#
# Copyright (c) 2013, Seth Chisamore
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

require "log4r"
require "shellwords"

require "vagrant/util/downloader"

module VagrantPlugins
  module Omnibus
    module Action
      # @author Seth Chisamore <schisamo@chef.io>
      #
      # This action installs Chef Omnibus packages at the desired version.
      class InstallChef
        def initialize(app, env)
          @app = app
          @logger =
            Log4r::Logger.new("vagrantplugins::omnibus::action::installchef")
          @machine = env[:machine]
          @install_script = find_install_script
        end

        def call(env)
          @app.call(env)

          return unless @machine.communicate.ready? && provision_enabled?(env)

          # Perform delayed validation
          @machine.config.omnibus.validate!(@machine)

          desired_version = @machine.config.omnibus.chef_version
          unless desired_version.nil?
            if installed_version == desired_version
              env[:ui].info I18n.t(
                "vagrant-omnibus.action.installed",
                version: desired_version
              )
            else
              fetch_or_create_install_script(env)
              env[:ui].info I18n.t(
                "vagrant-omnibus.action.installing",
                version: desired_version
              )
              install(desired_version, env)
              recover(env)
            end
          end
        end

        private

        # Determines which install script should be used to install the
        # Omnibus Chef package. Order of precedence:
        # 1. from config
        # 2. from env var
        # 3. default
        def find_install_script
          config_install_url || env_install_url || default_install_url
        end

        def default_install_url
          if windows_guest?
            "http://www.chef.io/chef/install.msi"
          else
            "https://www.chef.io/chef/install.sh"
          end
        end

        def config_install_url
          @machine.config.omnibus.install_url
        end

        def env_install_url
          ENV["OMNIBUS_INSTALL_URL"]
        end

        def cached_omnibus_download_dir
          "/tmp/vagrant-cache/vagrant_omnibus"
        end

        def cache_packages?
          @machine.config.omnibus.cache_packages
        end

        def cachier_present?
          defined?(VagrantPlugins::Cachier::Plugin)
        end

        def cachier_autodetect_enabled?
          @machine.config.cache.auto_detect
        end

        def download_to_cached_dir?
          cache_packages? && cachier_present? && cachier_autodetect_enabled?
        end

        def install_script_name
          if windows_guest?
            "install.bat"
          else
            "install.sh"
          end
        end

        def install_script_folder
          if windows_guest?
            "$env:temp/vagrant-omnibus"
          else
            "/tmp/vagrant-omnibus"
          end
        end

        def install_script_path
          File.join(install_script_folder, install_script_name)
        end

        def windows_guest?
          @machine.config.vm.guest.eql?(:windows)
        end

        def provision_enabled?(env)
          env.fetch(:provision_enabled, true)
        end

        def communication_opts
          if windows_guest?
            { shell: "powershell" }
          else
            { shell: "sh" }
          end
        end

        def installed_version
          version = nil
          opts = communication_opts
          opts[:error_check] = false if windows_guest?
          command = "echo $(chef-solo -v)"
          @machine.communicate.sudo(command, opts) do |type, data|
            if [:stderr, :stdout].include?(type)
              version_match = data.match(/^Chef: (.+)/)
              version = version_match.captures[0].strip if version_match
            end
          end
          version
        end

        #
        # Upload install script from Host's Vagrant TMP directory to guest
        # and executes.
        #
        def install(version, env)
          shell_escaped_version = Shellwords.escape(version)

          @machine.communicate.tap do |comm|
            unless windows_guest?
              comm.execute("mkdir -p #{install_script_folder}")
            end

            comm.upload(@script_tmp_path, install_script_path)

            if windows_guest?
              install_cmd = "& #{install_script_path} #{version}"
            else
              install_cmd = "sh #{install_script_path}"
              install_cmd << " -v #{shell_escaped_version}"
              if download_to_cached_dir?
                install_cmd << " -d #{cached_omnibus_download_dir}"
              end
              install_cmd << " 2>&1"
            end
            comm.sudo(install_cmd, communication_opts) do |type, data|
              if [:stderr, :stdout].include?(type)
                next if data =~ /stdin: is not a tty/
                env[:ui].info(data)
              end
            end
          end
        end

        #
        # Fetches or creates a platform specific install script to the Host's
        # Vagrant TMP directory.
        #
        def fetch_or_create_install_script(env)
          @script_tmp_path = env[:tmp_path].join(
            "#{Time.now.to_i}-#{install_script_name}"
          ).to_s

          @logger.info("Generating install script at: #{@script_tmp_path}")

          url = @install_script

          if File.file?(url) || url !~ /^[a-z0-9]+:.*$/i
            @logger.info("Assuming URL is a file.")
            file_path = File.expand_path(url)
            file_path = Vagrant::Util::Platform.cygwin_windows_path(file_path)
            url = "file:#{file_path}"
          end

          # Download the install.sh or create install.bat file to a temporary
          # path. We store the temporary path as an instance variable so that
          # the `#recover` method can access it.
          begin
            if windows_guest?
              # generate a install.bat file at the `@script_tmp_path` location
              #
              # We'll also disable Rubocop for this embedded PowerShell code:
              #
              # rubocop:disable LineLength, SpaceAroundBlockBraces
              #
              File.open(@script_tmp_path, "w") do |f|
                f.puts <<-EOH.gsub(/^\s{18}/, "")
                  @echo off
                  set version=%1
                  set dest=%~dp0chef-client-%version%-1.windows.msi
                  echo Downloading Chef %version% for Windows...
                  powershell -command "(New-Object System.Net.WebClient).DownloadFile('#{url}?v=%version%', '%dest%')"
                  echo Installing Chef %version%
                  msiexec /q /i %dest%
                EOH
              end
              # rubocop:enable LineLength, SpaceAroundBlockBraces
            else
              downloader = Vagrant::Util::Downloader.new(
                url,
                @script_tmp_path,
                {}
              )
              downloader.download!
            end
          rescue Vagrant::Errors::DownloaderInterrupted
            # The downloader was interrupted, so just return, because that
            # means we were interrupted as well.
            env[:ui].info(I18n.t("vagrant-omnibus.download.interrupted"))
            return
          end
        end

        def recover(env)
          if @script_tmp_path && File.exist?(@script_tmp_path)
            # Try extra hard to unlink the file so that it reliably works
            # on Windows hosts as well, see:
            # http://alx.github.io/2009/01/27/ruby-wundows-unlink.html
            file_deleted = false
            until file_deleted
              begin
                File.unlink(@script_tmp_path)
                file_deleted = true
              rescue Errno::EACCES
                @logger.debug("failed to unlink #{@script_tmp_path}. retry...")
              end
            end
          end
        end
      end
    end
  end
end