package utils import ( "bytes" "errors" "fmt" "io" "net/http" "regexp" "strconv" "strings" "time" ) const ( cacheMaxAgePattern = `max-age=(\d+)` ) var ( cacheMaxAgeRe *regexp.Regexp ) func init() { cacheMaxAgeRe = regexp.MustCompile(cacheMaxAgePattern) } type PageParams struct { Page int `json:"page"` PageSize int `json:"page_size"` } func (p *PageParams) Limit() int { if p.PageSize < 0 { return 0 } return p.PageSize } func (p *PageParams) Offset() int { if p.PageSize <= 0 { return 0 } return (p.Page - 1) * p.PageSize } func IsNoCache(r *http.Request, cacheTtl time.Duration) bool { cacheControl := r.Header.Get("cache-control") if strings.Contains(cacheControl, "no-cache") { return true } if match := cacheMaxAgeRe.FindStringSubmatch(cacheControl); match != nil && len(match) > 1 { if maxAge, _ := strconv.Atoi(match[1]); time.Duration(maxAge)*time.Second <= cacheTtl { return true } } return false } func ParsePageParams(r *http.Request) *PageParams { pageParams := &PageParams{} page := r.URL.Query().Get("page") pageSize := r.URL.Query().Get("page_size") if p, err := strconv.Atoi(page); err == nil { pageParams.Page = p } if p, err := strconv.Atoi(pageSize); err == nil && pageParams.Page > 0 { pageParams.PageSize = p } return pageParams } func ParsePageParamsWithDefault(r *http.Request, page, size int) *PageParams { pageParams := ParsePageParams(r) if pageParams.Page == 0 { pageParams.Page = page } if pageParams.PageSize == 0 { pageParams.PageSize = size } return pageParams } func ParseUserAgent(ua string) (string, string, error) { re := regexp.MustCompile(`(?iU)^(?:(?:wakatime|chrome|firefox)\/(?:v?[\d+.]+|unset)\s)?(?:$?(\w+)[-_].*$?.+\s)?([^\/\s]+)-wakatime\/.+$`) groups := re.FindAllStringSubmatch(ua, -1) if len(groups) == 0 || len(groups[0]) != 3 { return "", "", errors.New("failed to parse user agent string") } return groups[0][1], groups[0][2], nil } func RaiseForStatus(res *http.Response, err error) (*http.Response, error) { if err != nil { return res, err } if res.StatusCode >= 400 { message := "" contentType := res.Header.Get("content-type") if strings.HasPrefix(contentType, "text/") || strings.HasPrefix(contentType, "application/json") { body, _ := io.ReadAll(res.Body) res.Body.Close() res.Body = io.NopCloser(bytes.NewBuffer(body)) message = string(body) } return res, fmt.Errorf("got response status %d for '%s %s' - %s", res.StatusCode, res.Request.Method, res.Request.URL.String(), message) } return res, nil }