/**
 * Shared utility: get current session ID from environment or cache file.
 * Extracted from crud.ts during task-mcp → session-mcp fork (CF-762).
 */

import * as fs from 'fs';
import * as path from 'path';
import * as os from 'os';

export function getSessionId(): string {
  if (process.env.CLAUDE_SESSION_ID) {
    return process.env.CLAUDE_SESSION_ID;
  }

  const cacheFile = path.join(os.homedir(), '.cache', 'session-memory', 'current_session');
  try {
    const sessionId = fs.readFileSync(cacheFile, 'utf-8').trim();
    if (sessionId) return sessionId;
  } catch {
    // File doesn't exist or can't be read
  }

  const now = new Date();
  const timestamp = now.toISOString().replace(/[-:T]/g, '').slice(0, 15);
  return `session_${timestamp}`;
}