Find the line number of a key in a long yaml file

ymlfind.rb

#!/usr/bin/ruby
# frozen_string_literal: true

require 'yaml'

to_find = ARGV[0]
puts "Finding #{to_find}"
parts = to_find.split('.')

filename = 'config/locales/en.yml'
lines = File.readlines(filename)

current_lines_with_index = lines.each_with_index.to_a
current_base_idx = 0
current_indentation = -2
begin
  parts.each do |next_part|
    next_line = current_lines_with_index.select do |line, idx|
      line.strip.split(':').first == next_part && idx > current_base_idx
    end.reject do |line, _idx|
      indentation = line[/\A */].size
      indentation != current_indentation + 2
    end.min_by do |_, idx|
      idx
    end
    current_base_idx = next_line.last
    current_indentation = next_line.first[/\A */].size
    puts "#{next_part}: #{current_base_idx}"
  end
  puts "#{to_find} found at #{current_base_idx + 1}"
rescue
  puts "Could not find #{to_find}"
end