import React, { useContext, useEffect, useState } from 'react'; 
import { useParams } from 'wouter';
import { GoodTwo, Star } from '@icon-park/react';
import { getPostDetail, getPostComments, likePost, unlikePost, addCommentToPost, collectPost } from './api'; // 你的 API 函数
import './PostDetailPage.css';
import { UserContext } from '../../../context/UserContext'; // 用户上下文
import Header from '../../../components/Header';
import AuthButton from '../../../components/AuthButton';

const formatImageUrl = (url) => {
  if (!url) return '';

  if (url.startsWith('http')) return url;

  // 如果是 /images/... ，替换成 /uploads/post/...
  if (url.startsWith('/images/')) {
    // 这里把 /images/ 替换成 /uploads/post/
    return `http://localhost:5011/uploads/post/${url.slice('/images/'.length)}`;
  }

  // 其它情况默认直接拼接，不加斜杠
  return `http://localhost:5011${url.startsWith('/') ? '' : '/'}${url}`;
};


// 头像地址格式化，处理 avatarUrl 字段
export function formatAvatarUrlNoDefault(avatarUrl) {
  if (!avatarUrl) return '';
  if (avatarUrl.startsWith('http')) return avatarUrl;
  return `http://localhost:5011${avatarUrl}`;
}

const PostDetailPage = () => {
  const { postId } = useParams();
  const { user } = useContext(UserContext);

  const [postDetail, setPostDetail] = useState(null);
  const [comments, setComments] = useState([]);
  const [loading, setLoading] = useState(true);
  const [errorMsg, setErrorMsg] = useState('');
  const [newComment, setNewComment] = useState('');
  const [isLiked, setIsLiked] = useState(false);
  const [isCollected, setIsCollected] = useState(false);
  const [replyToCommentId, setReplyToCommentId] = useState(null);
  const [replyToUsername, setReplyToUsername] = useState(null);

  useEffect(() => {
    const fetchData = async () => {
      setLoading(true);
      setErrorMsg('');
      try {
        const postData = await getPostDetail(postId);
        setPostDetail(postData);
        const commentsData = await getPostComments(postId);
        setComments(commentsData);

        setIsLiked(!!postData.likedByUser);
        setIsCollected(!!postData.collectedByUser);
      } catch (err) {
        console.error(err);
        setErrorMsg('加载失败，请稍后重试');
      } finally {
        setLoading(false);
      }
    };
    fetchData();
  }, [postId]);

  // 点赞
  const toggleLike = async () => {
    if (!user) return alert('请先登录');
    try {
      if (isLiked) {
        await unlikePost(postId, user.userId);
        setIsLiked(false);
        setPostDetail(prev => ({
          ...prev,
          postLikeNum: prev.postLikeNum - 1,
        }));
      } else {
        await likePost(postId, user.userId);
        setIsLiked(true);
        setPostDetail(prev => ({
          ...prev,
          postLikeNum: prev.postLikeNum + 1,
        }));
      }
    } catch {
      alert('点赞失败，请稍后再试');
    }
  };

  // 收藏
  const toggleCollect = async () => {
    if (!user) return alert('请先登录');
    try {
      if (isCollected) {
        await collectPost(postId, user.userId, 'cancel');
        setIsCollected(false);
        setPostDetail(prev => ({
          ...prev,
          postCollectNum: prev.postCollectNum - 1,
        }));
      } else {
        await collectPost(postId, user.userId, 'collect');
        setIsCollected(true);
        setPostDetail(prev => ({
          ...prev,
          postCollectNum: prev.postCollectNum + 1,
        }));
      }
    } catch {
      alert('收藏失败，请稍后再试');
    }
  };

  // 添加评论
  const handleAddComment = async () => {
    if (!user || !user.userId) return alert('请先登录后再评论');
    if (!newComment.trim()) return alert('评论内容不能为空');

    try {
      const commentPayload = {
        content: newComment,
        userId: user.userId,
        isAnonymous: false,
        com_comment_id: replyToCommentId || null,
      };
      const commentData = await addCommentToPost(postId, commentPayload);

      const newCommentItem = {
        commentId: commentData?.commentId || Date.now(),
        post_id: postId,
        userId: user.userId,
        username: user.username || '匿名',
        content: newComment,
        commentTime: new Date().toISOString(),
        comCommentId: replyToCommentId,
        userAvatar: user.avatar_url || '',
      };

      setComments(prev => [newCommentItem, ...prev]);
      setNewComment('');
      setReplyToCommentId(null);
      setReplyToUsername(null);
    } catch (error) {
      alert(error.response?.data?.message || '评论失败，请稍后再试');
    }
  };

  // 回复按钮点击
  const handleReply = (commentId) => {
    setReplyToCommentId(commentId);
    const comment = comments.find(c => c.commentId === commentId);
    setReplyToUsername(comment?.username || comment?.userId || '未知用户');
  };

  // 查找回复的用户名
  const findUsernameByCommentId = (id) => {
    const comment = comments.find(c => c.commentId === id);
    return comment ? (comment.username || comment.userId || '未知用户') : '未知用户';
  };

  // 帖子图片处理，imgUrl 是单字符串，包装成数组
  const getPostImages = () => {
    if (!postDetail) return [];
    if (postDetail.imgUrl) return [formatImageUrl(postDetail.imgUrl)];
    return [];
  };

  return (
    <div className="post-detail-page">
      <Header />
      {loading ? (
        <p>加载中...</p>
      ) : errorMsg ? (
        <p className="error-text">{errorMsg}</p>
      ) : postDetail ? (
        <div className="post-detail">
          <h1>{postDetail.title}</h1>
          <div className="post-meta">
            <div className="post-user-info">
              {postDetail.avatarUrl ? (
                <img
                  className="avatar"
                  src={formatAvatarUrlNoDefault(postDetail.avatarUrl)}
                  alt={postDetail.username || '用户头像'}
                />
              ) : null}
              <span className="post-username">{postDetail.username || '匿名用户'}</span>
            </div>
            <span className="post-time">
              发布时间：{new Date(postDetail.postTime).toLocaleString()}
            </span>
          </div>

          <div className="post-content">
            <p>{postDetail.postContent}</p>
            <div className="post-images">
              {getPostImages().map((url, idx) => (
                <img key={idx} src={url} alt={`图片${idx + 1}`} />
              ))}
            </div>
          </div>

          <div className="post-actions">
            <button className="icon-btn" onClick={toggleLike} title="点赞">
              <GoodTwo theme="outline" size="20" fill={isLiked ? '#f00' : '#ccc'} />
              <span>{postDetail.postLikeNum}</span>
            </button>
            <button className="icon-btn" onClick={toggleCollect} title="收藏">
              <Star theme="outline" size="20" fill={isCollected ? '#ffd700' : '#ccc'} />
              <span>{postDetail.postCollectNum}</span>
            </button>
          </div>

          <hr className="divider" />

          <h3>评论区</h3>
          <div className="comments-section">
            {comments.length ? comments.map(comment => (
              <div key={comment.commentId} className="comment">
                <div className="comment-header">
                  <div className="comment-user-info">
                    {comment.userAvatar ? (
                      <img
                        className="avatar-small"
                        src={formatAvatarUrlNoDefault(comment.userAvatar)}
                        alt={comment.username || '用户头像'}
                      />
                    ) : null}
                    <span className="comment-username">{comment.username || '匿名用户'}</span>
                  </div>
                  <button className="reply-btn" onClick={() => handleReply(comment.commentId)}>回复</button>
                </div>

                <p className="comment-content">
                  {comment.comCommentId ? (
                    <>
                      <span className="reply-to">回复 {findUsernameByCommentId(comment.comCommentId)}：</span>
                      {comment.content}
                    </>
                  ) : (
                    comment.content
                  )}
                </p>

                <div className="comment-time">
                  {new Date(comment.commentTime).toLocaleString()}
                </div>

                {replyToCommentId === comment.commentId && (
                  <div className="reply-form">
                    <div className="replying-to">
                      回复 <strong>{replyToUsername}</strong>：
                    </div>
                    <textarea
                      placeholder="输入你的回复..."
                      value={newComment}
                      onChange={(e) => setNewComment(e.target.value)}
                    />
                    <div className="comment-options">
                      <AuthButton roles={['cookie', 'chocolate', 'ice-cream']} onClick={handleAddComment}>
                        发布回复
                      </AuthButton>

                      <button
                        onClick={() => {
                          setReplyToCommentId(null);
                          setReplyToUsername(null);
                          setNewComment('');
                        }}
                        style={{ marginLeft: '8px' }}
                      >
                        取消
                      </button>
                    </div>
                  </div>
                )}
              </div>
            )) : <p>暂无评论</p>}

            {!replyToCommentId && (
              <div className="add-comment-form">
                <textarea
                  placeholder="输入你的评论..."
                  value={newComment}
                  onChange={(e) => setNewComment(e.target.value)}
                />
                <div className="comment-options">
                  <AuthButton roles={['cookie', 'chocolate', 'ice-cream']} onClick={handleAddComment}>
                    发布评论
                  </AuthButton>

                </div>
              </div>
            )}
          </div>
        </div>
      ) : (
        <p>帖子不存在</p>
      )}
    </div>
  );
};

export default PostDetailPage;