require 'optparse'
require 'logger'
require 'yaml'
require 'rails'
require 'appsignal/version'
require 'appsignal/config'
require 'appsignal/auth_check'
require 'appsignal/marker'
require 'appsignal/transmitter'

module Appsignal
  class CLI
    AVAILABLE_COMMANDS = %w(notify_of_deploy api_check).freeze
    PROJECT_ROOT = ENV['PWD']

    class << self
      def run(argv=ARGV)
        unless File.exists?(File.join(PROJECT_ROOT, 'config/appsignal.yml'))
          puts 'No config file present at config/appsignal.yml'
          puts 'Log in to https://appsignal.com to get instructions on how to generate the config file.'
          exit(1)
        end
        options = {}
        global = global_option_parser(options)
        commands = command_option_parser(options)

        global.order!(argv)
        command = argv.shift
        if command
          if AVAILABLE_COMMANDS.include?(command)
            commands[command].parse!(argv)
            case command.to_sym
            when :notify_of_deploy
              notify_of_deploy(options)
            when :api_check
              api_check
            end
          else
            puts "Command '#{command}' does not exist, run appsignal -h to see the help"
            exit(1)
          end
        else
          # Print help
          puts global
          exit(0)
        end
      end

      def logger
        Logger.new($stdout)
      end

      def global_option_parser(options)
        OptionParser.new do |o|
          o.banner = 'Usage: appsignal <command> [options]'

          o.on '-v', '--version', "Print version and exit" do |arg|
            puts "Appsignal #{Appsignal::VERSION}"
            exit(0)
          end

          o.on '-h', '--help', "Show help and exit" do
            puts o
            exit(0)
          end

          o.separator ''
          o.separator "Available commands: #{AVAILABLE_COMMANDS.join(', ')}"
        end
      end

      def command_option_parser(options)
        {
          'notify_of_deploy' => OptionParser.new do |o|
            o.banner = 'Usage: appsignal notify_of_deploy [options]'

            o.on '--revision=<revision>', "The revision you're deploying" do |arg|
              options[:revision] = arg
            end

            o.on '--repository=<repository>', "The location of the main code repository" do |arg|
              options[:repository] = arg
            end

            o.on '--user=<user>', "The name of the user that's deploying" do |arg|
              options[:user] = arg
            end

            o.on '--environment=<rails_env>', "The environment you're deploying to" do |arg|
              options[:environment] = arg
            end
          end,
          'api_check' => OptionParser.new do |o|
            o.banner = %q(Usage: appsignal api_check

            This command checks the config file in config/appsignal.yml
            and tries to use the api_keys available in each environment to
            see if they work.)
          end
        }
      end

      def notify_of_deploy(options)
        validate_required_options([:revision, :repository, :user, :environment], options)
        Appsignal::Marker.new(
          {
            :revision => options[:revision],
            :repository => options[:repository],
            :user => options[:user]
          },
          PROJECT_ROOT,
          options[:environment],
          logger
        ).transmit
      end

      def api_check
        puts "\nReading config/appsignal.yml and attempting to use the config "\
          "in order to check if it is set up the way it should be.\n\n"
        Appsignal::Config.new(
          PROJECT_ROOT, '', logger
        ).load_all.each do |env, config|
          auth_check = ::Appsignal::AuthCheck.new(
            env,
            {:config => config, :logger => logger}
          )
          puts "[#{env}]"
          puts '  * Configured not to monitor this environment' unless config[:active]
          begin
            result = auth_check.perform
            case result
            when '200'
              puts '  * AppSignal has confirmed authorisation!'
            when '401'
              puts '  * API key not valid with AppSignal...'
            else
              puts '  * Could not confirm authorisation: '\
                "#{result.nil? ? 'nil' : result}"
            end
          rescue Exception => e
            puts "Something went wrong while trying to "\
              "authenticate with AppSignal: #{e}"
          end
        end
      end

      protected

      def validate_required_options(required_options, options)
        missing = required_options.select do |required_option|
          options[required_option].blank?
        end
        if missing.any?
          puts "Missing options: #{missing.join(', ')}"
          exit(1)
        end
      end
    end
  end
end