3 files changed, 106 insertions, 0 deletions

diff --git a/src/application/actions/subscribetopic/post.php b/src/application/actions/subscribetopic/post.php
new file mode 100644
index 0000000..78dad04
--- /dev/null
+++ b/src/application/actions/subscribetopic/post.php
@@ -0,0 +1,39 @@
+<?php
+
+/** @var ?User $currentUser */
+/** @var \mystic\forum\Database $db */
+
+use mystic\forum\orm\Subscription;
+use mystic\forum\orm\Topic;
+use mystic\forum\utils\RequestUtils;
+
+if (!$currentUser) {
+    http_response_code(403);
+    msg_error(__("You need to be logged in to delete topics!"));
+    exit;
+}
+
+$formId = "subscribetopic";
+$topicId = RequestUtils::getRequiredField("topic", $formId);
+
+$topic = new Topic();
+$topic->id = $topicId;
+
+if (!$db->fetch($topic)) {
+    http_response_code(404);
+    msg_error(__("No topic exists with this id"));
+    exit;
+}
+
+$subscription = new Subscription;
+$subscription->userId = $currentUser->id;
+$subscription->topicId = $topic->id;
+
+if ($db->fetchWhere($subscription, ["user_id", "topic_id"])) {
+    $db->delete($subscription);
+} else {
+    $subscription->id = $db->generateId();
+    $db->insert($subscription);
+}
+
+header("Location: ?_action=viewtopic&topic=" . urlencode($topic->id));
diff --git a/src/application/actions/viewtopic/get.php b/src/application/actions/viewtopic/get.php
index 636d791..56308bf 100644
--- a/src/application/actions/viewtopic/get.php
+++ b/src/application/actions/viewtopic/get.php
@@ -1,9 +1,12 @@
 <?php
 
 /** @var Post[] $posts */
+/** @var ?User $currentUser */
+/** @var \mystic\forum\Database $db */
 
 use mystic\forum\orm\Attachment;
 use mystic\forum\orm\Post;
+use mystic\forum\orm\Subscription;
 use mystic\forum\orm\TopicLogMessage;
 use mystic\forum\orm\User;
 
@@ -58,8 +61,20 @@ $allItems = array_map(function(Post|TopicLogMessage $item) use (&$db, &$topicAut
     }
 }, $allItems);
 
+$subscription = null;
+if ($currentUser !== null) {
+    $subscription = new Subscription;
+    $subscription->userId = $currentUser->id;
+    $subscription->topicId = $topic->id;
+    if (!$db->fetchWhere($subscription, ["user_id", "topic_id"])) {
+        $subscription = null;
+    }
+}
+
 render("view_topic.twig", [
     "topic" => $topic,
     "topicAuthor" => $topicAuthor,
     "allItems" => &$allItems,
+    "subscription" => $subscription,
+    "subscription_count" => count($db->fetchCustom(Subscription::class, "WHERE topic_id = $1", [ $topic->id ])),
 ]);
diff --git a/src/application/actions/viewtopic/post.php b/src/application/actions/viewtopic/post.php
index 1038222..b50a2e9 100644
--- a/src/application/actions/viewtopic/post.php
+++ b/src/application/actions/viewtopic/post.php
@@ -1,8 +1,18 @@
 <?php
 
 use mystic\forum\orm\Attachment;
+use mystic\forum\orm\PendingEmail;
 use mystic\forum\orm\Post;
+use mystic\forum\orm\Subscription;
+use mystic\forum\orm\User;
 use mystic\forum\utils\RequestUtils;
+use Symfony\Component\Mime\Address;
+
+/** @var string $formId */
+/** @var string $topicId */
+/** @var mystic\forum\orm\Topic $topic */
+/** @var \mystic\forum\Database $db */
+/** @var \mystic\forum\User $currentUser */
 
 if (!$currentUser) {
     http_response_code(403);
@@ -61,4 +71,46 @@ foreach ($attachments as $att) {
     $db->insert($attachment);
 }
 
+if (($_POST["subscribe"] ?? null) === "on") {
+    $subscription = new Subscription;
+    $subscription->userId = $currentUser->id;
+    $subscription->topicId = $topic->id;
+
+    if (!$db->fetchWhere($subscription, ["user_id", "topic_id"])) {
+        $subscription->id = $db->generateId();
+        $db->insert($subscription);
+    }
+}
+
+/** @var Subscription[] $allSubscriptions */
+$allSubscriptions = $db->fetchCustom(Subscription::class, "WHERE topic_id = $1 AND user_id <> $2", [ $topicId, $currentUser->id ]);
+
+foreach ($allSubscriptions as $subscription) {
+    $subUser = new User;
+    $subUser->id = $subscription->userId;
+    if (!$db->fetch($subUser))
+        continue;
+
+    $email = new PendingEmail;
+    $email->id = $db->generateId();
+    $email->sender = env("MAILER_FROM");
+    $email->recipient = (new Address($subUser->email, $subUser->displayName))->toString();
+    $email->subject = __("Someone made a new post in \"%topic%\"", [
+        "topic" => $topic->title,
+    ]);
+    $email->plaintextBody = __("Hello %name%,\n" . 
+        "\n" . 
+        "%otherName% has added the following post to \"%topic%\":\n" . 
+        "%content%\n" . 
+        "\n" . 
+        "Click here to view: %link%\n", [
+            "name" => $subUser->displayName,
+            "otherName" => $currentUser->displayName,
+            "topic" => $topic->title,
+            "content" => quote_message(html_entity_decode(renderPostSummary($message))),
+            "link" => env("PUBLIC_URL") . "?_action=viewtopic&topic=" . urlencode($topicId) . "#post-" . urlencode($item->id),
+        ]);
+    $db->insert($email);
+}
+
 header("Location: ?_action=viewtopic&topic=" . urlencode($topicId) . "#form");