import { createReadStream } from 'node:fs';
import { stat } from 'node:fs/promises';
import { extname } from 'node:path';
import { httpError } from '../http/httpError.mjs';
import { mimeTypes } from './mimeTypes.mjs';
import { resolveInside } from './resolveInside.mjs';

export async function serveFile(response, root, pathname, method) {
  const filePath = resolveInside(root, pathname);

  if (!filePath) {
    throw httpError(403, 'Forbidden');
  }

  const fileStat = await getFileStat(filePath);

  response.writeHead(200, {
    'Content-Length': fileStat.size,
    'Content-Type': mimeTypes[extname(filePath).toLowerCase()] || 'application/octet-stream',
    'X-Content-Type-Options': 'nosniff',
  });

  if (method === 'HEAD') {
    response.end();
    return;
  }

  createReadStream(filePath).pipe(response);
}

async function getFileStat(filePath) {
  let fileStat;
  try {
    fileStat = await stat(filePath);
  } catch {
    throw httpError(404, 'Not found');
  }

  if (!fileStat.isFile()) {
    throw httpError(404, 'Not found');
  }

  return fileStat;
}