require "lux/version"
require 'pathname'
require 'highline/import'
require 'shellwords'
require 'thor'
require 'uri'

# The Thor subclass containing useful tasks shared between the Lux
# standalone executable and Rake tasks.
#
class Lux::App < Thor

  desc "version", "Show the version"
  def version
    puts "Version #{Lux::VERSION}"
  end

  desc "check", "Check the integrity of the Git repositories"
  def check
    repobranch = `git symbolic-ref -q HEAD`.chomp.gsub(%r{^.*/},'')
    puts "Repository is on branch #{repobranch}"
    `git fetch --recurse-submodules=on-demand`
    nModuleErr = 0
    nModuleWarn = 0
    # Inspect the submodules currently checked out in turtle
    submodules = Hash[`git submodule status --recursive`.split(/\n/).map do |s|
      die "Bad submodule status #{s}" unless /^(?<flag>[-+U\s])(?<sha>[0-9a-f]{40})\s(?<path>\S+)(\s*\((?<ref>\S+)\))?$/ =~ s
      case flag
      when '-'
        Highline.say "Submodule at #{path} is <%= color('not initialized', RED) %>!"
        nModuleWarn += 1
      when '+'
        Highline.say "Submodule at #{path} is <%= color('not at correct commit', RED) %>!"
        nModuleErr += 1
      when 'U'
        Highline.say "Submodule at #{path} is <%= color('conflicted', RED) %>!"
        nModuleErr += 1
      else
        Highline.say "Submodule at #{path} is <%= color('OK', GREEN) %>"
      end
      [path, [flag, sha, ref]]
    end ]
    die "There were #{nModuleErr} submodule errors and #{nModuleWarn} warnings" if nModuleErr > 0
    # If the submodule status (above) was good, then we can ignore any submodule issues here
    changes = `git status --porcelain`.split(/\n/).reject do |ch|
      die "Bad status #{ch}" unless /^(?<x>.)(?<y>.)\s(?<path1>\S+)( -> (?<path2>\S+))?$/ =~ ch
      submodules.include? path1
    end
    if changes.size > 0
      die "Repository is not clean (#{changes.size} issues), use 'git status'"
    else
      HighLine.say "<%= color('Repository is clean', GREEN) %>"
    end
  end

  desc "start IMAGE", "Run a Docker image with user/home mapping"
  method_option :env, type: :string, aliases: '-e', desc: 'Path to environment file'
  method_option :name, type: :string, aliases: '-n', default: '<autogenerated>', desc: 'Docker container name'
  def start(image)
    image = findimage image
    raise "no image" if image.empty?
    puts "Starting #{image} container..."
    me, setup_cmd = user_setup_cmd()
    args = ["-v #{ENV['HOME']}:#{ENV['HOME']}"]
    args << "--env-file=#{options.env}" if options.env
    args << "--name=#{options.name}" unless options.name == '<autogenerated>'
    cid = `docker run -dit #{args.join(' ')} #{image} /bin/bash`.strip
    die "Container failed to start" unless cid =~ /^[a-z0-9]+$/
    system "docker exec #{cid} bash -c #{setup_cmd.shellescape}"
    puts "Type 'su [-] #{me}' then hit enter to attach to the container as yourself:"
    Kernel.exec "docker attach #{cid}"
  end

  EXCLUDE_VARS = %w{
    _ HOME PWD TMPDIR SSH_AUTH_SOCK SHLVL DISPLAY Apple_PubSub_Socket_Render SECURITYSESSIONID
    XPC_SERVICE_NAME XPC_FLAGS __CF_USER_TEXT_ENCODING TERM_PROGRAM TERM_PROGRAM_VERSION TERM_SESSION_ID
  }

  desc "exec IMAGE COMMAND", "Run a command inside a Docker container"
  method_option :env, type: :string, aliases: '-e', desc: 'Path to environment file'
  def exec(image, *command)
    image = findimage image
    me, setup_cmd = user_setup_cmd
    die "You must be within your home directory!" unless relwd = Pathname.pwd.to_s.gsub!(/^#{ENV['HOME']}/,'~')
    command.map!{|m| m.start_with?('/') ? Pathname.new(m).relative_path_from(Pathname.pwd) : m }
    env = ENV.reject{|k,v| EXCLUDE_VARS.include? k or v =~/\s+/}.map{|k,v| "#{k}=#{v.shellescape}"}
    env += IO.readlines(options.env).grep(/^(?!#)/).map(&:rstrip) if options.env
    cmd = setup_cmd + "su - #{me} -c 'cd #{relwd}; env -i #{env.join(' ')} #{command.join(' ')}'"
    args = ["-v #{ENV['HOME']}:#{ENV['HOME']}"]
    system "docker run --rm #{args.join(' ')} #{image} /bin/bash -c #{cmd.shellescape}"
  end

  desc "clean", "Destroy all exited containers"
  def clean
    exited = `docker ps -q -f status=exited`.gsub! /\n/,' '
    if exited and not exited.empty?
      system "docker rm #{exited}"
    else
      puts "No exited containers"
    end
  end

  desc "tidy", "Remove dangling Docker images"
  def tidy
    images = `docker images -f "dangling=true" -q`
    if images.size > 0
      system 'docker rmi $(docker images -f "dangling=true" -q)'
    else
      puts "No dangling images"
    end
  end

  desc "lsimages [PATTERN]", "List Docker images (with optional pattern)"
  method_option :regex, type: :boolean, aliases: '-r', default: false, desc: 'Pattern is a regular expression'
  def lsimages(pattern=nil)
    if options.regex
      pattern = '.*' unless pattern
      rx = Regexp.new(pattern)
      matcher = lambda {|s| rx.match(s)}
    else
      pattern = '*' unless pattern
      matcher = lambda {|s| File.fnmatch?(pattern, s)}
    end
    imagelines = `docker images`.split("\n")[1..-1].sort
    imagelines.each do |imageline|
      imageinfo = imageline.split(/\s+/)
      next if imageinfo[0] == '<none>'
      imagename = imageinfo[0]+':'+imageinfo[1]
      imagesize = imageinfo[-2]+' '+imageinfo[-1]
      imageage  = imageinfo[3..-3].join(' ')
      next unless matcher.call(imagename)
      printf "%-54s%-16s%10s\n", imagename, imageage, imagesize
    end
  end

  desc "rmimages [PATTERN]", "Remove Docker images (with optional pattern)"
  method_option :regex, type: :boolean, aliases: '-r', default: false, desc: 'Pattern is a regular expression'
  method_option :force, type: :boolean, aliases: '-f', default: false, desc: 'Do not prompt for confirmation'
  def rmimages(pattern=nil)
    if options.regex
      pattern = '.*' unless pattern
      rx = Regexp.new(pattern)
      matcher = lambda {|s| rx.match(s)}
    else
      pattern = '*' unless pattern
      matcher = lambda {|s| File.fnmatch?(pattern, s)}
    end
    imagelines = `docker images`.split("\n")[1..-1]
    imagelines.each do |imageline|
      imageinfo = imageline.split(/\s+/)
      next if imageinfo[0] == '<none>'
      imagename = imageinfo[0]+':'+imageinfo[1]
      imagesize = imageinfo[-2]+' '+imageinfo[-1]
      imageage  = imageinfo[3..-3].join(' ')
      next unless matcher.call(imagename)
      if options.force or (agree("Delete #{imagename} (#{imageage}, #{imagesize})? "){|q|q.echo=true})
        `docker rmi #{imageinfo[2]}`
        HighLine.say "Image <%= color('#{imagename}', RED)%> deleted"
      end
    end
  end

  desc "clobber", "Destroy all containers (even if running!)"
  def clobber
    clean
    running = `docker ps -q -f status=running`.gsub! /\n/,' '
    if running and not running.empty?
      system "docker rm -f #{running}"
    else
      puts "No running containers"
    end
  end

  desc "dockerip", "Show DOCKER_HOST IP address"
  def dockerip
    docker_url = URI(ENV['DOCKER_HOST'])
    name = docker_url.host
    if z = Socket.gethostbyname(name) rescue nil
        z.shift 3
        z.each do |a|
            name = a.unpack('CCCC').join('.') if a.size == 4
        end
    end
    puts "DOCKER_HOST=#{docker_url.to_s}"
    docker_url.host = name
    puts "export DOCKER_HOST=#{docker_url.to_s}"
  end

  private

  # Get the current list of images and make a guess at which one it is...
  #
  def findimage image
    local_images = `docker images`.strip.split("\n")[1..-1].map{|l| l.gsub!(/^(\S+)\s+(\S+).*/,'\1:\2')}.sort
    matching_images = local_images.select{|l| l.include? image }
    if matching_images.size > 0
      if image.count(':') == 0 and image.count('/') > 0
        matching_image = matching_images.select{|l| l.end_with? ':latest' }.first
      end
      unless matching_image
        matching_image = HighLine.choose do |menu|
          menu.header = 'List of matching (local) images'
          menu.choices(*matching_images)
          menu.choice('None of the above') { nil }
        end
        exit 2 unless matching_image
      end
    else
      matching_image = image
    end
    return matching_image
  end

  # Return two elements:
  # - user name (defaults to current user), and
  # - a bash script setup command
  #
  def user_setup_cmd user = `id -nu`.strip
    [user, <<-COMMAND.gsub(/^\s*/,'').gsub(/\n/,' ; ')]
      uid=$(echo $(stat -c %u:%g #{ENV['HOME']}) | cut -d: -f2)
      useradd -M -d #{ENV['HOME']} -u $uid -s #{ENV['SHELL']} #{user}
      echo "#{user} ALL=(ALL:ALL) NOPASSWD: ALL" > /etc/sudoers.d/#{user}
    COMMAND
  end

  def die msg, rc = 1
    HighLine.say HighLine.color(msg, HighLine::RED)
    exit(rc)
  end

end

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