require 'rails/generators'

class AirbrakeGenerator < Rails::Generators::Base

  class_option :api_key, :aliases => "-k", :type => :string, :desc => "Your Airbrake API key"
  class_option :heroku, :type => :boolean, :desc => "Use the Heroku addon to provide your Airbrake API key"
  class_option :app, :aliases => "-a", :type => :string, :desc => "Your Heroku app name (only required if deploying to >1 Heroku app)"

  def self.source_root
    @_airbrake_source_root ||= File.expand_path("../../../../../generators/airbrake/templates", __FILE__)
  end

  def install
    ensure_api_key_was_configured
    ensure_plugin_is_not_present
    append_capistrano_hook
    generate_initializer unless api_key_configured?
    determine_api_key if heroku?
    test_airbrake
  end

  private

  def ensure_api_key_was_configured
    if !options[:api_key] && !options[:heroku] && !api_key_configured?
      puts "Must pass --api-key or --heroku or create config/initializers/airbrake.rb"
      exit
    end
  end

  def ensure_plugin_is_not_present
    if plugin_is_present?
      puts "You must first remove the airbrake plugin. Please run: script/plugin remove airbrake"
      exit
    end
  end

  def append_capistrano_hook
    if File.exists?('config/deploy.rb') && File.exists?('Capfile')
      append_file('config/deploy.rb', <<-HOOK)

        require './config/boot'
        require 'airbrake/capistrano'
      HOOK
    end
  end

  def api_key_expression
    s = if options[:api_key]
      "'#{options[:api_key]}'"
    elsif options[:heroku]
      "ENV['AIRBRAKE_API_KEY']"
    end
  end

  def generate_initializer
    template 'initializer.rb', 'config/initializers/airbrake.rb'
  end

  def determine_api_key
    puts "Attempting to determine your API Key from Heroku..."
    ENV['AIRBRAKE_API_KEY'] = heroku_api_key
    if ENV['AIRBRAKE_API_KEY'].blank?
      puts "... Failed."
      puts "WARNING: We were unable to detect the Airbrake API Key from your Heroku environment."
      puts "Your Heroku application environment may not be configured correctly."
      exit 1
    else
      puts "... Done."
      puts "Heroku's Airbrake API Key is '#{ENV['AIRBRAKE_API_KEY']}'"
    end
  end

  def heroku_api_key
    app = options[:app] ? " --app #{options[:app]}" : ''
    `heroku console#{app} 'puts ENV[%{AIRBRAKE_API_KEY}]'`.split("\n").first
  end

  def heroku?
    options[:heroku] ||
      system("grep AIRBRAKE_API_KEY config/initializers/airbrake.rb") ||
      system("grep AIRBRAKE_API_KEY config/environment.rb")
  end

  def api_key_configured?
    File.exists?('config/initializers/airbrake.rb')
  end

  def test_airbrake
    puts run("rake airbrake:test --trace")
  end

  def plugin_is_present?
    File.exists?('vendor/plugins/airbrake')
  end
end