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

export const calculateAnchorage = (anchorage: Anchorage, materials: Materials, loads: Loads) => {
    const { count, diameter, material } = anchorage;
    const { P, Vx, Vz } = loads;

    // Steel Strength in Tension
    // Ase,N = effective cross sectional area
    // Simplified: 0.75 * Gross Area? Or lookup table.
    // 1" dia -> Gross = 0.785. Ase approx 0.606.
    // Let's use a simple approximation: Ase = 0.8 * Ag
    const Ag = Math.PI * Math.pow(diameter / 2, 2);
    const Ase = 0.8 * Ag;

    // futa (Tensile strength of anchor)
    // F1554-36: fut = 58 ksi
    // F1554-55: fut = 75 ksi
    // F1554-105: fut = 125 ksi
    let futa = 58;
    if (material === 'F1554-55') futa = 75;
    if (material === 'F1554-105') futa = 125;

    const phi_tension = 0.75;
    const Nsa = Ase * futa; // Nominal steel strength per rod
    const phiNn_total = phi_tension * Nsa * count;

    // Tension Demand
    // If P < 0 (Tension), or if Moment causes tension.
    // Simplified: Net Tension = -P (if P is compression)
    // Plus tension from moment?
    // For MVP, let's just use Axial Tension if P < 0.
    const Tu = P < 0 ? -P : 0;

    const tensionRatio = Tu / phiNn_total;

    // Shear Strength
    // Steel strength in shear
    // Vsa = 0.6 * Ase * futa
    const Vsa = 0.6 * Ase * futa;
    const phi_shear = 0.65;
    const phiVn_total = phi_shear * Vsa * count; // Assuming all anchors take shear (with washers welded)

    // Shear Demand
    const Vu = Math.sqrt(Vx * Vx + Vz * Vz);

    const shearRatio = Vu / phiVn_total;

    // Interaction
    // (Tu / phiNn) + (Vu / phiVn) <= 1.2 ? Or 5/3 power?
    // Simplified linear interaction for now
    const interactionRatio = tensionRatio + shearRatio;

    return {
        phiNn_total,
        phiVn_total,
        tensionRatio,
        shearRatio,
        interactionRatio,
        isSafe: interactionRatio <= 1.0
    };
};