import { spawn } 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');


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

    const sitespeedArgs = [
      job.url,
      '--browser', job.browser,
      '-n', String(job.runs),
      '--outputFolder', outputFolder,
      '--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');
    }

    // Do not force DISPLAY — sitespeed.io starts and manages its own Xvfb
    const env = { ...process.env };

    let child;

    if (isDocker) {
      // SITESPEED_BIN is set by start.sh from the build-time path discovery
      const bin = process.env.SITESPEED_BIN;
      if (!bin) {
        return reject(new Error(
          'SITESPEED_BIN is not set. The Docker build may not have found sitespeed.js.\n' +
          'Check build logs for "Build-time sitespeed.js found at:"'
        ));
      }
      onLine(`[runner] node ${bin}`);
      onLine(`[runner] DISPLAY=${env.DISPLAY}`);
      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}\n` +
          `Run: cd /home/malin/c0ding/sitespeed.io && npm install`
        ));
      }
      onLine(`[runner] node ${LOCAL_BIN.slice(-40)}...`);
      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); }
    });

    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); }
    });

    child.on('close', (code) => {
      if (code === 0) {
        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}`));
    });
  });
}