"use client"

import { Badge } from "@/components/ui/badge";
import { Avatar, AvatarFallback } from "@/components/ui/avatar";
import { gql, useQuery } from "@apollo/client";
import Link from "next/link";
import { formatDistanceToNow } from "date-fns";

const BLOG = gql`
    query Blog {
        blogs(filter: {
            isActive: true
            status: "published"
        },
        sort: {
            field: "createdAt"
            direction: "DESC"
        }
        ) {
            items {
                id
                title
                excerpt
                slug
                createdAt
                createdBy
                categoryId
                featuredImage
            }
        }
    }
`

const INFO = gql`
    query Info($tagId: String!, $categoryId: String!, $authorId: String!) {
        blogTag(id: $tagId) { 
            name
            slug
            color
        }

        blogCategory(id: $categoryId) {
            name
            slug
        }

        userWithGroups(id: $authorId) {
            user {
                username
            }
        }
    }
`

export default function Blog() {
    const { data, loading, error } = useQuery(BLOG);
    const items = data?.blogs?.items || [];

    if (loading) {
        return (
            <div className="w-full py-20 lg:py-40">
                <div className="container mx-auto">
                    <div className="text-center">Loading...</div>
                </div>
            </div>
        );
    }

    if (error) {
        return (
            <div className="w-full py-20 lg:py-40">
                <div className="container mx-auto">
                    <div className="text-center text-red-500">Error: {error.message}</div>
                </div>
            </div>
        );
    }

    return (
        <div className="w-full py-20 lg:py-40">
            <div className="container mx-auto flex flex-col gap-14">
                <div className="flex w-full flex-col sm:flex-row sm:justify-between sm:items-center gap-8">
                    <h4 className="text-3xl md:text-5xl tracking-tighter max-w-xl font-regular">
                        Latest articles
                    </h4>
                </div>

                {items.length === 0 ? (
                    <div className="text-center text-muted-foreground">No articles found</div>
                ) : (
                    <div className="grid grid-cols-1 md:grid-cols-2 gap-8">
                        {items.map((blog: any, index: number) => (
                            <BlogItem
                                key={blog.id}
                                blog={blog}
                                featured={index === 0}
                            />
                        ))}
                    </div>
                )}
            </div>
        </div>
    );
}

interface BlogItemProps {
    blog: {
        id: string;
        title: string;
        excerpt: string;
        slug: string;
        createdAt: string;
        createdBy: string;
        categoryId: string;
        featuredImage?: string;
    };
    featured?: boolean;
}

function BlogItem({ blog, featured = false }: BlogItemProps) {
    const timeAgo = formatDistanceToNow(new Date(blog.createdAt), { addSuffix: true });
    
    // 使用 INFO 查询获取详细信息
    const { data: infoData, loading: infoLoading } = useQuery(INFO, {
        variables: {
            tagId: blog.categoryId || "",
            categoryId: blog.categoryId,
            authorId: blog.createdBy
        },
        skip: !blog.categoryId || !blog.createdBy,
    });
    
    const category = infoData?.blogCategory;
    const author = infoData?.userWithGroups?.user;
    const tag = infoData?.blogTag;

    return (
        <Link href={`/blog/${blog.slug}`}>
            <div className={`flex flex-col gap-4 hover:opacity-75 cursor-pointer transition-opacity ${featured ? 'md:col-span-2' : ''
                }`}>
                {/* Featured Image */}
                <div className="bg-muted rounded-md aspect-video overflow-hidden">
                    {blog.featuredImage ? (
                        <img
                            src={blog.featuredImage}
                            alt={blog.title}
                            className="w-full h-full object-cover"
                        />
                    ) : (
                        <div className="w-full h-full bg-muted flex items-center justify-center text-muted-foreground">
                            No image
                        </div>
                    )}
                </div>

                {/* Meta Information */}
                <div className="flex flex-row gap-4 items-center">
                    <Badge 
                        variant="secondary" 
                        style={{ 
                            backgroundColor: tag?.color || undefined,
                            color: tag?.color ? '#ffffff' : undefined 
                        }}
                    >
                        {category?.name || tag?.name || 'Article'}
                    </Badge>
                    <div className="flex flex-row gap-2 text-sm items-center">
                        <span className="text-muted-foreground">By</span>
                        <Avatar className="h-6 w-6">
                            <AvatarFallback>
                                {author?.username?.charAt(0)?.toUpperCase() || 'A'}
                            </AvatarFallback>
                        </Avatar>
                        <span>{infoLoading ? 'Loading...' : (author?.username || 'Anonymous')}</span>
                        <span className="text-muted-foreground">•</span>
                        <span className="text-muted-foreground">{timeAgo}</span>
                    </div>
                </div>

                {/* Content */}
                <div className={`flex flex-col ${featured ? 'gap-2' : 'gap-1'}`}>
                    <h3 className={`max-w-3xl tracking-tight ${featured ? 'text-4xl' : 'text-2xl'
                        }`}>
                        {blog.title}
                    </h3>
                    <p className="max-w-3xl text-muted-foreground text-base">
                        {blog.excerpt || 'No excerpt available...'}
                    </p>
                </div>
            </div>
        </Link>
    );
}