From 9c3ea8dd803d6f0df768e3ae37f8c4ab2efbcc5c Mon Sep 17 00:00:00 2001
From: Brian Picciano <mediocregopher@gmail.com>
Date: Tue, 3 Aug 2021 16:28:22 -0600
Subject: [PATCH] implement finalize and unsubscribe endpoints

---
 srv/cmd/mediocre-blog/mailinglist.go  | 22 ++++++++---
 srv/cmd/mediocre-blog/main.go         | 13 +++++--
 srv/mailinglist/store.go              |  2 +-
 static/src/mailinglist/finalize.md    | 53 ++++++++++++++++++++++++++
 static/src/mailinglist/unsubscribe.md | 54 +++++++++++++++++++++++++++
 5 files changed, 133 insertions(+), 11 deletions(-)
 create mode 100644 static/src/mailinglist/finalize.md
 create mode 100644 static/src/mailinglist/unsubscribe.md

diff --git a/srv/cmd/mediocre-blog/mailinglist.go b/srv/cmd/mediocre-blog/mailinglist.go
index 4a1ddce..39ab0d4 100644
--- a/srv/cmd/mediocre-blog/mailinglist.go
+++ b/srv/cmd/mediocre-blog/mailinglist.go
@@ -32,18 +32,24 @@ func mailingListSubscribeHandler(ml mailinglist.MailingList) http.Handler {
 }
 
 func mailingListFinalizeHandler(ml mailinglist.MailingList) http.Handler {
+	var errInvalidSubToken = errors.New("invalid subToken")
+
 	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
 		subToken := r.PostFormValue("subToken")
 		if l := len(subToken); l == 0 || l > 128 {
-			badRequest(rw, r, errors.New("invalid subToken"))
+			badRequest(rw, r, errInvalidSubToken)
 			return
 		}
 
 		err := ml.FinalizeSubscription(subToken)
-		if errors.Is(err, mailinglist.ErrNotFound) ||
-			errors.Is(err, mailinglist.ErrAlreadyVerified) {
-			badRequest(rw, r, err)
+
+		if errors.Is(err, mailinglist.ErrNotFound) {
+			badRequest(rw, r, errInvalidSubToken)
 			return
+
+		} else if errors.Is(err, mailinglist.ErrAlreadyVerified) {
+			// no problem
+
 		} else if err != nil {
 			internalServerError(rw, r, err)
 			return
@@ -54,17 +60,21 @@ func mailingListFinalizeHandler(ml mailinglist.MailingList) http.Handler {
 }
 
 func mailingListUnsubscribeHandler(ml mailinglist.MailingList) http.Handler {
+	var errInvalidUnsubToken = errors.New("invalid unsubToken")
+
 	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
 		unsubToken := r.PostFormValue("unsubToken")
 		if l := len(unsubToken); l == 0 || l > 128 {
-			badRequest(rw, r, errors.New("invalid unsubToken"))
+			badRequest(rw, r, errInvalidUnsubToken)
 			return
 		}
 
 		err := ml.Unsubscribe(unsubToken)
+
 		if errors.Is(err, mailinglist.ErrNotFound) {
-			badRequest(rw, r, err)
+			badRequest(rw, r, errInvalidUnsubToken)
 			return
+
 		} else if err != nil {
 			internalServerError(rw, r, err)
 			return
diff --git a/srv/cmd/mediocre-blog/main.go b/srv/cmd/mediocre-blog/main.go
index 748e10b..b94d405 100644
--- a/srv/cmd/mediocre-blog/main.go
+++ b/srv/cmd/mediocre-blog/main.go
@@ -27,7 +27,7 @@ func main() {
 
 	logger := mlog.NewLogger(nil)
 
-	hostname := flag.String("hostname", "localhost:4000", "Hostname to advertise this server as")
+	publicURLStr := flag.String("public-url", "http://localhost:4000", "URL this service is accessible at")
 	listenAddr := flag.String("listen-addr", ":4000", "Address to listen for HTTP requests on")
 	dataDir := flag.String("data-dir", ".", "Directory to use for long term storage")
 
@@ -55,6 +55,11 @@ func main() {
 		logger.Fatal(context.Background(), "-ml-smtp-auth is required")
 	}
 
+	publicURL, err := url.Parse(*publicURLStr)
+	if err != nil {
+		loggerFatalErr(context.Background(), logger, "parsing -public-url", err)
+	}
+
 	var staticProxyURL *url.URL
 	if *staticProxyURLStr != "" {
 		var err error
@@ -79,7 +84,7 @@ func main() {
 	// initialization
 
 	ctx := mctx.Annotate(context.Background(),
-		"hostname", *hostname,
+		"publicURL", publicURL.String(),
 		"listenAddr", *listenAddr,
 		"dataDir", *dataDir,
 		"powTarget", fmt.Sprintf("%x", powTarget),
@@ -124,8 +129,8 @@ func main() {
 		Store:          mlStore,
 		Mailer:         mailer,
 		Clock:          clock,
-		FinalizeSubURL: *hostname + "/mailinglist/finalize.html",
-		UnsubURL:       *hostname + "/mailinglist/unsubscribe.html",
+		FinalizeSubURL: path.Join(publicURL.String(), "/mailinglist/finalize.html"),
+		UnsubURL:       path.Join(publicURL.String(), "/mailinglist/unsubscribe.html"),
 	})
 
 	mux := http.NewServeMux()
diff --git a/srv/mailinglist/store.go b/srv/mailinglist/store.go
index 185e14d..f9790c0 100644
--- a/srv/mailinglist/store.go
+++ b/srv/mailinglist/store.go
@@ -17,7 +17,7 @@ import (
 var (
 	// ErrNotFound is used to indicate an email could not be found in the
 	// database.
-	ErrNotFound = errors.New("no record for given email found")
+	ErrNotFound = errors.New("no record found")
 )
 
 // EmailIterator will iterate through a sequence of emails, returning the next
diff --git a/static/src/mailinglist/finalize.md b/static/src/mailinglist/finalize.md
new file mode 100644
index 0000000..fe8f741
--- /dev/null
+++ b/static/src/mailinglist/finalize.md
@@ -0,0 +1,53 @@
+---
+layout: page
+title: ""
+nofollow: true
+---
+
+<style>
+#result.success { color: green; }
+#result.fail { color: red; }
+</style>
+
+<span id="result"></span>
+
+<script>
+
+(async () => {
+    const resultSpan = document.getElementById("result");
+    
+    function setErr(errStr) {
+        resultSpan.className = "fail";
+        resultSpan.innerHTML = errStr;
+    }
+
+    const urlParams = new URLSearchParams(window.location.search);
+    const subToken = urlParams.get('subToken');
+
+    if (!subToken) {
+        setErr("No subscription token provided");
+        return;
+    }
+
+    const finalizeForm = new FormData();
+    finalizeForm.append('subToken', subToken);
+
+    const finalizeReq = new Request('/api/mailinglist/finalize', {
+        method: 'POST',
+        body: finalizeForm,
+    });
+
+    const res = await fetch(finalizeReq)
+        .then(response => response.json());
+
+    if (res.error) {
+        setErr(res.error);
+        return;
+    }
+
+    resultSpan.className = "success";
+    resultSpan.innerHTML = "Your email subscription has been finalized! Please go on about your day.";
+
+})();
+
+</script>
diff --git a/static/src/mailinglist/unsubscribe.md b/static/src/mailinglist/unsubscribe.md
new file mode 100644
index 0000000..6a118a0
--- /dev/null
+++ b/static/src/mailinglist/unsubscribe.md
@@ -0,0 +1,54 @@
+---
+layout: page
+title: ""
+nofollow: true
+---
+
+<style>
+#result.success { color: green; }
+#result.fail { color: red; }
+</style>
+
+<span id="result"></span>
+
+<script>
+
+(async () => {
+    const resultSpan = document.getElementById("result");
+    
+    function setErr(errStr) {
+        resultSpan.className = "fail";
+        resultSpan.innerHTML = errStr;
+    }
+
+    const urlParams = new URLSearchParams(window.location.search);
+    const unsubToken = urlParams.get('unsubToken');
+
+    if (!unsubToken) {
+        setErr("No unsubscribe token provided");
+        return;
+    }
+
+    const unsubscribeForm = new FormData();
+    unsubscribeForm.append('unsubToken', unsubToken);
+
+    const unsubscribeReq = new Request('/api/mailinglist/unsubscribe', {
+        method: 'POST',
+        body: unsubscribeForm,
+    });
+
+    const res = await fetch(unsubscribeReq)
+        .then(response => response.json());
+
+    if (res.error) {
+        setErr(res.error);
+        return;
+    }
+
+    resultSpan.className = "success";
+    resultSpan.innerHTML = "You have been unsubscribed! Please go on about your day.";
+
+})();
+
+</script>
+