From 7b6af31ed55c19e27d44e21b5673a357469e83ee Mon Sep 17 00:00:00 2001
From: Stefano Pigozzi <me@steffo.eu>
Date: Fri, 13 Dec 2024 02:43:06 +0100
Subject: [PATCH] `database`: Create `connect` feature

---
 .idea/acrate.iml                              |  1 +
 acrate_database/Cargo.toml                    |  4 +-
 .../src/bin/acrate_database_migrate.rs        | 33 ++++--------
 acrate_database/src/config.rs                 |  5 ++
 acrate_database/src/connect.rs                | 51 +++++++++++++++++++
 acrate_database/src/lib.rs                    |  8 +++
 6 files changed, 78 insertions(+), 24 deletions(-)
 create mode 100644 acrate_database/src/config.rs
 create mode 100644 acrate_database/src/connect.rs

diff --git a/.idea/acrate.iml b/.idea/acrate.iml
index ac0db0c..8ef4dcf 100644
--- a/.idea/acrate.iml
+++ b/.idea/acrate.iml
@@ -11,6 +11,7 @@
       <sourceFolder url="file://$MODULE_DIR$/acrate_rd/tests" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/acrate_mime/src" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/acrate_rdserver/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/acrate_database/tests" isTestSource="true" />
       <excludeFolder url="file://$MODULE_DIR$/target" />
     </content>
     <orderEntry type="inheritedJdk" />
diff --git a/acrate_database/Cargo.toml b/acrate_database/Cargo.toml
index d2afc81..f920aef 100644
--- a/acrate_database/Cargo.toml
+++ b/acrate_database/Cargo.toml
@@ -21,7 +21,9 @@ pretty_env_logger = { version = "0.5.0", optional = true }
 uuid = "1.11.0"
 
 [features]
-bin = ["diesel_migrations", "micronfig", "pretty_env_logger"]
+default = ["connect"]
+bin = ["diesel_migrations", "pretty_env_logger", "connect"]
+connect = ["micronfig"]
 
 [lib]
 name = "acrate_database"
diff --git a/acrate_database/src/bin/acrate_database_migrate.rs b/acrate_database/src/bin/acrate_database_migrate.rs
index c678882..b99a4a9 100644
--- a/acrate_database/src/bin/acrate_database_migrate.rs
+++ b/acrate_database/src/bin/acrate_database_migrate.rs
@@ -15,36 +15,23 @@
 use std::process::exit;
 use diesel::{Connection, PgConnection};
 use diesel_migrations::{EmbeddedMigrations, MigrationHarness};
-
-mod config {
-	micronfig::config! {
-		ACRATE_DATABASE_DATABASE_URL: String,
-	}
-}
+use acrate_database::connect::managed_connect_sync;
 
 pub const MIGRATIONS: EmbeddedMigrations = diesel_migrations::embed_migrations!();
 
-fn main() {
-	pretty_env_logger::init();
-	log::info!("Logging initialized successfully!");
-	
-	log::trace!("Determining database URL...");
-	let db = config::ACRATE_DATABASE_DATABASE_URL();
-	
-	log::debug!("Connecting to: {db:?}");
-	let mut db = match PgConnection::establish(db) {
-		Err(e) => {
-			log::error!("Failed to connect to the PostgreSQL database: {e:#?}");
-			exit(1);
-		}
-		Ok(db) => db,
-	};
-	
+fn managed_run_migrations(mut db: PgConnection) {
 	log::debug!("Running migrations...");
 	if let Err(e) = db.run_pending_migrations(MIGRATIONS) {
 		log::error!("Failed to perform migration: {e:#?}");
 		exit(2);
 	};
-	
 	log::info!("Migrations applied successfully!")
 }
+
+fn main() {
+	pretty_env_logger::init();
+	log::info!("Logging initialized successfully!");
+	
+	let db = managed_connect_sync();
+	managed_run_migrations(db);
+}
diff --git a/acrate_database/src/config.rs b/acrate_database/src/config.rs
new file mode 100644
index 0000000..e2d0bfe
--- /dev/null
+++ b/acrate_database/src/config.rs
@@ -0,0 +1,5 @@
+//! Configuration relative to the database that applies to all crates making use of it.
+
+micronfig::config! {
+	ACRATE_DATABASE_URL: String,
+}
diff --git a/acrate_database/src/connect.rs b/acrate_database/src/connect.rs
new file mode 100644
index 0000000..5127692
--- /dev/null
+++ b/acrate_database/src/connect.rs
@@ -0,0 +1,51 @@
+use diesel::{Connection, ConnectionResult, PgConnection};
+use diesel_async::{AsyncConnection, AsyncPgConnection};
+use crate::config;
+
+/// Create a [`PgConnection`] to the configured database.
+pub fn connect_sync() -> ConnectionResult<PgConnection> {
+	log::trace!("Determining the database URL for a sync connection...");
+	let database_url = config::ACRATE_DATABASE_URL();
+	
+	log::trace!("Establishing a sync connection to the database at: {database_url:?}");
+	PgConnection::establish(database_url)
+}
+
+/// Create an [`AsyncPgConnection`] to the configured database.
+pub async fn connect_async() -> ConnectionResult<AsyncPgConnection> {
+	log::trace!("Determining the database URL for an async connection...");
+	let database_url = config::ACRATE_DATABASE_URL();
+	
+	log::trace!("Establishing an async connection to the database at: {database_url:?}");
+	AsyncPgConnection::establish(database_url).await
+}
+
+/// Run [`connect_sync`], then handle errors by logging the error and exiting the process with `1`.
+pub fn managed_connect_sync() -> PgConnection {
+	log::trace!("Attempting a managed sync connection to the database...");
+	
+	match connect_sync() {
+		Err(e) => {
+			log::error!("Failed to connect to the database: {e:#?}");
+			std::process::exit(1);
+		},
+		Ok(conn) => {
+			conn
+		},
+	}
+}
+
+/// Run [`connect_async`], then handle errors by logging the error and exiting the process with `1`.
+pub async fn managed_connect_async() -> AsyncPgConnection {
+	log::trace!("Attempting a managed async connection to the database...");
+	
+	match connect_async().await {
+		Err(e) => {
+			log::error!("Failed to connect to the database: {e:#?}");
+			std::process::exit(1);
+		},
+		Ok(conn) => {
+			conn
+		},
+	}
+}
diff --git a/acrate_database/src/lib.rs b/acrate_database/src/lib.rs
index 42af5be..66a61d0 100644
--- a/acrate_database/src/lib.rs
+++ b/acrate_database/src/lib.rs
@@ -6,7 +6,15 @@
 mod schema;
 
 pub mod meta;
+
 mod macros;
 
+#[cfg(feature = "connect")]
+mod config;
+
+#[cfg(feature = "connect")]
+pub mod connect;
+
 pub use diesel;
+
 pub use diesel_async;