export function formatNumber(num, precision = 2) {
  if (!num && num !== 0) return '--'
  return Number(num).toFixed(precision)
}

export function formatDate(date, format = 'YYYY-MM-DD HH:mm:ss') {
  if (!date) return '--'
  const d = new Date(date)
  const year = d.getFullYear()
  const month = String(d.getMonth() + 1).padStart(2, '0')
  const day = String(d.getDate()).padStart(2, '0')
  const hours = String(d.getHours()).padStart(2, '0')
  const minutes = String(d.getMinutes()).padStart(2, '0')
  const seconds = String(d.getSeconds()).padStart(2, '0')

  return format
    .replace('YYYY', year)
    .replace('MM', month)
    .replace('DD', day)
    .replace('HH', hours)
    .replace('mm', minutes)
    .replace('ss', seconds)
}

export function formatBytes(bytes, precision = 2) {
  if (!bytes || bytes === 0) return '0 B'
  const k = 1024
  const sizes = ['B', 'KB', 'MB', 'GB', 'TB']
  const i = Math.floor(Math.log(bytes) / Math.log(k))
  return `${(bytes / Math.pow(k, i)).toFixed(precision)} ${sizes[i]}`
}

export function debounce(fn, delay = 300) {
  let timer = null
  return function (...args) {
    if (timer) clearTimeout(timer)
    timer = setTimeout(() => fn.apply(this, args), delay)
  }
}

export function throttle(fn, delay = 300) {
  let last = 0
  return function (...args) {
    const now = Date.now()
    if (now - last > delay) {
      last = now
      fn.apply(this, args)
    }
  }
}