use super::funejson::Value;
use super::charts_axis_axis_from_ticks::{axis_from_value, axis_line, check_orient, line_to_value};

/// One gridline per tick, from the axis line across the plot: up from a bottom
/// axis, down from a top one, right from a left axis and left from a right one.
///
/// # Panics
/// Panics on an unknown orient or a negative or non-finite length.
pub fn grid_lines(axis: &Axis, length: f64) -> Vec<Line> {
    check_orient(&axis.orient);
    if !length.is_finite() || length < 0.0 {
        panic!("length must be a finite number of zero or more, received {}", length);
    }
    let pos = axis.position;
    axis.ticks
        .iter()
        .map(|t| {
            let p = t.position;
            match axis.orient.as_str() {
                "bottom" => axis_line(p, pos, p, pos - length),
                "top" => axis_line(p, pos, p, pos + length),
                "left" => axis_line(pos, p, pos + length, p),
                _ => axis_line(pos, p, pos - length, p),
            }
        })
        .collect()
}

pub fn fune_vector(args: &[Value]) -> Value {
    Value::Arr(grid_lines(&axis_from_value(&args[0]), args[1].as_f64()).iter().map(line_to_value).collect())
}