feat(web/converse): Import repository r/2440

Imports the converse forum software I wrote a few years ago. I want to
clean this up a bit and try using Hotwire with it.

Note: The original repository was AGPL-3.0 licensed. I'm the copyright
holder and have relicensed it to GPL-3.0 in the commit that is being
merged.

Imported from: https://github.com/tazjin/converse

git-subtree-dir: web/converse
git-subtree-mainline: 386afdc794eefd5bcbc47a3fd7b898a07f69f978
git-subtree-split: 09168021e7405f6b83798d0b43aa6e69e744ae87
Change-Id: Ia8b587db5174ef5b3c52910d3d027199150c58e0

1 files changed, 282 insertions, 0 deletions

diff --git a/web/converse/src/db.rs b/web/converse/src/db.rs
new file mode 100644
index 000000000000..e20349944402
--- /dev/null
+++ b/web/converse/src/db.rs
@@ -0,0 +1,282 @@
+// Copyright (C) 2018-2021 Vincent Ambo <tazjin@tvl.su>
+//
+// This file is part of Converse.
+//
+// This program is free software: you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see
+// <https://www.gnu.org/licenses/>.
+
+//! This module implements the database connection actor.
+
+use actix::prelude::*;
+use diesel::{self, sql_query};
+use diesel::sql_types::Text;
+use diesel::prelude::*;
+use diesel::r2d2::{Pool, ConnectionManager};
+use models::*;
+use errors::{ConverseError, Result};
+
+/// The DB actor itself. Several of these will be run in parallel by
+/// `SyncArbiter`.
+pub struct DbExecutor(pub Pool<ConnectionManager<PgConnection>>);
+
+impl Actor for DbExecutor {
+    type Context = SyncContext<Self>;
+}
+
+/// Message used to request a list of threads.
+/// TODO: This should support page numbers.
+pub struct ListThreads;
+message!(ListThreads, Result<Vec<ThreadIndex>>);
+
+impl Handler<ListThreads> for DbExecutor {
+    type Result = <ListThreads as Message>::Result;
+
+    fn handle(&mut self, _: ListThreads, _: &mut Self::Context) -> Self::Result {
+        use schema::thread_index::dsl::*;
+
+        let conn = self.0.get()?;
+        let results = thread_index
+            .load::<ThreadIndex>(&conn)?;
+        Ok(results)
+    }
+}
+
+/// Message used to look up a user based on their email-address. If
+/// the user does not exist, it is created.
+pub struct LookupOrCreateUser {
+    pub email: String,
+    pub name: String,
+}
+
+message!(LookupOrCreateUser, Result<User>);
+
+impl Handler<LookupOrCreateUser> for DbExecutor {
+    type Result = <LookupOrCreateUser as Message>::Result;
+
+    fn handle(&mut self,
+              msg: LookupOrCreateUser,
+              _: &mut Self::Context) -> Self::Result {
+        use schema::users;
+        use schema::users::dsl::*;
+
+        let conn = self.0.get()?;
+
+        let opt_user = users
+            .filter(email.eq(&msg.email))
+            .first(&conn).optional()?;
+
+        if let Some(user) = opt_user {
+            Ok(user)
+        } else {
+            let new_user = NewUser {
+                email: msg.email,
+                name: msg.name,
+            };
+
+            let user: User = diesel::insert_into(users::table)
+                .values(&new_user)
+                .get_result(&conn)?;
+
+            info!("Created new user {} with ID {}", new_user.email, user.id);
+
+            Ok(user)
+        }
+    }
+}
+
+/// Message used to fetch a specific thread. Returns the thread and
+/// its posts.
+pub struct GetThread(pub i32);
+message!(GetThread, Result<(Thread, Vec<SimplePost>)>);
+
+impl Handler<GetThread> for DbExecutor {
+    type Result = <GetThread as Message>::Result;
+
+    fn handle(&mut self, msg: GetThread, _: &mut Self::Context) -> Self::Result {
+        use schema::threads::dsl::*;
+        use schema::simple_posts::dsl::id;
+
+        let conn = self.0.get()?;
+        let thread_result: Thread = threads
+            .find(msg.0).first(&conn)?;
+
+        let post_list = SimplePost::belonging_to(&thread_result)
+            .order_by(id.asc())
+            .load::<SimplePost>(&conn)?;
+
+        Ok((thread_result, post_list))
+    }
+}
+
+/// Message used to fetch a specific post.
+#[derive(Deserialize, Debug)]
+pub struct GetPost { pub id: i32 }
+
+message!(GetPost, Result<SimplePost>);
+
+impl Handler<GetPost> for DbExecutor {
+    type Result = <GetPost as Message>::Result;
+
+    fn handle(&mut self, msg: GetPost, _: &mut Self::Context) -> Self::Result {
+        use schema::simple_posts::dsl::*;
+        let conn = self.0.get()?;
+        Ok(simple_posts.find(msg.id).first(&conn)?)
+    }
+}
+
+/// Message used to update the content of a post.
+#[derive(Deserialize)]
+pub struct UpdatePost {
+    pub post_id: i32,
+    pub post: String,
+}
+
+message!(UpdatePost, Result<Post>);
+
+impl Handler<UpdatePost> for DbExecutor {
+    type Result = Result<Post>;
+
+    fn handle(&mut self, msg: UpdatePost, _: &mut Self::Context) -> Self::Result {
+        use schema::posts::dsl::*;
+        let conn = self.0.get()?;
+        let updated = diesel::update(posts.find(msg.post_id))
+            .set(body.eq(msg.post))
+            .get_result(&conn)?;
+
+        Ok(updated)
+    }
+}
+
+/// Message used to create a new thread
+pub struct CreateThread {
+    pub new_thread: NewThread,
+    pub post: String,
+}
+message!(CreateThread, Result<Thread>);
+
+impl Handler<CreateThread> for DbExecutor {
+    type Result = <CreateThread as Message>::Result;
+
+    fn handle(&mut self, msg: CreateThread, _: &mut Self::Context) -> Self::Result {
+        use schema::threads;
+        use schema::posts;
+
+        let conn = self.0.get()?;
+
+        conn.transaction::<Thread, ConverseError, _>(|| {
+            // First insert the thread structure itself
+            let thread: Thread = diesel::insert_into(threads::table)
+                .values(&msg.new_thread)
+                .get_result(&conn)?;
+
+            // ... then create the first post in the thread.
+            let new_post = NewPost {
+                thread_id: thread.id,
+                body: msg.post,
+                user_id: msg.new_thread.user_id,
+            };
+
+            diesel::insert_into(posts::table)
+                .values(&new_post)
+                .execute(&conn)?;
+
+            Ok(thread)
+        })
+    }
+}
+
+/// Message used to create a new reply
+pub struct CreatePost(pub NewPost);
+message!(CreatePost, Result<Post>);
+
+impl Handler<CreatePost> for DbExecutor {
+    type Result = <CreatePost as Message>::Result;
+
+    fn handle(&mut self, msg: CreatePost, _: &mut Self::Context) -> Self::Result {
+        use schema::posts;
+
+        let conn = self.0.get()?;
+
+        let closed: bool = {
+            use schema::threads::dsl::*;
+            threads.select(closed)
+                .find(msg.0.thread_id)
+                .first(&conn)?
+        };
+
+        if closed {
+            return Err(ConverseError::ThreadClosed {
+                id: msg.0.thread_id
+            })
+        }
+
+        Ok(diesel::insert_into(posts::table)
+           .values(&msg.0)
+           .get_result(&conn)?)
+    }
+}
+
+/// Message used to search for posts
+#[derive(Deserialize)]
+pub struct SearchPosts { pub query: String }
+message!(SearchPosts, Result<Vec<SearchResult>>);
+
+/// Raw PostgreSQL query used to perform full-text search on posts
+/// with a supplied phrase. For now, the query language is hardcoded
+/// to English and only "plain" queries (i.e. no searches for exact
+/// matches or more advanced query syntax) are supported.
+const SEARCH_QUERY: &'static str = r#"
+WITH search_query (query) AS (VALUES (plainto_tsquery('english', $1)))
+SELECT post_id,
+       thread_id,
+       author,
+       title,
+       ts_headline('english', body, query) AS headline
+  FROM search_index, search_query
+  WHERE document @@ query
+  ORDER BY ts_rank(document, query) DESC
+  LIMIT 50
+"#;
+
+impl Handler<SearchPosts> for DbExecutor {
+    type Result = <SearchPosts as Message>::Result;
+
+    fn handle(&mut self, msg: SearchPosts, _: &mut Self::Context) -> Self::Result {
+        let conn = self.0.get()?;
+
+        let search_results = sql_query(SEARCH_QUERY)
+            .bind::<Text, _>(msg.query)
+            .get_results::<SearchResult>(&conn)?;
+
+        Ok(search_results)
+    }
+}
+
+/// Message that triggers a refresh of the view used for full-text
+/// searching.
+pub struct RefreshSearchView;
+message!(RefreshSearchView, Result<()>);
+
+const REFRESH_QUERY: &'static str = "REFRESH MATERIALIZED VIEW search_index";
+
+impl Handler<RefreshSearchView> for DbExecutor {
+    type Result = Result<()>;
+
+    fn handle(&mut self, _: RefreshSearchView, _: &mut Self::Context) -> Self::Result {
+        let conn = self.0.get()?;
+        debug!("Refreshing search_index view in DB");
+        sql_query(REFRESH_QUERY).execute(&conn)?;
+        Ok(())
+    }
+}