use crate::beta_functions::{linearized_beta, BetaSystem};
use crate::coupling_space::{gravitational_fixed_point, CouplingPoint};

pub fn euler_step(system: BetaSystem, step: f64, point: CouplingPoint) -> CouplingPoint {
    point.add(linearized_beta(system, point).scale(step))
}

pub fn project_to_uv_safe(system: BetaSystem, point: CouplingPoint) -> CouplingPoint {
    let fp = gravitational_fixed_point(system.truncation);
    CouplingPoint {
        g_newton: point.g_newton.max(fp.g_newton),
        cosmological: point.cosmological.max(fp.cosmological),
        portal_coupling: if point.portal_coupling >= 0.0 { 0.0 } else { point.portal_coupling },
        ..point
    }
}

pub fn is_uv_safe(system: BetaSystem, point: CouplingPoint) -> bool {
    let fp = gravitational_fixed_point(system.truncation);
    point.g_newton >= fp.g_newton
        && point.cosmological >= fp.cosmological
        && point.portal_coupling == 0.0
}