use rand::Rng;
use std::fs::File;
use std::io::Write;
use std::process::Command;
use num_rational::Rational32;
use num_integer::Integer;

fn xerar_fraccion_aleatoria() -> (i32, i32) {
    let mut rng = rand::thread_rng();
    let numerador: i32 = rng.gen_range(1..=10);
    let denominador: i32 = rng.gen_range(1..=10);
    (numerador, denominador)
}

fn simplificar_fraccion(numerador: i32, denominador: i32) -> String {
    let fraccion = Rational32::new(numerador, denominador);
    if fraccion.is_integer() {
        format!("{}", fraccion.to_integer())
    } else {
        format!("\\frac{{{}}}{{{}}}", fraccion.numer(), fraccion.denom())
    }
}

fn xerar_operacion_con_fraccions() -> String {
    let mut rng = rand::thread_rng();
    let (a, b) = xerar_fraccion_aleatoria();
    let (c, d) = xerar_fraccion_aleatoria();

    let operacion = rng.gen_range(0..4);

    let (operacion_str, resultado) = match operacion {
        0 => (
            format!("\\frac{{{}}}{{{}}} + \\frac{{{}}}{{{}}}", a, b, c, d),
            simplificar_fraccion(a * d + b * c, b * d),
        ),
        1 => (
            format!("\\frac{{{}}}{{{}}} - \\frac{{{}}}{{{}}}", a, b, c, d),
            simplificar_fraccion(a * d - b * c, b * d),
        ),
        2 => (
            format!("\\frac{{{}}}{{{}}} \\times \\frac{{{}}}{{{}}}", a, b, c, d),
            simplificar_fraccion(a * c, b * d),
        ),
        3 => (
            format!("\\frac{{{}}}{{{}}} \\div \\frac{{{}}}{{{}}}", a, b, c, d),
            simplificar_fraccion(a * d, b * c),
        ),
        _ => unreachable!(),
    };

    format!(
        "\\subsection*{{\\( {} \\)}}\n\\textbf{{Solución:}} \\( {} \\)\n",
        operacion_str, resultado
    )
}

fn main() {
    let mut latex_content = String::from(r#"
\documentclass{article}
\usepackage{amsmath}
\usepackage{multicol}
\begin{document}
"#);

    for i in 1..=10 {
        if i > 1 {
            latex_content.push_str(r"\newpage");
        }
        latex_content.push_str(&format!("\\section*{{Boletín {}}}\n", i));
        latex_content.push_str(r"\begin{multicols}{2}");
        for _ in 0..20 {
            latex_content.push_str(&xerar_operacion_con_fraccions());
        }
        latex_content.push_str(r"\end{multicols}");
    }

    latex_content.push_str(r"\end{document}");

    let mut file = File::create("boletins_fraccions.tex").expect("Non se puido crear o arquivo");
    file.write_all(latex_content.as_bytes()).expect("Non se puido escribir no arquivo");

    // Compilar o arquivo LaTeX en PDF usando pdflatex
    Command::new("pdflatex")
        .arg("boletins_fraccions.tex")
        .output()
        .expect("Erro ao executar pdflatex");
}