#!/usr/bin/env node

import { readFileSync, writeFileSync } from "node:fs";
import { Resvg } from "@resvg/resvg-js";

const input  = process.argv[2];
const output = process.argv[3];
const margin = Number.parseFloat(process.argv[4] ?? "0");
const bg     = process.argv[5] ?? null;

if (!input || !output) {
	process.exit(1);
}

const raw = readFileSync(input, "utf8");

// Render once to compute tight bounding box
const resvg = new Resvg(raw, {
	fitTo: {
		mode: "original"
	}
});

const { width, height } = resvg.render();

// Resvg gives us rendered size, but we need geometry bounds.
// Use bounding box API instead:

const bbox = resvg.getBBox();

if (!bbox) {
	process.exit(1);
}

const x = bbox.x - margin;
const y = bbox.y - margin;
const w = bbox.width  + margin * 2;
const h = bbox.height + margin * 2;

// Rewrite root SVG viewBox safely
const updated = raw
	.replace(/viewBox="[^"]*"/, `viewBox="${x} ${y} ${w} ${h}"`)
	.replace(/\swidth="[^"]*"/, "")
	.replace(/\sheight="[^"]*"/, "");

let finalSvg = updated;

if (bg) {
	finalSvg = finalSvg.replace(
		/<svg\b([^>]*)>/,
		(match, attrs) => {
			if (/style=/.test(attrs)) {
				return `<svg${attrs.replace(
					/style="([^"]*)"/,
					(_, style) => `style="${style};background:${bg}"`
				)}>`;
			}
			return `<svg${attrs} style="background:${bg}">`;
		}
	);
}

writeFileSync(output, finalSvg);