import type { ProblemSpec } from "../spec/types";
import { formatNumber as n, formatString as s } from "./format";

/**
 * Render the specification as the MATLAB `params` struct. The controls edit the
 * spec; this block is what the solver actually reads, so the two cannot drift.
 */
export function generateParamsBlock(spec: ProblemSpec): string {
  const { plate, material, hole, thread, hammer, strike, probe, mic, render, rr, fem } = spec;
  const lines = [
    "% Problem specification, generated from the controls.  SI units: m, s, N, Pa, kg/m^3.",
    "% Coordinates are measured from the plate's centre, x to the right, y towards the threaded top edge.",
    "% Edit anything here or in the library files; the controls regenerate only this block.",
    "params = struct();",
    `params.plate    = struct('width', ${n(plate.width)}, 'height', ${n(plate.height)}, 'thickness', ${n(plate.thickness)});   % sides and thickness [m]`,
    `params.material = struct('name', ${s(material.name)}, 'E', ${n(material.E)}, 'nu', ${n(material.nu)}, 'rho', ${n(material.rho)}, 'Q', ${n(material.Q)});   % Young's modulus [Pa], Poisson's ratio, density [kg/m^3], structural quality factor`,
    `params.hole     = struct('diameter', ${n(hole.diameter)}, 'edge_offset', ${n(hole.edge_offset)});   % the suspension hole on the centreline, this far below the top edge [m]`,
    `params.thread   = struct('length', ${n(thread.length)}, 'dashpot', ${n(thread.dashpot)});   % thread length [m] (pendulum spring m g / L) and the loss at the hole [N s/m]`,
    `params.hammer   = struct('mass', ${n(hammer.mass)}, 'tip_radius', ${n(hammer.tip_radius)}, 'speed', ${n(hammer.speed)}, 'E', ${n(hammer.E)}, 'nu', ${n(hammer.nu)}, 'restitution', ${n(hammer.restitution)});   % mass [kg], tip radius [m], approach speed [m/s], tip modulus [Pa] and Poisson's ratio, nominal restitution`,
    `params.strike   = struct('x', ${n(strike.x)}, 'y', ${n(strike.y)});   % where the hammer lands [m from the centre]`,
    `params.probe    = struct('x', ${n(probe.x)}, 'y', ${n(probe.y)});   % where the time series are recorded [m from the centre]`,
    `params.mic      = struct('distance', ${n(mic.distance)}, 'air_density', ${n(mic.air_density)}, 'sound_speed', ${n(mic.sound_speed)});   % microphone on the plate's normal [m], air [kg/m^3], [m/s]`,
    `params.render   = struct('fs', ${n(render.fs)}, 'duration', ${n(render.duration)}, 'modes', ${n(render.modes)}, 'normalize_dbfs', ${n(render.normalize_dbfs)}, 'nframes', ${n(render.nframes)}, 'frame_span', ${n(render.frame_span)});   % sample rate [Hz] (modes kept below 0.47 fs), duration [s], mode cap, export peak [dBFS], frames over the first frame_span [s]`,
    `params.rr       = struct('basis_order', ${n(rr.basis_order)}, 'quadrature_order', ${n(rr.quadrature_order)}, 'grid', ${n(rr.grid)});   % Rayleigh-Ritz: Legendre order per side, quadrature points per side, display grid per side`,
    `params.fem      = struct('mesh_x', ${n(fem.mesh_x)}, 'mesh_y', ${n(fem.mesh_y)});   % finite elements: Q4 elements along x and y`,
  ];
  return lines.join("\n");
}