rpi-tui 0.3.23

//! User message component — port of `user-message.ts`.
//!
//! Renders the user's submitted text as markdown inside a padded [`Box`] with
//! a subtle background, wrapped in [OSC 133] prompt zone markers so capable
//! terminals can detect user/assistant boundaries. Where OSC 133 is
//! unsupported the sequences are harmless no-ops.
//!
//! Replaces the plain `> text` echo in the transcript.
//!
//! [OSC 133]: https://terminalguide.namepad.de/seq/osc-133/

use std::any::Any;
use std::sync::atomic::{AtomicU64, Ordering};
use std::sync::Mutex;

use super::component::Component;
use crate::box_component::Box;
use crate::markdown::Markdown;
use crate::theme::{theme, theme_revision};

const OSC133_ZONE_START: &str = "\x1b]133;A\x07";
const OSC133_ZONE_END: &str = "\x1b]133;B\x07";
const OSC133_ZONE_FINAL: &str = "\x1b]133;C\x07";

/// Component that renders a user message with a background and OSC133 markers.
pub struct UserMessageComponent {
    text: String,
    output_pad: usize,
    /// Prebuilt inner box (background `Box` + `Markdown`).
    ///
    /// Upstream builds this **once** in the constructor (`user-message.ts`
    /// `rebuild()`); rpi used to rebuild the `Box` + `Markdown` on every
    /// `render`, so the inner caches could never hit and each frame re-parsed
    /// every user message. Rebuild only on `invalidate` / `with_pad` / a theme
    /// change (the background colour is baked into the box).
    inner: Mutex<Box>,
    /// Theme revision the current inner box was built against.
    built_revision: AtomicU64,
}

fn build_box(text: &str, output_pad: usize) -> Box {
    let bg = theme().colors.surface;
    let content_box = Box::new(output_pad, 1);
    content_box.set_bg_fn(Some(std::sync::Arc::new(move |s: &str| bg.bg(s))));
    let md = Markdown::new(text.to_string(), 0, 0);
    content_box.add_child(std::sync::Arc::new(md));
    content_box
}

impl UserMessageComponent {
    /// Create a new user message component.
    ///
    /// `output_pad` is the horizontal+vertical padding inside the background
    /// box (mirrors the TS `outputPad`, default 1).
    pub fn new(text: impl Into<String>) -> Self {
        let text = text.into();
        let inner = build_box(&text, 1);
        Self {
            text,
            output_pad: 1,
            inner: Mutex::new(inner),
            built_revision: AtomicU64::new(theme_revision()),
        }
    }

    /// Override the inner padding.
    pub fn with_pad(self, pad: usize) -> Self {
        let inner = build_box(&self.text, pad);
        Self {
            text: self.text,
            output_pad: pad,
            inner: Mutex::new(inner),
            built_revision: AtomicU64::new(theme_revision()),
        }
    }
}

impl Component for UserMessageComponent {
    fn render(&self, width: usize) -> Vec<String> {
        // The background colour is baked into the inner box; rebuild it when
        // the live theme has changed since it was built.
        let revision = theme_revision();
        if self.built_revision.load(Ordering::Acquire) != revision {
            if let Ok(mut inner) = self.inner.lock() {
                *inner = build_box(&self.text, self.output_pad);
            }
            self.built_revision.store(revision, Ordering::Release);
        }

        let mut lines = match self.inner.lock() {
            Ok(inner) => inner.render(width),
            Err(_) => return Vec::new(),
        };
        if lines.is_empty() {
            return lines;
        }
        // Prepend zone-start to the first line, append zone-end+final to the
        // last line. These are zero-width escapes so visible layout is unchanged.
        let first = lines.first_mut().unwrap();
        first.insert_str(0, OSC133_ZONE_START);
        let last = lines.last_mut().unwrap();
        last.insert_str(0, OSC133_ZONE_END);
        last.insert_str(OSC133_ZONE_END.len(), OSC133_ZONE_FINAL);
        lines
    }

    fn invalidate(&self) {
        // Rebuild the inner box so a theme change is picked up by the baked-in
        // background colour, and so the Markdown cache is dropped.
        if let Ok(mut inner) = self.inner.lock() {
            *inner = build_box(&self.text, self.output_pad);
        }
        self.built_revision
            .store(theme_revision(), Ordering::Release);
    }

    fn as_any(&self) -> &dyn Any {
        self
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::ansi::strip_ansi;

    #[test]
    fn test_renders_non_empty() {
        let c = UserMessageComponent::new("Hello world");
        let lines = c.render(40);
        assert!(!lines.is_empty());
        // Should contain the text (after stripping ANSI/OSC).
        let joined = strip_ansi(&lines.join("\n"));
        assert!(joined.contains("Hello"));
    }

    #[test]
    fn test_osc133_markers_present() {
        let c = UserMessageComponent::new("Hi");
        let lines = c.render(40);
        let joined = lines.join("\n");
        assert!(joined.contains(OSC133_ZONE_START), "missing zone-start A");
        assert!(joined.contains(OSC133_ZONE_END), "missing zone-end B");
        assert!(joined.contains(OSC133_ZONE_FINAL), "missing zone-final C");
    }

    #[test]
    fn test_cjk_no_panic() {
        let c = UserMessageComponent::new("你好世界");
        let lines = c.render(6);
        assert!(!lines.is_empty());
    }
}