Add async email and topic subscribingv0.7.2

25 files changed, 395 insertions, 15 deletions

diff --git a/Dockerfile b/Dockerfile
index ccbf6e7..59b961a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,7 @@
 FROM php:8.3-apache-bookworm AS base
 RUN a2enmod rewrite
 RUN apt update && apt install -y \
+    cron \
     curl \
     git \
     libzip-dev \
@@ -21,7 +22,20 @@ RUN docker-php-ext-configure gd \
 RUN docker-php-ext-install gd zip pgsql intl
 RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
 
-FROM base AS dev
+FROM base AS with-cronjob
+COPY --chmod=644 ./crontab /tmp/crontab.tmp
+RUN crontab /tmp/crontab.tmp && \
+    rm -f /tmp/crontab.tmp
+RUN touch /var/log/cron.log && \
+    touch /var/log/jobs.log && \
+    touch /var/log/job-errors.log
+
+FROM with-cronjob AS with-scripts
+COPY --chmod=700 ./entrypoint.sh /entrypoint.sh
+COPY --chmod=700 ./with-env /with-env
+
+FROM with-scripts AS dev
+CMD ["/entrypoint.sh"]
 COPY ./000-default.conf /etc/apache2/sites-available/000-default.conf
 WORKDIR /var/www/html
 
diff --git a/crontab b/crontab
new file mode 100644
index 0000000..225f276
--- /dev/null
+++ b/crontab
@@ -0,0 +1 @@
+* * * * * /with-env /usr/local/bin/php /var/www/html/application/cron.php email >/var/log/jobs.log 2>/var/log/job-errors.log
diff --git a/entrypoint.sh b/entrypoint.sh
new file mode 100644
index 0000000..f559966
--- /dev/null
+++ b/entrypoint.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+
+set -e
+/etc/init.d/cron start
+tail -f /var/log/jobs.log /var/log/job-errors.log &
+apache2-foreground
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");
diff --git a/src/application/appdef.php b/src/application/appdef.php
index 1f51d97..d623cd1 100644
--- a/src/application/appdef.php
+++ b/src/application/appdef.php
@@ -1,3 +1,3 @@
 <?php
 
-const MYSTICBB_VERSION = "0.7.1";
+const MYSTICBB_VERSION = "0.7.2";
diff --git a/src/application/common.php b/src/application/common.php
new file mode 100644
index 0000000..113d598
--- /dev/null
+++ b/src/application/common.php
@@ -0,0 +1,12 @@
+<?php
+
+use mystic\forum\Database;
+use mystic\forum\exceptions\DatabaseConnectionException;
+
+function get_db(): Database {
+    return new Database(Database::getConnectionString("db", getenv("POSTGRES_USER"), getenv("POSTGRES_PASSWORD"), getenv("POSTGRES_DBNAME")));
+}
+
+function quote_message(string $message): string {
+    return implode("\n", array_map(fn($ln) => "> $ln", preg_split('~(*BSR_ANYCRLF)\R~', trim($message))));
+}
diff --git a/src/application/cron.php b/src/application/cron.php
new file mode 100644
index 0000000..094fe50
--- /dev/null
+++ b/src/application/cron.php
@@ -0,0 +1,42 @@
+<?php
+
+const __ROOT__ = __DIR__ . "/..";
+
+require_once __ROOT__ . "/vendor/autoload.php";
+require_once __ROOT__ . "/application/i18n.php";
+require_once __ROOT__ . "/application/common.php";
+
+function print_error(string $msg): void {
+    file_put_contents("php://stderr", $msg);
+}
+
+function check_sapi(): void {
+    if (PHP_SAPI !== "cli") {
+        http_response_code(500);
+        echo "Error: Can only be called via command line\n";
+        exit(1);
+    }
+}
+
+check_sapi();
+
+$job = $argv[1] ?? null;
+
+if ($job === null) {
+    print_error("Error: No job specified\nUsage: php cron.php <job>\n");
+    exit(1);
+}
+
+$jobsDir = __DIR__ . "/jobs";
+
+$availableJobs = array_map(fn($i) => pathinfo($i, PATHINFO_FILENAME), array_values(array_filter(scandir($jobsDir),
+    fn($i) => is_file($jobsDir . "/" . $i) && $i[0] !== "." && pathinfo($i, PATHINFO_EXTENSION) === "php")));
+
+if (!in_array($job, $availableJobs)) {
+    print_error("Error: Invalid job specified\nAvailable jobs are:\n" . implode("", array_map(fn($i) => "  $i\n", $availableJobs)));
+    exit(1);
+}
+
+$jobFile = $jobsDir . "/" . $job . ".php";
+
+include $jobFile;
diff --git a/src/application/jobs/email.php b/src/application/jobs/email.php
new file mode 100644
index 0000000..8bb97dc
--- /dev/null
+++ b/src/application/jobs/email.php
@@ -0,0 +1,33 @@
+<?php
+
+use mystic\forum\orm\PendingEmail;
+use Symfony\Component\Mailer\Exception\TransportExceptionInterface;
+use Symfony\Component\Mailer\Transport;
+use Symfony\Component\Mime\Email;
+
+check_sapi();
+
+$db = get_db();
+
+/** @var PendingEmail[] $pendingEmails */
+$pendingEmails = $db->fetchAll(PendingEmail::class);
+
+$transport = Transport::fromDsn(getenv("MAILER_DSN"));
+
+foreach ($pendingEmails as $pendingEmail) {
+    try {
+        $mail = (new Email)
+            ->from($pendingEmail->sender)
+            ->to($pendingEmail->recipient)
+            ->subject($pendingEmail->subject)
+        ;
+        if (!empty($pendingEmail->htmlBody))
+            $mail->html($pendingEmail->htmlBody);
+        if (!empty($pendingEmail->plaintextBody))
+            $mail->text($pendingEmail->plaintextBody);
+        $transport->send($mail);
+    } catch (TransportExceptionInterface $ex) {
+        print_error("Failed to send mail: " . $ex->getMessage() . "\n");
+    }
+    $db->delete($pendingEmail);
+}
diff --git a/src/application/messages/de.msg b/src/application/messages/de.msg
index 3ce96d4..c16d1d1 100644
--- a/src/application/messages/de.msg
+++ b/src/application/messages/de.msg
@@ -540,3 +540,34 @@ metadata({
 
 : "Page generation took %dur% second(s)"
 = "Seitenaufbau dauerte %dur% Sekunde(n)"
+
+: "Unsubscribe from topic"
+= "Thema deabonnieren"
+
+: "Subscribe to topic"
+= "Thema abonnieren"
+
+: "Someone made a new post in \"%topic%\""
+= "Jemand hat einen neuen Beitrag zu \"%topic%\" hinzugefügt"
+
+: "Hello %name%,\n"
+  "\n"
+  "%otherName% has added the following post to \"%topic%\":\n"
+  "%content%\n"
+  "\n"
+  "Click here to view: %link%\n"
+= "Hallo %name%,\n"
+  "\n"
+  "%otherName% hat den folgenden Beitrag zu \"%topic%\" hinzugefügt:\n"
+  "%content%\n"
+  "\n"
+  "Den Beitrag ansehen: %link%\n"
+
+:...
+- "%n% person is watching this topic"
+- "%n% people are watching this topic"
+- "Nobody is watching this topic"
+=...
+- "%n% Person beobachtet dieses Thema"
+- "%n% Personen beobachten dieses Thema"
+- "Niemand beobachtet dieses Thema"
diff --git a/src/application/mystic/forum/Database.php b/src/application/mystic/forum/Database.php
index 1c2d710..bca4ac9 100644
--- a/src/application/mystic/forum/Database.php
+++ b/src/application/mystic/forum/Database.php
@@ -46,12 +46,12 @@ class Database {
 
     protected function queryParams(string $query, array $params): Result|false {
         ++$this->queryCount;
-        return \pg_query_params  ($this->connection, $query, $params);
+        return \pg_query_params($this->connection, $query, $params);
     }
 
     protected function query(string $query): Result|false {
         ++$this->queryCount;
-        return \pg_query  ($this->connection, $query);
+        return \pg_query($this->connection, $query);
     }
 
     public static function generateId(int $length = 64): string {
diff --git a/src/application/mystic/forum/orm/PendingEmail.php b/src/application/mystic/forum/orm/PendingEmail.php
new file mode 100644
index 0000000..70622b3
--- /dev/null
+++ b/src/application/mystic/forum/orm/PendingEmail.php
@@ -0,0 +1,19 @@
+<?php
+
+namespace mystic\forum\orm;
+
+use mystic\forum\attributes\PrimaryKey;
+use mystic\forum\attributes\Table;
+use mystic\forum\orm\Entity;
+
+#[Table("public.emails")]
+class PendingEmail extends Entity {
+    #[PrimaryKey] public string $id;
+    public string $sender;
+    public string $recipient;
+    public string $subject;
+    public ?string $htmlBody;
+    public ?string $plaintextBody;
+
+    // TODO Attachments
+}
diff --git a/src/application/mystic/forum/orm/Subscription.php b/src/application/mystic/forum/orm/Subscription.php
new file mode 100644
index 0000000..6934685
--- /dev/null
+++ b/src/application/mystic/forum/orm/Subscription.php
@@ -0,0 +1,14 @@
+<?php
+
+namespace mystic\forum\orm;
+
+use mystic\forum\attributes\PrimaryKey;
+use mystic\forum\attributes\References;
+use mystic\forum\attributes\Table;
+
+#[Table("public.subscriptions")]
+class Subscription extends Entity {
+    #[PrimaryKey] public string $id;
+    #[References("public.topics", onDelete: References::CASCADE)] public string $topicId;
+    #[References("public.users", onDelete: References::CASCADE)] public string $userId;
+}
diff --git a/src/application/mystic/forum/utils/StringUtils.php b/src/application/mystic/forum/utils/StringUtils.php
index fd38915..94221fb 100644
--- a/src/application/mystic/forum/utils/StringUtils.php
+++ b/src/application/mystic/forum/utils/StringUtils.php
@@ -23,6 +23,8 @@ final class StringUtils {
     }
 
     public static function truncate(string $str, int $maxLength, string $ellipsis = "…"): string {
+        if ($maxLength < 0)
+            return $str;
         return mb_strimwidth($str, 0, $maxLength, $ellipsis);
     }
 }
diff --git a/src/application/templates/bootstrap-3/view_topic.twig b/src/application/templates/bootstrap-3/view_topic.twig
index 383dd41..7009afc 100644
--- a/src/application/templates/bootstrap-3/view_topic.twig
+++ b/src/application/templates/bootstrap-3/view_topic.twig
@@ -30,6 +30,12 @@
         or currentUser.hasPermission(permission("DELETE_OTHER_TOPIC"))
     ) %}
 
+{% set canSubscribe = currentUser is not null %}
+
+{% set isSubscribed =
+    currentUser is not null
+    and ctx.subscription is not null %}
+
 {% set title = ctx.topic.title %}
 {% extends "base.twig" %}
 
@@ -178,30 +184,40 @@
             {{ ctx.topic.title }}
             <div class="pull-right text-normal">
                 {% if canEdit and not ctx.topic.isLocked %}
-                    <button id="btn-edit-title" class="btn btn-default js-only"><span class="fa fa-pencil" aria-hidden="true"></span> {{ __("Edit title") }}</button>
+                    <button id="btn-edit-title" class="btn btn-default btn-xs js-only"><span class="fa fa-pencil" aria-hidden="true"></span> {{ __("Edit title") }}</button>
                 {% endif %}
                 {% if canReply %}
-                    <button id="btn-reply" class="btn btn-default js-only"><span class="fa fa-comment" aria-hidden="true"></span> {{ __("Reply") }}</button>
+                    <button id="btn-reply" class="btn btn-default btn-xs js-only"><span class="fa fa-comment" aria-hidden="true"></span> {{ __("Reply") }}</button>
+                {% endif %}
+                {% if canSubscribe %}
+                    <form action="?_action=subscribetopic" method="post" class="seamless-inline">
+                        <input type="hidden" name="topic" value="{{ ctx.topic.id }}">
+                        {% if isSubscribed %}
+                            <button type="submit" class="btn btn-xs btn-default"><span class="fa fa-bell-slash" aria-hidden="true"></span> {{ __("Unsubscribe from topic") }}</button>
+                        {% else %}
+                            <button type="submit" class="btn btn-xs btn-default"><span class="fa fa-bell" aria-hidden="true"></span> {{ __("Subscribe to topic") }}</button>
+                        {% endif %}
+                    </form>
                 {% endif %}
                 {% if canEdit %}
                     {% if ctx.topic.isLocked %}
                         <form action="?_action=locktopic" method="post" class="seamless-inline">
                             <input type="hidden" name="topic" value="{{ ctx.topic.id }}">
                             <input type="hidden" name="locked" value="false">
-                            <button type="submit" class="btn btn-success"><span class="fa fa-unlock" aria-hidden="true"></span> {{ __("Unlock topic") }}</button>
+                            <button type="submit" class="btn btn-success btn-xs"><span class="fa fa-unlock" aria-hidden="true"></span> {{ __("Unlock topic") }}</button>
                         </form>
                     {% else %}
                         <form action="?_action=locktopic" method="post" class="seamless-inline">
                             <input type="hidden" name="topic" value="{{ ctx.topic.id }}">
                             <input type="hidden" name="locked" value="true">
-                            <button type="submit" class="btn btn-warning"><span class="fa fa-lock" aria-hidden="true"></span> {{ __("Lock topic") }}</button>
+                            <button type="submit" class="btn btn-warning btn-xs"><span class="fa fa-lock" aria-hidden="true"></span> {{ __("Lock topic") }}</button>
                         </form>
                     {% endif %}
                 {% endif %}
                 {% if canDelete %}
                     <form action="?_action=deletetopic" method="post" class="seamless-inline">
                         <input type="hidden" name="topic" value="{{ ctx.topic.id }}">
-                        <button type="submit" class="btn btn-danger"><span class="fa fa-trash" aria-hidden="true"></span> {{ __("Delete topic") }}</button>
+                        <button type="submit" class="btn btn-danger btn-xs"><span class="fa fa-trash" aria-hidden="true"></span> {{ __("Delete topic") }}</button>
                     </form>
                 {% endif %}
             </div>
@@ -209,7 +225,14 @@
         {{ __("Started by %user% on %date%", {
             "user": (ctx.topicAuthor is not null) ? ('<a href="?_action=viewuser&amp;user=' ~ ctx.topicAuthor.id|url_encode|e("html") ~ '">' ~ ctx.topicAuthor.displayName|e("html") ~ '</a>') : __("(deleted)"),
             "date": '<span class="_time">' ~ ctx.topic.creationDate.format("c")|e("html") ~ '</span>',
-        }) }}
+        }) }} &bull; {{ ___(
+            "%n% person is watching this topic",
+            "%n% people are watching this topic",
+            ctx.subscription_count,
+            {
+                n: ctx.subscription_count,
+            },
+        ) }}
     </div>
     {% if canEdit %}
         <form action="?_action=updatetopic" method="post" id="editHeading" style="display: none;" class="form-inline seamless-inline">
@@ -351,6 +374,11 @@ $(function() {
             }) }}</label>
             <input type="file" name="files[]" id="i_files" multiple accept="*/*">
         </div>
+        {% if not isSubscribed %}
+            <div class="checkbox">
+                <label><input type="checkbox" name="subscribe" value="on" checked> {{ __("Subscribe to topic") }}</label>
+            </div>
+        {% endif %}
         <button type="submit" class="btn btn-success">{{ __("Post reply") }} <span class="fa fa-send" aria-hidden="true"></span></button>
     </form>
 {% else %}
diff --git a/src/application/templates/modern/view_topic.twig b/src/application/templates/modern/view_topic.twig
index 733ce1b..c064b1c 100644
--- a/src/application/templates/modern/view_topic.twig
+++ b/src/application/templates/modern/view_topic.twig
@@ -30,6 +30,12 @@
         or currentUser.hasPermission(permission("DELETE_OTHER_TOPIC"))
     ) %}
 
+{% set canSubscribe = currentUser is not null %}
+
+{% set isSubscribed =
+    currentUser is not null
+    and ctx.subscription is not null %}
+
 {% set title = ctx.topic.title %}
 {% extends "base.twig" %}
 
@@ -189,6 +195,20 @@
                         <svg viewBox="0 0 24 24" class="icon"><polyline points="9 17 4 12 9 7"/><path d="M20 18v-2a4 4 0 0 0-4-4H4"/></svg>
                     </button>
                 {% endif %}
+                {% if canSubscribe %}
+                    <form action="?_action=subscribetopic" method="post" class="seamless-inline">
+                        <input type="hidden" name="topic" value="{{ ctx.topic.id }}">
+                        {% if isSubscribed %}
+                            <button type="submit" class="btn btn-iconic" title="{{ __("Unsubscribe from topic") }}">
+                                <svg viewBox="0 0 24 24" class="icon"><path d="M10.268 21a2 2 0 0 0 3.464 0" /><path d="M3.262 15.326A1 1 0 0 0 4 17h16a1 1 0 0 0 .74-1.673C19.41 13.956 18 12.499 18 8A6 6 0 0 0 6 8c0 4.499-1.411 5.956-2.738 7.326" /></svg>
+                            </button>
+                        {% else %}
+                            <button type="submit" class="btn btn-iconic" title="{{ __("Subscribe to topic") }}">
+                                <svg viewBox="0 0 24 24" class="icon"><path d="M10.268 21a2 2 0 0 0 3.464 0"/><path d="M17 17H4a1 1 0 0 1-.74-1.673C4.59 13.956 6 12.499 6 8a6 6 0 0 1 .258-1.742"/><path d="m2 2 20 20"/><path d="M8.668 3.01A6 6 0 0 1 18 8c0 2.687.77 4.653 1.707 6.05"/></svg>
+                            </button>
+                        {% endif %}
+                    </form>
+                {% endif %}
                 {% if canEdit %}
                     {% if ctx.topic.isLocked %}
                         <form action="?_action=locktopic" method="post">
@@ -221,7 +241,14 @@
         {{ __("Started by %user% on %date%", {
             "user": (ctx.topicAuthor is not null) ? ('<a href="?_action=viewuser&amp;user=' ~ ctx.topicAuthor.id|url_encode|e("html") ~ '">' ~ ctx.topicAuthor.displayName|e("html") ~ '</a>') : __("(deleted)"),
             "date": '<span class="_time">' ~ ctx.topic.creationDate.format("c")|e("html") ~ '</span>',
-        }) }}
+        }) }} &bull; {{ ___(
+            "%n% person is watching this topic",
+            "%n% people are watching this topic",
+            ctx.subscription_count,
+            {
+                n: ctx.subscription_count,
+            },
+        ) }}
     </div>
     {% if canEdit %}
         <form action="?_action=updatetopic" method="post" id="editHeading" hidden>
@@ -348,6 +375,11 @@ document.addEventListener("DOMContentLoaded", function() {
             }) }}</label>
             <input type="file" name="files[]" id="i_files" multiple accept="*/*">
         </div>
+        {% if not isSubscribed %}
+            <div class="checkbox">
+                <label><input type="checkbox" name="subscribe" value="on" checked> {{ __("Subscribe to topic") }}</label>
+            </div>
+        {% endif %}
         <button type="submit" class="btn btn-success">
             <span>{{ __("Post reply") }}</span>
             <svg viewBox="0 0 24 24" class="icon"><path d="M3.714 3.048a.498.498 0 0 0-.683.627l2.843 7.627a2 2 0 0 1 0 1.396l-2.842 7.627a.498.498 0 0 0 .682.627l18-8.5a.5.5 0 0 0 0-.904z"/><path d="M6 12h16"/></svg>
diff --git a/src/application/templates/old/view_topic.twig b/src/application/templates/old/view_topic.twig
index 613de49..70d0d67 100644
--- a/src/application/templates/old/view_topic.twig
+++ b/src/application/templates/old/view_topic.twig
@@ -30,6 +30,12 @@
         or currentUser.hasPermission(permission("DELETE_OTHER_TOPIC"))
     ) %}
 
+{% set canSubscribe = currentUser is not null %}
+
+{% set isSubscribed =
+    currentUser is not null
+    and ctx.subscription is not null %}
+
 {% set title = ctx.topic.title %}
 {% extends "base.twig" %}
 
@@ -76,6 +82,16 @@
                         #}</form>
                     {%- endif -%}
                 {%- endif -%}
+                {%- if canSubscribe -%}
+                    <form action="?_action=subscribetopic" method="post" class="inline">{#
+                        #}<input type="hidden" name="topic" value="{{ ctx.topic.id }}">
+                        {%- if isSubscribed -%}
+                            <button type="submit" class="seamless m-r"><img src="/ui/theme-files/old/unsubscribe.gif" width="16" height="16" draggable="false" alt="{{ __("Unsubscribe from topic") }}"></button>
+                        {%- else -%}
+                            <button type="submit" class="seamless m-r"><img src="/ui/theme-files/old/subscribe.gif" width="16" height="16" draggable="false" alt="{{ __("Subscribe to topic") }}"></button>
+                        {%- endif -%}
+                    </form>
+                {%- endif -%}
                 {%- if canDelete -%}
                     <form action="?_action=deletetopic" method="post" class="inline">{#
                         #}<input type="hidden" name="topic" value="{{ ctx.topic.id }}">{#
@@ -87,7 +103,14 @@
         {{ __("Started by %user% on %date%", {
             "user": (ctx.topicAuthor is not null) ? ('<a href="?_action=viewuser&amp;user=' ~ ctx.topicAuthor.id|url_encode|e("html") ~ '">' ~ ctx.topicAuthor.displayName|e("html") ~ '</a>') : __("(deleted)"),
             "date": '<span class="_time">' ~ ctx.topic.creationDate.format("c")|e("html") ~ '</span>',
-        }) }}
+        }) }} &bull; {{ ___(
+            "%n% person is watching this topic",
+            "%n% people are watching this topic",
+            ctx.subscription_count,
+            {
+                n: ctx.subscription_count,
+            },
+        ) }}
     </div>
     {% if canEdit %}
         <form action="?_action=updatetopic" method="post" id="editHeading" style="display: none;" class="inline">
@@ -216,6 +239,10 @@ $(function() {
         }) }}</label><br>
         <input type="file" name="files[]" id="i_files" multiple accept="*/*"><br>
         <br>
+        {% if not isSubscribed %}
+            <label><input type="checkbox" name="subscribe" value="on" checked> {{ __("Subscribe to topic") }}</label><br>
+            <br>
+        {% endif %}
         <button type="submit">{{ __("Post reply") }}</button>
     </form>
 {% else %}
diff --git a/src/index.php b/src/index.php
index 8036a19..0580523 100644
--- a/src/index.php
+++ b/src/index.php
@@ -9,6 +9,8 @@ use mystic\forum\orm\Topic;
 use mystic\forum\orm\TopicLogMessage;
 use mystic\forum\orm\User;
 use mystic\forum\orm\UserPermissions;
+use mystic\forum\orm\PendingEmail;
+use mystic\forum\orm\Subscription;
 use mystic\forum\utils\RequestUtils;
 use mystic\forum\utils\StringUtils;
 use Twig\Environment;
@@ -244,11 +246,11 @@ function expandTags(string $contents): string {
     }, $contents);
 }
 
-function renderPostSummary(string $contents): string {
+function renderPostSummary(string $contents, int $maxLength = 100): string {
     $contents = renderPost($contents);
     // remove spoiler contents so they don't appear in summaries
     $contents = preg_replace('/<!--##SPOILER_START##-->(.*?)<!--##SPOILER_END##-->/s', '[ ' . __("Spoiler") . ' ]', $contents);
-    return htmlentities(html_entity_decode(StringUtils::truncate(strip_tags($contents), 100)));
+    return htmlentities(html_entity_decode(StringUtils::truncate(strip_tags($contents), $maxLength)));
 }
 
 function renderPost(string $contents): string {
@@ -299,6 +301,7 @@ function env(string $key): ?string {
 
 require_once __DIR__ . "/vendor/autoload.php";
 require_once __DIR__ . "/application/i18n.php";
+require_once __DIR__ . "/application/common.php";
 
 if ($_SERVER["REQUEST_METHOD"] === "GET" && isset($_GET["lang"])) {
     parse_str($_SERVER["QUERY_STRING"], $query);
@@ -319,7 +322,7 @@ i18n_locale($user_locale);
 
 $db = null;
 try {
-    $db = new Database(Database::getConnectionString("db", getenv("POSTGRES_USER"), getenv("POSTGRES_PASSWORD"), getenv("POSTGRES_DBNAME")));
+    $db = get_db();
 } catch (DatabaseConnectionException $ex) {
     msg_error(
         __("Failed to connect to database:\n%details%", [
@@ -337,6 +340,8 @@ $db->ensureTable(Topic::class);
 $db->ensureTable(Post::class);
 $db->ensureTable(Attachment::class);
 $db->ensureTable(TopicLogMessage::class);
+$db->ensureTable(PendingEmail::class);
+$db->ensureTable(Subscription::class);
 
 $superuser = new User();
 $superuser->id = "SUPERUSER";
diff --git a/src/ui/theme-files/modern/theme.css b/src/ui/theme-files/modern/theme.css
index 1f1cc3a..3a5f4af 100644
--- a/src/ui/theme-files/modern/theme.css
+++ b/src/ui/theme-files/modern/theme.css
@@ -224,6 +224,9 @@ footer {
         display: block;
     }
 }
+.checkbox {
+    margin-block: 8px;
+}
 .form-inline {
     display: inline-flex;
     margin: 0;
diff --git a/src/ui/theme-files/old/subscribe.gif b/src/ui/theme-files/old/subscribe.gif
new file mode 100644
index 0000000..195067c
--- /dev/null
+++ b/src/ui/theme-files/old/subscribe.gif
diff --git a/src/ui/theme-files/old/subscribe.png b/src/ui/theme-files/old/subscribe.png
new file mode 100644
index 0000000..2d3049d
--- /dev/null
+++ b/src/ui/theme-files/old/subscribe.png
diff --git a/src/ui/theme-files/old/unsubscribe.gif b/src/ui/theme-files/old/unsubscribe.gif
new file mode 100644
index 0000000..27f230a
--- /dev/null
+++ b/src/ui/theme-files/old/unsubscribe.gif
diff --git a/src/ui/theme-files/old/unsubscribe.png b/src/ui/theme-files/old/unsubscribe.png
new file mode 100644
index 0000000..396f009
--- /dev/null
+++ b/src/ui/theme-files/old/unsubscribe.png
diff --git a/with-env b/with-env
new file mode 100644
index 0000000..aabba50
--- /dev/null
+++ b/with-env
@@ -0,0 +1,5 @@
+#!/bin/bash
+
+set -e
+. <(xargs -0 bash -c 'printf "export %q\n" "$@"' -- < /proc/1/environ)
+$@