auth.go

package main

import (
	"fmt"
	"log"
	"net/http"
	"strings"

	"github.com/jaehue/simple-chat/Godeps/_workspace/src/github.com/stretchr/gomniauth"
	"github.com/jaehue/simple-chat/Godeps/_workspace/src/github.com/stretchr/gomniauth/providers/facebook"
	"github.com/jaehue/simple-chat/Godeps/_workspace/src/github.com/stretchr/gomniauth/providers/github"
	"github.com/jaehue/simple-chat/Godeps/_workspace/src/github.com/stretchr/gomniauth/providers/google"
	"github.com/jaehue/simple-chat/Godeps/_workspace/src/github.com/stretchr/objx"
)

func init() {
	// set up gomniauth
	gomniauth.SetSecurityKey("some long key")
	gomniauth.WithProviders(
		facebook.New("key", "secret",
			"http://localhost:8080/auth/callback/facebook"),
		github.New("key", "secret",
			"http://localhost:8080/auth/callback/github"),
		google.New("636296155193-3u8lt2kmcr42mt49qmcvoq726dv9q9kj.apps.googleusercontent.com", "pq9s2KpbPyt6g-0kDM_ef-7F",
			"http://simplechat.jang.io/auth/callback/google"),
	)
}

func loginHandler(w http.ResponseWriter, r *http.Request) {
	segs := strings.Split(r.URL.Path, "/")
	action := segs[2]
	provider := segs[3]
	switch action {
	case "login":
		provider, err := gomniauth.Provider(provider)
		if err != nil {
			log.Fatalln("Error when trying to get provider", provider, "-", err)
		}
		loginUrl, err := provider.GetBeginAuthURL(nil, nil)
		if err != nil {
			log.Fatalln("Error when trying to GetBeginAuthURL for", provider, "-", err)
		}
		w.Header().Set("Location", loginUrl)
		w.WriteHeader(http.StatusTemporaryRedirect)
	case "callback":

		provider, err := gomniauth.Provider(provider)
		if err != nil {
			log.Fatalln("Error when trying to get provider", provider, "-", err)
		}

		creds, err := provider.CompleteAuth(objx.MustFromURLQuery(r.URL.RawQuery))
		if err != nil {
			log.Fatalln("Error when trying to complete auth for", provider, "-", err)
		}

		user, err := provider.GetUser(creds)
		if err != nil {
			log.Fatalln("Error when trying to get user from", provider, "-", err)
		}

		authCookieValue := objx.New(map[string]interface{}{
			"name":       user.Name(),
			"avatar_url": user.AvatarURL(),
		}).MustBase64()
		http.SetCookie(w, &http.Cookie{
			Name:  "auth",
			Value: authCookieValue,
			Path:  "/"})

		w.Header()["Location"] = []string{"/chat"}
		w.WriteHeader(http.StatusTemporaryRedirect)
	default:
		w.WriteHeader(http.StatusNotFound)
		fmt.Fprintf(w, "Auth action %s not supported", action)
	}
}