feat: make the web version fully working (#67)

Reviewed-on: #67

crates/state/src/web_database.rs

@@ -0,0 +1,62 @@
+use std::cell::RefCell;
+use std::sync::Arc;
+
+use nostr_memory::prelude::*;
+use nostr_sqlite::prelude::NostrSqlite;
+use sqlite_wasm_rs::WasmOsCallback;
+use sqlite_wasm_vfs::relaxed_idb;
+
+const DATABASE_PATH: &str = "coop.sqlite3";
+const VFS_NAME: &str = "coop-relaxed-idb";
+
+thread_local! {
+    static DATABASE: RefCell<Option<NostrSqlite>> = const { RefCell::new(None) };
+}
+
+/// Install the IndexedDB storage backend and open the database.
+pub async fn open() {
+    match open_persistent().await {
+        Some(database) => DATABASE.with(|slot| *slot.borrow_mut() = Some(database)),
+        None => log::error!("Falling back to the in-memory nostr database"),
+    }
+}
+
+/// Hand the opened database to the client constructor
+pub(crate) fn take() -> Arc<dyn NostrDatabase> {
+    let database = DATABASE.with(|slot| slot.borrow_mut().take());
+
+    match database {
+        Some(database) => Arc::new(database),
+        None => {
+            log::error!("Persistent web database was not opened, falling back to memory");
+            Arc::new(MemoryDatabase::unbounded())
+        }
+    }
+}
+
+/// Open the database on IndexedDB storage, or `None` when unavailable
+async fn open_persistent() -> Option<NostrSqlite> {
+    let options = relaxed_idb::RelaxedIdbCfgBuilder::new()
+        .vfs_name(VFS_NAME)
+        .build();
+
+    if let Err(e) = relaxed_idb::install::<WasmOsCallback>(&options, true).await {
+        log::warn!("IndexedDB storage unavailable: {e:?}");
+        return None;
+    }
+
+    match NostrSqlite::builder()
+        .persistent_with_vfs(DATABASE_PATH, VFS_NAME)
+        .build()
+        .await
+    {
+        Ok(database) => {
+            log::info!("Nostr database opened on IndexedDB storage");
+            Some(database)
+        }
+        Err(e) => {
+            log::error!("Failed to open the nostr database on IndexedDB: {e:?}");
+            None
+        }
+    }
+}