#
# Copyright (C) 2010-2016 dtk contributors
#
# This file is part of the dtk project.
#
# 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.
#
module DTK
  module NodeAgent
    class Installer
      require 'facter'

      # read configuration
      CONFIG = eval(File.open(File.expand_path('../config/install.config', File.dirname(__FILE__))) {|f| f.read })

      # get OS facts
      @osfamily     = Facter.value('osfamily').downcase
      @osname       = Facter.value('operatingsystem')
      @osmajrelease = Facter.value('operatingsystemmajrelease')
      @osarch       = Facter.value('architecture')
      @distcodename = Facter.value('lsbdistcodename')

      def self.run(argv)
        require 'optparse'
        require 'fileutils'
        require 'dtk-node-agent/version'

        @@options = parse(argv)

        unless Process.uid == 0
          puts "dtk-node-agent must be started with root/sudo privileges."
          exit(1)
        end

        if @osfamily == 'debian'
              # set up apt and install packages
              shell "apt-get update --fix-missing"
              shell "apt-get install -y build-essential wget curl git libicu-dev zlib1g-dev"
              # install upgrades
              Array(CONFIG[:upgrades][:debian]).each do |package|
                shell "apt-get install -y #{package}"
              end
              shell "wget http://apt.puppetlabs.com/puppetlabs-release-#{@distcodename}.deb"
              puts "Installing Puppet Labs repository..."
              shell "dpkg -i puppetlabs-release-#{@distcodename}.deb"
              puts "Installing Puppet Labs repository..."
              shell "dpkg -i puppetlabs-release-#{@distcodename}.deb"
              # install logstash forwarder
              logstash_forwarder_url = CONFIG[:logstash_forwarder_deb64]
              logstash_forwarder_package = logstash_forwarder_url.rpartition('/').last
              shell "wget #{logstash_forwarder_url}"
              puts "Installing logstash-forwarder"
              shell "dpkg -i #{logstash_forwarder_package}"
              shell "apt-get update"
              shell "rm puppetlabs-release-#{@distcodename}.deb #{logstash_forwarder_package}"
              # pin down the puppetlabs apt repo
              FileUtils.cp("#{base_dir}/src/etc/apt/preferences.d/puppetlabs", "/etc/apt/preferences.d/puppetlabs")
            elsif @osfamily == 'redhat'
              shell "yum -y install yum-utils wget curl libicu-devel zlib-devel"
              # do a full upgrade
              shell "yum -y update"
              case @osmajrelease
              when "5"
                shell "rpm -ivh #{CONFIG[:puppetlabs_el5_rpm_repo]}"
                @osarch == 'X86_64' ? (shell "rpm -ivh #{CONFIG[:rpm_forge_el5_X86_64_repo]}") : (shell "rpm -ivh #{CONFIG[:rpm_forge_el5_i686_repo]}")
              # 20xx is the major release naming pattern of Amazon Linux
              when "6", "n/a", "2015", "2014", "2016"
                shell "rpm -ivh #{CONFIG[:puppetlabs_el6_rpm_repo]}"
                @osarch == 'X86_64' ? (shell "rpm -ivh #{CONFIG[:rpm_forge_el6_X86_64_repo]}") : (shell "rpm -ivh #{CONFIG[:rpm_forge_el6_i686_repo]}")
                shell "yum-config-manager --disable rpmforge-release"
                shell "yum-config-manager --enable rpmforge-extras"
              when "7"
                shell "rpm -ivh #{CONFIG[:puppetlabs_el7_rpm_repo]}"
              else
                puts "#{@osname} #{@osmajrelease} is not supported. Exiting now..."
                exit(1)
              end
              shell "yum -y install git"
              # install upgrades
              Array(CONFIG[:upgrades][:redhat]).each do |package|
                shell "yum -y install #{package}"
                shell "yum -y update #{package}"
              end
              # install ec2-run-user-data init script
              # but only if the machine is running on AWS
              if `curl -m 5 -sI http://169.254.169.254/latest/meta-data/`.include? '200 OK'
                FileUtils.cp("#{base_dir}/src/etc/init.d/ec2-run-user-data", "/etc/init.d/ec2-run-user-data") unless File.exist?("/etc/init.d/ec2-run-user-data")
                set_init("ec2-run-user-data")
              end
              # install logstash-forwarder
              puts "Installing logstash-forwarder"
              shell "rpm -ivh #{CONFIG[:logstash_forwarder_rpm64]}"
              FileUtils.cp("#{base_dir}/src/etc/init.d/logstash-forwarder.rpm.init", "/etc/init.d/logstash-forwarder")
              set_init("logstash-forwarder")
            else
              puts "Unsuported OS for automatic agent installation. Exiting now..."
              exit(1)
            end

            puts "Installing additions Puppet..."
            install_additions

            puts "Installing DTK Arbiter"
            install_arbiter
          end

          private

          def self.parse(argv)
            options = {}
            parser = OptionParser.new do |opts|
              opts.banner = <<-BANNER
              usage:

              dtk-node-agent [-p|--puppet-version] [-v|--version]
              BANNER
              opts.on("-d",
                "--debug",
                "enable debug mode")  { |v| options[:debug] = true }
              opts.on_tail("-v",
                "--version",
                "Print the version and exit.") do
                puts ::DtkNodeAgent::VERSION
                exit(0)
              end
              opts.on_tail("-h",
                "--help",
                "Print this help message.") do
                puts parser
                exit(0)
              end
            end

            parser.parse!(argv)

            options

          rescue OptionParser::InvalidOption => e
            $stderr.puts e.message
            exit(12)
          end

          def self.shell(cmd)
            puts "running: #{cmd}" if @@options[:debug]
            output = `#{cmd}`
            puts output if @@options[:debug]
            if $?.exitstatus != 0
              puts "Executing command \`#{cmd}\` failed"
              puts "Command output:"
              puts output
            end
          end

          def self.install_additions
            # create puppet group
            shell "groupadd puppet" unless `grep puppet /etc/group`.include? "puppet"
            # create necessary dirs
            [ '/var/log/puppet/',
              '/var/lib/puppet/lib/puppet/indirector',
              '/etc/puppet/modules',
              '/usr/share/dtk/modules'
              ].map! { |p| FileUtils.mkdir_p(p) unless File.directory?(p) }
            # copy puppet libs
            FileUtils.cp_r(Dir.glob("#{base_dir}/puppet_additions/puppet_lib_base/puppet/indirector/*"), "/var/lib/puppet/lib/puppet/indirector/")
            # copy dtk/r8 puppet module
            FileUtils.cp_r(Dir.glob("#{base_dir}/puppet_additions/modules/*"), "/usr/share/dtk/modules/")
            # symlink dtk/r8 puppet module
            FileUtils.ln_sf("/usr/share/dtk/modules/dtk", "/etc/puppet/modules/")
            FileUtils.ln_sf("/usr/share/dtk/modules/r8", "/etc/puppet/modules/")
          end

          def self.base_dir
            File.expand_path('../..', File.dirname(__FILE__))
          end

          def self.is_systemd
            File.exist?("/etc/systemd/system")
          end

          def self.set_init(script)
            shell "chmod +x /etc/init.d/#{script}"
            if @osfamily == 'debian'
              shell "update-rc.d #{script} defaults"
            elsif @osfamily == 'redhat'
              shell "chkconfig --level 345 #{script} on"
              # in case of a systemd system, reload the daemons
              if is_systemd
                shell "systemctl daemon-reload"
                shell "systemctl enable #{script}.service"
              end
            end
          end

          def self.install_arbiter
            arbiter_branch = CONFIG[:arbiter_branch] || 'stable'
            shell "git clone -b #{arbiter_branch} https://github.com/dtk/dtk-arbiter /usr/share/dtk/dtk-arbiter"
            Dir.chdir "/usr/share/dtk/dtk-arbiter"
            shell "bundle install --without development"
            puts "Installing dtk-arbiter init script"
            FileUtils.ln_sf("/usr/share/dtk/dtk-arbiter/etc/#{@osfamily}.dtk-arbiter.init", "/etc/init.d/dtk-arbiter")
            # copy the service file, since systemd doesn't follow symlinks
            FileUtils.cp("/usr/share/dtk/dtk-arbiter/etc/systemd.dtk-arbiter.service", "/etc/systemd/system/dtk-arbiter.service") if is_systemd
            set_init("dtk-arbiter")
            puts "Installing dtk-arbiter monit config."
            monit_cfg_path = (@osfamily == 'debian') ? "/etc/monit/conf.d" : "/etc/monit.d"
            set_init("monit")
            logrotate_cfg_path = "/usr/share/dtk/dtk-arbiter/etc/dtk-arbiter.logrotate"
            FileUtils.ln_sf("/usr/share/dtk/dtk-arbiter/etc/dtk-arbiter.monit", "#{monit_cfg_path}/dtk-arbiter") if File.exist?(monit_cfg_path)
            FileUtils.cp(logrotate_cfg_path, "/etc/logrotate.d/dtk-arbiter") if File.exist?(logrotate_cfg_path)
          end
    end
  end
end