const fs = require('fs');
const path = require('path');
const { HISTORY_FILE, HISTORY_LIMIT } = require('./config');

function loadHistory() {
  try {
    if (fs.existsSync(HISTORY_FILE)) return JSON.parse(fs.readFileSync(HISTORY_FILE, 'utf-8'));
  } catch {}
  return [];
}

function saveHistory(history) {
  fs.mkdirSync(path.dirname(HISTORY_FILE), { recursive: true });
  fs.writeFileSync(HISTORY_FILE, JSON.stringify(history, null, 2), 'utf-8');
}

function addHistory(entry) {
  const history = loadHistory();
  history.unshift({ ...entry, timestamp: new Date().toISOString() });
  if (history.length > HISTORY_LIMIT) history.length = HISTORY_LIMIT;
  saveHistory(history);
}

function formatTime(isoStr) {
  const date = new Date(isoStr);
  const pad = value => String(value).padStart(2, '0');
  return `${date.getFullYear()}-${pad(date.getMonth() + 1)}-${pad(date.getDate())} ${pad(date.getHours())}:${pad(date.getMinutes())}`;
}

module.exports = { loadHistory, saveHistory, addHistory, formatTime };