const fs = require('fs');
const fsp = require('fs/promises');
const path = require('path');
const { buildTimesheetPdfLocation, getPdfBaseDir } = require('../helpers/pdf-paths');

async function ensureDirectoryExists(dirPath) {
  await fsp.mkdir(dirPath, { recursive: true });
}

async function fileExists(filePath) {
  try {
    await fsp.access(filePath, fs.constants.F_OK);
    return true;
  } catch {
    return false;
  }
}

async function savePdfBufferAtomic(targetPath, buffer) {
  const dir = path.dirname(targetPath);
  await ensureDirectoryExists(dir);

  const tmpPath = `${targetPath}.tmp-${process.pid}-${Date.now()}`;
  await fsp.writeFile(tmpPath, buffer);
  await fsp.rename(tmpPath, targetPath);
}

function resolvePdfLocationFromTimesheetRow(timesheetRow) {
  return buildTimesheetPdfLocation(timesheetRow);
}

function resolveAbsolutePathFromRelative(relativePath) {
  const baseDir = getPdfBaseDir();
  return path.join(baseDir, relativePath);
}

module.exports = {
  ensureDirectoryExists,
  fileExists,
  savePdfBufferAtomic,
  resolvePdfLocationFromTimesheetRow,
  resolveAbsolutePathFromRelative,
};