class NutrientMeasurement < ApplicationRecord
  NUTRIENT_FIELDS = %i[
    nno3 p k ca mg s na cl si fe zn b mn cu mo nnh4
  ].freeze

  validates :measured_on, presence: true
  validates :measured_on, uniqueness: true

  def self.data_series_for(*nutrients)
    nutrients.map do |formula|
      { name: formula, data: self.order(:measured_on).pluck(:measured_on, formula) }
    end
  end

  def self.nutrient_fields
    NUTRIENT_FIELDS
  end
end