//分頁方法，根據傳遞過來的頁數，每頁數，總數，返回分頁的內容 7個頁數 前 1，2，3，4，5 后 的格式返回,小于5頁返回具體頁數
func Paginator(page, prepage int, nums int64) map[string]interface{} {

 var firstpage int //前一頁地址
 var lastpage int //后一頁地址
 //根據nums總數，和prepage每頁數量 生成分頁總數
 totalpages := int(math.Ceil(float64(nums) / float64(prepage))) //page總數
 if page > totalpages {
  page = totalpages
 }
 if page = 0 {
  page = 1
 }
 var pages []int
 switch {
 case page >= totalpages-5  totalpages > 5: //最后5頁
  start := totalpages - 5 + 1
  firstpage = page - 1
  lastpage = int(math.Min(float64(totalpages), float64(page+1)))
  pages = make([]int, 5)
  for i, _ := range pages {
   pages[i] = start + i
  }
 case page >= 3  totalpages > 5:
  start := page - 3 + 1
  pages = make([]int, 5)
  firstpage = page - 3
  for i, _ := range pages {
   pages[i] = start + i
  }
  firstpage = page - 1
  lastpage = page + 1
 default:
  pages = make([]int, int(math.Min(5, float64(totalpages))))
  for i, _ := range pages {
   pages[i] = i + 1
  }
  firstpage = int(math.Max(float64(1), float64(page-1)))
  lastpage = page + 1
  //fmt.Println(pages)
 }
 paginatorMap := make(map[string]interface{})
 paginatorMap["pages"] = pages
 paginatorMap["totalpages"] = totalpages
 paginatorMap["firstpage"] = firstpage
 paginatorMap["lastpage"] = lastpage
 paginatorMap["currpage"] = page
 return paginatorMap
}

func main(){
 pageSize := 3 
 var rsCount int64 = 100
 currentPage := 8
 res := Paginator(currentPage,pageSize,rsCount)
 fmt.Println(res) 
}