feat: initialize rust backend with axum server, seaorm models, and project scaffolding

backend/src/db.rs

@@ -0,0 +1,42 @@
+//! Database connection and migrations.
+
+use sea_orm::{ConnectionTrait, Database, DatabaseConnection, DbBackend, DbErr, Schema, Statement};
+use sea_orm::sea_query::SqliteQueryBuilder;
+
+use crate::config::Config;
+use crate::models::bio::{biomarker_entry, biomarker_type};
+use crate::models::user::{session, user};
+
+/// Connect to the SQLite database.
+pub async fn connect(config: &Config) -> Result<DatabaseConnection, DbErr> {
+    let db_path = &config.paths.database;
+
+    // Ensure the data directory exists
+    if let Some(parent) = std::path::Path::new(db_path).parent() {
+        std::fs::create_dir_all(parent).ok();
+    }
+
+    let db_url = format!("sqlite:{}?mode=rwc", db_path);
+    Database::connect(&db_url).await
+}
+
+/// Run migrations to create tables if they don't exist.
+pub async fn run_migrations(db: &DatabaseConnection) -> Result<(), DbErr> {
+    let schema = Schema::new(DbBackend::Sqlite);
+
+    // Create table statements
+    let statements = vec![
+        schema.create_table_from_entity(user::Entity),
+        schema.create_table_from_entity(session::Entity),
+        schema.create_table_from_entity(biomarker_type::Entity),
+        schema.create_table_from_entity(biomarker_entry::Entity),
+    ];
+
+    for mut stmt in statements {
+        let sql = stmt.if_not_exists().to_string(SqliteQueryBuilder);
+        db.execute(Statement::from_string(DbBackend::Sqlite, sql))
+            .await?;
+    }
+
+    Ok(())
+}