import { spawn, execSync } from 'child_process';
import { join, dirname } from 'path';
import { fileURLToPath } from 'url';
import { existsSync } from 'fs';

const __dirname = dirname(fileURLToPath(import.meta.url));
const LOCAL_BIN = join(__dirname, '..', 'sitespeed.io', 'bin', 'sitespeed.js');
const REPORTS_DIR = process.env.REPORTS_DIR || join(__dirname, 'reports');

export function runTest(job, onLine) {
  return new Promise((resolve, reject) => {
    const outputFolder = join(REPORTS_DIR, job.id);
    const isDocker = !!process.env.IN_DOCKER;

    // Log to docker logs (stdout of main process) so it appears in `docker logs`
    console.log(`[runner] REPORTS_DIR=${REPORTS_DIR}`);
    console.log(`[runner] outputFolder=${outputFolder}`);

    const sitespeedArgs = [
      job.url,
      '--browser', job.browser,
      '-n', String(job.runs),
      '--outputFolder', outputFolder,
      '--plugins.add', 'analysisstorer', // not in default set — needed to write pageSummary JSON
      '--sustainable.enable',
      '--sustainable.useGreenWebHostingAPI',
      '--axe.enable',
      '--coach',
    ];

    if (job.mobile) sitespeedArgs.push('--mobile');

    if (isDocker) {
      sitespeedArgs.push('--browsertime.chrome.args', 'no-sandbox');
      sitespeedArgs.push('--browsertime.chrome.args', 'disable-dev-shm-usage');
      sitespeedArgs.push('--browsertime.chrome.args', 'disable-gpu');
    }

    const env = { ...process.env };

    let child;

    if (isDocker) {
      const bin = process.env.SITESPEED_BIN;
      if (!bin) {
        return reject(new Error(
          'SITESPEED_BIN is not set. Check build logs for "Build-time sitespeed.js found at:"'
        ));
      }
      console.log(`[runner] spawning: node ${bin} ${sitespeedArgs.slice(0,3).join(' ')} ...`);
      child = spawn('node', [bin, ...sitespeedArgs], { cwd: __dirname, env });
    } else {
      if (!existsSync(LOCAL_BIN)) {
        return reject(new Error(`Local sitespeed.io not found at ${LOCAL_BIN}`));
      }
      child = spawn('node', [LOCAL_BIN, ...sitespeedArgs], { cwd: __dirname, env });
    }

    const allLines = [];

    child.stdout.on('data', (data) => {
      const lines = data.toString().split('\n').filter(Boolean);
      for (const line of lines) {
        allLines.push(line);
        onLine(line);
        // Mirror INFO/ERROR lines to docker logs too
        if (line.includes('INFO:') || line.includes('ERROR:') || line.includes('stored in')) {
          console.log('[sitespeed]', line);
        }
      }
    });

    child.stderr.on('data', (data) => {
      const lines = data.toString().split('\n').filter(Boolean);
      for (const line of lines) {
        allLines.push('[stderr] ' + line);
        onLine('[stderr] ' + line);
        if (line.includes('ERROR:')) console.error('[sitespeed stderr]', line);
      }
    });

    child.on('close', (code) => {
      if (code === 0) {
        // Log what was actually written so we can debug the parser
        try {
          const found = execSync(
            `find "${outputFolder}" -name "*.json" 2>/dev/null | head -30`,
            { encoding: 'utf8' }
          ).trim();
          console.log(`[runner] JSON files written:\n${found || '(none found)'}`);
        } catch {}
        resolve(outputFolder);
      } else {
        const tail = allLines.slice(-20).join('\n');
        reject(new Error(`sitespeed.io exited with code ${code}\n${tail}`));
      }
    });

    child.on('error', (err) => {
      reject(new Error(`Failed to spawn process: ${err.message}`));
    });
  });
}