From bf106852890b25f983bbd764d00510a0c35d3018 Mon Sep 17 00:00:00 2001
From: Burcu Dogan <jbd@google.com>
Date: Tue, 17 Jun 2014 15:53:08 +0200
Subject: [PATCH] Adding app engine implementations.

---
 google/appengine.go   | 48 +++++++++++++++++++++++++++++++++++++++++++
 google/appenginevm.go | 48 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+)
 create mode 100644 google/appengine.go
 create mode 100644 google/appenginevm.go

diff --git a/google/appengine.go b/google/appengine.go
new file mode 100644
index 0000000..6bdf0a4
--- /dev/null
+++ b/google/appengine.go
@@ -0,0 +1,48 @@
+// +build appengine
+
+package google
+
+import (
+	"strings"
+
+	"appengine"
+	"github.com/golang/oauth2"
+)
+
+type AppEngineConfig struct {
+	context appengine.Context
+	scopes  []string
+	cache   oauth2.Cache
+}
+
+func NewAppEngineConfig(context appengine.Context, scopes []string) *AppEngineConfig {
+	return &AppEngineConfig{context: context, scopes: scopes}
+}
+
+func (c *AppEngineConfig) NewTransport() oauth2.Transport {
+	return oauth2.NewAuthorizedTransport(c, nil)
+}
+
+func (c *AppEngineConfig) NewTransportWithCache(cache oauth2.Cache) (oauth2.Transport, error) {
+	token, err := cache.Read()
+	if err != nil {
+		return nil, err
+	}
+	c.cache = cache
+	return oauth2.NewAuthorizedTransport(c, token), nil
+}
+
+func (c *AppEngineConfig) FetchToken(existing *oauth2.Token) (*oauth2.Token, error) {
+	token, expiry, err := appengine.AccessToken(c.context, strings.Join(c.scopes, " "))
+	if err != nil {
+		return nil, err
+	}
+	return &oauth2.Token{
+		AccessToken: token,
+		Expiry:      expiry,
+	}, nil
+}
+
+func (c *AppEngineConfig) Cache() oauth2.Cache {
+	return c.cache
+}
diff --git a/google/appenginevm.go b/google/appenginevm.go
new file mode 100644
index 0000000..4a4fcdd
--- /dev/null
+++ b/google/appenginevm.go
@@ -0,0 +1,48 @@
+// +build appenginevm
+
+package google
+
+import (
+	"strings"
+
+	"github.com/golang/oauth2"
+	"google.golang.org/appengine"
+)
+
+type AppEngineConfig struct {
+	context appengine.Context
+	scopes  []string
+	cache   oauth2.Cache
+}
+
+func NewAppEngineConfig(context appengine.Context, scopes []string) *AppEngineConfig {
+	return &AppEngineConfig{context: context, scopes: scopes}
+}
+
+func (c *AppEngineConfig) NewTransport() oauth2.Transport {
+	return oauth2.NewAuthorizedTransport(c, nil)
+}
+
+func (c *AppEngineConfig) NewTransportWithCache(cache oauth2.Cache) (oauth2.Transport, error) {
+	token, err := cache.Read()
+	if err != nil {
+		return nil, err
+	}
+	c.cache = cache
+	return oauth2.NewAuthorizedTransport(c, token), nil
+}
+
+func (c *AppEngineConfig) FetchToken(existing *oauth2.Token) (*oauth2.Token, error) {
+	token, expiry, err := appengine.AccessToken(c.context, strings.Join(c.scopes, " "))
+	if err != nil {
+		return nil, err
+	}
+	return &oauth2.Token{
+		AccessToken: token,
+		Expiry:      expiry,
+	}, nil
+}
+
+func (c *AppEngineConfig) Cache() oauth2.Cache {
+	return c.cache
+}