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

require "pathname"

PATHS = {
  xdg_config: ".config/rubocop/config.yml",
  xdg_issues: ".config/rubocop/issues.yml",
  config: ".rubocop.yml",
  todo: ".rubocop_todo.yml"
}.freeze

class Updater
  def initialize root: Pathname.pwd, paths: PATHS
    @root = root
    @paths = paths
  end

  def call
    prompt
    check_xdg_configuration
    check_standard_configuration
    copy_configuration
    remove_inheritance
    generate_issues
    apply_changes
  end

  private

  attr_reader :root, :paths

  def prompt
    puts "Update RuboCop configuration with outstanding issues (y/n)?"

    return if gets.chomp == "y"

    puts "RuboCop configuration update canceled."
    exit
  end

  def check_xdg_configuration
    return if full_path(:xdg_config).exist?

    abort "RuboCop XDG configuration must exist before proceeding."
  end

  def check_standard_configuration
    return unless full_path(:config).exist?

    abort "RuboCop configuration exists. Please use a XDG configuration instead."
  end

  def copy_configuration = full_path(:config).write full_path(:xdg_config).read

  def generate_issues = system "bundle exec rubocop --auto-gen-config"

  def remove_inheritance
    full_path(:config).then do |path|
      content = path.read.sub(/inherit_from:\s(issues|\.rubocop_todo.).yml/, "")
      path.write content
    end
  end

  def apply_changes
    config_path = full_path :config
    todo_path = full_path :todo

    if todo_path.empty?
      puts "No changes were detected."
    else
      full_path(:xdg_issues).write todo_path.read
    end

    config_path.delete
    todo_path.delete
  end

  def full_path(key) = root.join(paths.fetch(key))
end

Updater.new.call