// Package xhttp contains small helpers extending the standard net/http
// package for working with HTTP responses from external services.
package xhttp

import "net/http"

// IsRateLimited reports whether resp is a rate-limited rejection:
// a 429, or a 403 with Retry-After present or a zeroed remaining count.
// The remaining count is read from X-RateLimit-Remaining (GitHub) or the
// unprefixed RateLimit-Remaining (GitLab, IETF draft).
//
// Reset headers are not a signal: providers attach them to non-throttled
// responses as well. GitHub can return 403 with positive remaining and no
// Retry-After; those require body inspection and are not detected.
func IsRateLimited(resp *http.Response) bool {
	if resp == nil {
		return false
	}
	switch resp.StatusCode {
	case http.StatusTooManyRequests:
		return true
	case http.StatusForbidden:
		return resp.Header.Get("Retry-After") != "" ||
			resp.Header.Get("X-RateLimit-Remaining") == "0" ||
			resp.Header.Get("RateLimit-Remaining") == "0"
	default:
		return false
	}
}