class Pry::Command::CodeCollector

def self.inject_options(opt)
  @input_expression_ranges = []
  @output_result_ranges = []
  opt.on :l, :lines, "Restrict to a subset of lines. Takes a line number " \
                     "or range",
         optional_argument: true, as: Range, default: 1..-1
  opt.on :o, :out, "Select lines from Pry's output result history. " \
                   "Takes an index or range",
         optional_argument: true, as: Range, default: -5..-1 do |r|
    output_result_ranges << (r || (-5..-1))
  end
  opt.on :i, :in, "Select lines from Pry's input expression history. " \
                  "Takes an index or range",
         optional_argument: true, as: Range, default: -5..-1 do |r|
    input_expression_ranges << (r || (-5..-1))
  end
  opt.on :s, :super, "Select the 'super' method. Can be repeated to " \
                     "traverse the ancestors",
         as: :count
  opt.on :d, :doc, "Select lines from the code object's documentation"
end

def bad_option_combination?
  [opts.present?(:in), opts.present?(:out),
   !args.empty?].count(true) > 1
end

def code_object
  Pry::CodeObject.lookup(obj_name, pry_instance, super: opts[:super])
end

def code_object_doc
  (code_object && code_object.doc) || could_not_locate(obj_name)
end

def code_object_source_or_file
  (code_object && code_object.source) || file_content
end

def content
  @content ||=
    begin
      if bad_option_combination?
        raise CommandError,
              "Only one of --out, --in, --doc and CODE_OBJECT may " \
              "be specified."
      end
      content = if opts.present?(:o)
                  pry_output_content
                elsif opts.present?(:i)
                  pry_input_content
                elsif opts.present?(:d)
                  code_object_doc
                else
                  code_object_source_or_file
                end
      restrict_to_lines(content, line_range)
    end
end

def convert_to_range(range)
  return range if range.is_a?(Range)
  (range..range)
end

def could_not_locate(name)
  raise CommandError, "Cannot locate: #{name}!"
end

def file_content
  if File.exist?(obj_name)
    # Set the file accessor.
    self.file = obj_name
    File.read(obj_name)
  else
    could_not_locate(obj_name)
  end
end

def initialize(args, opts, pry_instance)
  @args = args
  @opts = opts
  @pry_instance = pry_instance
end

def line_range
  opts.present?(:lines) ? one_index_range_or_number(opts[:lines]) : 0..-1
end

def obj_name
  @obj_name ||= args.empty? ? "" : args.join(" ")
end

def pry_array_content_as_string(array, ranges)
  all = ''
  ranges.each do |range|
    if convert_to_range(range).first == 0
      raise CommandError, "Minimum value for range is 1, not 0."
    end
    ranged_array = Array(array[range]) || []
    ranged_array.compact.each { |v| all += yield(v) }
  end
  all
end

def pry_input_content
  pry_array_content_as_string(
    pry_instance.input_ring, self.class.input_expression_ranges
  ) { |v| v }
end

def pry_output_content
  pry_array_content_as_string(
    pry_instance.output_ring,
    self.class.output_result_ranges,
    &:pretty_inspect
  )
end

def restrict_to_lines(content, range)
  Array(content.lines.to_a[range]).join
end