class VagrantFoodtasterServer
  class Server
    def initialize(app, env)
      @env = env
      @app = app

      begin
        require 'sahara/session/virtualbox'
      rescue LoadError
        raise RuntimeError, <<-EOT.strip_heredoc
          Cannot find `sahara' plugin. Please, make sure that `sahara' plugin is installed using command:
          $ vagrant plugin list

          If `sahara' plugin is not installed, install it:
          $ vagrant plugin install sahara
        EOT
      end
    end

    def version
      VagrantFoodtasterServer::VERSION
    end

    def redirect_stdstreams(stdout, stderr)
      $stdout = stdout
      $stderr = stderr
    end

    def prepare_vm(vm_name)
      unless vm_prepared?(vm_name)
        vm = get_vm(vm_name)
        sahara = sahara_for(vm)

        if vm.state.id.to_s != 'running'
          chef_run_list = get_chef_solo_run_list(vm)
          provision_types = [:shell, :puppet]

          unless chef_run_list.empty?
            provision_types << :chef_solo
          end

          vm.action(:up,
                    provision_types: provision_types,
                    provision_enabled: true)
        end

        unless sahara.is_snapshot_mode_on?
          sahara.on
        end
      end
    end

    def rollback_vm(vm_name)
      vm = get_vm(vm_name)

      sahara_for(vm).rollback
    end

    def shutdown_vm(vm_name)
      vm = get_vm(vm_name)

      vm.action(:halt)
    end

    def vm_defined?(vm_name)
      @env.machine_names.include?(vm_name)
    end

    def vm_prepared?(vm_name)
      vm = get_vm(vm_name)
      sahara = sahara_for(vm)

      vm.state.id.to_s == 'running' && sahara.is_snapshot_mode_on?
    end

    def run_chef_on_vm(vm_name, current_run_config)
      vm = get_vm(vm_name)

      validate_vm!(vm)

      chef_solo_config = vm.config.vm.provisioners.find { |p| p.name == :chef_solo }

      provisioner_klass = Vagrant.plugin("2").manager.provisioners[:chef_solo]
      provisioner = provisioner_klass.new(vm, chef_solo_config.config)

      current_run_chef_solo_config = apply_current_run_config(vm.config, current_run_config)
      provisioner.configure(current_run_chef_solo_config)

      begin
        provisioner.provision
      rescue Exception
        raise RuntimeError, "Chef Run failed on #{vm_name} with config #{current_run_config.inspect}"
      end
    end

    def execute_command_on_vm(vm_name, command)
      vm = get_vm(vm_name)
      exec_result = {}

      exec_result[:exit_status] = vm.communicate.sudo(command, error_check: false) do |stream_type, data|
        exec_result[stream_type] = exec_result[stream_type].to_s + data
      end

      exec_result
    end

    private

    def sahara_for(vm)
      Sahara::Session::Virtualbox.new(vm)
    end

    def get_chef_solo_run_list(vm)
      vm.config.vm.provisioners.map do |c|
        if c.name == :chef_solo
          c.config.run_list
        else
          nil
        end
      end.compact.flatten
    end

    def get_vm(vm_name)
      @env.machine(vm_name, :virtualbox)
    end

    def validate_vm!(vm)
      chef_solo_config = vm.config.vm.provisioners.find { |p| p.name == :chef_solo }

      unless chef_solo_config
        raise RuntimeError, <<-EOT.strip_heredoc
          VM '#{vm.name}' doesn't have a configured chef-solo provisioner, which is requied by Foodtaster to run specs on this VM.
          Please, add dummy chef-solo provisioner to your Vagrantfile, like this:
          config.vm.provision :chef_solo do |chef|
            chef.cookbooks_path = %w[site-cookbooks]
          end
        EOT
      end
    end

    def apply_current_run_config(vm_config, current_run_config)
      modified_config = vm_config.dup

      provisioner_index = modified_config.vm.provisioners.find_index do |prov|
        prov.name == :chef_solo
      end

      modified_config.vm.provisioners[provisioner_index].config.run_list = current_run_config[:run_list]
      modified_config.vm.provisioners[provisioner_index].config.json = current_run_config[:json]

      modified_config
    end
  end
end