feat: implement a basic backend (#1)

Reviewed-on: https://git.reya.su/reya/signed/pulls/1

crates/signed_state/src/lib.rs

@@ -0,0 +1,50 @@
+mod backend;
+mod profile;
+mod repo;
+mod repo_list;
+
+use std::path::Path;
+
+pub use backend::{Backend, BackendEvent};
+use gpui::{App, AppContext, Entity};
+pub use profile::{Profile, ProfileStore, shorten_pubkey};
+pub use repo::RepoStore;
+pub use repo_list::RepoListStore;
+use signed_nostr::NostrBackend;
+
+/// Initialize the backend and stores, and install them as globals. Call once
+/// at startup, before opening any window that uses the stores.
+#[cfg(not(target_arch = "wasm32"))]
+pub fn init(db_path: impl AsRef<Path>, cx: &mut App) -> Entity<Backend> {
+    // rustls uses the `aws_lc_rs` provider by default; ignore if already installed.
+    rustls::crypto::aws_lc_rs::default_provider()
+        .install_default()
+        .ok();
+
+    let path = db_path.as_ref().to_path_buf();
+    let inner = cx.foreground_executor().block_on(async move {
+        NostrBackend::new(path)
+            .await
+            .expect("failed to initialize nostr backend")
+    });
+
+    let entity = cx.new(|cx| Backend::new(inner, cx));
+    Backend::set_global(entity.clone(), cx);
+
+    ProfileStore::set_global(cx.new(ProfileStore::new), cx);
+
+    entity
+}
+
+/// Initialize the backend with an in-memory database on wasm.
+#[cfg(target_arch = "wasm32")]
+pub fn init(cx: &mut App) -> Entity<Backend> {
+    let inner = NostrBackend::new().expect("failed to initialize nostr backend");
+
+    let entity = cx.new(|cx| Backend::new(inner, cx));
+    Backend::set_global(entity.clone(), cx);
+
+    ProfileStore::set_global(cx.new(ProfileStore::new), cx);
+
+    entity
+}