/**
 * CommentItem 评论项组件 - 小红书 / 贴吧式平铺列表
 * 支持嵌套回复显示、楼层号、身份标识、删除评论、图片显示
 */

import React, { useMemo, useState } from 'react';
import { View, TouchableOpacity, StyleSheet, Alert } from 'react-native';
import { MaterialCommunityIcons } from '@expo/vector-icons';
import { formatDistanceToNow } from 'date-fns';
import { zhCN } from 'date-fns/locale';
import { spacing, borderRadius, fontSizes, useAppColors, type AppColors } from '../../theme';
import { Comment, CommentImage } from '../../types';
import Text from '../common/Text';
import Avatar from '../common/Avatar';
import { CompactImageGrid, ImageGridItem } from '../common';

interface CommentItemProps {
  comment: Comment;
  onUserPress: () => void;
  onReply: () => void;
  onLike: () => void;
  floorNumber?: number; // 楼层号
  isAuthor?: boolean; // 是否是楼主
  replyToUser?: string; // 回复给哪位用户
  onReplyPress?: (comment: Comment) => void; // 点击评论的评论
  allReplies?: Comment[]; // 所有回复列表，用于根据 target_id 查找被回复用户
  onLoadMoreReplies?: (commentId: string) => void; // 加载更多回复的回调
  isCommentAuthor?: boolean; // 当前用户是否为评论作者
  onDelete?: (comment: Comment) => void; // 删除评论的回调
  onImagePress?: (images: ImageGridItem[], index: number) => void; // 点击图片查看大图
  currentUserId?: string; // 当前用户ID，用于判断子评论作者
}

function createCommentItemStyles(colors: AppColors) {
  return StyleSheet.create({
    container: {
      flexDirection: 'row',
      paddingTop: spacing.md,
      paddingBottom: spacing.md,
      paddingHorizontal: spacing.md,
      backgroundColor: colors.background.paper,
      borderBottomWidth: StyleSheet.hairlineWidth,
      borderBottomColor: colors.divider,
    },
    content: {
      flex: 1,
      marginLeft: spacing.sm,
      minWidth: 0,
    },
    header: {
      flexDirection: 'row',
      justifyContent: 'space-between',
      alignItems: 'center',
      marginBottom: spacing.xs,
      gap: spacing.xs,
    },
    userInfo: {
      flexDirection: 'row',
      alignItems: 'center',
      flexWrap: 'wrap',
      flex: 1,
      minWidth: 0,
    },
    metaDot: {
      fontSize: fontSizes.xs,
      color: colors.text.hint,
      marginHorizontal: 2,
    },
    username: {
      fontWeight: '600',
      fontSize: fontSizes.sm,
      color: colors.text.primary,
      marginRight: spacing.xs,
    },
    badge: {
      paddingHorizontal: 4,
      paddingVertical: 1,
      borderRadius: 2,
      marginRight: spacing.xs,
    },
    smallBadge: {
      paddingHorizontal: 2,
      paddingVertical: 0,
    },
    authorBadge: {
      backgroundColor: colors.primary.main,
    },
    adminBadge: {
      backgroundColor: colors.error.main,
    },
    badgeText: {
      color: colors.text.inverse,
      fontSize: fontSizes.xs,
      fontWeight: '600',
    },
    smallBadgeText: {
      color: colors.text.inverse,
      fontSize: 9,
      fontWeight: '600',
    },
    timeText: {
      fontSize: fontSizes.xs,
      flexShrink: 0,
    },
    floorPlain: {
      fontSize: fontSizes.xs,
      flexShrink: 0,
    },
    replyReference: {
      marginBottom: spacing.xs,
    },
    commentContent: {
      marginBottom: spacing.xs,
    },
    text: {
      lineHeight: 22,
      fontSize: fontSizes.md,
      color: colors.text.primary,
    },
    actions: {
      flexDirection: 'row',
      alignItems: 'center',
      marginTop: spacing.xs,
      flexWrap: 'wrap',
    },
    actionButton: {
      flexDirection: 'row',
      alignItems: 'center',
      marginRight: spacing.lg,
      paddingVertical: 4,
      paddingRight: spacing.xs,
    },
    actionText: {
      marginLeft: 4,
      fontSize: fontSizes.xs,
    },
    subRepliesContainer: {
      marginTop: spacing.sm,
      marginLeft: 0,
      paddingLeft: spacing.sm,
      paddingVertical: spacing.xs,
      borderLeftWidth: 2,
      borderLeftColor: colors.divider,
      backgroundColor: colors.background.default,
    },
    subReplyItem: {
      flexDirection: 'row',
      alignItems: 'flex-start',
      marginBottom: spacing.md,
    },
    subReplyItemLast: {
      marginBottom: 0,
    },
    subReplyBody: {
      fontSize: fontSizes.sm,
      lineHeight: 20,
      marginTop: 2,
    },
    subReplyContent: {
      flex: 1,
      marginLeft: spacing.xs,
    },
    subReplyHeader: {
      flexDirection: 'row',
      alignItems: 'center',
      marginBottom: 2,
    },
    subReplyAuthor: {
      fontWeight: '600',
      color: colors.text.primary,
      marginRight: spacing.xs,
    },
    moreRepliesButton: {
      marginTop: spacing.xs,
      paddingVertical: spacing.xs,
    },
    replyToText: {
      fontSize: fontSizes.xs,
    },
    replyToName: {
      fontSize: fontSizes.xs,
      fontWeight: '500',
    },
    subReplyActions: {
      flexDirection: 'row',
      alignItems: 'center',
      marginTop: spacing.xs,
    },
    subActionButton: {
      flexDirection: 'row',
      alignItems: 'center',
      marginRight: spacing.sm,
      paddingVertical: 2,
    },
    subActionText: {
      marginLeft: 2,
      fontSize: fontSizes.xs,
    },
  });
}

const CommentItem: React.FC<CommentItemProps> = ({
  comment,
  onUserPress,
  onReply,
  onLike,
  floorNumber,
  isAuthor = false,
  replyToUser,
  onReplyPress,
  allReplies,
  onLoadMoreReplies,
  isCommentAuthor = false,
  onDelete,
  onImagePress,
  currentUserId,
}) => {
  const colors = useAppColors();
  const styles = useMemo(() => createCommentItemStyles(colors), [colors]);
  const [isDeleting, setIsDeleting] = useState(false);
  // 格式化时间
  const formatTime = (dateString: string): string => {
    try {
      return formatDistanceToNow(new Date(dateString), {
        addSuffix: true,
        locale: zhCN,
      });
    } catch {
      return '';
    }
  };

  // 格式化数字
  const formatNumber = (num: number): string => {
    if (num >= 10000) {
      return (num / 10000).toFixed(1) + 'w';
    }
    if (num >= 1000) {
      return (num / 1000).toFixed(1) + 'k';
    }
    return num.toString();
  };

  // 处理图片点击
  const handleImagePress = (index: number) => {
    if (onImagePress && comment.images && comment.images.length > 0) {
      const images: ImageGridItem[] = comment.images.map(img => ({
        id: img.url,
        url: img.url,
      }));
      onImagePress(images, index);
    }
  };

  // 渲染评论图片 - 使用 CompactImageGrid
  const renderCommentImages = () => {
    if (!comment.images || comment.images.length === 0) {
      return null;
    }

    const gridImages: ImageGridItem[] = comment.images.map(img => ({
      id: img.url,
      url: img.url,
    }));

    return (
      <CompactImageGrid
        images={gridImages}
        maxDisplayCount={6}
        gap={4}
        borderRadius={borderRadius.sm}
        showMoreOverlay
        onImagePress={onImagePress}
      />
    );
  };

  // 处理删除评论
  const handleDelete = () => {
    if (!onDelete || isDeleting) return;
    
    Alert.alert(
      '删除评论',
      '确定要删除这条评论吗？删除后将无法恢复。',
      [
        {
          text: '取消',
          style: 'cancel',
        },
        {
          text: '删除',
          style: 'destructive',
          onPress: async () => {
            setIsDeleting(true);
            try {
              await onDelete(comment);
            } catch (error) {
              console.error('删除评论失败:', error);
              Alert.alert('删除失败', '删除评论时发生错误，请稍后重试');
            } finally {
              setIsDeleting(false);
            }
          },
        },
      ],
    );
  };

  // 渲染身份标识
  const renderBadges = () => {
    const badges = [];
    const authorId = comment.author?.id || '';
    
    if (isAuthor) {
      badges.push(
        <View key="author" style={[styles.badge, styles.authorBadge]}>
          <Text variant="caption" style={styles.badgeText}>楼主</Text>
        </View>
      );
    }
    
    if (authorId === '1') { // 管理员
      badges.push(
        <View key="admin" style={[styles.badge, styles.adminBadge]}>
          <Text variant="caption" style={styles.badgeText}>管理员</Text>
        </View>
      );
    }
    
    return badges;
  };

  // 渲染楼层号
  const renderFloorNumber = () => {
    if (!floorNumber) return null;
    
    // 获取楼层显示文本
    const getFloorText = (floor: number): string => {
      switch (floor) {
        case 1:
          return '沙发';
        case 2:
          return '板凳';
        case 3:
          return '地板';
        default:
          return `${floor}楼`;
      }
    };
    
    return (
      <Text variant="caption" color={colors.text.hint} style={styles.floorPlain}>
        {getFloorText(floorNumber)}
      </Text>
    );
  };

  // 根据 target_id 查找被回复用户的昵称
  const getTargetUserNickname = (targetId: string): string => {
    // 首先在顶级评论中查找
    if (comment.id === targetId) {
      return comment.author?.nickname || '用户';
    }
    // 然后在回复列表中查找
    if (allReplies) {
      const targetComment = allReplies.find(r => r.id === targetId);
      if (targetComment) {
        return targetComment.author?.nickname || '用户';
      }
    }
    // 最后在当前评论的 replies 中查找
    if (comment.replies) {
      const targetComment = comment.replies.find(r => r.id === targetId);
      if (targetComment) {
        return targetComment.author?.nickname || '用户';
      }
    }
    return '用户';
  };

  // 渲染子评论图片
  const renderSubReplyImages = (reply: Comment) => {
    if (!reply.images || reply.images.length === 0) {
      return null;
    }

    const gridImages: ImageGridItem[] = reply.images.map(img => ({
      id: img.url,
      url: img.url,
    }));

    return (
      <CompactImageGrid
        images={gridImages}
        maxDisplayCount={3}
        gap={4}
        borderRadius={borderRadius.sm}
        showMoreOverlay
        onImagePress={onImagePress}
      />
    );
  };

  // 处理子评论删除
  const handleSubReplyDelete = (reply: Comment) => {
    if (!onDelete || isDeleting) return;
    
    Alert.alert(
      '删除回复',
      '确定要删除这条回复吗？删除后将无法恢复。',
      [
        {
          text: '取消',
          style: 'cancel',
        },
        {
          text: '删除',
          style: 'destructive',
          onPress: async () => {
            setIsDeleting(true);
            try {
              await onDelete(reply);
            } catch (error) {
              console.error('删除回复失败:', error);
              Alert.alert('删除失败', '删除回复时发生错误，请稍后重试');
            } finally {
              setIsDeleting(false);
            }
          },
        },
      ],
    );
  };

  // 渲染评论的评论（子评论）- 抖音/b站风格：平铺展示
  const renderSubReplies = () => {
    if (!comment.replies || comment.replies.length === 0) {
      return null;
    }

    const commentAuthorId = comment.author?.id || '';

    return (
      <View style={styles.subRepliesContainer}>
        {comment.replies.map((reply, replyIndex) => {
          const replyAuthorId = reply.author?.id || '';
          const isLastReply = replyIndex === comment.replies!.length - 1;
          // 根据 target_id 获取被回复的用户昵称
          const targetId = reply.target_id;
          const targetNickname = targetId ? getTargetUserNickname(targetId) : null;
          // 判断当前用户是否为子评论作者
          const isSubReplyAuthor = currentUserId === replyAuthorId;
          
          return (
            <TouchableOpacity
              key={reply.id}
              style={[styles.subReplyItem, isLastReply && styles.subReplyItemLast]}
              onPress={() => onReplyPress?.(reply)}
              activeOpacity={0.7}
            >
              <Avatar
                source={reply.author?.avatar}
                size={24}
                name={reply.author?.nickname || '用户'}
              />
              <View style={styles.subReplyContent}>
                <View style={styles.subReplyHeader}>
                  <Text variant="caption" style={styles.subReplyAuthor}>
                    {reply.author?.nickname || '用户'}
                  </Text>
                  {replyAuthorId === commentAuthorId && (
                    <View style={[styles.badge, styles.authorBadge, styles.smallBadge]}>
                      <Text variant="caption" style={styles.smallBadgeText}>楼主</Text>
                    </View>
                  )}
                  {/* 显示回复引用：aaa 回复 bbb */}
                  {targetNickname && (
                    <>
                      <Text variant="caption" color={colors.text.hint} style={styles.replyToText}>
                        {' '}回复
                      </Text>
                      <Text variant="caption" color={colors.primary.main} style={styles.replyToName}>
                        {targetNickname}
                      </Text>
                    </>
                  )}
                </View>
                {/* 显示回复内容（如果有文字） */}
                {reply.content ? (
                  <Text variant="body" color={colors.text.primary} style={styles.subReplyBody}>
                    {reply.content}
                  </Text>
                ) : null}
                {/* 显示回复图片（如果有图片） */}
                {renderSubReplyImages(reply)}
                {/* 子评论操作按钮 */}
                <View style={styles.subReplyActions}>
                  <TouchableOpacity
                    style={styles.subActionButton}
                    onPress={() => onReplyPress?.(reply)}
                  >
                    <MaterialCommunityIcons name="reply" size={12} color={colors.text.hint} />
                    <Text variant="caption" color={colors.text.hint} style={styles.subActionText}>
                      回复
                    </Text>
                  </TouchableOpacity>
                  {/* 删除按钮 - 子评论作者可见 */}
                  {isSubReplyAuthor && (
                    <TouchableOpacity
                      style={styles.subActionButton}
                      onPress={() => handleSubReplyDelete(reply)}
                      disabled={isDeleting}
                    >
                      <MaterialCommunityIcons
                        name={isDeleting ? 'loading' : 'delete-outline'}
                        size={12}
                        color={colors.text.hint}
                      />
                      <Text variant="caption" color={colors.text.hint} style={styles.subActionText}>
                        {isDeleting ? '删除中' : '删除'}
                      </Text>
                    </TouchableOpacity>
                  )}
                </View>
              </View>
            </TouchableOpacity>
          );
        })}
        {comment.replies_count > (comment.replies?.length || 0) && (
          <TouchableOpacity
            style={styles.moreRepliesButton}
            onPress={() => onLoadMoreReplies?.(comment.id)}
          >
            <Text variant="caption" color={colors.primary.main}>
              展开剩余 {comment.replies_count - (comment.replies?.length || 0)} 条回复
            </Text>
          </TouchableOpacity>
        )}
      </View>
    );
  };

  return (
    <View style={styles.container}>
      {/* 用户头像 - 略大便于点击，与正文左对齐 */}
      <TouchableOpacity onPress={onUserPress} activeOpacity={0.7}>
        <Avatar
          source={comment.author?.avatar}
          size={40}
          name={comment.author?.nickname}
        />
      </TouchableOpacity>

      {/* 评论内容 */}
      <View style={styles.content}>
        {/* 用户信息行 - QQ频道风格 */}
        <View style={styles.header}>
          <View style={styles.userInfo}>
            <TouchableOpacity onPress={onUserPress} activeOpacity={0.7}>
              <Text variant="body" style={styles.username} numberOfLines={1}>
                {comment.author?.nickname || '用户'}
              </Text>
            </TouchableOpacity>
            {renderBadges()}
            <Text style={styles.metaDot}>·</Text>
            <Text variant="caption" color={colors.text.hint} style={styles.timeText}>
              {formatTime(comment.created_at || '')}
            </Text>
          </View>
          {renderFloorNumber()}
        </View>

        {/* 回复引用 */}
        {replyToUser && (
          <View style={styles.replyReference}>
            <Text variant="caption" color={colors.primary.main}>
              回复 @{replyToUser}:
            </Text>
          </View>
        )}

        {/* 评论文本 - 非气泡样式 */}
        <View style={styles.commentContent}>
          <Text variant="body" color={colors.text.primary} style={styles.text}>
            {comment.content}
          </Text>
        </View>

        {/* 评论图片 */}
        {renderCommentImages()}

        {/* 操作按钮 - 更紧凑 */}
        <View style={styles.actions}>
          {/* 点赞 */}
          <TouchableOpacity style={styles.actionButton} onPress={onLike}>
            <MaterialCommunityIcons
              name={comment.is_liked ? 'heart' : 'heart-outline'}
              size={14}
              color={comment.is_liked ? colors.error.main : colors.text.hint}
            />
            <Text
              variant="caption"
              color={comment.is_liked ? colors.error.main : colors.text.hint}
              style={styles.actionText}
            >
              {comment.likes_count > 0 ? formatNumber(comment.likes_count) : '赞'}
            </Text>
          </TouchableOpacity>

          {/* 回复 */}
          <TouchableOpacity style={styles.actionButton} onPress={onReply}>
            <MaterialCommunityIcons name="reply" size={14} color={colors.text.hint} />
            <Text variant="caption" color={colors.text.hint} style={styles.actionText}>
              回复
            </Text>
          </TouchableOpacity>

          {/* 删除按钮 - 只对评论作者显示 */}
          {isCommentAuthor && (
            <TouchableOpacity
              style={styles.actionButton}
              onPress={handleDelete}
              disabled={isDeleting}
            >
              <MaterialCommunityIcons
                name={isDeleting ? 'loading' : 'delete-outline'}
                size={14}
                color={colors.text.hint}
              />
              <Text variant="caption" color={colors.text.hint} style={styles.actionText}>
                {isDeleting ? '删除中' : '删除'}
              </Text>
            </TouchableOpacity>
          )}
        </View>

        {/* 评论的评论（子评论）- 抖音/b站风格：平铺展示不开新层级 */}
        {renderSubReplies()}
      </View>
    </View>
  );
};

export default CommentItem;