use num_traits::One;
use perplex_num::Perplex;
use plotters::prelude::*;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let root = BitMapBackend::new("./examples/sectors.jpg", (600, 600)).into_drawing_area();
    root.fill(&WHITE)?;
    let (t_min, t_max, x_min, x_max) = (-2, 2, -2, 2);

    let mut chart = ChartBuilder::on(&root)
        .caption("Hyperbolic Sectors", ("sans-serif", 50).into_font())
        .margin(15)
        .x_label_area_size(50)
        .y_label_area_size(50)
        .build_cartesian_2d(
            t_min as f64..t_max as f64,
            (x_min as f64 - 0.5)..x_max as f64,
        )?;
    let font = ("sans-serif", 20).into_font();
    chart
        .configure_mesh()
        .max_light_lines(2)
        .label_style(font.clone())
        .x_labels(3)
        .y_labels(3)
        .x_label_formatter(&|t| format!("t={:.0}", t))
        .y_label_formatter(&|x| format!("x={:.0}", x))
        .draw()?;
    let h = Perplex::h();
    let e = Perplex::one();
    let z = Perplex {
        t: 2.0_f64.sqrt(),
        x: 1.0,
    };
    let label_offset = (10, 0);
    let klein_sector = [
        ("1 Right", e),
        ("h Up", h),
        ("-1 Left", -e),
        ("-h Down", -h),
        ("z (√2, 1)", z),
        ("h z (1, √2)", h * z),
        ("-z (-√2, -1)", -z),
        ("-h z (-1, -√2)", -h * z),
    ];
    // Draw a diagonal line where x = y
    chart
        .draw_series(LineSeries::new(
            (x_min..=x_max).map(|x| (x as f64, x as f64)),
            BLACK,
        ))?
        .label("Light-like numbers t=±x")
        .legend(|(x, y)| PathElement::new(vec![(x, y), (x + 20, y)], BLACK));
    chart.draw_series(LineSeries::new(
        (x_min..=x_max).map(|x| (x as f64, -x as f64)),
        BLACK,
    ))?;
    let d = z.squared_distance();
    let mut hyperbola_ru = Vec::new();
    let mut hyperbola_rd = Vec::new();
    let mut hyperbola_ul = Vec::new();
    let mut hyperbola_ur = Vec::new();
    let mut hyperbola_lu = Vec::new();
    let mut hyperbola_ld = Vec::new();
    let mut hyperbola_dl = Vec::new();
    let mut hyperbola_dr = Vec::new();
    (0..=100_000)
        .map(|i| d + i as f64 * (t_max as f64 - d) / 100_000.0)
        .for_each(|t| {
            let x = (t * t - d).sqrt();
            hyperbola_ru.push((t, x));
            hyperbola_rd.push((t, -x));
            hyperbola_ul.push((-x, t));
            hyperbola_ur.push((x, t));
            hyperbola_lu.push((-t, x));
            hyperbola_ld.push((-t, -x));
            hyperbola_dl.push((-x, -t));
            hyperbola_dr.push((x, -t));
        });
    // Draw the hyperbolas
    let hyperbolas = [
        (hyperbola_ru, &BLUE, 1),
        (hyperbola_rd, &BLUE, 0),
        (hyperbola_ul, &GREEN, -1),
        (hyperbola_ur, &GREEN, 0),
        (hyperbola_lu, &BLUE, 0),
        (hyperbola_ld, &BLUE, 0),
        (hyperbola_dl, &GREEN, 0),
        (hyperbola_dr, &GREEN, 0),
    ];
    for (hyperbola, color, legend_d) in hyperbolas {
        let points = hyperbola
            .into_iter()
            .filter(|&(_t, x)| (x <= x_max as f64 && x >= x_min as f64));
        let draw_result = chart.draw_series(LineSeries::new(points, color))?;
        let legend = match legend_d {
            1 => format!("Hyperbola defined by t²-x²={:.1}", d),
            -1 => format!("Hyperbola defined by t²-x²=-{:.1}", d),
            _ => String::from(""),
        };
        if !legend.is_empty() {
            draw_result
                .label(legend)
                .legend(|(x, y)| PathElement::new(vec![(x, y), (x + 20, y)], color.to_owned()));
        }
    }
    // Plot the Perplex numbers
    chart.draw_series(klein_sector.into_iter().map(|(label, z)| {
        let coord = (z.t, z.x);
        EmptyElement::at(coord)
            + Circle::new((0, 0), 3, RED.filled())
            + Text::new(label, label_offset, font.clone())
    }))?;

    chart
        .configure_series_labels()
        .position(SeriesLabelPosition::LowerMiddle)
        .label_font(font.clone())
        .draw()?;
    Ok(())
}