blob: 9825e705d24dc6e620c28ae4271893a0051b2b4d [file] [log] [blame]
// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build ignore
//
// usage:
//
// go run genzabbrs.go -output zoneinfo_abbrs_windows.go
//
package main
import (
"bytes"
"encoding/xml"
"flag"
"go/format"
"io"
"log"
"net/http"
"os"
"sort"
"text/template"
"time"
)
var filename = flag.String("output", "zoneinfo_abbrs_windows.go", "output file name")
// getAbbrs finds timezone abbreviations (standard and daylight saving time)
// for location l.
func getAbbrs(l *time.Location) (st, dt string) {
t := time.Date(time.Now().Year(), 0, 1, 0, 0, 0, 0, l)
abbr1, off1 := t.Zone()
for i := 0; i < 12; i++ {
t = t.AddDate(0, 1, 0)
abbr2, off2 := t.Zone()
if abbr1 != abbr2 {
if off2-off1 < 0 { // southern hemisphere
abbr1, abbr2 = abbr2, abbr1
}
return abbr1, abbr2
}
}
return abbr1, abbr1
}
type zone struct {
WinName string
UnixName string
StTime string
DSTime string
}
const wzURL = "https://raw.githubusercontent.com/unicode-org/cldr/master/common/supplemental/windowsZones.xml"
type MapZone struct {
Other string `xml:"other,attr"`
Territory string `xml:"territory,attr"`
Type string `xml:"type,attr"`
}
type SupplementalData struct {
Zones []MapZone `xml:"windowsZones>mapTimezones>mapZone"`
}
func readWindowsZones() ([]*zone, error) {
r, err := http.Get(wzURL)
if err != nil {
return nil, err
}
defer r.Body.Close()
data, err := io.ReadAll(r.Body)
if err != nil {
return nil, err
}
var sd SupplementalData
err = xml.Unmarshal(data, &sd)
if err != nil {
return nil, err
}
zs := make([]*zone, 0)
for _, z := range sd.Zones {
if z.Territory != "001" {
// to avoid dups. I don't know why.
continue
}
l, err := time.LoadLocation(z.Type)
if err != nil {
return nil, err
}
st, dt := getAbbrs(l)
zs = append(zs, &zone{
WinName: z.Other,
UnixName: z.Type,
StTime: st,
DSTime: dt,
})
}
return zs, nil
}
func main() {
flag.Parse()
zs, err := readWindowsZones()
if err != nil {
log.Fatal(err)
}
sort.Slice(zs, func(i, j int) bool {
return zs[i].UnixName < zs[j].UnixName
})
var v = struct {
URL string
Zs []*zone
}{
wzURL,
zs,
}
var buf bytes.Buffer
err = template.Must(template.New("prog").Parse(prog)).Execute(&buf, v)
if err != nil {
log.Fatal(err)
}
data, err := format.Source(buf.Bytes())
if err != nil {
log.Fatal(err)
}
err = os.WriteFile(*filename, data, 0644)
if err != nil {
log.Fatal(err)
}
}
const prog = `
// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Code generated by genzabbrs.go; DO NOT EDIT.
// Based on information from {{.URL}}
package time
type abbr struct {
std string
dst string
}
var abbrs = map[string]abbr{
{{range .Zs}} "{{.WinName}}": {"{{.StTime}}", "{{.DSTime}}"}, // {{.UnixName}}
{{end}}}
`