import 'package:flutter/material.dart';
import 'package:patbond_flutter/core/theme/app_theme.dart';
import 'package:patbond_flutter/core/widgets/like_button.dart';
import 'package:patbond_flutter/core/widgets/pet_avatar.dart';
import 'package:patbond_flutter/core/widgets/post_media_grid.dart';
import 'package:patbond_flutter/features/community/community_display.dart';
import 'package:patbond_flutter/features/community/community_models.dart';
import 'package:patbond_flutter/widgets/common.dart';

/// 帖子卡三形态（05 号规范 §2.1/§3.1）：home 私有 `_PostCard` 的升级
/// 迁移，按媒体形态分支——
///
/// | 形态 | 媒体区 |
/// | --- | --- |
/// | 单图（mediaCount ≤ 1 且有封面） | 通栏出血 4:3 |
/// | 多图（mediaCount > 1） | [PostMediaGrid] 折叠封面（FeedCard 契约只带封面 + 计数），水平 padding 14 |
/// | 纯文字（无封面） | 无媒体区，正文放宽 ≤6 行、15/1.6 |
///
/// 头部行：作者头像 32 + 名字 14/w700 + 时间 12 `inkSoft`；求助帖
/// 元信息尾追加 `TagPill(accent)`。降级作者（[AuthorSummary.isDegraded]）
/// 渲染占位头像 + 「宠友」。操作行：[LikeButton]（点赞 / 收藏）+ 评论
/// 计数 + 分享，各钮触控 44；互动回调传 null 即纯展示（T3-14 形态，
/// ToggleSync 接线属 T3-15/16）。
class PostCard extends StatelessWidget {
  const PostCard({
    required this.card,
    super.key,
    this.onTap,
    this.onLikeTap,
    this.onCommentTap,
    this.onBookmarkTap,
    this.onShareTap,
    this.now,
  });

  final FeedCard card;

  /// 整卡点按（帖子详情入口）。
  final VoidCallback? onTap;

  final VoidCallback? onLikeTap;
  final VoidCallback? onCommentTap;
  final VoidCallback? onBookmarkTap;
  final VoidCallback? onShareTap;

  /// 相对时间的参考时钟（测试注入；缺省取当前时间）。
  final DateTime? now;

  bool get _isTextOnly => card.coverImage == null;

  @override
  Widget build(BuildContext context) {
    return Card(
      clipBehavior: Clip.antiAlias,
      child: InkWell(
        onTap: onTap,
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            _header(context),
            if (card.coverImage != null)
              card.mediaCount > 1
                  ? Padding(
                      padding: const EdgeInsets.symmetric(horizontal: 14),
                      child: PostMediaGrid(
                        urls: [card.coverImage!.url],
                        totalCount: card.mediaCount,
                      ),
                    )
                  : AspectRatio(
                      aspectRatio: 4 / 3,
                      child: RemoteImage(url: card.coverImage!.url),
                    ),
            _body(context),
            _actionRow(),
          ],
        ),
      ),
    );
  }

  Widget _header(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.all(14),
      child: Row(
        children: [
          PetAvatar(size: PetAvatarSize.sm, url: card.author.avatarUrl),
          const SizedBox(width: 10),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  authorDisplayName(card.author),
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  style: const TextStyle(
                    fontSize: 14,
                    fontWeight: FontWeight.w700,
                  ),
                ),
                const SizedBox(height: 2),
                Row(
                  children: [
                    Text(
                      feedRelativeTime(card.publishedAt, now: now),
                      style: const TextStyle(
                        color: AppColors.inkSoft,
                        fontSize: 12,
                      ),
                    ),
                    if (card.category == PostCategory.help) ...[
                      const SizedBox(width: 6),
                      const TagPill('求助', color: AppColors.accent),
                    ],
                  ],
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }

  Widget _body(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.fromLTRB(14, 12, 14, 0),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          if (card.title != null) ...[
            Text(
              card.title!,
              maxLines: 1,
              overflow: TextOverflow.ellipsis,
              style: Theme.of(context).textTheme.titleMedium,
            ),
            const SizedBox(height: 6),
          ],
          Text(
            card.contentPreview,
            // 纯文字帖放宽至 6 行并升字号补偿视觉重量（§2.1）。
            maxLines: _isTextOnly ? 6 : 2,
            overflow: TextOverflow.ellipsis,
            style: _isTextOnly
                ? const TextStyle(
                    color: AppColors.ink,
                    fontSize: 15,
                    height: 1.6,
                  )
                : Theme.of(context).textTheme.bodyMedium,
          ),
        ],
      ),
    );
  }

  Widget _actionRow() {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 2),
      child: Row(
        children: [
          LikeButton(
            variant: LikeButtonVariant.like,
            active: card.likedByMe,
            count: card.likeCount,
            onPressed: onLikeTap,
            semanticLabel: '点赞',
          ),
          const SizedBox(width: 4),
          _CommentCount(count: card.commentCount, onPressed: onCommentTap),
          const SizedBox(width: 4),
          LikeButton(
            variant: LikeButtonVariant.bookmark,
            active: card.bookmarkedByMe,
            count: card.bookmarkCount,
            onPressed: onBookmarkTap,
            semanticLabel: '收藏',
          ),
          const Spacer(),
          InkWell(
            onTap: onShareTap,
            borderRadius: BorderRadius.circular(AppRadius.pill),
            child: const SizedBox(
              width: 44,
              height: 44,
              child: Icon(
                Icons.ios_share_outlined,
                size: 20,
                color: AppColors.inkSoft,
              ),
            ),
          ),
        ],
      ),
    );
  }
}

/// 评论计数钮（与 LikeButton 同视觉规格，无激活态）。
class _CommentCount extends StatelessWidget {
  const _CommentCount({required this.count, this.onPressed});

  final int count;
  final VoidCallback? onPressed;

  @override
  Widget build(BuildContext context) {
    return InkWell(
      onTap: onPressed,
      borderRadius: BorderRadius.circular(AppRadius.pill),
      child: ConstrainedBox(
        constraints: const BoxConstraints(minWidth: 44, minHeight: 44),
        child: Padding(
          padding: const EdgeInsets.symmetric(horizontal: 8),
          child: Row(
            mainAxisSize: MainAxisSize.min,
            children: [
              const Icon(
                Icons.chat_bubble_outline,
                size: 20,
                color: AppColors.inkSoft,
              ),
              const SizedBox(width: 4),
              Text(
                '$count',
                style: const TextStyle(
                  color: AppColors.inkSoft,
                  fontSize: 13,
                  fontWeight: FontWeight.w600,
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}