use crate::element::{BoxElement, Element, FlexDirection, TextElement};
use crate::style::{fit_visible, wrap_words, Color, Style};
#[derive(Debug, Clone)]
pub struct SideNotePanel {
title: String,
question: Option<String>,
answer: Option<String>,
loading_text: String,
footer: Option<String>,
max_body_lines: usize,
fill_height: bool,
indent: usize,
title_color: Color,
question_color: Color,
answer_color: Color,
muted_color: Color,
}
impl SideNotePanel {
pub fn new(title: impl Into<String>) -> Self {
Self {
title: title.into(),
question: None,
answer: None,
loading_text: "thinking...".to_string(),
footer: None,
max_body_lines: 12,
fill_height: false,
indent: 2,
title_color: Color::Yellow,
question_color: Color::Yellow,
answer_color: Color::Yellow,
muted_color: Color::BrightBlack,
}
}
pub fn question(mut self, question: impl Into<String>) -> Self {
let question = question.into();
if !question.is_empty() {
self.question = Some(question);
}
self
}
pub fn answer(mut self, answer: impl Into<String>) -> Self {
let answer = answer.into();
if !answer.is_empty() {
self.answer = Some(answer);
}
self
}
pub fn loading_text(mut self, text: impl Into<String>) -> Self {
self.loading_text = text.into();
self
}
pub fn footer(mut self, footer: impl Into<String>) -> Self {
let footer = footer.into();
if !footer.is_empty() {
self.footer = Some(footer);
}
self
}
pub fn max_body_lines(mut self, max: usize) -> Self {
self.max_body_lines = max.max(1);
self
}
pub fn fill_height(mut self, enabled: bool) -> Self {
self.fill_height = enabled;
self
}
pub fn indent(mut self, indent: usize) -> Self {
self.indent = indent;
self
}
pub fn title_color(mut self, color: Color) -> Self {
self.title_color = color;
self
}
pub fn question_color(mut self, color: Color) -> Self {
self.question_color = color;
self
}
pub fn answer_color(mut self, color: Color) -> Self {
self.answer_color = color;
self
}
pub fn muted_color(mut self, color: Color) -> Self {
self.muted_color = color;
self
}
pub fn title_value(&self) -> &str {
&self.title
}
pub fn question_value(&self) -> Option<&str> {
self.question.as_deref()
}
pub fn answer_value(&self) -> Option<&str> {
self.answer.as_deref()
}
pub fn view(&self, width: u16, height: usize) -> String {
let width = width as usize;
if width == 0 || height == 0 {
return String::new();
}
let mut lines = self.render_lines(width);
lines.truncate(height);
if self.fill_height {
while lines.len() < height {
lines.push(String::new());
}
}
lines
.into_iter()
.map(|line| fit_visible(&line, width))
.collect::<Vec<_>>()
.join("\n")
}
pub fn element<Msg>(&self, width: u16) -> Element<Msg> {
let width = width as usize;
let mut children = Vec::new();
children.push(Element::Text(
TextElement::new(self.indented(&self.title))
.fg(self.title_color)
.bold(),
));
if let Some(question) = self.question.as_deref() {
for row in self.wrap_prefixed("Q: ", question, width) {
children.push(Element::Text(
TextElement::new(row).fg(self.question_color).bold(),
));
}
}
let body = self.answer.as_deref().unwrap_or(&self.loading_text);
for row in self
.wrap_prefixed("", body, width)
.into_iter()
.take(self.max_body_lines)
{
children.push(Element::Text(TextElement::new(row).fg(self.answer_color)));
}
if let Some(footer) = self.footer.as_deref() {
children.push(Element::Text(
TextElement::new(self.indented(footer)).fg(self.muted_color),
));
}
Element::Box(
BoxElement::new()
.direction(FlexDirection::Column)
.children(children),
)
}
fn render_lines(&self, width: usize) -> Vec<String> {
let mut lines = vec![Style::new()
.fg(self.title_color)
.bold()
.render(&fit_visible(&self.indented(&self.title), width))];
if let Some(question) = self.question.as_deref() {
for row in self.wrap_prefixed("Q: ", question, width) {
lines.push(
Style::new()
.fg(self.question_color)
.bold()
.render(&fit_visible(&row, width)),
);
}
}
let body = self.answer.as_deref().unwrap_or(&self.loading_text);
for row in self
.wrap_prefixed("", body, width)
.into_iter()
.take(self.max_body_lines)
{
lines.push(
Style::new()
.fg(self.answer_color)
.render(&fit_visible(&row, width)),
);
}
if let Some(footer) = self.footer.as_deref() {
lines.push(
Style::new()
.fg(self.muted_color)
.render(&fit_visible(&self.indented(footer), width)),
);
}
lines
}
fn wrap_prefixed(&self, prefix: &str, text: &str, width: usize) -> Vec<String> {
let indent = " ".repeat(self.indent);
let first_prefix = format!("{indent}{prefix}");
let continuation_prefix = " ".repeat(first_prefix.chars().count());
let first_width = width
.saturating_sub(crate::style::visible_len(&first_prefix))
.max(1);
let continuation_width = width
.saturating_sub(crate::style::visible_len(&continuation_prefix))
.max(1);
let mut rows = Vec::new();
for line in text.lines() {
let wrapped = wrap_words(line, first_width);
if wrapped.is_empty() {
rows.push(first_prefix.clone());
continue;
}
for (index, part) in wrapped.into_iter().enumerate() {
if index == 0 {
rows.push(format!("{first_prefix}{part}"));
} else {
for continuation in wrap_words(&part, continuation_width) {
rows.push(format!("{continuation_prefix}{continuation}"));
}
}
}
}
if rows.is_empty() {
rows.push(first_prefix);
}
rows
}
fn indented(&self, value: &str) -> String {
format!("{}{}", " ".repeat(self.indent), value)
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::style::{strip_ansi, visible_len};
fn sample() -> SideNotePanel {
SideNotePanel::new("↘ by the way · Esc to close")
.question("Can we reuse this panel for background side questions?")
.answer("Yes. It renders a compact answer body and keeps rows width-safe.")
.footer("side-channel")
}
#[test]
fn renders_title_question_answer_and_footer() {
let rendered = sample().view(48, 8);
let plain = strip_ansi(&rendered);
assert!(plain.contains("by the way"));
assert!(plain.contains("Q: Can we reuse"));
assert!(plain.contains("compact answer"));
assert!(plain.contains("side-channel"));
for line in rendered.lines() {
assert_eq!(visible_len(line), 48, "{line:?}");
}
}
#[test]
fn loading_state_uses_fallback_answer() {
let rendered = SideNotePanel::new("↘ by the way")
.question("still working?")
.loading_text("thinking...")
.view(32, 4);
let plain = strip_ansi(&rendered);
assert!(plain.contains("still working"));
assert!(plain.contains("thinking"));
}
#[test]
fn caps_answer_lines() {
let rendered = SideNotePanel::new("note")
.answer("one\ntwo\nthree\nfour")
.max_body_lines(2)
.view(24, 5);
let plain = strip_ansi(&rendered);
assert!(plain.contains("one"));
assert!(plain.contains("two"));
assert!(!plain.contains("three"));
}
#[test]
fn cjk_text_wraps_by_display_width() {
let rendered = SideNotePanel::new("提示")
.question("中文问题 with a long suffix")
.answer("中文答案 with another long suffix")
.view(20, 8);
assert!(strip_ansi(&rendered).contains("中文"));
for line in rendered.lines() {
assert_eq!(visible_len(line), 20, "{line:?}");
}
}
#[test]
fn fill_height_pads_remaining_rows() {
let rendered = sample().fill_height(true).view(32, 10);
assert_eq!(rendered.lines().count(), 10);
for line in rendered.lines() {
assert_eq!(visible_len(line), 32, "{line:?}");
}
}
#[test]
fn zero_size_renders_empty_string() {
assert_eq!(sample().view(0, 4), "");
assert_eq!(sample().view(40, 0), "");
}
#[test]
fn element_produces_column() {
let el: Element<()> = sample().element(48);
match el {
Element::Box(column) => {
assert_eq!(column.style.flex_direction, FlexDirection::Column);
assert!(!column.children.is_empty());
}
_ => panic!("expected Box"),
}
}
}