From 735ac7ffb3fdb9b7bd9b2fb7bf98f33df3de72b7 Mon Sep 17 00:00:00 2001
From: Mihai Parparita <mihai@persistent.info>
Date: Sat, 20 Dec 2014 21:38:09 -0800
Subject: [PATCH] Better handling of GitHub OAuth errors when sending digest
 emails.

Fail silently if we can't even get an email address, otherwise send an error
email to the user.
---
 app/app.go                                 |  6 ++---
 app/retrogit.go                            | 29 ++++++++++++++++++++++
 app/templates/digest-email.html            | 21 +---------------
 app/templates/github-auth-error-email.html | 16 ++++++++++++
 app/templates/shared/email-footer.html     | 24 ++++++++++++++++++
 5 files changed, 73 insertions(+), 23 deletions(-)
 create mode 100644 app/templates/github-auth-error-email.html
 create mode 100644 app/templates/shared/email-footer.html

diff --git a/app/app.go b/app/app.go
index c999430..c429ddf 100644
--- a/app/app.go
+++ b/app/app.go
@@ -334,9 +334,9 @@ func loadTemplates() (templates map[string]*Template) {
 		templateName := filepath.Base(templateFileName)
 		templateName = strings.TrimSuffix(templateName, filepath.Ext(templateName))
 		fileNames := make([]string, 0, len(sharedFileNames)+2)
-		// The base template has to come first, except for the email template, which
-		// doesn't use it
-		if templateName != "digest-email" {
+		// The base template has to come first, except for email ones, which
+		// don't use it.
+		if !strings.HasSuffix(templateName, "-email") {
 			fileNames = append(fileNames, "templates/base/page.html")
 		}
 		fileNames = append(fileNames, templateFileName)
diff --git a/app/retrogit.go b/app/retrogit.go
index d100bcb..4149c90 100644
--- a/app/retrogit.go
+++ b/app/retrogit.go
@@ -284,6 +284,15 @@ func sendDigestForAccount(account *Account, c appengine.Context) (bool, error) {
 
 	emailAddress, err := account.GetDigestEmailAddress(githubClient)
 	if err != nil {
+		if gitHubError, ok := (err).(*github.ErrorResponse); ok {
+			gitHubStatus := gitHubError.Response.StatusCode
+			if gitHubStatus == http.StatusUnauthorized ||
+				gitHubStatus == http.StatusForbidden {
+				c.Errorf("  GitHub auth error while getting email adddress, skipping: %s", err.Error())
+				return false, nil
+			}
+		}
+
 		return false, err
 	}
 	if emailAddress == "disabled" {
@@ -292,6 +301,26 @@ func sendDigestForAccount(account *Account, c appengine.Context) (bool, error) {
 
 	digest, err := newDigest(c, githubClient, account)
 	if err != nil {
+		if gitHubError, ok := (err).(*github.ErrorResponse); ok {
+			gitHubStatus := gitHubError.Response.StatusCode
+			if gitHubStatus == http.StatusUnauthorized ||
+				gitHubStatus == http.StatusForbidden {
+				c.Errorf("  GitHub auth error while getting digest, sending error email: %s", err.Error())
+				var authErrorHtml bytes.Buffer
+				if err := templates["github-auth-error-email"].Execute(&authErrorHtml, nil); err != nil {
+					return false, err
+				}
+
+				digestMessage := &mail.Message{
+					Sender:   "RetroGit <digests@retrogit.com>",
+					To:       []string{emailAddress},
+					Subject:  "RetroGit Digest Error",
+					HTMLBody: authErrorHtml.String(),
+				}
+				err = mail.Send(c, digestMessage)
+				return false, err
+			}
+		}
 		return false, err
 	}
 	if digest.Empty() {
diff --git a/app/templates/digest-email.html b/app/templates/digest-email.html
index 9ddbc57..27b2fe9 100644
--- a/app/templates/digest-email.html
+++ b/app/templates/digest-email.html
@@ -1,22 +1,3 @@
 {{template "digest" .Digest}}
 
-<hr noshade size="1" color="#ccc">
-
-<div style="{{style "proportional" "email-footer"}}">
-
-  <p style="{{style "email-footer.paragraph"}}">
-    You are receiving this email because you set up a
-    <a href="{{absoluteRouteUrl "index"}}" style="{{style "email-footer.link"}}">RetroGit</a> account.
-  </p>
-
-  <p style="{{style "email-footer.paragraph"}}">
-   <a href="{{absoluteRouteUrl "settings"}}" style="{{style "email-footer.link"}}">Update your email preferences</a>
-   | <a href="{{absoluteRouteUrl "view-digest"}}" style="{{style "email-footer.link"}}">View digest in browser</a>
-  </p>
-
-  <p style="{{style "email-footer.paragraph"}}">
-    RetroGit is a project by
-    <a href="http://persistent.info" style="{{style "email-footer.link"}}">Mihai Parparita</a>.
-  </p>
-
-</div>
+{{template "email-footer"}}
diff --git a/app/templates/github-auth-error-email.html b/app/templates/github-auth-error-email.html
new file mode 100644
index 0000000..231edc3
--- /dev/null
+++ b/app/templates/github-auth-error-email.html
@@ -0,0 +1,16 @@
+<p>
+  A RetroGit digest could not be generated for your account due to a GitHub
+  authentication error. You may have revoked RetroGit's access (you can see this
+  on your <a href="https://github.com/settings/applications">GitHub settings
+  page</a>). If you wish to grant it access again, use the button below:
+</p>
+
+<form id="sign-in-form" method="POST" action="{{absoluteRouteUrl "sign-in"}}">
+  <input type="submit" class="action-button" value="Sign In with GitHub">
+  <label>
+    <input type="checkbox" name="include_private" value="1" checked>
+    Include private repositories
+  </label>
+</form>
+
+{{template "email-footer"}}
diff --git a/app/templates/shared/email-footer.html b/app/templates/shared/email-footer.html
new file mode 100644
index 0000000..96e71b6
--- /dev/null
+++ b/app/templates/shared/email-footer.html
@@ -0,0 +1,24 @@
+{{define "email-footer"}}
+
+<hr noshade size="1" color="#ccc">
+
+<div style="{{style "proportional" "email-footer"}}">
+
+  <p style="{{style "email-footer.paragraph"}}">
+    You are receiving this email because you set up a
+    <a href="{{absoluteRouteUrl "index"}}" style="{{style "email-footer.link"}}">RetroGit</a> account.
+  </p>
+
+  <p style="{{style "email-footer.paragraph"}}">
+   <a href="{{absoluteRouteUrl "settings"}}" style="{{style "email-footer.link"}}">Update your email preferences</a>
+   | <a href="{{absoluteRouteUrl "view-digest"}}" style="{{style "email-footer.link"}}">View digest in browser</a>
+  </p>
+
+  <p style="{{style "email-footer.paragraph"}}">
+    RetroGit is a project by
+    <a href="http://persistent.info" style="{{style "email-footer.link"}}">Mihai Parparita</a>.
+  </p>
+
+</div>
+
+{{end}}