session-runner.js

const path = require('path');

function createSessionRunner({ spawn, sessionsDir, timeoutMs } = {}) {
  const spawnFn = spawn || require('child_process').spawn;
  const defaultDir = sessionsDir || process.env.SESSIONS_DIR || path.join(__dirname, '..', 'opencode-sessions');
  const defaultTimeout = timeoutMs || 30000;

  function createSession({ prompt, directory, title }) {
    return new Promise((resolve, reject) => {
      if (!prompt || !prompt.trim()) {
        reject(new Error('Prompt is required'));
        return;
      }

      const args = [
        'run', prompt.trim(),
        '--format', 'json',
        '--dangerously-skip-permissions'
      ];

      const cwd = directory || process.env.HOME || defaultDir;

      if (directory) {
        args.push('--dir', directory);
      }

      const child = spawnFn('opencode', args, { cwd });

      let sessionId = null;
      let buffer = '';
      let resolved = false;
      let timeout;

      function doResolve(value) {
        if (!resolved) {
          resolved = true;
          if (timeout) clearTimeout(timeout);
          resolve(value);
        }
      }

      function doReject(reason) {
        if (!resolved) {
          resolved = true;
          if (timeout) clearTimeout(timeout);
          reject(reason);
        }
      }

      child.stdout.on('data', (data) => {
        buffer += data.toString();
        const lines = buffer.split('\n');
        buffer = lines.pop(); // Keep incomplete line in buffer

        for (const line of lines) {
          if (!line.trim()) continue;
          try {
            const event = JSON.parse(line);
            if (event.type === 'step_start' && !sessionId) {
              sessionId = event.session_id || event.sessionId;
            }
            if (sessionId) {
              doResolve({ sessionId, processing: true });
              child.stdout.removeAllListeners('data');
              return;
            }
          } catch (e) {
            // Ignore non-JSON lines
          }
        }
      });

      child.on('error', (err) => {
        doReject(err);
      });

      child.on('close', (code) => {
        if (sessionId) {
          doResolve({ sessionId, processing: true });
        } else {
          doReject(new Error(`Process exited with code ${code} without producing a session ID`));
        }
      });

      timeout = setTimeout(() => {
        child.kill();
        doReject(new Error('Timeout waiting for session ID from opencode run'));
      }, defaultTimeout);
    });
  }

  return { createSession };
}

module.exports = { createSessionRunner };