1 files changed, 317 insertions, 0 deletions
diff --git a/web/converse/src/db.rs b/web/converse/src/db.rs
new file mode 100644
index 000000000000..a0d8915504d6
--- /dev/null
+++ b/web/converse/src/db.rs
@@ -0,0 +1,317 @@
+// 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 executor, which holds the
+//! database connection and performs queries on it.
+
+use crate::errors::{ConverseError, Result};
+use crate::models::*;
+use actix::prelude::*;
+use diesel::prelude::*;
+use diesel::r2d2::{ConnectionManager, Pool};
+use diesel::sql_types::Text;
+use diesel::{self, sql_query};
+
+/// 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
+"#;
+
+const REFRESH_QUERY: &'static str = "REFRESH MATERIALIZED VIEW search_index";
+
+pub struct DbExecutor(pub Pool<ConnectionManager<PgConnection>>);
+
+impl DbExecutor {
+    /// Request a list of threads.
+    // TODO(tazjin): This should support pagination.
+    pub fn list_threads(&self) -> Result<Vec<ThreadIndex>> {
+        use crate::schema::thread_index::dsl::*;
+
+        let conn = self.0.get()?;
+        let results = thread_index.load::<ThreadIndex>(&conn)?;
+        Ok(results)
+    }
+
+    /// Look up a user based on their email-address. If the user does
+    /// not exist, it is created.
+    pub fn lookup_or_create_user(&self, user_email: &str, user_name: &str) -> Result<User> {
+        use crate::schema::users;
+        use crate::schema::users::dsl::*;
+
+        let conn = self.0.get()?;
+
+        let opt_user = users.filter(email.eq(email)).first(&conn).optional()?;
+
+        if let Some(user) = opt_user {
+            Ok(user)
+        } else {
+            let new_user = NewUser {
+                email: user_email.to_string(),
+                name: user_name.to_string(),
+            };
+
+            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)
+        }
+    }
+
+    /// Fetch a specific thread and return it with its posts.
+    pub fn get_thread(&self, thread_id: i32) -> Result<(Thread, Vec<SimplePost>)> {
+        use crate::schema::simple_posts::dsl::id;
+        use crate::schema::threads::dsl::*;
+
+        let conn = self.0.get()?;
+        let thread_result: Thread = threads.find(thread_id).first(&conn)?;
+
+        let post_list = SimplePost::belonging_to(&thread_result)
+            .order_by(id.asc())
+            .load::<SimplePost>(&conn)?;
+
+        Ok((thread_result, post_list))
+    }
+
+    /// Fetch a specific post.
+    pub fn get_post(&self, post_id: i32) -> Result<SimplePost> {
+        use crate::schema::simple_posts::dsl::*;
+        let conn = self.0.get()?;
+        Ok(simple_posts.find(post_id).first(&conn)?)
+    }
+
+    /// Update the content of a post.
+    pub fn update_post(&self, post_id: i32, post_text: String) -> Result<Post> {
+        use crate::schema::posts::dsl::*;
+        let conn = self.0.get()?;
+        let updated = diesel::update(posts.find(post_id))
+            .set(body.eq(post_text))
+            .get_result(&conn)?;
+
+        Ok(updated)
+    }
+
+    /// Create a new thread.
+    pub fn create_thread(&self, new_thread: NewThread, post_text: String) -> Result<Thread> {
+        use crate::schema::{posts, threads};
+
+        let conn = self.0.get()?;
+
+        conn.transaction::<Thread, ConverseError, _>(|| {
+            // First insert the thread structure itself
+            let thread: Thread = diesel::insert_into(threads::table)
+                .values(&new_thread)
+                .get_result(&conn)?;
+
+            // ... then create the first post in the thread.
+            let new_post = NewPost {
+                thread_id: thread.id,
+                body: post_text,
+                user_id: new_thread.user_id,
+            };
+
+            diesel::insert_into(posts::table)
+                .values(&new_post)
+                .execute(&conn)?;
+
+            Ok(thread)
+        })
+    }
+
+    /// Create a new post.
+    pub fn create_post(&self, new_post: NewPost) -> Result<Post> {
+        use crate::schema::posts;
+
+        let conn = self.0.get()?;
+
+        let closed: bool = {
+            use crate::schema::threads::dsl::*;
+            threads
+                .select(closed)
+                .find(new_post.thread_id)
+                .first(&conn)?
+        };
+
+        if closed {
+            return Err(ConverseError::ThreadClosed {
+                id: new_post.thread_id,
+            });
+        }
+
+        Ok(diesel::insert_into(posts::table)
+            .values(&new_post)
+            .get_result(&conn)?)
+    }
+
+    /// Search for posts.
+    pub fn search_posts(&self, query: String) -> Result<Vec<SearchResult>> {
+        let conn = self.0.get()?;
+
+        let search_results = sql_query(SEARCH_QUERY)
+            .bind::<Text, _>(query)
+            .get_results::<SearchResult>(&conn)?;
+
+        Ok(search_results)
+    }
+
+    /// Trigger a refresh of the view used for full-text searching.
+    pub fn refresh_search_view(&self) -> Result<()> {
+        let conn = self.0.get()?;
+        debug!("Refreshing search_index view in DB");
+        sql_query(REFRESH_QUERY).execute(&conn)?;
+        Ok(())
+    }
+}
+
+// Old actor implementation:
+
+impl Actor for DbExecutor {
+    type Context = SyncContext<Self>;
+}
+
+/// 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, _: LookupOrCreateUser, _: &mut Self::Context) -> Self::Result {
+        unimplemented!()
+    }
+}
+
+/// 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, _: GetThread, _: &mut Self::Context) -> Self::Result {
+        unimplemented!()
+    }
+}
+
+/// 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, _: GetPost, _: &mut Self::Context) -> Self::Result {
+        unimplemented!()
+    }
+}
+
+/// 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, _: UpdatePost, _: &mut Self::Context) -> Self::Result {
+        unimplemented!()
+    }
+}
+
+/// 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, _: CreateThread, _: &mut Self::Context) -> Self::Result {
+        unimplemented!()
+    }
+}
+
+/// 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, _: CreatePost, _: &mut Self::Context) -> Self::Result {
+        unimplemented!()
+    }
+}
+
+/// Message used to search for posts
+#[derive(Deserialize)]
+pub struct SearchPosts {
+    pub query: String,
+}
+message!(SearchPosts, Result<Vec<SearchResult>>);
+
+impl Handler<SearchPosts> for DbExecutor {
+    type Result = <SearchPosts as Message>::Result;
+
+    fn handle(&mut self, _: SearchPosts, _: &mut Self::Context) -> Self::Result {
+        unimplemented!()
+    }
+}
+
+/// Message that triggers a refresh of the view used for full-text
+/// searching.
+pub struct RefreshSearchView;
+message!(RefreshSearchView, Result<()>);
+
+impl Handler<RefreshSearchView> for DbExecutor {
+    type Result = Result<()>;
+
+    fn handle(&mut self, _: RefreshSearchView, _: &mut Self::Context) -> Self::Result {
+        unimplemented!()
+    }
+}