import type { Geometry, Materials, Loads } from '../types/design';

export const calculateBearing = (geometry: Geometry, materials: Materials, loads: Loads) => {
    const { plateShape, widthZ, lengthX, diameter, support } = geometry;
    const { fc } = materials;
    const { P } = loads;

    // Bearing Area A1
    let A1 = 0;
    if (plateShape === 'rectangular') {
        A1 = widthZ * lengthX;
    } else {
        A1 = Math.PI * Math.pow(diameter / 2, 2);
    }

    // Support Area A2 (Simplified: assume support is the concrete pier size)
    // In reality, A2 is the area of the supporting surface that is geometrically similar to and concentric with the loaded area.
    // We'll use the full support area for now.
    let A2 = 0;
    // Support is defined by Wp1, Lp1 (top) and Wp2, Lp2 (bottom)? 
    // Let's assume Wp1/Lp1 is the top surface dimensions.
    // If circular support is not explicitly handled in inputs (inputs show Wp1/Lp1), assume rect support for rect plate?
    // Or if plate is circular, support might be circular.
    // Let's use Wp1 * Lp1 for now.
    A2 = support.widthWp1 * support.lengthLp1;

    // If A2 < A1, that's an issue (plate larger than support), but let's assume A2 >= A1.
    if (A2 < A1) A2 = A1;

    const sqrtA2A1 = Math.min(Math.sqrt(A2 / A1), 2);

    // Nominal Strength Pp
    // AISC J8: Pp = 0.85 * fc * A1 * sqrt(A2/A1) <= 1.7 * fc * A1
    const phi = 0.65; // LRFD for bearing
    const Pp = 0.85 * fc * A1 * sqrtA2A1;
    const maxPp = 1.7 * fc * A1;

    const Pn = Math.min(Pp, maxPp);
    const phiPn = phi * Pn;

    // Check
    // If P is negative (tension), bearing is 0? Or P is compression?
    // Usually P is compression positive in these apps? 
    // Screenshot shows "Axial Force P 0.0 kip".
    // Let's assume P > 0 is compression.

    const bearingRatio = P > 0 ? P / phiPn : 0;

    return {
        phiPn,
        bearingRatio,
        isSafe: bearingRatio <= 1.0
    };
};