class DiscoAppGenerator < Rails::Generators::Base

  source_root File.expand_path('../templates', __FILE__)

  # Copy a number of template files to the top-level directory of our application:
  #
  #  - .env and .env.local for settings environment variables in development with dotenv-rails;
  #  - Slightly customised version of the default Rails .gitignore;
  #  - Default simple Procfile for Heroku.
  #
  def copy_root_files
    %w(.env .env.local .gitignore Procfile).each do |file|
      copy_file "root/#{file}", file
    end
  end

  # Remove a number of root files.
  def remove_root_files
    %w(README.rdoc).each do |file|
      remove_file file
    end
  end

  # Configure the application's Gemfile.
  def configure_gems
    # Remove sqlite from the general Gemfile.
    gsub_file 'Gemfile', /^# Use sqlite3 as the database for Active Record\ngem 'sqlite3'/m, ''

    # Add gems common to all environments.
    gem 'shopify_app', '~> 6.4.1'
    gem 'sidekiq', '~> 4.0.2'
    gem 'puma', '~> 2.14.0'
    gem 'bootstrap-sass', '~> 3.3.5.1'
    gem 'activerecord-session_store', '~> 0.1.2'
    gem 'activeresource', github: 'shopify/activeresource', tag: '4.2-threadsafe'

    # Add gems for development and testing only.
    gem_group :development, :test do
      gem 'sqlite3', '~> 1.3.11'
      gem 'dotenv-rails', '~> 2.0.2'
      gem 'minitest-reporters', '~> 1.0.19'
      gem 'guard', '~> 2.13.0'
      gem 'guard-minitest', '~> 2.4.4'
    end

    # Add gems for production only.
    gem_group :production do
      gem 'pg', '~> 0.18.3'
      gem 'rails_12factor', '~> 0.0.3'
    end
  end

  # Run bundle install to add our new gems before running tasks.
  def bundle_install
    Bundler.with_clean_env do
      run 'bundle install'
    end
  end

  # Make any required adjustments to the application configuration.
  def configure_application
    # The force_ssl flag is commented by default for production.
    # Uncomment to ensure config.force_ssl = true in production.
    uncomment_lines 'config/environments/production.rb', /force_ssl/

    # Set defaults for various charge attributes.
    application "config.x.shopify_charges_default_trial_days = 14\n"
    application "config.x.shopify_charges_default_price = 10.00"
    application "config.x.shopify_charges_default_type = :recurring"
    application "# Set defaults for charges created by the application"

    # Set the "real charges" config variable to false explicitly by default.
    # Only in production do we read from the environment variable and
    # potentially have it become true.
    application "config.x.shopify_charges_real = false\n"
    application "# Explicitly prevent real charges being created by default"
    application "config.x.shopify_charges_real = ENV['SHOPIFY_CHARGES_REAL'] == 'true'\n", env: :production
    application "# Allow real charges in production with an ENV variable", env: :production

    # Configure session storage.
    application "ActiveRecord::SessionStore::Session.table_name = 'disco_app_sessions'"
    application "ActionDispatch::Session::ActiveRecordStore.session_class = DiscoApp::Session"
    application "# Configure custom session storage"

    # Set Sidekiq as the queue adapter in production.
    application "config.active_job.queue_adapter = :sidekiq\n", env: :production
    application "# Use Sidekiq as the active job backend", env: :production

    # Ensure the application configuration uses the DEFAULT_HOST environment
    # variable to set up support for reverse routing absolute URLS (needed when
    # generating Webhook URLs for example).
    application "routes.default_url_options[:host] = ENV['DEFAULT_HOST']\n"
    application "# Set the default host for absolute URL routing purposes"

    # Add loading of the default application proxy prefix to set up support for
    # reverse routings absolute proxy URLS.
    application "config.x.shopify_app_proxy_prefix = ENV['SHOPIFY_APP_PROXY_PREFIX']\n"
    application "# Set the application proxy path for absolute URL routing purposes"

    # Add the Shopify application name to the configuration.
    application "config.x.shopify_app_name = ENV['SHOPIFY_APP_NAME']\n"
    application "# Set the name of the application"

    # Copy over the default puma configuration.
    copy_file 'config/puma.rb', 'config/puma.rb'
  end

  # Set up routes.
  def setup_routes
    route "mount DiscoApp::Engine, at: '/'"
  end

  # Run shopify_app:install
  def shopify_app_install
    generate 'shopify_app:install'
  end

  # Copy template files to the appropriate location. In some cases, we'll be
  # overwriting or removing existing files or those created by ShopifyApp.
  def copy_and_remove_files
    # Copy initializers
    copy_file 'initializers/shopify_app.rb', 'config/initializers/shopify_app.rb'
    copy_file 'initializers/disco_app.rb', 'config/initializers/disco_app.rb'
    copy_file 'initializers/shopify_session_repository.rb', 'config/initializers/shopify_session_repository.rb'
    copy_file 'initializers/session_store.rb', 'config/initializers/session_store.rb'

    # Copy default home controller and view
    copy_file 'controllers/home_controller.rb', 'app/controllers/home_controller.rb'
    copy_file 'views/home/index.html.erb', 'app/views/home/index.html.erb'

    # Copy assets
    copy_file 'assets/javascripts/application.js', 'app/assets/javascripts/application.js'
    copy_file 'assets/stylesheets/application.scss', 'app/assets/stylesheets/application.scss'

    # Remove application.css
    remove_file 'app/assets/stylesheets/application.css'

    # Remove the layout files created by ShopifyApp
    remove_file 'app/views/layouts/application.html.erb'
    remove_file 'app/views/layouts/embedded_app.html.erb'
  end

  # Add the Disco App test helper to test/test_helper.rb
  def add_test_helper
    inject_into_file 'test/test_helper.rb', "require 'disco_app/test_help'\n", { after: "require 'rails/test_help'\n" }
  end

  # Copy engine migrations over.
  def install_migrations
    rake 'disco_app:install:migrations'
  end

  # Run migrations.
  def migrate
    rake 'db:migrate'
  end

  # Lock down the application to a specific Ruby version:
  #
  #  - Via .ruby-version file for rbenv in development;
  #  - Via a Gemfile line in production.
  #
  # This should be the last operation, to allow all other operations to run in the initial Ruby version.
  def set_ruby_version
    copy_file 'root/.ruby-version', '.ruby-version'
    prepend_to_file 'Gemfile', "ruby '2.3.0'\n"
  end

end