package main
import (
"bytes"
"encoding/xml"
"fmt"
"io"
"log"
"net/http"
"net/http/cookiejar"
"strings"
"text/template"
"time"
)
type FolderId struct {
Id string `xml:",attr"`
ChangeKey string `xml:",attr"`
}
type CalendarItem struct {
Subject string
UID string
Start time.Time
End time.Time
}
type EWSCalendar struct {
httpClient *http.Client
url string
username string
password string
}
func NewEWSCalendar(url, username, password string) *EWSCalendar {
// Prepare a cookie jar, since EWS uses some.
jar, err := cookiejar.New(nil)
if err != nil {
panic(err)
}
return &EWSCalendar{
httpClient: &http.Client{
Jar: jar,
},
url: url,
username: username,
password: password,
}
}
func (e *EWSCalendar) prepareRequest(body io.Reader) (req *http.Request, err error) {
req, err = http.NewRequest(http.MethodPost, e.url, body)
req.Header.Set("Content-Type", "text/xml")
req.Header.Set("Accept", "text/xml")
req.SetBasicAuth(e.username, e.password)
return
}
func (e *EWSCalendar) getCalendarFolderID() (id *FolderId, err error) {
req, err := e.prepareRequest(strings.NewReader(folderIdRequest))
if err != nil {
return
}
resp, err := e.httpClient.Do(req)
if err != nil {
return
}
if resp.StatusCode != http.StatusOK {
err = fmt.Errorf("unexpected status when querying folderID: %d", resp.StatusCode)
return
}
d := xml.NewDecoder(resp.Body)
defer resp.Body.Close()
for {
var t xml.Token
t, err = d.Token()
if err == io.EOF {
err = nil
return
} else if err != nil {
return
}
switch t := t.(type) {
case xml.StartElement:
if t.Name.Local == "FolderId" {
id = &FolderId{}
err = d.DecodeElement(id, &t)
// The first one is enough
return
}
}
}
}
func (e *EWSCalendar) getCalendarItems(folder *FolderId, start, end time.Time) (items []CalendarItem, err error) {
b := &bytes.Buffer{}
model := struct {
FolderId *FolderId
StartDate string
EndDate string
}{folder, start.Format(time.RFC3339), end.Format(time.RFC3339)}
err = calendarQuery.Execute(b, &model)
if err != nil {
return
}
req, err := e.prepareRequest(b)
if err != nil {
return
}
resp, err := e.httpClient.Do(req)
if err != nil {
return
}
if resp.StatusCode != http.StatusOK {
err = fmt.Errorf("unexpected status when querying calendar items: %d", resp.StatusCode)
return
}
d := xml.NewDecoder(resp.Body)
defer resp.Body.Close()
for {
var t xml.Token
t, err = d.Token()
if err == io.EOF {
err = nil
return
} else if err != nil {
return
}
switch t := t.(type) {
case xml.StartElement:
if t.Name.Local == "CalendarItem" {
item := CalendarItem{}
err = d.DecodeElement(&item, &t)
items = append(items, item)
}
}
}
return
}
func main() {
e := NewEWSCalendar("https://outlook.live.com/EWS/Exchange.asmx", "", "")
id, err := e.getCalendarFolderID()
if err != nil {
log.Println(err)
return
}
items, err := e.getCalendarItems(id, time.Now().AddDate(0, -1, 0), time.Now().AddDate(0, 2, 0))
if err != nil {
log.Println(err)
return
}
for _, item := range items {
fmt.Printf("%#v\n", item)
}
}
const folderIdRequest = `
AllProperties
`
var calendarQuery = template.Must(template.New("calendarQuery").Parse(`
IdOnly
`))