String balancer

balancer.rb

# frozen_string_literal: true

class Message
  def initialize(content)
    @content = content
  end

  def balanced?
    return false unless allowed_string?(@content)

    content_dup = @content.dup
    if content_dup[0] == '(' && content_dup[-1] == ')'
      remove_side_brackets(content_dup)
    end

    sanitized_content = remove_emoji(content_dup)
    stack = []

    sanitized_content.each_char do |ch|
      case ch
      when '('
        stack << ch
      when ')'
        return false if stack.empty?

        stack.pop
      end
    end

    stack.empty?
  end

  def allowed_string?(msg)
    msg.each_char do |char|
      return false unless valid_char?(char)
    end
  end

  def valid_char?(char)
    !!(char =~ /^[a-z\s.:.).(]/)
  end

  def remove_side_brackets(content)
    content[0] = ''
    content[content.size - 1] = ''
    content
  end

  def remove_emoji(msg)
    msg.gsub(':)', '')
       .gsub(':(', '')
  end
end

# Test cases
test_cases = ['hola', '(hola)', '(()', '(:)', 'no voy (:()', 'hoy pm: fiesta :):)', ':((', 'a (b (c (d) c) b) a :)']

test_cases.each { |tc| puts Message.new(tc).balanced? }