module LoanCreator::BorrowerTimetable

Constants

BORROWER_FINANCIAL_ATTRIBUTES

Public Instance Methods

borrower_timetable(*lenders_timetables) click to toggle source
# File lib/loan_creator/borrower_timetable.rb, line 15
def borrower_timetable(*lenders_timetables)
  raise ArgumentError.new('Array of LoanCreator::Timetable expected') unless Array === lenders_timetables
  raise ArgumentError.new('At least one LoanCreator::Timetable expected') unless lenders_timetables.length > 0
  lenders_timetables.each do |lender_timetable|
    raise ArgumentError.new('Array of LoanCreator::Timetable expected') unless LoanCreator::Timetable === lender_timetable
  end

  borrower_timetable = LoanCreator::Timetable.new(
    starting_index: lenders_timetables.first.starting_index,
    loan: lenders_timetables.first.loan
  )

  # Borrower timetable is not concerned with computation-related value (delta, etc.),
  # thus we start with all values to zero, then we override only BORROWER_FINANCIAL_ATTRIBUTES.
  all_zero = LoanCreator::Term::ARGUMENTS.each_with_object({}) { |k, h| h[k] = bigd('0') }

  # Group lenders' terms by index
  transposed_terms = lenders_timetables.map(&:terms).transpose
  # For each term, sum each required element
  # First borrower's term contains the sums of lenders' first terms' elements (LoanCreator::Term::ARGUMENT), etc.
  transposed_terms.each do |arr|
    term = BORROWER_FINANCIAL_ATTRIBUTES.each_with_object({}) do |k, h|
      h[k] = arr.inject(bigd('0')) { |sum, tt| sum + tt.send(k) }
    end
    borrower_timetable << LoanCreator::Term.new(**all_zero.merge(term))
  end
  borrower_timetable
end