export type CookieOptions = {
  path?: string
  domain?: string
  expires?: Date | string | number
  maxAge?: number
  secure?: boolean
  httpOnly?: boolean
  sameSite?: 'lax' | 'strict' | 'none'
}

export function serializeCookie(name: string, value: string, options: CookieOptions = {}): string {
  const enc = encodeURIComponent
  let cookie = `${name}=${enc(value)}`
  if (options.maxAge != null) cookie += `; Max-Age=${Math.floor(options.maxAge)}`
  if (options.expires != null) {
    const date = typeof options.expires === 'number' ? new Date(options.expires) : new Date(options.expires)
    cookie += `; Expires=${date.toUTCString()}`
  }
  if (options.domain) cookie += `; Domain=${options.domain}`
  if (options.path) cookie += `; Path=${options.path}`
  if (options.secure) cookie += `; Secure`
  if (options.httpOnly) cookie += `; HttpOnly`
  if (options.sameSite) cookie += `; SameSite=${options.sameSite === 'none' ? 'None' : options.sameSite === 'lax' ? 'Lax' : 'Strict'}`
  return cookie
}

export function parseCookieHeader(header: string | undefined): Record<string, string> {
  const raw = header || ''
  const out: Record<string, string> = {}
  raw.split(';').map(s => s.trim()).filter(Boolean).forEach(kv => {
    const idx = kv.indexOf('=')
    const k = idx >= 0 ? kv.slice(0, idx) : kv
    const v = idx >= 0 ? decodeURIComponent(kv.slice(idx + 1)) : ''
    out[k] = v
  })
  return out
}

export function parseDocumentCookies(): Record<string, string> {
  if (typeof document === 'undefined') return {}
  return parseCookieHeader(document.cookie)
}


/**
// server 侧中间件
import { parseCookieHeader, serializeCookie } from './src/compose/cookieUtils'

app.use(async (ctx, next) => {
  const cookies = parseCookieHeader(ctx.request.headers.cookie as string)

  // 读取
  const token = cookies['demo_token']

  // 写入（HttpOnly 更安全）
  if (!token) {
    const setItem = serializeCookie('demo_token', 'from-mw', {
      httpOnly: true, path: '/', sameSite: 'lax'
    })
    ctx.set('Set-Cookie', [setItem])
  }

  await next()
})
 */