feat: nip4e (#188)

* encryption keys

* .

* .

* move nip4e to device crate

* .

* .

* use i18n for device crate

* refactor

* refactor

* .

* add reset button

* send message with encryption keys

* clean up

* .

* choose signer

* fix

* update i18n

* fix sending

crates/key_store/src/lib.rs

@@ -0,0 +1,96 @@
+use std::sync::{Arc, LazyLock};
+
+use gpui::{App, AppContext, Context, Entity, Global, Task};
+use smallvec::{smallvec, SmallVec};
+
+use crate::backend::{FileProvider, KeyBackend, KeyringProvider};
+
+pub mod backend;
+
+static DISABLE_KEYRING: LazyLock<bool> =
+    LazyLock::new(|| std::env::var("DISABLE_KEYRING").is_ok_and(|value| !value.is_empty()));
+
+pub fn init(cx: &mut App) {
+    KeyStore::set_global(cx.new(KeyStore::new), cx);
+}
+
+struct GlobalKeyStore(Entity<KeyStore>);
+
+impl Global for GlobalKeyStore {}
+
+pub struct KeyStore {
+    /// Key Store for storing credentials
+    pub backend: Arc<dyn KeyBackend>,
+
+    /// Whether the keystore has been initialized
+    pub initialized: bool,
+
+    /// Tasks for asynchronous operations
+    _tasks: SmallVec<[Task<()>; 1]>,
+}
+
+impl KeyStore {
+    /// Retrieve the global keys state
+    pub fn global(cx: &App) -> Entity<Self> {
+        cx.global::<GlobalKeyStore>().0.clone()
+    }
+
+    /// Set the global keys instance
+    pub(crate) fn set_global(state: Entity<Self>, cx: &mut App) {
+        cx.set_global(GlobalKeyStore(state));
+    }
+
+    /// Create a new keys instance
+    pub(crate) fn new(cx: &mut Context<Self>) -> Self {
+        // Use the file system for keystore in development or when the user specifies it
+        let use_file_keystore = cfg!(debug_assertions) || *DISABLE_KEYRING;
+
+        // Construct the key backend
+        let backend: Arc<dyn KeyBackend> = if use_file_keystore {
+            Arc::new(FileProvider::default())
+        } else {
+            Arc::new(KeyringProvider)
+        };
+
+        // Only used for testing keyring availability on the user's system
+        let read_credential = cx.read_credentials("Coop");
+
+        let mut tasks = smallvec![];
+
+        tasks.push(
+            // Verify the keyring availability
+            cx.spawn(async move |this, cx| {
+                let result = read_credential.await;
+
+                this.update(cx, |this, cx| {
+                    if let Err(e) = result {
+                        log::error!("Keyring error: {e}");
+                        // For Linux:
+                        // The user has not installed secret service on their system
+                        // Fall back to the file provider
+                        this.backend = Arc::new(FileProvider::default());
+                    }
+                    this.initialized = true;
+                    cx.notify();
+                })
+                .ok();
+            }),
+        );
+
+        Self {
+            backend,
+            initialized: false,
+            _tasks: tasks,
+        }
+    }
+
+    /// Returns the key backend.
+    pub fn backend(&self) -> Arc<dyn KeyBackend> {
+        Arc::clone(&self.backend)
+    }
+
+    /// Returns true if the keystore is a file key backend.
+    pub fn is_using_file_keystore(&self) -> bool {
+        self.backend.name() == "file"
+    }
+}