zeta: Add CLI tool for querying edit predictions and related context (#35491)

Release Notes:

- N/A

---------

Co-authored-by: Marshall Bowers <git@maxdeviant.com>

crates/zeta_cli/src/headless.rs

@@ -0,0 +1,128 @@
+use client::{Client, ProxySettings, UserStore};
+use extension::ExtensionHostProxy;
+use fs::RealFs;
+use gpui::http_client::read_proxy_from_env;
+use gpui::{App, AppContext, Entity};
+use gpui_tokio::Tokio;
+use language::LanguageRegistry;
+use language_extension::LspAccess;
+use node_runtime::{NodeBinaryOptions, NodeRuntime};
+use project::Project;
+use project::project_settings::ProjectSettings;
+use release_channel::AppVersion;
+use reqwest_client::ReqwestClient;
+use settings::{Settings, SettingsStore};
+use std::path::PathBuf;
+use std::sync::Arc;
+use util::ResultExt as _;
+
+/// Headless subset of `workspace::AppState`.
+pub struct ZetaCliAppState {
+    pub languages: Arc<LanguageRegistry>,
+    pub client: Arc<Client>,
+    pub user_store: Entity<UserStore>,
+    pub fs: Arc<dyn fs::Fs>,
+    pub node_runtime: NodeRuntime,
+}
+
+// TODO: dedupe with crates/eval/src/eval.rs
+pub fn init(cx: &mut App) -> ZetaCliAppState {
+    let app_version = AppVersion::load(env!("ZED_PKG_VERSION"));
+    release_channel::init(app_version, cx);
+    gpui_tokio::init(cx);
+
+    let mut settings_store = SettingsStore::new(cx);
+    settings_store
+        .set_default_settings(settings::default_settings().as_ref(), cx)
+        .unwrap();
+    cx.set_global(settings_store);
+    client::init_settings(cx);
+
+    // Set User-Agent so we can download language servers from GitHub
+    let user_agent = format!(
+        "Zed/{} ({}; {})",
+        app_version,
+        std::env::consts::OS,
+        std::env::consts::ARCH
+    );
+    let proxy_str = ProxySettings::get_global(cx).proxy.to_owned();
+    let proxy_url = proxy_str
+        .as_ref()
+        .and_then(|input| input.parse().ok())
+        .or_else(read_proxy_from_env);
+    let http = {
+        let _guard = Tokio::handle(cx).enter();
+
+        ReqwestClient::proxy_and_user_agent(proxy_url, &user_agent)
+            .expect("could not start HTTP client")
+    };
+    cx.set_http_client(Arc::new(http));
+
+    Project::init_settings(cx);
+
+    let client = Client::production(cx);
+    cx.set_http_client(client.http_client());
+
+    let git_binary_path = None;
+    let fs = Arc::new(RealFs::new(
+        git_binary_path,
+        cx.background_executor().clone(),
+    ));
+
+    let mut languages = LanguageRegistry::new(cx.background_executor().clone());
+    languages.set_language_server_download_dir(paths::languages_dir().clone());
+    let languages = Arc::new(languages);
+
+    let user_store = cx.new(|cx| UserStore::new(client.clone(), cx));
+
+    extension::init(cx);
+
+    let (mut tx, rx) = watch::channel(None);
+    cx.observe_global::<SettingsStore>(move |cx| {
+        let settings = &ProjectSettings::get_global(cx).node;
+        let options = NodeBinaryOptions {
+            allow_path_lookup: !settings.ignore_system_version,
+            allow_binary_download: true,
+            use_paths: settings.path.as_ref().map(|node_path| {
+                let node_path = PathBuf::from(shellexpand::tilde(node_path).as_ref());
+                let npm_path = settings
+                    .npm_path
+                    .as_ref()
+                    .map(|path| PathBuf::from(shellexpand::tilde(&path).as_ref()));
+                (
+                    node_path.clone(),
+                    npm_path.unwrap_or_else(|| {
+                        let base_path = PathBuf::new();
+                        node_path.parent().unwrap_or(&base_path).join("npm")
+                    }),
+                )
+            }),
+        };
+        tx.send(Some(options)).log_err();
+    })
+    .detach();
+    let node_runtime = NodeRuntime::new(client.http_client(), None, rx);
+
+    let extension_host_proxy = ExtensionHostProxy::global(cx);
+
+    language::init(cx);
+    debug_adapter_extension::init(extension_host_proxy.clone(), cx);
+    language_extension::init(
+        LspAccess::Noop,
+        extension_host_proxy.clone(),
+        languages.clone(),
+    );
+    language_model::init(client.clone(), cx);
+    language_models::init(user_store.clone(), client.clone(), cx);
+    languages::init(languages.clone(), node_runtime.clone(), cx);
+    prompt_store::init(cx);
+    terminal_view::init(cx);
+
+    ZetaCliAppState {
+        languages,
+        client,
+        user_store,
+        fs,
+        node_runtime,
+    }
+}