add subscribing and unsubscribing to threads

apps/threads.lua

@@ -9,6 +9,7 @@ local models = require("models")
 local Topics = models.Topics
 local Threads = models.Threads
 local Posts = models.Posts
+local Subscriptions = models.Subscriptions
 
 local POSTS_PER_PAGE = 10
 
@@ -97,7 +98,18 @@ app:get("thread", "/:slug", function(self)
   self.other_topics = db.query("SELECT topics.id, topics.name FROM topics")
   self.me = util.get_logged_in_user_or_transient(self)
   self.posts = posts
-
+  
+  if self.me:is_logged_in() then
+    self.is_subscribed = false
+    local subscription = Subscriptions:find({user_id = self.me.id, thread_id = thread.id})
+    if subscription then
+      self.is_subscribed = true
+      if posts[#posts].created_at > subscription.last_seen then
+        subscription:update({last_seen = os.time()})
+      end
+    end
+  end
+  
   self.page_title = thread.title
 
   return {render = "threads.thread"}
@@ -133,6 +145,10 @@ app:post("thread", "/:slug", function(self)
     return {redirect_to = self:url_for("thread", {slug = thread.slug}, {page = last_page}) .. "#latest-post"}
   end
   
+  if self.params.subscribe == "on" then
+    Subscriptions:create({user_id = user.id, thread_id = thread.id, last_seen = os.time()})
+  end
+  
   return {redirect_to = self:url_for("thread", {slug = thread.slug}, {page = last_page}) .. "#latest-post"}
 end)
 
@@ -206,4 +222,32 @@ app:post("thread_move", "/:slug/move", function(self)
   return {redirect_to = self:url_for("thread", {slug = self.params.slug})}
 end)
 
+app:post("thread_subscribe", "/:slug/subscribe", function(self)
+  local user = util.get_logged_in_user(self)
+  if not user then
+    return {status = 403}
+  end
+  local thread = Threads:find({slug = self.params.slug})
+  if not thread then
+    return {status = 404}
+  end
+  local subscription = Subscriptions:find({user_id = user.id, thread_id = thread.id})
+  if self.params.subscribe == "subscribe" then
+    local now = os.time()
+    if subscription then
+      subscription:delete()
+    end
+    Subscriptions:create({user_id = user.id, thread_id = thread.id, last_seen = now})
+    return {redirect_to = self:url_for("thread", {slug = thread.slug}, {after = self.params.first_visible_post})}
+  elseif self.params.subscribe == "unsubscribe" then
+    if not subscription then
+      return {status = 404}
+    end
+    subscription:delete()
+    return {redirect_to = self:url_for("thread", {slug = thread.slug}, {after = self.params.first_visible_post})}
+  end
+  
+  return {status = 400}
+end)
+
 return app

migrations.lua

@@ -102,4 +102,15 @@ return {
     
     db.query("CREATE INDEX idx_rate_limit_user_method ON api_rate_limits (user_id, method)")
   end,
+  
+  [13] = function ()
+    schema.create_table("subscriptions", {
+      {"id", types.integer{primary_key = true}},
+      {"user_id", "INTEGER REFERENCES users(id) ON DELETE CASCADE"},
+      {"thread_id", "INTEGER REFERENCES threads(id) ON DELETE CASCADE"},
+      {"last_seen", "INTEGER DEFAULT (unixepoch(CURRENT_TIMESTAMP)) NOT NULL"},
+    })
+    
+    db.query("CREATE INDEX idx_subscription_user_thread ON subscriptions (user_id, thread_id)")
+  end,
 }

models.lua

@@ -40,6 +40,7 @@ local ret = {
   PostHistory = Model:extend("post_history"),
   Sessions = Model:extend("sessions"),
   Avatars = Model:extend("avatars"),
+  Subscriptions = Model:extend("subscriptions"),
 }
 
 return ret

util.lua

@@ -105,13 +105,16 @@ function util.split_sentences(sentences, max_sentences)
 end
 
 ---@return string
-function util.get_post_url(req, post_id)
+function util.get_post_url(req, post_id, hash)
+  hash = hash ~= false
   local post = Posts:find({id = post_id})
   if not post then return "" end
   local thread = Threads:find({id = post.thread_id})
   if not thread then return "" end
   
-  return req:url_for("thread", {slug = thread.slug}, {after = post_id}) .. "#post-" .. post_id
+  local url = req:url_for("thread", {slug = thread.slug}, {after = post_id})
+  if not hash then return url end
+  return url .. "#post-" .. post_id
 end
 
 function util.infobox_message(msg)

views/common/babycode-editor.etlua

@@ -6,6 +6,12 @@
 %>
 <form class="post-edit-form" method="post" action="<%= url or "" %>">
   <% render ("views.common.babycode-editor-component", {ta_name = ta_name, prefill = prefill}) %>
+  <% if not cancel_url then %>
+    <span>
+      <input type="checkbox" id="subscribe" name="subscribe" checked>
+      <label for="subscribe">Subscribe to thread</label>
+    </span>
+  <% end %>
   <span>
   <input type=submit value="<%= save_button_text %>">
     <% if cancel_url then %>

views/threads/thread.etlua

@@ -14,29 +14,36 @@
     <% if is_stickied then %> &bullet; <i>stickied, so it's probably important</i>
     <% end %>
     </span>
-    <% if can_lock then %>
     <div>
-      <form class="modform" action="<%= url_for("thread_lock", {slug = thread.slug}) %>" method="post">
-        <input type=hidden value="<%= not is_locked %>" name="target_op">
-        <input class="warn" type="submit" value="<%= is_locked and "Unlock thread" or "Lock thread" %>">
-      </form>
-      <% if me:is_mod() then %>
-        <form class="modform" action="<%= url_for("thread_sticky", {slug = thread.slug}) %>" method="post">
-          <input type=hidden value="<%= not is_stickied %>" name="target_op">
-          <input class="warn" type="submit" value="<%= is_stickied and "Unsticky thread" or "Sticky thread" %>">
-        </form>
-        <form class="modform" action="<%= url_for("thread_move", {slug = thread.slug}) %>" method="post">
-          <label for="new_topic_id">Move to topic:</label>
-          <select style="width:200px;" id="new_topic_id" name="new_topic_id" autocomplete="off">
-            <% for _, topic in ipairs(other_topics) do %>
-              <option value="<%= topic.id %>" <%- thread.topic_id == topic.id and "selected disabled" or "" %>><%= topic.name %></option>
-            <% end %>
-          </select>
-          <input class="warn" type="submit" value="Move thread">
+      <% if me:is_logged_in() then %>
+        <form class="modform" action="<%= url_for("thread_subscribe", {slug = thread.slug}) %>" method="post">
+          <input type="hidden" name="first_visible_post" value=<%= posts[1].id %>>
+          <input type="hidden" name="subscribe" value=<%= is_subscribed and "unsubscribe" or "subscribe" %>>
+          <input type="submit" value="<%= is_subscribed and "Unsubscribe" or "Subscribe" %>">
         </form>
       <% end %>
+      <% if can_lock then %>
+        <form class="modform" action="<%= url_for("thread_lock", {slug = thread.slug}) %>" method="post">
+          <input type=hidden value="<%= not is_locked %>" name="target_op">
+          <input class="warn" type="submit" value="<%= is_locked and "Unlock thread" or "Lock thread" %>">
+        </form>
+        <% if me:is_mod() then %>
+          <form class="modform" action="<%= url_for("thread_sticky", {slug = thread.slug}) %>" method="post">
+            <input type=hidden value="<%= not is_stickied %>" name="target_op">
+            <input class="warn" type="submit" value="<%= is_stickied and "Unsticky thread" or "Sticky thread" %>">
+          </form>
+          <form class="modform" action="<%= url_for("thread_move", {slug = thread.slug}) %>" method="post">
+            <label for="new_topic_id">Move to topic:</label>
+            <select style="width:200px;" id="new_topic_id" name="new_topic_id" autocomplete="off">
+              <% for _, topic in ipairs(other_topics) do %>
+                <option value="<%= topic.id %>" <%- thread.topic_id == topic.id and "selected disabled" or "" %>><%= topic.name %></option>
+              <% end %>
+            </select>
+            <input class="warn" type="submit" value="Move thread">
+          </form>
+        <% end %>
+      <% end %>
     </div>
-    <% end %>
   </nav>
   <% for i, post in ipairs(posts) do %>
     <% render("views.threads.post", {post = post, render_sig = true, is_latest = i == #posts}) %>