UPDATE: split the webapp in a widget and the app itself

This splits the webapp in:

* IronCalc (the widget to be published on npmjs)
* The frontend for our "service"
* Adds "dummy code" for the backend using sqlite

webapp/app.ironcalc.com/server/src/database.rs

@@ -0,0 +1,48 @@
+use std::io;
+
+use rocket_db_pools::Connection;
+
+use rocket_db_pools::{sqlx, Database};
+
+#[derive(Database)]
+#[database("ironcalc")]
+pub struct IronCalcDB(sqlx::SqlitePool);
+
+pub async fn get_model_list_from_db(mut db: Connection<IronCalcDB>) -> Result<Vec<String>, io::Error> {
+    let row: Vec<(String, )> = sqlx::query_as("SELECT * FROM models")
+        .fetch_all(&mut **db)
+        .await
+        .unwrap();
+    Ok(row.into_iter().map(|s| s.0).collect())
+}
+
+pub async fn add_model(
+    mut db: Connection<IronCalcDB>,
+    hash: &str,
+    bytes: &[u8],
+) -> Result<(), io::Error> {
+    sqlx::query("INSERT INTO models (hash, bytes) VALUES (?, ?)")
+        .bind(hash)
+        .bind(bytes)
+        .execute(&mut **db)
+        .await
+        .map_err(|e| {
+            io::Error::new(
+                io::ErrorKind::Other,
+                format!("Failed to save to the database: {}", e),
+            )
+        })?;
+    Ok(())
+}
+
+pub async fn select_model(
+    mut db: Connection<IronCalcDB>,
+    hash: &str,
+) -> Result<Vec<u8>, io::Error> {
+    let row: (Vec<u8>,) = sqlx::query_as("SELECT bytes FROM models WHERE hash = ?")
+        .bind(hash)
+        .fetch_one(&mut **db)
+        .await
+        .unwrap();
+    Ok(row.0)
+}