html-tty

#!/usr/bin/env node
"use strict";

new Promise((resolve, reject) => {
	const fs = require("fs");
	if(process.argv[2])
		resolve(fs.readFileSync(process.argv[2], "utf8"));
	else{
		let input = "";
		process.stdin.setEncoding("UTF8");
		process.stdin.on("error", error => reject(error));
		process.stdin.on("readable", () => {
			const chunk = process.stdin.read();
			null !== chunk ? input += chunk : resolve(input);
		});
	}
}).then(data => {
	// If input isn't ditroff, bail with a meaningful error message
	if(!/^x\s*T\s+\S/.test(data.replace(/^\s*#.*$/gm, "").trim())){
		const reason = /(?:^|\n)\.\S+/.test(data)
			? "input appears to be unprocessed Roff source"
			: "input does not contain a ditroff(7) header";
		process.stderr.write(`html-tty: Aborting, ${reason}\n`);
		process.exit(2);
	}
	const htmlTTY = new (require("..").TTYRenderer)();
	const isRaw = /\x08/.test(data);
	let output = htmlTTY.process(data, isRaw);
	if(process.stdout.isTTY)
		output = output
			.replace(/^\n+/,   "")
			.replace(/<b>/g,   "\x1B[1m")
			.replace(/<u>/g,   "\x1B[4m")
			.replace(/<\/b>/g, "\x1B[22m")
			.replace(/<\/u>/g, "\x1B[24m")
			.replace(/<b data-sgr="(\d+)"[^>]+>/g,    "\x1B[1;38;5;$1m")
			.replace(/<u data-sgr="(\d+)"[^>]+>/g,    "\x1B[4;38;5;$1m")
			.replace(/<span data-sgr="(\d+)"[^>]+>/g, "\x1B[38;5;$1m")
			.replace(/<\/span>/g, "\x1B[39m")
			.replace(/<a[^>]+>|<\/a>/g, "")
			.replace(/&lt;/g,  "<")
			.replace(/&gt;/g,  ">")
			.replace(/&amp;/g, "&")
			.replace(/&#(\d+);/g, (_, char) => String.fromCharCode(char));
	process.stdout.write(output + "\n");
}).catch(error => {
	console.error(error);
	process.exit(1);
});