require 'open3'
require 'ostruct'
require 'net/ssh'

module Gearship
  class Cli < Thor
    include Thor::Actions

    desc 'init', 'Initialize gearship project'
    def init(project = 'gearship')
      do_init(project)
    end

    desc 'go [mission] [--sudo]', 'Send gearship on a mission'
    method_options :sudo => false
    def go(target, *args)
      do_go(target, *args)
    end

    desc 'compile', 'Compile gearship project for debugging'
    def compile(mission = nil)
      do_compile(mission)
    end

    desc 'version', 'Show gearship version'
    def version
      puts Gem.loaded_specs['gearship'].version.to_s
    end

    no_tasks do
      include Gearship::Utility

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

      def do_init(project)
        copy_file 'templates/.gitignore',                            "#{project}/.gitignore"
        copy_file 'templates/gearship.yml',                          "#{project}/gearship.yml"
        copy_file 'templates/gearship.sh',                             "#{project}/gearship.sh"
        
        copy_file 'templates/actions/configure_firewall.sh',         "#{project}/actions/configure_firewall.sh"
        copy_file 'templates/actions/install_basics.sh',             "#{project}/actions/install_basics.sh"
        copy_file 'templates/actions/install_docker.sh',             "#{project}/actions/install_docker.sh"
        copy_file 'templates/actions/pull_latest_image.sh',          "#{project}/actions/pull_latest_image.sh"
        copy_file 'templates/actions/remove_container.sh',                  "#{project}/actions/remove_container.sh"
        copy_file 'templates/actions/start_container.sh',                  "#{project}/actions/start_container.sh"
        
        copy_file 'templates/missions/install_container.sh',               "#{project}/missions/install_container.sh"
        copy_file 'templates/missions/setup_host.sh',                "#{project}/missions/setup_host.sh"
        copy_file 'templates/missions/update_container.sh',                "#{project}/missions/update_container.sh"
        
        copy_file 'templates/cargo/sample.conf',                     "#{project}/cargo/sample.conf"
      end

      def do_go(*args)
        mission = args[0]
        
        do_compile(mission)
        
        sudo = 'sudo ' if options.sudo?
        user, host, port = parse_target(@config['attributes']['ssh_target'])
        endpoint = "#{user}@#{host}"

        # Remove server key from known hosts to avoid mismatch errors when VMs change.
        `ssh-keygen -R #{host} 2> /dev/null`

        remote_commands = <<-EOS
        rm -rf ~/gearship &&
        mkdir ~/gearship &&
        cd ~/gearship &&
        tar xz &&
        #{sudo}bash gearship.sh
        EOS

        remote_commands.strip! << ' && rm -rf ~/gearship' if @config['preferences'] and @config['preferences']['erase_remote_folder']

        local_commands = <<-EOS
        cd compiled
        tar cz . | ssh -o 'StrictHostKeyChecking no' #{endpoint} -p #{port} '#{remote_commands}'
        EOS

        Open3.popen3(local_commands) do |stdin, stdout, stderr|
          stdin.close
          t = Thread.new do
            while (line = stderr.gets)
              print line.color(:red)
            end
          end
          while (line = stdout.gets)
            print line.color(:green)
          end
          t.join
        end
      end

      def do_compile(mission)
        abort_with 'You must be in the gearship folder' unless File.exists?('gearship.yml')
        abort_with "#{mission} doesn't exist!" if mission and !File.exists?("missions/#{mission}.sh")

        @config = YAML.load(File.read('gearship.yml'))

        @config['attributes'] ||= {}
        @config['attributes'].update(Hash[@instance_attributes.map{|k,v| [k.to_s, v] }]) if @instance_attributes

        (@config['attributes'] || {}).each {|key, value| create_file "compiled/attributes/#{key}", value }

        cache_remote_actions = @config['preferences'] && @config['preferences']['cache_remote_actions']
        (@config['actions'] || []).each do |key, value|
          next if cache_remote_actions and File.exists?("compiled/actions/#{key}.sh")
          get value, "compiled/actions/#{key}.sh"
        end

        copy_or_template = (@config['preferences'] && @config['preferences']['eval_erb']) ? :template : :copy_file
        copy_local_files(@config, copy_or_template)

        if mission
          if copy_or_template == :template
            template File.expand_path('gearship.sh'), 'compiled/_gearship.sh'
            create_file 'compiled/gearship.sh', File.binread('compiled/_gearship.sh') << "\n" << File.binread("compiled/missions/#{mission}.sh")
          else
            create_file 'compiled/gearship.sh', File.binread('gearship.sh') << "\n" << File.binread("missions/#{mission}.sh")
          end
        else
          send copy_or_template, File.expand_path('gearship.sh'), 'compiled/gearship.sh'
        end
      end

      def parse_target(target)
        target.match(/(.*@)?(.*?)(:.*)?$/)
        config = Net::SSH::Config.for($2)
        [ ($1 && $1.delete('@') || config[:user] || 'root'), 
          config[:host_name] || $2, 
          ($3 && $3.delete(':') || config[:port] && config[:port].to_s || '22') ]
      end

      def copy_local_files(config, copy_or_template)
        @attributes = OpenStruct.new(config['attributes'])
        files = Dir['{actions,missions,cargo}/**/*'].select { |file| File.file?(file) }
        files.each { |file| send copy_or_template, File.expand_path(file), File.expand_path("compiled/#{file}") }

        (config['files'] || []).each {|file| send copy_or_template, File.expand_path(file), "compiled/cargo/#{File.basename(file)}" }
      end
    end
  end
end