import convert from "convert";
import { Length } from "convert";

export type length_t = {
    l: number; u: Length;
};

export type area_t = length_t & {
    w: number;
};

export type dimensions_t = area_t | length_t;


export const isArea = (d: dimensions_t) => ("width" in d);
export const isLength = (d: dimensions_t) => (!("width" in d));
export const dimensionType = (d: dimensions_t) => isArea(d) ? "area" : "length"; export function matchDimensions(d1: dimensions_t, d2: dimensions_t) {
    if (!(
        (isArea(d1) && isArea(d2)) ||
        (isLength(d1) && isLength(d2))
    )) {
        throw new Error(`Dimension mismatch: ${JSON.stringify(d1)} / ${JSON.stringify(d1)}`);
    }

    return {
        l: convert(d1.l, d1.u).to(d2.u),
        u: d2.u,
        ...(
            "w" in d1 ?
                { w: convert(d1.w, d1.u).to(d2.u), }
                : {}
        )
    };
}

/**
 * Gets the total length of a carpet roll based on a diameter
 * @param outerDiameter Outer diameter of the carpet roll
 * @param innerDiameter Inner diameter of the carpet roll (the "hole")
 * @param numRings Number of "rings" or "layers,"" just like a tree 🙂 🌲
 */
export function diameterToLength(outerDiameter: length_t, innerDiameter: length_t, numRings: number) {
    if (outerDiameter.u !== innerDiameter.u) {
        throw new Error("diameter units must match!")
    }
    const thickness = (((outerDiameter.l - innerDiameter.l) / 2) / numRings);
    return {
        l: Math.PI * (Math.pow(outerDiameter.l, 2) / 4) - (Math.pow(innerDiameter.l, 2) / 4) / thickness,
        u: innerDiameter.u,
    };
}