class HighLine::List

def build
  slice_by_cols
  transpose if transpose_mode
  col_down  if col_down_mode
  self
end

def col_down
  slice_by_rows
  transpose
  self
end

def cols=(cols)
  @cols = cols
  build
end

def initialize(items, options = {})
  @items          = items.to_a.dup.freeze
  @transpose_mode = options.fetch(:transpose) { false }
  @col_down_mode  = options.fetch(:col_down)  { false }
  @cols           = options.fetch(:cols)      { 1 }
  build
end

def items_sliced_by_cols
  items.each_slice(cols).to_a
end

def items_sliced_by_rows
  items.each_slice(row_count).to_a
end

def list
  @list.dup
end

def row_count
  (items.count / cols.to_f).ceil
end

def row_join_str_size
  row_join_string.size
end

def row_join_string
  @row_join_string ||= "  "
end

def slice_by_cols
  @list = items_sliced_by_cols
  self
end

def slice_by_rows
  @list = items_sliced_by_rows
  self
end

def stringfy(row)
  row.compact.join(row_join_string) + "\n"
end

def to_a
  list
end

def to_s
  list.map { |row| stringfy(row) }.join
end

def transpose
  first_row = @list[0]
  other_rows = @list[1..-1]
  @list = first_row.zip(*other_rows)
  self
end