import { createHash } from 'node:crypto';
import { readFileSync, writeFileSync, readdirSync, statSync } from 'node:fs';
import { join, dirname } from 'node:path';
import { fileURLToPath } from 'node:url';

const BUILD_DIR = join(dirname(fileURLToPath(import.meta.url)), '..', 'build');
const scriptRe = /<script(?![^>]*\bsrc=)[^>]*>([\s\S]*?)<\/script>/gi;

function* walk(dir) {
	for (const entry of readdirSync(dir)) {
		const path = join(dir, entry);
		if (statSync(path).isDirectory()) yield* walk(path);
		else if (entry.endsWith('.html')) yield path;
	}
}

// La politique complète (hors script-src) est lue depuis build/_headers,
// unique source de vérité partagée avec .htaccess
const headers = readFileSync(join(BUILD_DIR, '_headers'), 'utf8');
const cspLine = headers
	.split('\n')
	.map((line) => line.trim())
	.find((line) => line.startsWith('Content-Security-Policy:'));
if (!cspLine) throw new Error('[csp] Content-Security-Policy introuvable dans build/_headers');
const sharedPolicy = cspLine
	.slice('Content-Security-Policy:'.length)
	.trim()
	// frame-ancestors est ignoré (et logué) dans une balise meta : il reste porté par l'en-tête HTTP
	.replace(/frame-ancestors 'none';\s*/, '');

let pages = 0;

for (const file of walk(BUILD_DIR)) {
	const html = readFileSync(file, 'utf8');
	const hashes = new Set();

	for (const match of html.matchAll(scriptRe)) {
		const content = match[1];
		if (!content.trim()) continue;
		hashes.add(`'sha256-${createHash('sha256').update(content).digest('base64')}'`);
	}

	if (hashes.size === 0) continue;

	const csp = `default-src 'self'; script-src 'self' ${[...hashes].join(' ')}; ${sharedPolicy}`;
	const meta = `<meta http-equiv="Content-Security-Policy" content="${csp}" />`;

	const anchor = html.match(/<meta charset="[^"]+"\s*\/?>/);
	if (!anchor) {
		console.warn(`[csp] pas d'ancre charset dans ${file}, page ignorée`);
		continue;
	}

	writeFileSync(file, html.replace(anchor[0], `${anchor[0]}\n\t\t${meta}`));
	pages++;
}

console.log(`[csp] meta CSP complète injectée dans ${pages} page(s)`);