: () => setState(() => _replyTo = null),
          ),
        ],
      ),
    );
  }

  /// 댓글 판 — 댓글마다 그 댓글의 번역 댓글을 대댓글 자리에, 글 본문의 번역 댓글은
  /// 댓글 뒤에 붙인다. 둘 다 없으면 시안의 빈 상태.
  Widget _commentList(
    List<LoungeComment> comments,
    TranslationRepository? t,
    Map<String, List<TranslationEntry>> byTarget,
  ) {
    final ownTranslations = byTarget[_root] ?? const [];
    if (comments.isEmpty && ownTranslations.isEmpty) {
      return ColoredBox(
        color: AppColors.cosmicVoid,
        child: Padding(
          padding: const EdgeInsets.all(32),
          child: Column(
            children: [
              Image.asset(
                'assets/figma/icon-message-circle.png',
                width: 48,
                height: 48,
                color: const Color(0xFF4F4F4F),
              ),
              const SizedBox(height: AppSpace.s4),
              Text(
                context.l10n.commentFirst,
                style: loungeText(12, AppColors.onCosmicVariant),
              ),
            ],
          ),
        ),
      );
    }
    const gap = EdgeInsets.fromLTRB(16, 0, 16, 12);
    return ColoredBox(
      color: AppColors.cosmicVoid,
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          for (final c in comments) ...[
            _CommentRow(
              comment: c,
              onDelete: c.isMine ? () => _deleteComment(c) : null,
              onTranslate: t == null
                  ? null
                  : () => setState(
                      () => _replyTo = (
                        path: '$_root/comments/${c.id}',
                        name: c.authorName,
                      ),
                    ),
            ),
            for (final e in byTarget['$_root/comments/${c.id}'] ?? const [])
              Padding(
                padding: gap,
                child: TranslationCommentCard(
                  entry: e,
                  repository: t!,
                  reply: true,
                ),
              ),
          ],
          for (final e in ownTranslations)
            Padding(
              padding: gap,
              child: TranslationCommentCard(entry: e, repository: t!),
            ),
        ],
      ),
    );
  }

  Future<void> _moderate(BuildContext context, String action) async {
    final post = _post;
    switch (action) {
      case 'edit':
        final updated = await Navigator.of(context, rootNavigator: true)
            .push<LoungePost>(
              MaterialPageRoute(
                builder: (_) => LoungeComposeScreen(
                  initialBody: post.body,
                  allowPhotos: false,
                  onSubmit: (d) => widget.repository.updatePost(post, d.body),
                ),
              ),
            );
        if (updated != null && mounted) _update(updated);
      case 'delete':
        if (!await confirmOverlay(context, context.l10n.postDeleteConfirm))
          return;
        await _run(() async {
          await widget.repository.deletePost(post);
          widget.onChanged?.call(null);
          if (mounted) Navigator.pop(this.context);
        });
      case 'report':
        final reason = await Navigator.of(context, rootNavigator: true)
            .push<String>(
              MaterialPageRoute(
                builder: (_) => ReportScreen(
                  target: ModerationTarget(
                    authorName: post.authorName,
                    title: loungePostText(post),
                  ),
                ),
              ),
            );
        if (reason == null) return;
        await _run(() async {
          await widget.repository.reportPost(post, reason);
          if (mounted) _toast(this.context, context.l10n.reportReceived);
        });
      case 'block':
        if (!await confirmBlock(context, post.authorName)) return;
        await _run(() async {
          await widget.repository.blockAuthor(post);
          widget.onChanged?.call(null);
          // 명세 — 차단 처리 후 목록으로 돌아간다.
          if (mounted) Navigator.pop(this.context);
        });
    }
  }
}

/// 댓글 한 줄 — 닉네임 · 작성 시각 · 본문. 내 댓글에만 삭제가 붙는다.
/// [onTranslate] 는 이 댓글을 골라 번역 댓글을 다는 지구본(시안 라운지 변형 `252:163306`).
class _CommentRow extends StatelessWidget {
  const _CommentRow({required this.comment, this.onDelete, this.onTranslate});

  final LoungeComment comment;
  final VoidCallback? onDelete;
  final VoidCallback? onTranslate;

  @override
  Widget build(BuildContext context) => Padding(
    padding: const EdgeInsets.fromLTRB(16, 12, 8, 12),
    child: Row(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Expanded(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text(
                '${comment.authorName} · ${relativeTime(comment.createdAt)}',
                style: loungeText(12, AppColors.onCosmicMuted),
              ),
              const SizedBox(height: 4),
              Text(comment.body, style: loungeText(14, AppColors.onCosmic)),
            ],
          ),
        ),
        if (onTranslate != null)
          IconButton(
            tooltip: context.l10n.translationWrite,
            visualDensity: VisualDensity.compact,
            onPressed: onTranslate,
            icon: const ImageIcon(
              AppIcons.globe,
              size: 16,
              color: AppColors.onCosmicMuted,
            ),
          ),
        if (onDelete != null)
          TextButton(
            onPressed: onDelete,
            style: TextButton.styleFrom(
              foregroundColor: AppColors.onCosmicMuted,
            ),
            child: Text(context.l10n.commonDelete),
          ),
      ],
    ),
  );
}

/// 글 쓰기 — 시안 `244:21746`. 제목 칸 없이 본문 한 칸(설계서 §2.6 posts 에 제목 없음).
///
/// [onSubmit] 이 저장을 맡는다. 실패하면 이 화면에 남아 사유를 띄우므로 쓴 글이
/// 날아가지 않는다. 성공하면 [onSubmit] 이 돌려준 글을 들고 닫힌다.
class LoungeComposeScreen extends StatefulWidget {
  const LoungeComposeScreen({
    super.key,
    this.initialBody = '',
    this.allowPhotos = true,
    this.picker = pickPhotoWithPlugin,
    this.onSubmit,
  });

  final String initialBody;

  /// 수정 화면은 사진을 바꾸지 않는다 — 본문만 고친다(규칙상 `imageUrls` 도
  /// 고칠 수 있으나 업로드 · 삭제 동선이 한 벌 더 필요해진다).
  final bool allowPhotos;
  final PhotoPicker picker;
  final Future<LoungePost> Function(PostDraft draft)? onSubmit;

  @override
  State<LoungeComposeScreen> createState() => _LoungeComposeScreenState();
}

class _LoungeComposeScreenState extends State<LoungeComposeScreen> {
  late final _body = TextEditingController(text: widget.initialBody);
  final _photos = <PickedPhoto>[];
  bool _saving = false;

  bool get _ready => _body.text.trim().isNotEmpty && !_saving;

  @override
  void initState() {
    super.initState();
    _body.addListener(() => setState(() {}));
  }

  @override
  void dispose() {
    _body.dispose();
    super.dispose();
  }

  /// 사진 한 장을 골라 1차 검증(B-44 — 5 장 · 10MB · 이미지 형식)을 지난 것만 붙인다.
  Future<void> _pick(PhotoSource source) async {
    try {
      final photo = await widget.picker(source);
      if (photo == null) return;
      checkLoungePhotos([..._photos, photo]);
      setState(() => _photos.add(photo));
    } catch (e) {
      if (mounted) _toast(context, loungeError(e));
    }
  }

  Future<void> _submit() async {
    final draft = PostDraft(
      title: '',
      body: _body.text.trim(),
      photos: List.unmodifiable(_photos),
    );
    final submit = widget.onSubmit;
    if (submit == null) {
      Navigator.pop(context);
      return;
    }
    setState(() => _saving = true);
    try {
      final post = await submit(draft);
      if (mounted) Navigator.pop(context, post);
    } catch (e) {
      if (!mounted) return;
      setState(() => _saving = false);
      _toast(context, loungeError(e));
    }
  }

  @override
  Widget build(BuildContext context) => Scaffold(
    appBar: AppBar(
      leading: const CloseButton(),
      title: Text(
        widget.initialBody.isEmpty
            ? context.l10n.postWrite
            : context.l10n.postEdit,
      ),
      actions: [
        TextButton(
          onPressed: _ready ? _submit : null,
          style: TextButton.styleFrom(
            foregroundColor: AppColors.onCosmic,
            disabledForegroundColor: const Color(0xFF474747),
            textStyle: loungeText(
              14,
              AppColors.onCosmic,
            ).copyWith(fontWeight: FontWeight.w600, height: 1),
            minimumSize: const Size(56, 56),
          ),
          child: Text(context.l10n.commonDone),
        ),
      ],
    ),
    body: SafeArea(
      child: Column(
        children: [
          if (_saving) const LinearProgressIndicator(),
          Expanded(
            child: Padding(
              padding: const EdgeInsets.fromLTRB(16, 22, 16, 16),
              child: TextField(
                controller: _body,
                // 규칙의 글 상한과 같은 수.
                maxLength: 5000,
                buildCounter: _noCounter,
                maxLines: null,
                expands: true,
                textAlignVertical: TextAlignVertical.top,
                style: loungeText(15, AppColors.onCosmic),
                decoration: InputDecoration(
                  hintText: context.l10n.loungeHint,
                  hintStyle: loungeText(
                    15,
                    const Color(0xFF6B6B6B),
                  ).copyWith(height: 1),
                  border: InputBorder.none,
                  enabledBorder: InputBorder.none,
                  focusedBorder: InputBorder.none,
                  filled: false,
                  isDense: true,
                  contentPadding: EdgeInsets.zero,
                ),
              ),
            ),
          ),
          // 고른 사진 — 누르면 뺀다.
          if (_photos.isNotEmpty)
            SizedBox(
              height: 64,
              child: ListView.separated(
                scrollDirection: Axis.horizontal,
                padding: const EdgeInsets.symmetric(horizontal: 16),
                itemCount: _photos.length,
                separatorBuilder: (_, _) => const SizedBox(width: 8),
                itemBuilder: (_, i) => GestureDetector(
                  onTap: () => setState(() => _photos.removeAt(i)),
                  child: ClipRRect(
                    borderRadius: BorderRadius.circular(6),
                    child: Image.memory(
                      _photos[i].bytes,
                      width: 64,
                      height: 64,
                      fit: BoxFit.cover,
                      semanticLabel: context.l10n.photoRemove('${i + 1}'),
                    ),
                  ),
                ),
              ),
            ),
          // 사진 첨부 — 시안 하단 도구 줄(카메라 · 앨범 28, 간격 20).
          if (widget.allowPhotos)
            Padding(
              padding: const EdgeInsets.fromLTRB(16, 8, 16, 8),
              child: Row(
                children: [
                  for (final (asset, label, source) in [
                    (
                      'assets/figma/icon-compose-camera.png',
                      context.l10n.camera,
                      PhotoSource.camera,
                    ),
                    (
                      'assets/figma/icon-image.png',
                      context.l10n.album,
                      PhotoSource.gallery,
                    ),
                  ]) ...[
                    InkResponse(
                      radius: 20,
                      onTap: _saving ? null : () => _pick(source),
                      child: Image.asset(
                        asset,
                        width: 28,
                        height: 28,
                        semanticLabel: label,
                      ),
                    ),
                    const SizedBox(width: 20),
                  ],
                ],
              ),
            ),
        ],
      ),
    ),
  );
}

/// 글자 수 표시는 시안에 없다 — 상한만 건다.
Widget? _noCounter(
  BuildContext context, {
  required int currentLength,
  required bool isFocused,
  required int? maxLength,
}) => null;

String _mmss(Duration d) =>
    '${d.inMinutes.toString().padLeft(2, '0')}:${(d.inSeconds % 60).toString().padLeft(2, '0')}';