Support multiple pinned messages & related

- Rename `info_updated` -> `info_updates` to be consistent with `updates`.
- Relax triggers to only update `info_updates` instead of both updates
  and info_updates, and fix some trigger statements that were updating
  the wrong value.
- Add table for tracking (multiple) pinned messages.
- Trigger info_updates update when pinning/unpinning.

src/models.rs

@@ -160,8 +160,6 @@ pub struct Room {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub description: Option<String>,
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub pinned_message_id: Option<i64>,
-    #[serde(skip_serializing_if = "Option::is_none")]
     pub image_file_id: Option<i64>,
     pub created: f64,
     pub updates: i64,
@@ -177,7 +175,6 @@ impl Room {
             token: row.get(row.column_index("token")?)?,
             name: row.get(row.column_index("name")?)?,
             description: row.get(row.column_index("description")?)?,
-            pinned_message_id: row.get(row.column_index("pinned")?)?,
             image_file_id: row.get(row.column_index("image")?)?,
             created: row.get(row.column_index("created")?)?,
             updates: row.get(row.column_index("updates")?)?,
@@ -232,11 +229,13 @@ pub struct RoomMetadata {
     /// The human-readable room name
     pub name: String,
     /// Text description of the room
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub description: Option<String>,
     /// ID of an uploaded file that contains the image for this room
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub image_id: Option<i64>,
-    /// ID of a pinned message in this room
-    pub pinned_id: Option<i64>,
+    /// IDs of any pinned message in this room.
+    pub pinned_messages: Vec<i64>,
     /// List of non-admin public moderator Session IDs.  This list includes both room-specific and
     /// global moderators, but not admins and only if the moderator is configured as visible.
     pub moderators: Vec<String>,
@@ -246,14 +245,17 @@ pub struct RoomMetadata {
     pub admins: Vec<String>,
     /// List of hidden moderator Session IDs.  This field is omitted if the requesting user is not
     /// a moderator or admin.
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub hidden_mods: Option<Vec<String>>,
     /// List of hidden admin Session IDs.  This field is omitted if the requesting user is not a
     /// moderator or admin.
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub hidden_admins: Option<Vec<String>>,
-    /// Whether or not the requesting user has moderator powers.
-    pub moderator: bool,
-    /// Whether or not the requesting user has admin powers.
-    pub admin: bool
+    /// Will be present and true if the requesting user has moderator powers, omitted otherwise.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub moderator: Option<bool>,
+    /// Will be present and true if the requesting user has admin powers, omitted otherwise.
+    pub admin: Option<bool>
 }
 
 #[derive(Debug, Deserialize)]

src/schema.sql

@@ -10,9 +10,8 @@ CREATE TABLE rooms (
     description TEXT, /* Publicly visible room description */
     image INTEGER REFERENCES files(id) ON DELETE SET NULL,
     created FLOAT NOT NULL DEFAULT ((julianday('now') - 2440587.5)*86400.0), /* unix epoch */
-    pinned INTEGER REFERENCES messages(id) ON DELETE SET NULL,
     updates INTEGER NOT NULL DEFAULT 0, /* +1 for each new message, edit or deletion */
-    info_updated INTEGER NOT NULL DEFAULT 0, /* +1 for any room metadata update (name/desc/image/pinned/mods) */
+    info_updates INTEGER NOT NULL DEFAULT 0, /* +1 for any room metadata update (name/desc/image/pinned/mods) */
     read BOOLEAN NOT NULL DEFAULT TRUE, /* Whether users can read by default */
     write BOOLEAN NOT NULL DEFAULT TRUE, /* Whether users can post by default */
     upload BOOLEAN NOT NULL DEFAULT TRUE, /* Whether file uploads are allowed */
@@ -77,12 +76,13 @@ BEGIN
     WHERE id = NEW.id;
 END;
 
--- Trigger to remove the room's pinned message when that message is deleted
-CREATE TRIGGER messages_unpin_on_delete AFTER UPDATE OF data ON messages
-FOR EACH ROW WHEN NEW.data IS NULL
-BEGIN
-    UPDATE rooms SET pinned = NULL WHERE id = OLD.room AND pinned = OLD.id;
-END;
+CREATE TABLE pinned_messages (
+    room INTEGER NOT NULL REFERENCES rooms(id) ON DELETE CASCADE,
+    message INTEGER NOT NULL REFERENCES rooms(id) ON DELETE CASCADE,
+    updated INTEGER NOT NULL  DEFAULT 0, /* set to the room's `info_updated` counter when pinned (used for ordering). */
+    PRIMARY KEY(room, message)
+);
+
 
 -- Trigger to handle moving a message from one room to another; we reset the posted time to now, and
 -- reset the updated value to the new room's value so that the moved message is treated as a brand new message in
@@ -214,50 +214,62 @@ BEGIN
 END;
 
 
--- Triggers to update `rooms.info_updated` on metadata column changes
+-- Triggers to update `rooms.info_updates` on metadata column changes
 CREATE TRIGGER room_metadata_update AFTER UPDATE ON rooms
 FOR EACH ROW WHEN
     NEW.name IS NOT OLD.name OR
     NEW.description IS NOT OLD.description OR
-    NEW.image IS NOT OLD.image OR
-    NEW.pinned IS NOT OLD.pinned
+    NEW.image IS NOT OLD.image
 BEGIN
-    UPDATE rooms SET updates = updates + 1, info_updated = updates + 1 WHERE id = NEW.id;
+    UPDATE rooms SET updates = updates + 1, info_updates = info_updates + 1 WHERE id = NEW.id;
 END;
--- Triggers to update `info_updated` when the mod list changes:
+-- Triggers to update `info_updates` when the mod list changes:
 CREATE TRIGGER room_metadata_mods_insert AFTER INSERT ON user_permission_overrides
 FOR EACH ROW WHEN NEW.moderator OR NEW.admin
 BEGIN
-    UPDATE rooms SET updates = updates + 1, info_updated = updates + 1 WHERE id = NEW.room;
+    UPDATE rooms SET info_updates = info_updates + 1 WHERE id = NEW.room;
 END;
 CREATE TRIGGER room_metadata_mods_update AFTER UPDATE ON user_permission_overrides
 FOR EACH ROW WHEN NEW.moderator != OLD.moderator OR NEW.admin != OLD.admin
 BEGIN
-    UPDATE rooms SET updates = updates + 1, info_updated = updates + 1 WHERE id = NEW.room;
+    UPDATE rooms SET info_updates = info_updates + 1 WHERE id = NEW.room;
 END;
 CREATE TRIGGER room_metadata_mods_delete AFTER DELETE ON user_permission_overrides
 FOR EACH ROW WHEN OLD.moderator OR OLD.admin
 BEGIN
-    UPDATE rooms SET updates = updates + 1, info_updated = updates + 1 WHERE id = OLD.room;
+    UPDATE rooms SET info_updates = info_updates + 1 WHERE id = OLD.room;
 END;
--- Trigger to update `info_updated` of all rooms whenever we add/remove a global moderator/admin
+-- Trigger to update `info_updates` of all rooms whenever we add/remove a global moderator/admin
 -- because global mod settings affect the permissions of all rooms (and polling clients need to pick
 -- up on this).
 CREATE TRIGGER room_metadata_global_mods_insert AFTER INSERT ON users
 FOR EACH ROW WHEN (NEW.admin OR NEW.moderator) AND NEW.visible_mod
 BEGIN
-    UPDATE rooms SET updates = updates + 1, info_updated = updates + 1; -- WHERE everything!
+    UPDATE rooms SET info_updates = info_updates + 1; -- WHERE everything!
 END;
 CREATE TRIGGER room_metadata_global_mods_update AFTER UPDATE ON users
 FOR EACH ROW WHEN (NEW.moderator != OLD.moderator OR NEW.admin != OLD.admin) AND (NEW.visible_mod OR OLD.visible_mod)
 BEGIN
-    UPDATE rooms SET updates = updates + 1, info_updated = updates + 1; -- WHERE everything!
+    UPDATE rooms SET info_updates = info_updates + 1; -- WHERE everything!
 END;
 CREATE TRIGGER room_metadata_global_mods_delete AFTER DELETE ON users
 FOR EACH ROW WHEN (OLD.moderator OR OLD.admin) AND OLD.visible_mod
 BEGIN
-    UPDATE rooms SET updates = updates + 1, info_updated = updates + 1; -- WHERE everything!
+    UPDATE rooms SET info_updates = info_updates + 1; -- WHERE everything!
 END;
+-- Triggers for change to pinned messages
+CREATE TRIGGER room_metadata_pinned_add AFTER INSERT ON pinned_messages
+FOR EACH ROW
+BEGIN
+    UPDATE rooms SET info_updates = info_updates + 1 WHERE id = NEW.room;
+    UPDATE pinned_messages SET updated = (SELECT info_updates FROM rooms WHERE id = NEW.room) WHERE id = NEW.id;
+END;
+CREATE TRIGGER room_metadata_pinned_remove AFTER DELETE ON pinned_messages
+FOR EACH ROW
+BEGIN
+    UPDATE rooms SET info_updates = info_updates + 1 WHERE id = OLD.room;
+END;
+
 
 
 -- View of permissions; for users with an entry in user_permissions we use those values; for null