1 files changed, 68 insertions, 0 deletions
diff --git a/auth/file_source.go b/auth/file_source.go
new file mode 100644
index 0000000..1c1150b
--- /dev/null
+++ b/auth/file_source.go
@@ -0,0 +1,68 @@
+package auth
+
+import (
+    "golang.org/x/oauth2"
+    "encoding/json"
+    "os"
+    "io/ioutil"
+)
+
+
+func FileSource(path string, token *oauth2.Token, conf *oauth2.Config) oauth2.TokenSource {
+    return &fileSource{
+        tokenPath: path,
+        tokenSource: conf.TokenSource(oauth2.NoContext, token),
+    }
+}
+
+type fileSource struct {
+    tokenPath string
+    tokenSource oauth2.TokenSource
+}
+
+func (self *fileSource) Token() (*oauth2.Token, error) {
+    token, err := self.tokenSource.Token()
+    if err != nil {
+        return token, err
+    }
+
+    // Save token to file
+    SaveToken(self.tokenPath, token)
+
+    return token, nil
+}
+
+func ReadToken(path string) (*oauth2.Token, bool, error) {
+    if !fileExists(path) {
+        return nil, false, nil
+    }
+
+    content, err := ioutil.ReadFile(path)
+    if err != nil {
+        return nil, true, err
+    }
+    token := &oauth2.Token{}
+    return token, true, json.Unmarshal(content, token)
+}
+
+func SaveToken(path string, token *oauth2.Token) error {
+    data, err := json.MarshalIndent(token, "", "  ")
+    if err != nil {
+        return err
+    }
+
+    if err = mkdir(path); err != nil {
+        return err
+    }
+
+    // Write to temp file first
+    tmpFile := path + ".tmp"
+    err = ioutil.WriteFile(tmpFile, data, 0600)
+    if err != nil {
+        os.Remove(tmpFile)
+        return err
+    }
+
+    // Move file to correct path
+    return os.Rename(tmpFile, path)
+}