import type { Context } from "../index.js"

/**
 * Logari.Reader hook to convert a log's content into HTML
 */
export function HyperText({ user: { instance }, content, cache, gif }: Context): { html: string, gif: string | null } {
	if (content === 'please add gifs') return { html: '', gif: 'https://todepond.com/lab/login/gif.gif' }
	/**
	 * This regex has six hardcoded usernames, for the six users who have legacy usernames that include a space in them.
	 * Going forward, it is expected that no more usernames with spaces will be created. If such a username was to be registered,
	 * mentions of it with be disregarded.
	 */
	const mentionRegex = /(@(?:(?:lord cat)|(?:Jarvis Jordan)|(?:the beep man)|(?:Welcome back)|(?:Julia Eepy Moe)|(?:PodeTond 💚)|(?:[^ @]+))(?:@[a-z0-9.]+)?)/gi
	const operations = {
		"**": "b",
		"*": "i",
		"_": "i",
		"`": "code"
	}

	const isOdd = (n: number) => !(n % 2)
	const queue: string[] = []

	const html = content
		.replace(/&/g, '&')
		.replace(/</g, '&lt;')
		.replace(/>/g, '&gt;')
		.replace(/"/g, '&quot;')
		.replace(/'/g, '&#39;')
		.replace(/^&gt; /, '<blockquote>')
		.split(/(\\[\\`\*_]|\`|\*\*|\*|_)/ig)
		.map((str: string, i: number) => {
			if (isOdd(i))
				return str.split(mentionRegex)
					.map((str: string, i: number) => {
						// mentions
						const [, name, inst = instance] = str.split('@')
						const mention = `${name}@${inst}`
						if (isOdd(i) || !cache.has(mention)) return str
						else return `<a data-mention="${mention}">${str}</a>`
					})
					.join('')
			else {
				// markup
				if (str.startsWith('\\')) return str.substring(1)
				const closingTime = queue.includes(str)
				if (closingTime) {
					queue.splice(queue.indexOf(str), 1)
				} else queue.unshift(str)
				return `<${((closingTime ? '/' : '') + operations[str as keyof typeof operations])}>`
			}
		})
		.join('')

		// add unclosed tags
		+ queue.map(op => `</${operations[op as keyof typeof operations]}>`)
			.join('')
		+ (content.startsWith('> ') ? '</blockquote>' : '')

	return { html, gif }
}