use super::svg::{wrap_in_svg, DEFAULT_GRID_COLOR, DEFAULT_TEXT_COLOR};
pub fn generate_line_chart(data: &[(String, i64)]) -> String {
if data.is_empty() {
return r##""##.to_string();
}
let width = 800.0;
let height = 300.0;
let pad_left = 60.0;
let pad_right = 30.0;
let pad_top = 30.0;
let pad_bottom = 40.0;
let chart_w = width - pad_left - pad_right;
let chart_h = height - pad_top - pad_bottom;
// Find max value for scaling
let max_val = data.iter().map(|(_, v)| *v).max().unwrap_or(0);
let max_y = if max_val == 0 { 10.0 } else { max_val as f64 };
// Y-axis grid ticks
let mut inner_content = String::new();
let ticks = 4;
for i in 0..=ticks {
let pct = i as f64 / ticks as f64;
let y = pad_top + chart_h - (pct * chart_h);
let val = (pct * max_y).round() as i64;
inner_content.push_str(&format!(
r##"
{}"##,
pad_left, y, width - pad_right, y, DEFAULT_GRID_COLOR, pad_left - 10.0, y, DEFAULT_TEXT_COLOR, val
));
}
// Coordinates calculations
let count = data.len();
let step_x = if count > 1 {
chart_w / (count - 1) as f64
} else {
chart_w
};
let mut points = Vec::new();
for (i, &(_, val)) in data.iter().enumerate() {
let x = pad_left + (i as f64 * step_x);
let y = pad_top + chart_h - ((val as f64 / max_y) * chart_h);
points.push((x, y));
}
// Path strings
let mut line_path = String::new();
let mut area_path = String::new();
if !points.is_empty() {
line_path.push_str(&format!("M {:.1} {:.1}", points[0].0, points[0].1));
area_path.push_str(&format!("M {:.1} {:.1}", points[0].0, pad_top + chart_h));
area_path.push_str(&format!("L {:.1} {:.1}", points[0].0, points[0].1));
for &(x, y) in points.iter().skip(1) {
line_path.push_str(&format!(" L {:.1} {:.1}", x, y));
area_path.push_str(&format!(" L {:.1} {:.1}", x, y));
}
let last_x = points[points.len() - 1].0;
area_path.push_str(&format!(" L {:.1} {:.1} Z", last_x, pad_top + chart_h));
}
// X-axis labels
let mut x_labels = String::new();
let label_step = (count / 7).max(1);
for (i, (label, _)) in data.iter().enumerate() {
if i % label_step == 0 || i == count - 1 {
let x = points[i].0;
let short_label = if label.len() == 10 {
&label[5..]
} else {
label
};
x_labels.push_str(&format!(
r##"{}"##,
x, height - 15.0, DEFAULT_TEXT_COLOR, short_label
));
x_labels.push_str(&format!(
r##""##,
x,
pad_top + chart_h,
x,
pad_top + chart_h + 5.0,
DEFAULT_GRID_COLOR
));
}
}
// Draw little circles on points
let mut dots = String::new();
if count < 40 {
for &(x, y) in &points {
dots.push_str(&format!(
r##""##,
x, y
));
}
}
inner_content.push_str(&format!(
r##"
{}
{}"##,
area_path, line_path, dots, x_labels
));
wrap_in_svg(width, height, &inner_content)
}