// ============================================================
// FENTON 2013 parity tests — drives the TS port against vectors
// captured from the authoritative vanilla implementation.
// ============================================================

import { describe, expect, it } from 'vitest';
import * as fs from 'node:fs';
import * as path from 'node:path';
import { fentonWeightForAge, neonatalAssess, type Sex } from './fenton';

interface FentonCase {
  name: string;
  inputs: { sex: Sex; gaWeeks: number; weightGrams: number };
  output: { L: number; M: number; S: number; z: number; percentile: number };
}
interface NeonatalCase {
  name: string;
  inputs: { weeks: number; days: number; weightGrams: number; sex: Sex };
  output: { gaDecimal: number; L: number; M: number; S: number; z: number; percentile: number; expectedWeight: number };
}
interface Vectors { fenton: FentonCase[]; neonatal: NeonatalCase[] }

const vectors: Vectors = JSON.parse(
  fs.readFileSync(path.join(__dirname, '..', '..', 'e2e', 'fixtures', 'calc-vectors.json'), 'utf8'),
);

describe('Fenton 2013 weight-for-GA — parity with vanilla calculators.js', () => {
  it.each(vectors.fenton)('$name', ({ inputs, output }) => {
    const actual = fentonWeightForAge(inputs.gaWeeks, inputs.weightGrams, inputs.sex);
    expect(actual.L).toBeCloseTo(output.L, 10);
    expect(actual.M).toBeCloseTo(output.M, 6);
    expect(actual.S).toBeCloseTo(output.S, 10);
    expect(actual.z).toBeCloseTo(output.z, 10);
    expect(actual.percentile).toBeCloseTo(output.percentile, 10);
  });
});

describe('Neonatal peditools Fenton — parity with vanilla bedside/neonatal.js', () => {
  it.each(vectors.neonatal)('$name', ({ inputs, output }) => {
    const actual = neonatalAssess(inputs.weeks, inputs.days, inputs.weightGrams, inputs.sex);
    expect(actual.gaDecimal).toBeCloseTo(output.gaDecimal, 10);
    expect(actual.L).toBeCloseTo(output.L, 10);
    expect(actual.M).toBeCloseTo(output.M, 6);
    expect(actual.S).toBeCloseTo(output.S, 10);
    expect(actual.z).toBeCloseTo(output.z, 10);
    expect(actual.percentile).toBeCloseTo(output.percentile, 10);
    expect(actual.expectedWeight).toBe(output.expectedWeight);
  });
});