yapi-core 0.4.0

//! What extensions show, as pi's `ExtensionUIContext`: dialogs,
//! notifications, footer statuses, widgets, the editor and custom components.

use std::sync::Arc;
use std::time::Duration;

use futures_util::future::BoxFuture;
use serde_json::Value;
use tokio_util::sync::CancellationToken;

/// How a notification is shown.
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
pub enum NotifyKind {
    /// A status message.
    #[default]
    Info,
    /// A warning.
    Warning,
    /// An error.
    Error,
}

impl NotifyKind {
    /// pi's name for the kind.
    pub fn as_str(self) -> &'static str {
        match self {
            NotifyKind::Info => "info",
            NotifyKind::Warning => "warning",
            NotifyKind::Error => "error",
        }
    }
}

/// What extensions see of the terminal.
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
pub struct TerminalState {
    /// Its size in columns and rows.
    pub size: (usize, usize),
    /// The prompt editor, or an extension's editor in its place, has the
    /// keyboard, rather than a selector, a dialog or an extension component,
    /// as pi-tui's `focusedComponent` tells.
    pub editor_focused: bool,
}

/// pi's `ExtensionUIDialogOptions`: when a dialog closes on its own.
#[derive(Clone, Debug, Default)]
pub struct DialogOptions {
    /// Closes the dialog as cancelled after this long. Interactive dialogs
    /// count down in their title.
    pub timeout: Option<Duration>,
    /// Closes the dialog as cancelled once cancelled.
    pub cancel: Option<CancellationToken>,
}

/// pi's `WidgetPlacement`: where a widget goes.
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
pub enum Placement {
    /// Above the editor.
    #[default]
    AboveEditor,
    /// Below the editor.
    BelowEditor,
}

/// pi's `WorkingIndicatorOptions`: the animation shown while the agent works.
#[derive(Clone, Debug, Default, PartialEq)]
pub struct WorkingIndicator {
    /// Frames drawn as given, escape sequences included. `None` keeps the
    /// default spinner frames, and an empty list hides the indicator.
    pub frames: Option<Vec<String>>,
    /// Milliseconds per frame, or `None` for the default.
    pub interval_ms: Option<u64>,
}

/// What a widget shows.
#[derive(Clone, Debug)]
pub enum Widget {
    /// Lines of text with escape sequences.
    Lines(Vec<String>),
    /// A component the extension renders.
    Component(RemoteComponent),
}

/// The extension runtime side of components: renders them and delivers
/// input to them.
pub trait ComponentHost: Send + Sync {
    /// The lines of component `handle` at `width` columns: text with escape
    /// sequences, and pi-tui's cursor marker where a focused component wants
    /// the cursor. Empty once the component is gone.
    fn render(&self, handle: u32, width: u16) -> BoxFuture<'static, Vec<String>>;

    /// Delivers raw terminal input to component `handle`.
    fn input(&self, handle: u32, data: &str);

    /// Delivers pi-tui's `TuiMouseEvent` `event` to component `handle`,
    /// after the input delivered before it. Resolves to whether the
    /// component took it, as pi-tui's `dispatchMouseEvent` decides.
    fn mouse(&self, handle: u32, event: &Value) -> BoxFuture<'static, bool>;

    /// Sends `op` to editor component `handle`, after the input delivered
    /// before it: `{"op": "setText", "text"}`, `{"op": "addToHistory",
    /// "text"}`, `{"op": "insertTextAtCursor", "text", "apart"}`, or
    /// `{"op": "configure", "border", "paddingX", "autocompleteMaxVisible",
    /// "focused", "rows"}`. `apart` sets the text apart from the words
    /// around the cursor, and `border` is a thinking level or `bashMode`.
    fn editor_op(&self, handle: u32, op: &Value);

    /// Runs the runtime's `onTerminalInput` listeners over raw input `keys`,
    /// in order. Answers the keys left to handle, as the listeners
    /// transformed them, without those they consumed or emptied.
    fn terminal_input(&self, keys: Vec<String>) -> BoxFuture<'static, Vec<String>>;

    /// The suggestions of the runtime's autocomplete providers for pi's
    /// provider arguments `request`, as for [`ExtensionUi::suggestions`],
    /// with what applying each item gives: `{"prefix", "items", "applied":
    /// [{"lines", "cursorLine", "cursorCol"}]}`, or `Null`.
    fn suggestions(&self, request: Value) -> BoxFuture<'static, Value>;
}

/// A pi-tui component that lives in an extension runtime.
#[derive(Clone)]
pub struct RemoteComponent {
    runtime: u64,
    handle: u32,
    host: Arc<dyn ComponentHost>,
}

impl std::fmt::Debug for RemoteComponent {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("RemoteComponent")
            .field("runtime", &self.runtime)
            .field("handle", &self.handle)
            .finish_non_exhaustive()
    }
}

impl RemoteComponent {
    /// Component `handle` of `host`, the runtime numbered `runtime`.
    pub fn new(runtime: u64, handle: u32, host: Arc<dyn ComponentHost>) -> RemoteComponent {
        RemoteComponent {
            runtime,
            handle,
            host,
        }
    }

    /// What identifies it across runtimes: the runtime's number and its
    /// handle there.
    pub fn key(&self) -> (u64, u32) {
        (self.runtime, self.handle)
    }

    /// Its lines at `width` columns (see [`ComponentHost::render`]).
    pub fn render(&self, width: u16) -> BoxFuture<'static, Vec<String>> {
        self.host.render(self.handle, width)
    }

    /// Delivers raw terminal input.
    pub fn input(&self, data: &str) {
        self.host.input(self.handle, data);
    }

    /// Delivers a mouse event (see [`ComponentHost::mouse`]).
    pub fn mouse(&self, event: &Value) -> BoxFuture<'static, bool> {
        self.host.mouse(self.handle, event)
    }

    /// Sends an operation to the editor it is, as
    /// [`ComponentHost::editor_op`] describes.
    pub fn editor_op(&self, op: &Value) {
        self.host.editor_op(self.handle, op);
    }
}

/// The options of pi's `custom`: how a custom component is shown.
#[derive(Clone, Debug, Default)]
pub struct CustomOptions {
    /// Over the screen instead of in the editor's place.
    pub overlay: bool,
    /// pi's `OverlayOptions`: anchor, size and margins.
    pub overlay_options: Value,
}

/// pi's `ExtensionUIContext` as a mode implements it. Dialogs a mode cannot
/// show resolve as cancelled. Everything else does nothing by default.
pub trait ExtensionUi: Send + Sync {
    /// Whether a person can answer dialogs.
    fn has_ui(&self) -> bool;

    /// pi's `ctx.shutdown()`: the mode exits once the agent is idle.
    fn shutdown(&self) {}

    /// Shows a message.
    fn notify(&self, message: &str, kind: NotifyKind);

    /// Shows a message that names no kind. Hosts show it as information,
    /// and RPC forwards it without a kind, as pi does.
    fn notify_untyped(&self, message: &str) {
        self.notify(message, NotifyKind::Info);
    }

    /// Asks to pick one of `options`, resolving to `None` when cancelled.
    fn select(
        &self,
        _title: &str,
        _options: Vec<String>,
        _dialog: DialogOptions,
    ) -> BoxFuture<'static, Option<String>> {
        Box::pin(async { None })
    }

    /// Asks for a line of text, resolving to `None` when cancelled.
    fn input(
        &self,
        _title: &str,
        _placeholder: Option<&str>,
        _dialog: DialogOptions,
    ) -> BoxFuture<'static, Option<String>> {
        Box::pin(async { None })
    }

    /// Asks a yes or no question, resolving to `false` when cancelled.
    fn confirm(
        &self,
        _title: &str,
        _message: &str,
        _dialog: DialogOptions,
    ) -> BoxFuture<'static, bool> {
        Box::pin(async { false })
    }

    /// Asks for multi-line text starting from `prefill`, resolving to `None`
    /// when cancelled.
    fn editor(&self, _title: &str, _prefill: Option<&str>) -> BoxFuture<'static, Option<String>> {
        Box::pin(async { None })
    }

    /// Sets the footer status `key`, or clears it.
    fn set_status(&self, _key: &str, _text: Option<&str>) {}

    /// Sets widget `key`, or removes it. Without a placement it goes above
    /// the editor.
    fn set_widget(&self, _key: &str, _widget: Option<Widget>, _placement: Option<Placement>) {}

    /// Replaces the footer, or restores the built-in one.
    fn set_footer(&self, _component: Option<RemoteComponent>) {}

    /// Replaces the startup header, or restores the built-in one.
    fn set_header(&self, _component: Option<RemoteComponent>) {}

    /// Sets the terminal title.
    fn set_title(&self, _title: &str) {}

    /// Completions an extension computed in the background are ready. The
    /// editor asks for its suggestions again.
    fn refresh_completions(&self) {}

    /// Sets the message shown while the agent works, or restores the default.
    fn set_working_message(&self, _message: Option<&str>) {}

    /// Shows or hides the indicator shown while the agent works.
    fn set_working_visible(&self, _visible: bool) {}

    /// Sets the animation shown while the agent works, or restores the
    /// default spinner.
    fn set_working_indicator(&self, _indicator: Option<WorkingIndicator>) {}

    /// Sets the label of hidden thinking blocks, or restores the default.
    fn set_hidden_thinking_label(&self, _label: Option<&str>) {}

    /// Replaces the editor's text.
    fn set_editor_text(&self, _text: &str) {}

    /// Pastes into the editor as a terminal paste would.
    fn paste_to_editor(&self, text: &str) {
        self.set_editor_text(text);
    }

    /// The editor's text.
    fn editor_text(&self) -> String {
        String::new()
    }

    /// Whether [`ExtensionUi::custom`] and component widgets are shown.
    fn shows_components(&self) -> bool {
        false
    }

    /// Replaces the editor with `editor`, or restores the built-in one.
    /// `embeds_status` when the editor shows the working status in its top
    /// border.
    fn set_editor(&self, _editor: Option<RemoteComponent>, _embeds_status: bool) {}

    /// The extension's editor now holds `text`, paste markers expanded.
    fn editor_changed(&self, _text: &str) {}

    /// The extension's editor submitted `text`.
    fn editor_submit(&self, _text: &str) {}

    /// The extension's editor asks for app action `action`, a key binding id
    /// such as `app.interrupt`.
    fn editor_action(&self, _action: &str) {}

    /// Starts passing raw input through the `onTerminalInput` listeners of
    /// extension runtime `runtime`, which `listeners` runs, or stops with
    /// `None`. Runtimes' listeners see input in the order they started.
    fn set_terminal_input(&self, _runtime: u64, _listeners: Option<Arc<dyn ComponentHost>>) {}

    /// Completes through the providers composed with
    /// `addAutocompleteProvider`, which `providers` runs. `triggers` open
    /// completion too. They replace the providers of the runtime that set
    /// them before.
    fn set_autocomplete(&self, _providers: Arc<dyn ComponentHost>, _triggers: Vec<String>) {}

    /// What the built-in provider suggests for pi's provider arguments
    /// `request`, `{"lines", "cursorLine", "cursorCol", "force"}` with
    /// UTF-16 columns: pi's `AutocompleteSuggestions`, or `Null`.
    fn suggestions(&self, _request: Value) -> BoxFuture<'static, Value> {
        Box::pin(async { Value::Null })
    }

    /// The built-in provider's `applyCompletion` for `{"lines",
    /// "cursorLine", "cursorCol", "item", "prefix"}`: `{"lines",
    /// "cursorLine", "cursorCol"}`.
    fn apply_completion(&self, _request: &Value) -> Value {
        Value::Null
    }

    /// Whether raw input `data` is an extension shortcut, which then runs.
    fn editor_shortcut(&self, _data: &str) -> bool {
        false
    }

    /// The key bindings components match keys against: `{"kitty",
    /// "bindings": {id: [key]}, "actions": [id]}`, where `actions` are the
    /// app actions an extension's editor can ask for. `Null` keeps pi-tui's
    /// defaults.
    fn keybindings(&self) -> Value {
        Value::Null
    }

    /// Shows `component` with keyboard focus until [`ExtensionUi::close`].
    fn custom(&self, _component: RemoteComponent, _options: CustomOptions) {}

    /// Removes the custom component `component`.
    fn close(&self, _component: RemoteComponent) {}

    /// Removes the editor, widgets, footer and header that extension runtime
    /// `runtime` showed, which it lost when it restarted. The built-in
    /// editor, footer and header return.
    fn drop_components(&self, _runtime: u64) {}

    /// Shows a screen of the `/mcp` manager with keyboard focus, opening the
    /// manager. [`McpScreen::Close`] closes it. Without the TUI the screen
    /// is dropped, which closes its menu.
    ///
    /// [`McpScreen::Close`]: crate::mcp::extension::McpScreen::Close
    fn mcp_manager(&self, _screen: crate::mcp::extension::McpScreen) {}

    /// Components changed and need rendering.
    fn request_render(&self) {}

    /// An extension registered transcript renderers or a Markdown
    /// transformer after its session started. What draws next uses them.
    fn renderers_changed(&self) {}

    /// Whether tool output is expanded.
    fn tools_expanded(&self) -> bool {
        false
    }

    /// Expands or collapses tool output.
    fn set_tools_expanded(&self, _expanded: bool) {}

    /// The terminal's state, kept current as it changes, or `None` without a
    /// terminal, as in print, JSON and RPC modes.
    fn terminal(&self) -> Option<tokio::sync::watch::Receiver<TerminalState>> {
        None
    }

    /// What custom footers read: `{"gitBranch", "statuses": [[key, text]],
    /// "providers"}`.
    fn footer_data(&self) -> Value {
        Value::Null
    }

    /// The theme as escape sequences, and the colors they come from:
    /// `{"name", "mode", "fg": {token: sequence}, "bg": {token: sequence},
    /// "dim": [token], "colors": {token: color}}`. `Null` leaves text
    /// unstyled.
    fn theme(&self) -> Value {
        Value::Null
    }

    /// The theme called `name`, as [`ExtensionUi::theme`] describes it, or
    /// `Null` when there is none.
    fn get_theme(&self, _name: &str) -> Value {
        Value::Null
    }

    /// pi's `getAllThemes`: the themes [`ExtensionUi::set_theme`] can switch
    /// to, as `[{"name", "path"}]` with no `path` for a theme without a file.
    /// Empty without a UI that switches themes, as in pi's RPC mode.
    fn all_themes(&self) -> Value {
        Value::Array(Vec::new())
    }

    /// Switches to `theme`: a theme name, which is saved as `/settings`
    /// saves it, or a theme document `{"name", "appearance", "colors"}`,
    /// which is not saved. The error says why it could not.
    fn set_theme(&self, _theme: &Value) -> Result<(), String> {
        Err("UI not available".into())
    }

    /// A handler of extension `path` failed on `event`, with the error's
    /// stack when the runtime gave one. By default it reports as print mode
    /// does.
    fn extension_error(&self, path: &str, _event: &str, error: &str, _stack: Option<&str>) {
        use std::io::Write as _;
        let _ = writeln!(std::io::stderr(), "Extension error ({path}): {error}");
    }
}

/// The UI of print and JSON modes: nothing is shown.
pub struct NoUi;

impl ExtensionUi for NoUi {
    fn has_ui(&self) -> bool {
        false
    }

    fn notify(&self, _message: &str, _kind: NotifyKind) {}
}