import type { ListParams } from '@/types'

export const PER_PAGE_OPTIONS = [10, 20, 50] as const
export const DEFAULT_PER_PAGE = 20

export function parseListParams(searchParams: URLSearchParams): ListParams {
  const search = searchParams.get('search') || ''
  const perPage = Math.min(
    Math.max(parseInt(searchParams.get('perPage') || String(DEFAULT_PER_PAGE), 10), 1),
    100,
  )
  const page = Math.max(parseInt(searchParams.get('page') || '1', 10), 1)
  const sort = searchParams.get('sort') || undefined
  const order = (searchParams.get('order') === 'asc' ? 'asc' : 'desc') as 'asc' | 'desc'

  return { search, perPage, page, sort, order }
}

export function calcPagination(total: number, page: number, perPage: number) {
  const lastPage = Math.max(Math.ceil(total / perPage), 1)
  return {
    total,
    page: Math.min(page, lastPage),
    perPage,
    lastPage,
    offset: (Math.min(page, lastPage) - 1) * perPage,
  }
}

/** Generate CSV content from rows */
export function generateCsv(
  rows: Record<string, unknown>[],
  columns: { key: string; label: string }[],
): string {
  const BOM = '\uFEFF'
  const header = columns.map((c) => escapeCsv(c.label)).join(',')
  const body = rows
    .map((row) => columns.map((c) => escapeCsv(String(row[c.key] ?? ''))).join(','))
    .join('\n')

  return `${BOM + header}\n${body}`
}

function escapeCsv(value: string): string {
  if (value.includes(',') || value.includes('"') || value.includes('\n')) {
    return `"${value.replace(/"/g, '""')}"`
  }
  return value
}

export function formatTimestamp(ts: number): string {
  if (!ts) return 'N/A'
  return new Date(ts * 1000).toLocaleString()
}