box-o-sand/wherewhen/google_calendar.go

78 lines
1.8 KiB
Go

package main
import (
"context"
"encoding/json"
"fmt"
"net/http"
"net/url"
"os"
"os/user"
"path/filepath"
"github.com/sirupsen/logrus"
"golang.org/x/oauth2"
)
func getClient(ctx context.Context, config *oauth2.Config) *http.Client {
cacheFile, err := tokenCacheFile()
if err != nil {
logrus.Fatalf("Unable to get path to cached credential file. %v", err)
}
tok, err := tokenFromFile(cacheFile)
if err != nil {
tok = getTokenFromWeb(config)
saveToken(cacheFile, tok)
}
return config.Client(ctx, tok)
}
func getTokenFromWeb(config *oauth2.Config) *oauth2.Token {
authURL := config.AuthCodeURL("state-token", oauth2.AccessTypeOffline)
fmt.Printf("Go to the following link in your browser then type the "+
"authorization code: \n%v\n", authURL)
var code string
if _, err := fmt.Scan(&code); err != nil {
logrus.Fatalf("Unable to read authorization code %v", err)
}
tok, err := config.Exchange(oauth2.NoContext, code)
if err != nil {
logrus.Fatalf("Unable to retrieve token from web %v", err)
}
return tok
}
func tokenCacheFile() (string, error) {
usr, err := user.Current()
if err != nil {
return "", err
}
tokenCacheDir := filepath.Join(usr.HomeDir, ".credentials")
os.MkdirAll(tokenCacheDir, 0700)
return filepath.Join(tokenCacheDir,
url.QueryEscape("wherewhen.json")), err
}
func tokenFromFile(file string) (*oauth2.Token, error) {
f, err := os.Open(file)
if err != nil {
return nil, err
}
t := &oauth2.Token{}
err = json.NewDecoder(f).Decode(t)
defer f.Close()
return t, err
}
func saveToken(file string, token *oauth2.Token) {
fmt.Printf("Saving credential file to: %s\n", file)
f, err := os.OpenFile(file, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
if err != nil {
logrus.Fatalf("Unable to cache oauth token: %v", err)
}
defer f.Close()
json.NewEncoder(f).Encode(token)
}