# frozen_string_literal: true

def list_files(base_dir, pattern = '*')
  Dir[File.join("#{base_dir}", pattern)]
end

def list_js_files(base_dir)
  list_files(base_dir, '**/*.es6')
end

def grep_files(files, regex)
  files.select { |file| grep_file(file, regex) }
end

def grep_file(file, regex)
  lines = File.open(file).grep(regex)
  lines.count > 0 ? file : nil
end

RSpec.describe 'Coding style' do
  describe 'Javascript' do
    it 'prevents this.get("foo") pattern' do
      js_files = list_js_files('app/assets/javascripts')
      offenses = grep_files(js_files, /this\.get\("\w+"\)/)

      expect(offenses).to be_empty, <<~TEXT
        Do not use this.get("foo") accessor for single property, instead
        prefer to use this.foo

        Offenses:
        #{offenses.join("\n")}
      TEXT
    end
  end

  describe 'Post Migrations' do
    def check_offenses(files, method_name, constant_name)
      method_name_regex = /#{Regexp.escape(method_name)}/
      constant_name_regex = /#{Regexp.escape(constant_name)}/
      offenses = files.reject { |file| is_valid?(file, method_name_regex, constant_name_regex) }

      expect(offenses).to be_empty, <<~TEXT
        You need to use the constant #{constant_name} when you use
        #{method_name} in order to help with restoring backups.

        Please take a look at existing migrations to see how to use it correctly.

        Offenses:
        #{offenses.join("\n")}
      TEXT
    end

    def is_valid?(file, method_name_regex, constant_name_regex)
      contains_method_name = File.open(file).grep(method_name_regex).any?
      contains_constant_name = File.open(file).grep(constant_name_regex).any?

      contains_method_name ? contains_constant_name : true
    end

    it 'ensures dropped tables and columns are stored in constants' do
      migration_files = list_files('db/post_migrate', '**/*.rb')

      check_offenses(migration_files, "ColumnDropper.execute_drop", "DROPPED_COLUMNS")
      check_offenses(migration_files, "TableDropper.execute_drop", "DROPPED_TABLES")
    end
  end
end