export const numericSort = {
  asc: (a,b) => a[0] - b[0],
  desc: (a,b) => b[0] - a[0],
}
export const stringSort = {
  asc: (a,b) => a[0].localeCompare(b[0]),
  desc: (a,b) => b[0].localeCompare(a[0]),
}
export const orderByFn = (s='name asc') => {
  const [field='name', direction='asc'] = s.split(' ')
  let mapFn, sortFn
  switch (field) {
    case 'epoch':
      mapFn = a => [parseInt(a.epoch || a.epochs) || 0, a]
      sortFn = numericSort[direction]
      break
    case 'size':
      mapFn = a => [parseInt(a.size) || 0, a]
      sortFn = numericSort[direction]
      break
    case 'date':
      mapFn = a => [+new Date(a.date || a.created_at), a]
      sortFn = numericSort[direction]
      break
    case 'updated_at':
      mapFn = a => [+new Date(a.updated_at), a]
      sortFn = numericSort[direction]
      break
    case 'priority':
      mapFn = a => [parseInt(a.priority) || parseInt(a.id) || 1000, a]
      sortFn = numericSort[direction]
      break
    case 'name':
    default:
      mapFn = a => [a.name || "", a]
      sortFn = stringSort[direction]
      break
  }
  return { mapFn, sortFn }
}