import { describe, expect, it } from 'vitest';
import { weightStandardData } from '../../mockData/weightStandardData.ts';
import { getTargetGainForAge, getTargetWeightForAge } from '../weight.ts';

function rowForDoc(docWeight: number) {
  return weightStandardData.data.find((row) => row.day === docWeight)!;
}

describe('getTargetWeightForAge', () => {
  it('uses the exact DOC-weight row and age column', () => {
    const row = rowForDoc(42);
    expect(getTargetWeightForAge(1, 42)).toBe(row.values[0]);
    expect(getTargetWeightForAge(35, 42)).toBe(row.values[34]);
  });

  it('clamps below-range DOC weight to the 35 g row', () => {
    const row = rowForDoc(35);
    expect(getTargetWeightForAge(7, 20)).toBe(row.values[6]);
    expect(getTargetWeightForAge(7, 30)).toBe(row.values[6]);
  });

  it('clamps above-range DOC weight to the 51 g row', () => {
    const row = rowForDoc(51);
    expect(getTargetWeightForAge(7, 52)).toBe(row.values[6]);
    expect(getTargetWeightForAge(7, 60)).toBe(row.values[6]);
  });

  it('returns null for ages outside 1..35', () => {
    expect(getTargetWeightForAge(0, 42)).toBeNull();
    expect(getTargetWeightForAge(36, 42)).toBeNull();
  });
});

describe('getTargetGainForAge', () => {
  it('returns day-over-day delta from the DOC-weight row', () => {
    const row = rowForDoc(40);
    expect(getTargetGainForAge(2, 40)).toBe(row.values[1]! - row.values[0]!);
  });

  it('returns null for age 1', () => {
    expect(getTargetGainForAge(1, 40)).toBeNull();
  });
});