munch-ease-frontend/src/units.js

export const equivalentUnits = {
  kg: {
    kgs: 1,
    kilograms: 1,
    kilogram: 1,

    g: 1000,
    gram: 1000,
    grams: 1000,

    lb: 2.20462,
    lbs: 2.20462,
    pound: 2.20462,
    pounds: 2.20462,
  },
  litres: {
    l: 1,
    liter: 1,
    litre: 1,

    ml: 1000,
    milliliters: 1000,
    milliliter: 1000,

    'fl oz': 33.814,
    'fluid ounce': 33.814,
    'fluid ounces': 33.814,

    cup: 4.22675,
    cups: 4.22675,

    tbsp: 67.628,
    tablespoon: 67.628,
    tablespoons: 67.628,

    tsp: 202.884,
    teaspoon: 202.884,
    teaspoons: 202.884,

    pt: 2.11338,
    pint: 2.11338,
    pints: 2.11338,

    qt: 1.05669,
    quart: 1.05669,
    quarts: 1.05669,

    gal: 0.264172,
    gallon: 0.264172,
    gallons: 0.264172,

    oz: 35.1951,
    ounce: 35.1951,
  },
  items: {
    item: 1,
    items: 1,
    pcs: 1,
    piece: 1,
    pieces: 1,
    florets: 8, // Broccoli
    head: 1, // Broccoli
    heads: 1, // Broccoli
    slice: 10, // Bread
    slices: 10, // Bread
    loaf: 1, // Bread
    loaves: 1, // Bread
    cloves: 8, // Garlic
    bulb: 1, // Garlic
    bulbs: 1, // Garlic
    stalk: 1, // Celery
    stalks: 1, // Celery
    bunch: 1, // Cilantro
    bunches: 1, // Cilantro
    sprig: 1, // Cilantro
    sprigs: 1, // Cilantro
    cans: 1, // Canned goods
    can: 1, // Canned goods
    pack: 1, // Packaged goods
    packs: 1, // Packaged goods
    package: 1, // Packaged goods
    packages: 1, // Packaged goods
    container: 1, // Packaged goods
    containers: 1, // Packaged goods
  },
}

function getBaseUnit(unit) {
  for (const unitType in equivalentUnits) {
    if (unit in equivalentUnits[unitType]) {
      return unitType
    }
  }

  return null
}

export function getConversionFactor(unit) {
  if (unit in equivalentUnits) {
    return { unit, factor: 1 }
  }

  const unitLower = unit.toLowerCase()
  if (unitLower in equivalentUnits) {
    return { unit: unitLower, factor: 1 }
  }

  const baseUnit = getBaseUnit(unit)
  if (baseUnit) {
    return {
      unit: baseUnit,
      factor: equivalentUnits[baseUnit][unit],
    }
  }

  const baseUnitLower = getBaseUnit(unitLower)
  if (baseUnitLower) {
    return {
      unit: baseUnitLower,
      factor: equivalentUnits[baseUnitLower][unitLower],
    }
  }

  return null
}

export function calculateTotals(quantityList) {
  const totals = {}
  for (const quantity of quantityList) {
    const baseUnit = getConversionFactor(quantity.unit) ?? { unit: quantity.unit, factor: 1 }
    const factor = baseUnit.factor
    const unit = baseUnit.unit

    if (!totals[unit]) {
      totals[unit] = 0
    }

    totals[unit] += quantity.quantity / factor
  }

  return Object.keys(totals).map((unit) => ({ unit, quantity: totals[unit] }))
}