require 'erb'
require 'ostruct'
require 'io/console'
require 'appsignal/demo'

module Appsignal
  class CLI
    class Install
      extend CLI::Helpers

      EXCLUDED_ENVIRONMENTS = ['test'].freeze

      class << self
        def run(push_api_key)
          puts
          puts colorize "#######################################", :green
          puts colorize "## Starting AppSignal Installer      ##", :green
          puts colorize "## --------------------------------- ##", :green
          puts colorize "## Need help?  support@appsignal.com ##", :green
          puts colorize "## Docs?       docs.appsignal.com    ##", :green
          puts colorize "#######################################", :green
          puts
          unless push_api_key
            puts colorize 'Problem encountered:', :red
            puts '  No push API key entered.'
            puts '  - Sign up for AppSignal and follow the instructions'
            puts "  - Already signed up? Click 'New app' on the account overview page"
            puts
            puts colorize 'Exiting installer...', :red
            return
          end
          config = new_config
          config[:push_api_key] = push_api_key

          print 'Validating API key'
          periods
          puts
          begin
            auth_check = Appsignal::AuthCheck.new(config)
            unless auth_check.perform == '200'
              puts "\n  API key '#{config[:push_api_key]}' is not valid, please get a new one on https://appsignal.com"
              return
            end
          rescue => e
            puts "  There was an error validating your API key:"
            puts colorize "'#{e}'", :red
            puts "  Please try again"
            return
          end
          puts colorize '  API key valid!', :green
          puts

          if installed_frameworks.include?(:rails)
            install_for_rails(config)
          elsif installed_frameworks.include?(:padrino)
            install_for_padrino(config)
          elsif installed_frameworks.include?(:grape)
            install_for_grape(config)
          elsif installed_frameworks.include?(:sinatra)
            install_for_sinatra(config)
          else
            puts "We could not detect which framework you are using. We'd be very grateful if you email us on support@appsignal.com with information about your setup."
          end
        end

        def install_for_rails(config)
          require File.expand_path(File.join(Dir.pwd, 'config/application.rb'))

          puts 'Installing for Ruby on Rails'

          config[:name] = Rails.application.class.parent_name

          name_overwritten = yes_or_no("  Your app's name is: '#{config[:name]}' \n  Do you want to change how this is displayed in AppSignal? (y/n): ")
          puts
          if name_overwritten
            config[:name] = required_input("  Choose app's display name: ")
            puts
          end

          configure(config, rails_environments, name_overwritten)
          done_notice
        end

        def install_for_sinatra(config)
          puts 'Installing for Sinatra'
          config[:name] = required_input('  Enter application name: ')
          puts
          configure(config, ['development', 'production', 'staging'], true)

          puts "Finish Sinatra configuration"
          puts "  Sinatra requires some manual configuration."
          puts "  Add this line beneath require 'sinatra':"
          puts
          puts "  require 'appsignal/integrations/sinatra'"
          puts
          puts "  You can find more information in the documentation:"
          puts "  http://docs.appsignal.com/getting-started/supported-frameworks.html#sinatra"
          press_any_key
          done_notice
        end

        def install_for_padrino(config)
          puts 'Installing for Padrino'
          config[:name] = required_input('  Enter application name: ')
          puts
          configure(config, ['development', 'production', 'staging'], true)

          puts "Finish Padrino installation"
          puts "  Padrino requires some manual configuration."
          puts "  After installing the gem, add the following line to /config/boot.rb:"
          puts
          puts "  require 'appsignal/integrations/padrino"
          puts
          puts "  You can find more information in the documentation:"
          puts "  http://docs.appsignal.com/getting-started/supported-frameworks.html#padrino"
          press_any_key
          done_notice
        end

        def install_for_grape(config)
          puts 'Installing for Grape'

          config[:name] = required_input('  Enter application name: ')
          puts

          configure(config, ['development', 'production', 'staging'], true)

          puts "Manual Grape configuration needed"
          puts "  See the installation instructions at:"
          puts "  http://docs.appsignal.com/getting-started/supported-frameworks.html#grape"
          press_any_key
          done_notice
        end

        def install_for_capistrano
          capfile = File.join(Dir.pwd, 'Capfile')
          return unless File.exist?(capfile)
          return if File.read(capfile) =~ %r{require ['|"]appsignal/capistrano}

          puts 'Installing for Capistrano'
          print '  Adding AppSignal integration to Capfile'
          File.open(capfile, 'a') do |f|
            f.write "\nrequire 'appsignal/capistrano'\n"
          end
          periods
          puts
          puts
        end

        def configure(config, environments, name_overwritten)
          install_for_capistrano

          ENV["APPSIGNAL_APP_ENV"] = "development"

          puts "How do you want to configure AppSignal?"
          puts "  (1) a config file"
          puts "  (2) environment variables"
          loop do
            print "  Choose (1/2): "
            case ask_for_input
            when '1'
              puts
              print "Writing config file"
              periods
              puts
              puts colorize "  Config file written to config/appsignal.yml", :green
              write_config_file(
                :push_api_key => config[:push_api_key],
                :app_name => config[:name],
                :environments => environments
              )
              puts
              break
            when '2'
              ENV["APPSIGNAL_ACTIVE"] = "true"
              ENV["APPSIGNAL_PUSH_API_KEY"] = config[:push_api_key]
              ENV["APPSIGNAL_APP_NAME"] = config[:name]

              puts
              puts "Add the following environment variables to configure AppSignal:"
              puts "  export APPSIGNAL_PUSH_API_KEY=#{config[:push_api_key]}"
              if name_overwritten
                puts "  export APPSIGNAL_APP_NAME=#{config[:name]}"
              end
              puts
              puts "  See the documentation for more configuration options:"
              puts "  http://docs.appsignal.com/gem-settings/configuration.html"
              press_any_key
              break
            end
          end
        end

        def done_notice
          sleep 0.3
          puts colorize "#####################################", :green
          puts colorize "## AppSignal installation complete ##", :green
          puts colorize "#####################################", :green
          sleep 0.3
          puts
          if Gem.win_platform?
            puts 'The AppSignal agent currently does not work on Windows, please push these changes to your test/staging/production environment'
          else
            puts "  Sending example data to AppSignal..."
            if Appsignal::Demo.transmit
              puts "  Example data sent!"
              puts "  It may take about a minute for the data to appear on https://appsignal.com/accounts"
              puts
              puts "  Please return to your browser and follow the instructions."
            else
              puts "  Couldn't start the AppSignal agent and send example data to AppSignal.com"
              puts "  Please use `appsignal diagnose` to debug your configuration."
            end
          end
        end

        def installed_frameworks
          [].tap do |out|
            begin
              require 'rails'
              out << :rails
            rescue LoadError
            end
            begin
              require 'sinatra'
              out << :sinatra
            rescue LoadError
            end
            begin
              require 'padrino'
              out << :padrino
            rescue LoadError
            end
            begin
              require 'grape'
              out << :grape
            rescue LoadError
            end
          end
        end

        def rails_environments
          Dir.glob(
            File.join(Dir.pwd, 'config/environments/*.rb')
          ).map { |o| File.basename(o, ".rb") }.sort - EXCLUDED_ENVIRONMENTS
        end

        def write_config_file(data)
          template = ERB.new(
            File.read(File.join(File.dirname(__FILE__), "../../../resources/appsignal.yml.erb")),
            nil,
            '-'
          )

          config = template.result(OpenStruct.new(data).instance_eval { binding })

          FileUtils.mkdir_p(File.join(Dir.pwd, 'config'))
          File.write(File.join(Dir.pwd, 'config/appsignal.yml'), config)
        end

        def new_config
          Appsignal::Config.new(Dir.pwd, "")
        end
      end
    end
  end
end