const { spawn } = require('child_process');
const fs = require('fs');
const path = require('path');

const PROJECT_DIR = process.env.PROJECT_DIR || path.resolve(__dirname, '..', '..');
const DIST_TARGET_DIR = process.env.DIST_TARGET_DIR || '';

function copyDirRecursive(src, dest) {
  fs.mkdirSync(dest, { recursive: true });
  for (const entry of fs.readdirSync(src, { withFileTypes: true })) {
    const srcPath = path.join(src, entry.name);
    const destPath = path.join(dest, entry.name);
    if (entry.isDirectory()) {
      copyDirRecursive(srcPath, destPath);
    } else {
      fs.copyFileSync(srcPath, destPath);
    }
  }
}

/** Runs `npm run build` in the Astro project and, if configured, publishes
 * the resulting dist/ into the shared volume nginx serves from. */
function runBuild() {
  return new Promise((resolve) => {
    let child;
    try {
      child = spawn('npm', ['run', 'build'], { cwd: PROJECT_DIR, shell: true });
    } catch (err) {
      resolve({ ok: false, output: '', error: `Build konnte nicht gestartet werden: ${err.message}` });
      return;
    }

    let output = '';
    child.stdout.on('data', (chunk) => (output += chunk.toString()));
    child.stderr.on('data', (chunk) => (output += chunk.toString()));

    child.on('error', (err) => {
      resolve({ ok: false, output, error: `Build konnte nicht gestartet werden: ${err.message}` });
    });

    child.on('close', (code) => {
      if (code !== 0) {
        resolve({ ok: false, output, error: `Build fehlgeschlagen (Exit-Code ${code}).` });
        return;
      }

      if (DIST_TARGET_DIR) {
        try {
          const distDir = path.join(PROJECT_DIR, 'dist');
          copyDirRecursive(distDir, DIST_TARGET_DIR);
        } catch (err) {
          resolve({ ok: false, output, error: `Build ok, aber Kopieren fehlgeschlagen: ${err.message}` });
          return;
        }
      }

      resolve({ ok: true, output });
    });
  });
}

module.exports = { runBuild };