import { readFileSync, writeFileSync, existsSync, mkdirSync } from 'fs';
import { getAgentHubDir, getCounterPath } from './paths.js';

const prefixes: Record<string, string> = {
  task: 'TSK',
  handoff: 'HOF',
  decision: 'DEC',
  memory: 'MEM',
};

export type CounterType = keyof typeof prefixes;

export function getNextId(cwd: string, type: CounterType): string {
  const path = getCounterPath(cwd);
  const counters: Record<string, number> = existsSync(path)
    ? JSON.parse(readFileSync(path, 'utf-8'))
    : {};

  const current = counters[type] ?? 0;
  const next = current + 1;
  counters[type] = next;

  mkdirSync(getAgentHubDir(cwd), { recursive: true });
  writeFileSync(path, JSON.stringify(counters, null, 2));

  return `${prefixes[type]}-${String(next).padStart(4, '0')}`;
}