import path from 'node:path'
import { writeFileSync } from 'node:fs'
import { Feed } from 'feed'
import { type SiteConfig, createContentLoader } from 'vitepress'
import { site as baseUrl, description, name } from '../config/meta'

function reName(name: string) {
    if (!name) name = 'Anda Toshiki'
    return name === 'Anda Toshiki' ? 'andatoshiki' : name
}

function getGithubLink(name: string) {
    return `https://github.com/${reName(name)}`
}

export async function genFeed(config: SiteConfig) {
    const feed = new Feed({
        title: name,
        description,
        id: baseUrl,
        link: baseUrl,
        language: 'en-US',
        image: 'https://note.toshiki.dev/logo-308px.png',
        favicon: `${baseUrl}/favicon.ico`,
        copyright: 'Copyright (c) 2023-present, Anda Toshiki at Toshiki Dev',
    })

    const posts = await createContentLoader('**/*.md', {
        excerpt: true,
        render: true,
    }).load()

    posts.sort((a, b) => +new Date(b.frontmatter?.date as string) - +new Date(a.frontmatter?.date as string))

    for (const { url, frontmatter, html } of posts) {
        let postTitle = 'No Title'
        postTitle = html?.match(/<h1 id=(.*)>(.*?)<a .*?>/)?.[2] || postTitle
        feed.addItem({
            title: frontmatter?.title || postTitle,
            id: `${baseUrl}${url.slice(1)}`,
            link: `${baseUrl}${url.slice(1)}`,
            guid: `${baseUrl}${url.slice(1)}`,
            description: html,
            content: html,
            author: [
                {
                    name: frontmatter?.author || 'Anda Toshiki',
                    link: frontmatter?.author ? getGithubLink(frontmatter?.author) : undefined,
                },
            ],
            date: frontmatter?.date || new Date('2021-07-01'),
        })
    }

    writeFileSync(path.join(config.outDir, 'feed.xml'), feed.rss2())
}