package nhttp

import (
	"io"
	"net"
	_http "net/http"
)

// unsupportedTEError reports unsupported transfer-encodings.
type unsupportedTEError struct {
	err string
}

func (uste *unsupportedTEError) Error() string {
	return uste.err
}

// isUnsupportedTEError checks if the error is of type
// unsupportedTEError. It is usually invoked with a non-nil err.
func isUnsupportedTEError(err error) bool {
	_, ok := err.(*unsupportedTEError)
	return ok
}

// isCommonNetReadError reports whether err is a common error
// encountered during reading a request off the network when the
// client has gone away or had its read fail somehow. This is used to
// determine which logs are interesting enough to log about.
func isCommonNetReadError(err error) bool {
	if err == io.EOF {
		return true
	}
	if neterr, ok := err.(net.Error); ok && neterr.Timeout() {
		return true
	}
	if oe, ok := err.(*net.OpError); ok && oe.Op == "read" {
		return true
	}
	return false
}

// statusError is an error used to respond to a request with an HTTP status.
// The text should be plain text without user info or other embedded errors.
type statusError struct {
	code int
	text string
}

func (e statusError) Error() string { return _http.StatusText(e.code) + ": " + e.text }