Files
openfoodnetwork/app/services/weights_and_measures.rb
Gaetan Craig-Riou e33ed5141b Fix weigths and measures
Use variant_unit, variant_unit_scale from the variant
2024-10-14 14:56:46 +11:00

117 lines
3.8 KiB
Ruby

# frozen_string_literal: true
class WeightsAndMeasures
def initialize(variant)
@variant = variant
@units = UNITS
end
def scale_for_unit_value
largest_unit = find_largest_unit(scales_for_variant_unit, system)
return [nil, nil] unless largest_unit
[largest_unit[0], largest_unit[1]["name"]]
end
def system
return "custom" unless scales = scales_for_variant_unit(ignore_available_units: true)
variant_scale = @variant.variant_unit_scale&.to_f
return "custom" unless variant_scale.present? && variant_scale.positive?
scales[variant_scale]['system']
end
# @returns enumerable with label and value for select
def self.variant_unit_options
available_units_sorted.flat_map do |measurement, measurement_info|
measurement_info.filter_map do |scale, unit_info|
# Our code is based upon English based number formatting
# Some language locales like +hu+ uses a comma(,) for decimal separator
# While in English, decimal separator is represented by a period.
# e.g. en: 0.001, hu: 0,001
# Hence the results become "weight_0,001" for hu while or code recognizes "weight_0.001"
scale_clean =
ActiveSupport::NumberHelper.number_to_rounded(scale, precision: nil, significant: false,
strip_insignificant_zeros: true,
locale: :en)
[
"#{I18n.t(measurement)} (#{unit_info['name']})", # Label (eg "Weight (g)")
"#{measurement}_#{scale_clean}", # Scale ID (eg "weight_1")
]
end
end <<
[
I18n.t('items'),
'items'
]
end
def self.available_units
CurrentConfig.get(:available_units).split(",")
end
def self.available_units_sorted
self::UNITS.transform_values do |measurement_info|
# Filter to only include available units
measurement_info.filter do |_scale, unit_info|
available_units.include?(unit_info['name'])
end.
# Remove duplicates by name
uniq do |_scale, unit_info|
unit_info['name']
end.
# Sort by unit number
sort.to_h
end
end
private
UNITS = {
'weight' => {
0.001 => { 'name' => 'mg', 'system' => 'metric' },
1.0 => { 'name' => 'g', 'system' => 'metric' },
1000.0 => { 'name' => 'kg', 'system' => 'metric' },
1_000_000.0 => { 'name' => 'T', 'system' => 'metric' },
28.35 => { 'name' => 'oz', 'system' => 'imperial' },
28.349523125 => { 'name' => 'oz', 'system' => 'imperial' },
453.6 => { 'name' => 'lb', 'system' => 'imperial' },
453.59237 => { 'name' => 'lb', 'system' => 'imperial' },
},
'volume' => {
0.001 => { 'name' => 'mL', 'system' => 'metric' },
0.01 => { 'name' => 'cL', 'system' => 'metric' },
0.1 => { 'name' => 'dL', 'system' => 'metric' },
1.0 => { 'name' => 'L', 'system' => 'metric' },
1000.0 => { 'name' => 'kL', 'system' => 'metric' },
4.54609 => { 'name' => 'gal', 'system' => 'imperial' },
}
}.freeze
def scales_for_variant_unit(ignore_available_units: false)
return @units[@variant.variant_unit] if ignore_available_units
@units[@variant.variant_unit]&.reject { |_scale, unit_info|
self.class.available_units.exclude?(unit_info['name'])
}
end
# Find the largest available and compatible unit where unit_value comes
# to >= 1 when expressed in it.
# If there is none available where this is true, use the smallest available unit.
def find_largest_unit(scales, product_scale_system)
return nil unless scales
largest_unit = scales.select { |scale, unit_info|
unit_info['system'] == product_scale_system &&
@variant.unit_value / scale >= 1
}.max
return scales.first if largest_unit.nil?
largest_unit
end
end