package pg

import (
	"io"
	"net"

	"github.com/go-pg/pg/internal"
)

var ErrNoRows = internal.ErrNoRows
var ErrMultiRows = internal.ErrMultiRows

type Error interface {
	Field(byte) string
	IntegrityViolation() bool
}

var _ Error = (*internal.PGError)(nil)

func isBadConn(err error, allowTimeout bool) bool {
	if err == nil {
		return false
	}
	if _, ok := err.(internal.Error); ok {
		return false
	}
	if pgErr, ok := err.(Error); ok && pgErr.Field('S') != "FATAL" {
		return false
	}
	if allowTimeout {
		if netErr, ok := err.(net.Error); ok && netErr.Timeout() {
			return false
		}
	}
	return true
}

func isNetworkError(err error) bool {
	if err == io.EOF {
		return true
	}
	_, ok := err.(net.Error)
	return ok
}