module Slotty

# File lib/slotty.rb, line 13
def get_slots(for_range:, slot_length_mins:, interval_mins:, as: :full, exclude_times: [])
  raise InvalidDateError, "for_value must be type of Range" unless for_range.is_a?(Range)
  raise InvalidSlotLengthError, "slot_length_mins must be an integer" unless slot_length_mins.is_a?(Integer)
  raise InvalidIntervalError, "interval_mins must be an integer" unless interval_mins.is_a?(Integer)
  raise InvalidExclusionError, "exclude_times must be an array of time ranges" unless exclude_times.is_a?(Array) && exclude_times.all? { |t| t.is_a?(Range) }

  slot_length = slot_length_mins * 60
  interval = interval_mins * 60

  slots = Array.new(0)

  potential_slot = Slot.new(range: for_range.begin..(for_range.begin + slot_length))

  while Timeframe.covers?(for_range, potential_slot)
    if potential_slot.has_overlaps?(exclude_times)
      potential_slot = Slot.new(range: (potential_slot.begin + interval)..(potential_slot.begin + interval + slot_length))

      next
    end

    raise InvalidFormatError, "cannot format slot in this way" unless potential_slot.respond_to?(as)

    slots << potential_slot.send(as)

    potential_slot = Slot.new(range: (potential_slot.begin + interval)..(potential_slot.begin + interval + slot_length))
  end

  slots
end