import _ from 'lodash';
import acanthro from './growthstandards/acanthro.json';
import bmianthro from './growthstandards/bmianthro.json';
import hcanthro from './growthstandards/hcanthro.json';
import lenanthro from './growthstandards/lenanthro.json';
import ssanthro from './growthstandards/ssanthro.json';
import tsanthro from './growthstandards/tsanthro.json';
import weianthro from './growthstandards/weianthro.json';
import wfhanthro from './growthstandards/wfhanthro.json';
import wflanthro from './growthstandards/wflanthro.json';

const growthStandards: any = {
  acanthro,
  bmianthro,
  hcanthro,
  lenanthro,
  ssanthro,
  tsanthro,
  weianthro,
  wfhanthro,
  wflanthro,
};

// rounding function
function round(value: number, digitsPastDecimal = 3): number {
  const multiplier = parseFloat('1'.padEnd(digitsPastDecimal+1,'0'))
  return Math.round((value + Number.EPSILON) * multiplier) / multiplier
}

// Lookup function for growth standards
function lookupGrowthStandards(key: number | Array<number>,
  colKeyMatch: string | Array<string>, filename: string): Record<string, any> | undefined {
  if (_.isEmpty(key)) return undefined;

  const attributes = growthStandards[filename];

  if (Array.isArray(colKeyMatch) && Array.isArray(key)
      && key.length && colKeyMatch.length && key.length > 1 && key.length === colKeyMatch.length) {
    let multioutput = attributes;
    colKeyMatch.forEach((colKey: string, index) => {
      if (Array.isArray(multioutput)) { 
        multioutput = multioutput.filter((n) => n[colKey] === key[index])
      }; // eslint-disable-line max-len
    });

    return multioutput[0] || undefined;
  }
  const output = !Array.isArray(colKeyMatch) ? attributes.find(
    (n: Record<string, any>) => n[colKeyMatch] === key,
  ) : undefined;
  return output || undefined;
}
// days of the month constant
const ANTHRO_DAYS_OF_MONTH: number = 30.4375;

//  cleans the sex variable
function standardize_sex_var(sex: string | number): 1 | 2 | undefined {
  const out = (typeof sex === 'number') ? _.toLower(_.trim(sex.toString())) : _.toLower(_.trim(sex));
  if (out === 'm' || out === '1') {
    return 1;
  }
  if (out === 'f' || out === '2') {
    return 2;
  }
  console.error("Sex variable not 'm', 'f', '1', or '2'");
  return undefined;
}

function standardize_oedema_var(oedema: string): string {
  const outOedema = _.toLower(_.trim(oedema));
  if (outOedema === '1') return 'y';
  if (outOedema === '2') return 'n';
  if (outOedema === 'y') return 'y';
  return 'n';
}

function age_to_days(age: number, isAgeInMonth: boolean): number {
  // age in days is always treated as rounded integers
  if (isAgeInMonth) {
    return round(age * ANTHRO_DAYS_OF_MONTH);
  }
  return age;
}

function age_to_months(age: number, isAgeInMonth: boolean): number {
  if (isAgeInMonth) {
    return age;
  }
  return age / ANTHRO_DAYS_OF_MONTH;
}

// ' Groups age in months into groups
// ' @param age_in_months numeric vector of positive ages
// ' @noRd
function anthro_age_groups(age_in_months: number): string | undefined {
  if (typeof age_in_months !== 'number') return undefined;
  if (age_in_months > 0 && age_in_months <= 5) return '00-05 mo';
  if (age_in_months > 5 && age_in_months <= 11) return '06-11 mo';
  if (age_in_months > 11 && age_in_months <= 23) return '12-23 mo';
  if (age_in_months > 23 && age_in_months <= 35) return '24-35 mo';
  if (age_in_months > 35 && age_in_months <= 47) return '36-47 mo';
  if (age_in_months > 47 && age_in_months <= 59) return '48-59 mo';
  return undefined;
}

export {
  lookupGrowthStandards,
  standardize_sex_var,
  standardize_oedema_var,
  age_to_days,
  age_to_months,
  anthro_age_groups,
  round
};