Make the Rust client the sole app

app/src/desktop/app.rs

@@ -0,0 +1,337 @@
+use crate::client::api::{ApiClient, SessionSummary, UreqTransport};
+use crate::client::event_stream::{StreamItem, follow_session_events};
+use crate::client::transcript_fold::{
+    TranscriptItem, fold_event, fold_page, group_tool_runs, raw_seq,
+};
+use event_model::SeqEvent;
+use iris::prelude::*;
+use std::{
+    process,
+    sync::{
+        Arc,
+        atomic::{AtomicU64, Ordering},
+    },
+    thread,
+};
+
+const LIST_WIDTH: f32 = 260.0;
+
+enum AppEvent {
+    Sessions(Result<Vec<SessionSummary>, String>),
+    TranscriptLoaded {
+        session_id: String,
+        generation: u64,
+        result: Result<Vec<TranscriptItem>, String>,
+    },
+    StreamEvent {
+        session_id: String,
+        generation: u64,
+        event: SeqEvent,
+    },
+    StreamEnded {
+        session_id: String,
+        generation: u64,
+        message: Option<String>,
+    },
+    SendFailed(String),
+}
+
+pub fn run() {
+    DesktopApp::<Client>::run();
+}
+
+#[derive(DesktopUiState)]
+struct Client {
+    ui_state: DesktopUiState,
+    api: Arc<ApiClient<UreqTransport>>,
+    stream_transport: Arc<UreqTransport>,
+    proxy: Proxy<AppEvent>,
+    sessions: Vec<SessionSummary>,
+    selected: Option<String>,
+    items: Vec<TranscriptItem>,
+    list_ptr: WeakWidget<WidgetPtr>,
+    transcript_ptr: WeakWidget<WidgetPtr>,
+    screen: Option<crate::ui::TranscriptScreen>,
+    generation: Arc<AtomicU64>,
+}
+
+impl DesktopAppState for Client {
+    type Event = AppEvent;
+
+    fn new(
+        mut ui_state: DesktopUiState,
+        rsc: &mut DesktopRsc<Self>,
+        proxy: Proxy<AppEvent>,
+    ) -> Self {
+        let (server, ca_pem) = super::startup::load_startup_config().unwrap_or_else(|e| {
+            eprintln!("desktop-app: {e}");
+            process::exit(2);
+        });
+        let build_transport =
+            || UreqTransport::new(server.base_url(), server.token.clone(), &ca_pem);
+        let (rest_transport, stream_transport) = build_transport()
+            .and_then(|rest| build_transport().map(|stream| (rest, stream)))
+            .unwrap_or_else(|e| {
+                eprintln!(
+                    "desktop-app: couldn't set up TLS to {}: {e}",
+                    server.base_url()
+                );
+                process::exit(1);
+            });
+        let api = Arc::new(ApiClient::new(rest_transport));
+        let stream_transport = Arc::new(stream_transport);
+
+        let list_ptr = WidgetPtr::new().add(rsc);
+        let transcript_ptr = WidgetPtr::new().add(rsc);
+        let loading = placeholder(rsc, "Loading sessions...");
+        transcript_ptr(rsc).set(loading);
+
+        (list_ptr.width(LIST_WIDTH), transcript_ptr.width(rest(1)))
+            .span(Dir::RIGHT)
+            .set_root(rsc, &mut ui_state);
+
+        let client = Self {
+            ui_state,
+            api,
+            stream_transport,
+            proxy,
+            sessions: Vec::new(),
+            selected: None,
+            items: Vec::new(),
+            list_ptr,
+            transcript_ptr,
+            screen: None,
+            generation: Arc::new(AtomicU64::new(0)),
+        };
+        client.spawn_fetch_sessions();
+        client
+    }
+
+    fn event(&mut self, event: AppEvent, rsc: &mut DesktopRsc<Self>) {
+        match event {
+            AppEvent::Sessions(Ok(sessions)) => {
+                self.sessions = sessions;
+                self.rebuild_list(rsc);
+                if self.selected.is_none() {
+                    self.show_message(rsc, "Select a session.");
+                }
+            }
+            AppEvent::Sessions(Err(message)) => {
+                self.show_message(rsc, &format!("Couldn't list sessions: {message}"));
+            }
+            AppEvent::TranscriptLoaded {
+                session_id,
+                generation,
+                result,
+            } => {
+                if self.current(&session_id, generation) {
+                    match result {
+                        Ok(items) => {
+                            self.items = items;
+                            self.rebuild_transcript(rsc);
+                        }
+                        Err(message) => {
+                            self.show_message(
+                                rsc,
+                                &format!("Couldn't load {session_id}: {message}"),
+                            );
+                        }
+                    }
+                }
+            }
+            AppEvent::StreamEvent {
+                session_id,
+                generation,
+                event,
+            } => {
+                if self.current(&session_id, generation) {
+                    let old_items = self.items.clone();
+                    self.items = fold_event(&self.items, &event);
+                    match self.screen.as_mut() {
+                        Some(screen) => screen.apply(rsc, &old_items, &self.items),
+                        None => self.rebuild_transcript(rsc),
+                    }
+                }
+            }
+            AppEvent::StreamEnded {
+                session_id,
+                generation,
+                message: Some(message),
+            } => {
+                if self.current(&session_id, generation) {
+                    eprintln!("desktop-app: {session_id}'s live connection ended: {message}");
+                }
+            }
+            AppEvent::StreamEnded { .. } => {}
+            AppEvent::SendFailed(message) => {
+                eprintln!("desktop-app: couldn't send: {message}");
+            }
+        }
+        self.ui_state.window.request_redraw();
+    }
+}
+
+impl Client {
+    fn current(&self, session_id: &str, generation: u64) -> bool {
+        self.selected.as_deref() == Some(session_id)
+            && self.generation.load(Ordering::SeqCst) == generation
+    }
+
+    fn show_message(&mut self, rsc: &mut DesktopRsc<Self>, message: &str) {
+        let widget = placeholder(rsc, message);
+        (self.transcript_ptr)(rsc).set(widget);
+    }
+
+    fn spawn_fetch_sessions(&self) {
+        let api = self.api.clone();
+        let proxy = self.proxy.clone();
+        thread::spawn(move || {
+            let result = api.fetch_sessions().map_err(|e| e.to_string());
+            let _ = proxy.send_event(AppEvent::Sessions(result));
+        });
+    }
+
+    fn rebuild_list(&mut self, rsc: &mut DesktopRsc<Self>) {
+        let list = Span::empty(Dir::DOWN).gap(2).add(rsc);
+        for session in &self.sessions {
+            let selected = self.selected.as_deref() == Some(session.id.as_str());
+            let row = session_row(rsc, session, selected);
+            list(rsc).push(row);
+        }
+        let tree = list
+            .background(rect(Srgba8::rgb(24, 24, 28)))
+            .add_strong(rsc)
+            .any();
+        (self.list_ptr)(rsc).set(tree);
+    }
+
+    fn select_session(&mut self, rsc: &mut DesktopRsc<Self>, session_id: String) {
+        let generation = self.generation.fetch_add(1, Ordering::SeqCst) + 1;
+        self.selected = Some(session_id.clone());
+        self.items.clear();
+        self.screen = None;
+        self.rebuild_list(rsc);
+        self.show_message(rsc, "Loading transcript...");
+
+        let api = self.api.clone();
+        let stream_transport = self.stream_transport.clone();
+        let proxy = self.proxy.clone();
+        let live_generation = self.generation.clone();
+        thread::spawn(move || {
+            let page: Result<Vec<serde_json::Value>, String> = api
+                .fetch_transcript_page(&session_id, None, 200, true)
+                .map_err(|e| e.to_string());
+            let after = page
+                .as_ref()
+                .ok()
+                .and_then(|values| raw_seq(values.last()?))
+                .unwrap_or(0);
+            let result = page.and_then(|values| fold_page(&values));
+            let _ = proxy.send_event(AppEvent::TranscriptLoaded {
+                session_id: session_id.clone(),
+                generation,
+                result,
+            });
+
+            let stop = || live_generation.load(Ordering::SeqCst) != generation;
+            if stop() {
+                return;
+            }
+            let outcome =
+                follow_session_events(&*stream_transport, &session_id, after, |item| match item {
+                    StreamItem::Open | StreamItem::Reset => !stop(),
+                    StreamItem::Event { event, .. } => {
+                        if stop() {
+                            return false;
+                        }
+                        let _ = proxy.send_event(AppEvent::StreamEvent {
+                            session_id: session_id.clone(),
+                            generation,
+                            event,
+                        });
+                        true
+                    }
+                });
+            let _ = proxy.send_event(AppEvent::StreamEnded {
+                session_id,
+                generation,
+                message: outcome.err().map(|e| e.to_string()),
+            });
+        });
+    }
+
+    fn send_message(&mut self, session_id: String, text: String) {
+        let api = self.api.clone();
+        let proxy = self.proxy.clone();
+        thread::spawn(move || {
+            if let Err(e) = api.send_message(&session_id, &text, &[]) {
+                let _ = proxy.send_event(AppEvent::SendFailed(e.to_string()));
+            }
+        });
+    }
+
+    fn rebuild_transcript(&mut self, rsc: &mut DesktopRsc<Self>) {
+        let in_progress = self
+            .screen
+            .as_ref()
+            .map(|screen| screen.composer.field.edit(rsc).text.text().to_string())
+            .filter(|t| !t.is_empty());
+
+        let rows = group_tool_runs(&self.items);
+        let (screen, tree) = crate::ui::build_tree(rsc, rows);
+
+        if let Some(text) = in_progress {
+            screen.composer.field.edit(rsc).set(&text);
+        }
+        if let Some(session_id) = self.selected.clone() {
+            let field = screen.composer.field;
+            rsc.register_event(field, Submit, move |ctx, rsc| {
+                let text = field.edit(rsc).take();
+                let text = text.trim().to_string();
+                if !text.is_empty() {
+                    ctx.state.send_message(session_id.clone(), text);
+                }
+            });
+        }
+
+        (self.transcript_ptr)(rsc).set(tree);
+        self.screen = Some(screen);
+    }
+}
+
+fn session_row(
+    rsc: &mut DesktopRsc<Client>,
+    session: &SessionSummary,
+    selected: bool,
+) -> StrongWidget {
+    let bg = if selected {
+        Srgba8::rgb(58, 90, 138)
+    } else {
+        Srgba8::rgb(38, 38, 44)
+    };
+    let id = session.id.clone();
+    let label = format!("{}\n{}", session.title, session.status);
+    wtext(label)
+        .color(PaintId::WHITE)
+        .wrap(true)
+        .pad(10)
+        .width(rest(1))
+        .background(rect(bg))
+        .on(
+            CursorSense::click(),
+            move |ctx, rsc: &mut DesktopRsc<Client>| {
+                ctx.state.select_session(rsc, id.clone());
+            },
+        )
+        .add_strong(rsc)
+        .any()
+}
+
+fn placeholder(rsc: &mut DesktopRsc<Client>, message: &str) -> StrongWidget {
+    wtext(message.to_string())
+        .color(PaintId::WHITE)
+        .wrap(true)
+        .pad(16)
+        .add_strong(rsc)
+        .any()
+}

app/src/desktop/config.rs

@@ -0,0 +1,16 @@
+use crate::client::config::EnrollmentStore;
+use std::path::PathBuf;
+
+pub fn config_dir() -> PathBuf {
+    let base = std::env::var_os("XDG_CONFIG_HOME")
+        .map(PathBuf::from)
+        .unwrap_or_else(|| {
+            let home = std::env::var_os("HOME").expect("HOME must be set");
+            PathBuf::from(home).join(".config")
+        });
+    base.join("ai-app-desktop")
+}
+
+pub fn store() -> EnrollmentStore {
+    EnrollmentStore::new(config_dir())
+}

app/src/desktop/mod.rs

@@ -0,0 +1,3 @@
+pub mod app;
+pub mod config;
+pub mod startup;

app/src/desktop/startup.rs

@@ -0,0 +1,67 @@
+//! The desktop binary's command line and the enrolment it resolves --
+//! `--link`/`--ca`, parsed once at startup and again from `app.rs`'s
+//! `Client::new`. Here rather than in `src/bin_desktop.rs` because both
+//! callers are in the library; the binary is only `fn main`.
+
+use crate::client::config::EnrolledServer;
+use std::{env, fs, path::PathBuf};
+
+use super::config;
+
+struct Args {
+    ca_path: Option<PathBuf>,
+    link: Option<String>,
+}
+
+fn parse_args() -> Result<Args, String> {
+    let mut ca_path = None;
+    let mut link = None;
+    let mut args = env::args().skip(1);
+    while let Some(arg) = args.next() {
+        match arg.as_str() {
+            "--ca" => ca_path = Some(PathBuf::from(args.next().ok_or("--ca needs a path")?)),
+            "--link" => link = Some(args.next().ok_or("--link needs a value")?),
+            other => return Err(format!("unrecognised argument '{other}'")),
+        }
+    }
+    Ok(Args { ca_path, link })
+}
+
+pub fn load_startup_config() -> Result<(EnrolledServer, Vec<u8>), String> {
+    let args = parse_args()?;
+    let store = config::store();
+    let server = match args.link {
+        Some(link) => {
+            let server = EnrolledServer::parse_link(&link)?;
+            store
+                .save(&server)
+                .map_err(|e| format!("couldn't save the enrollment: {e}"))?;
+            server
+        }
+        None => store
+            .load()
+            .map_err(|e| format!("couldn't read the saved enrollment: {e}"))?
+            .ok_or_else(|| {
+                format!(
+                    "no server enrolled yet under {} -- pass --link 'aiapp://enroll?...' \
+                     once (app/ui-sandbox.sh's start banner prints one)",
+                    config::config_dir().display()
+                )
+            })?,
+    };
+    // `--ca` wins where it was given, so a caller can point a link's
+    // server at a certificate it did not carry -- and so the flag still
+    // means what it did before the link could carry one.
+    let ca_pem = match (&args.ca_path, &server.ca_pem) {
+        (Some(path), _) => fs::read(path)
+            .map_err(|e| format!("couldn't read the CA at {}: {e}", path.display()))?,
+        (None, Some(pem)) => pem.clone().into_bytes(),
+        (None, None) => {
+            return Err("this enrollment carries no CA -- pass --ca PATH (e.g. \
+                 ~/.config/ai-app/certs/ca.pem), or enrol again with a link \
+                 minted by a server that includes one"
+                .to_string());
+        }
+    };
+    Ok((server, ca_pem))
+}