Implement recent mailboxes feature

themes/bootstrap/templates/_base.html

@@ -28,7 +28,22 @@
         </div>
         <div id="navbar" class="collapse navbar-collapse">
           <ul class="nav navbar-nav">
-            <li id="nav-mail"><a href="/" accesskey="1">Mail</a></li>
+            {{with .ctx.Session.Values.recentMailboxes}}
+            <li id="nav-mail" class="dropdown">
+              <a class="dropdown-toggle"
+                 href="#"
+                 accesskey="1"
+                 data-toggle="dropdown"
+                 role="button"
+                 aria-haspopup="true"
+                 aria-expanded="false">Recent Mailboxes <span class="caret"></span></a>
+              <ul class="dropdown-menu">
+                {{range .}}
+                <li><a href="{{reverse "MailboxIndex"}}?name={{.}}">{{.}}</a></li>
+                {{end}}
+              </ul>
+            </li>
+            {{end}}
             <li id="nav-status"><a href="/status" accesskey="2">Status</a></li>
           </ul>
           <form class="navbar-form navbar-right" action="{{reverse "MailboxIndex"}}" method="GET">

web/mailbox_controller.go

@@ -49,6 +49,9 @@ func MailboxIndex(w http.ResponseWriter, req *http.Request, ctx *Context) (err e
 		return nil
 	}
 
+	// Remember this mailbox was visited
+	RememberMailbox(ctx, name)
+
 	return RenderTemplate("mailbox/index.html", w, map[string]interface{}{
 		"ctx":      ctx,
 		"name":     name,

web/recent.go

@@ -0,0 +1,31 @@
+package web
+
+const (
+	// maximum mailboxes to remember
+	maxRemembered = 8
+	// session value key; referenced in templates, do not change
+	mailboxKey = "recentMailboxes"
+)
+
+// RememberMailbox manages the list of recently accessed mailboxes stored in the session
+func RememberMailbox(ctx *Context, mailbox string) {
+	recent := RecentMailboxes(ctx)
+	newRecent := make([]string, 1, maxRemembered)
+	newRecent[0] = mailbox
+
+	for _, recBox := range recent {
+		// Insert until newRecent is full, but don't repeat the new mailbox
+		if len(newRecent) < maxRemembered && mailbox != recBox {
+			newRecent = append(newRecent, recBox)
+		}
+	}
+
+	ctx.Session.Values[mailboxKey] = newRecent
+}
+
+// RecentMailboxes returns a slice of the most recently accessed mailboxes
+func RecentMailboxes(ctx *Context) []string {
+	val := ctx.Session.Values[mailboxKey]
+	recent, _ := val.([]string)
+	return recent
+}