require 'yaml'
require 'open3'
require 'json'

module PuppetlabsSpecHelper; end
module PuppetlabsSpecHelper::Tasks; end

module PuppetlabsSpecHelper::Tasks::FixtureHelpers
  # This is a helper for the self-symlink entry of fixtures.yml
  def source_dir
    Dir.pwd
  end

  # @return [String] - the name of current module
  def module_name
    raise ArgumentError unless File.file?('metadata.json') && File.readable?('metadata.json')

    metadata = JSON.parse(File.read('metadata.json'))
    metadata_name = metadata.fetch('name', nil) || ''

    raise ArgumentError if metadata_name.empty?

    metadata_name.split('-').last
  rescue JSON::ParserError, ArgumentError
    File.basename(Dir.pwd).split('-').last
  end

  # @return [Hash] - returns a hash of all the fixture repositories
  # @example
  # {"puppetlabs-stdlib"=>{"target"=>"https://gitlab.com/puppetlabs/puppet-stdlib.git",
  # "ref"=>nil, "branch"=>"master", "scm"=>nil,
  # }}
  def repositories
    @repositories ||= fixtures('repositories') || {}
  end

  # @return [Hash] - returns a hash of all the fixture forge modules
  # @example
  # {"puppetlabs-stdlib"=>{"target"=>"spec/fixtures/modules/stdlib",
  # "ref"=>nil, "branch"=>nil, "scm"=>nil,
  # "flags"=>"--module_repository=https://myforge.example.com/", "subdir"=>nil}}
  def forge_modules
    @forge_modules ||= fixtures('forge_modules') || {}
  end

  # @return [Hash] - a hash of symlinks specified in the fixtures file
  def symlinks
    @symlinks ||= fixtures('symlinks') || {}
  end

  # @return [Hash] - returns a hash with the module name and the source directory
  def auto_symlink
    { module_name => '#{source_dir}' }
  end

  # @return [Boolean] - true if the os is a windows system
  def windows?
    !!File::ALT_SEPARATOR
  end

  def fixtures(category)
    fixtures_yaml = if ENV['FIXTURES_YML']
                      ENV['FIXTURES_YML']
                    elsif File.exist?('.fixtures.yml')
                      '.fixtures.yml'
                    elsif File.exist?('.fixtures.yaml')
                      '.fixtures.yaml'
                    else
                      false
                    end

    begin
      fixtures = if fixtures_yaml
                   YAML.load_file(fixtures_yaml) || { 'fixtures' => {} }
                 else
                   { 'fixtures' => {} }
                 end
    rescue Errno::ENOENT
      raise("Fixtures file not found: '#{fixtures_yaml}'")
    rescue Psych::SyntaxError => e
      raise("Found malformed YAML in '#{fixtures_yaml}' on line #{e.line} column #{e.column}: #{e.problem}")
    end

    unless fixtures.include?('fixtures')
      # File is non-empty, but does not specify fixtures
      raise("No 'fixtures' entries found in '#{fixtures_yaml}'; required")
    end

    fixture_defaults = if fixtures.include? 'defaults'
                         fixtures['defaults']
                       else
                         {}
                       end

    fixtures = fixtures['fixtures']

    if fixtures['symlinks'].nil?
      fixtures['symlinks'] = auto_symlink
    end

    result = {}
    if fixtures.include?(category) && !fixtures[category].nil?
      defaults = { 'target' => 'spec/fixtures/modules' }

      # load defaults from the `.fixtures.yml` `defaults` section
      # for the requested category and merge them into my defaults
      if fixture_defaults.include? category
        defaults = defaults.merge(fixture_defaults[category])
      end

      fixtures[category].each do |fixture, opts|
        # convert a simple string fixture to a hash, by
        # using the string fixture as the `repo` option of the hash.
        if opts.instance_of?(String)
          opts = { 'repo' => opts }
        end
        # there should be a warning or something if it's not a hash...
        next unless opts.instance_of?(Hash)
        # merge our options into the defaults to get the
        # final option list
        opts = defaults.merge(opts)

        next unless include_repo?(opts['puppet_version'])

        real_target = eval('"' + opts['target'] + '"')
        real_source = eval('"' + opts['repo'] + '"')

        result[real_source] = validate_fixture_hash!(
          'target' => File.join(real_target, fixture),
          'ref'    => opts['ref'] || opts['tag'],
          'branch' => opts['branch'],
          'scm'    => opts['scm'],
          'flags'  => opts['flags'],
          'subdir' => opts['subdir'],
        )
      end
    end
    result
  end

  def validate_fixture_hash!(hash)
    # Can only validate git based scm
    return hash unless hash['scm'] == 'git'

    # Forward slashes in the ref aren't allowed. And is probably a branch name.
    raise ArgumentError, "The ref for #{hash['target']} is invalid (Contains a forward slash). If this is a branch name, please use the 'branch' setting instead." if hash['ref'] =~ %r{\/}

    hash
  end

  def include_repo?(version_range)
    if version_range && defined?(SemanticPuppet)
      puppet_spec = Gem::Specification.find_by_name('puppet')
      puppet_version = SemanticPuppet::Version.parse(puppet_spec.version.to_s)

      constraint = SemanticPuppet::VersionRange.parse(version_range)
      constraint.include?(puppet_version)
    else
      true
    end
  end

  def clone_repo(scm, remote, target, _subdir = nil, ref = nil, branch = nil, flags = nil)
    args = []
    case scm
    when 'hg'
      args.push('clone')
      args.push('-b', branch) if branch
      args.push(flags) if flags
      args.push(remote, target)
    when 'git'
      args.push('clone')
      args.push('--depth 1') unless ref
      args.push('-b', branch) if branch
      args.push(flags) if flags
      args.push(remote, target)
    else
      raise "Unfortunately #{scm} is not supported yet"
    end
    result = system("#{scm} #{args.flatten.join ' '}")
    unless File.exist?(target)
      raise "Failed to clone #{scm} repository #{remote} into #{target}"
    end
    result
  end

  def update_repo(scm, target)
    args = case scm
           when 'hg'
             ['pull']
           when 'git'
             ['fetch'].tap do |git_args|
               git_args << '--unshallow' if shallow_git_repo?
             end
           else
             raise "Unfortunately #{scm} is not supported yet"
           end
    system("#{scm} #{args.flatten.join(' ')}", chdir: target)
  end

  def shallow_git_repo?
    File.file?(File.join('.git', 'shallow'))
  end

  def revision(scm, target, ref)
    args = []
    case scm
    when 'hg'
      args.push('update', '--clean', '-r', ref)
    when 'git'
      args.push('reset', '--hard', ref)
    else
      raise "Unfortunately #{scm} is not supported yet"
    end
    result = system("#{scm} #{args.flatten.join ' '}", chdir: target)
    raise "Invalid ref #{ref} for #{target}" unless result
  end

  def valid_repo?(scm, target, remote)
    return false unless File.directory?(target)
    return true if scm == 'hg'

    return true if git_remote_url(target) == remote

    warn "Git remote for #{target} has changed, recloning repository"
    FileUtils.rm_rf(target)
    false
  end

  def git_remote_url(target)
    output, status = Open3.capture2e('git', '-C', target, 'remote', 'get-url', 'origin')
    status.success? ? output.strip : nil
  end

  def remove_subdirectory(target, subdir)
    unless subdir.nil?
      Dir.mktmpdir do |tmpdir|
        FileUtils.mv(Dir.glob("#{target}/#{subdir}/{.[^\.]*,*}"), tmpdir)
        FileUtils.rm_rf("#{target}/#{subdir}")
        FileUtils.mv(Dir.glob("#{tmpdir}/{.[^\.]*,*}"), target.to_s)
      end
    end
  end

  # creates a logger so we can log events with certain levels
  def logger
    unless @logger
      require 'logger'
      level = if ENV['ENABLE_LOGGER']
                Logger::DEBUG
              else
                Logger::INFO
              end
      @logger = Logger.new(STDERR)
      @logger.level = level
    end
    @logger
  end

  def module_working_directory
    # The problem with the relative path is that PMT doesn't expand the path properly and so passing in a relative path here
    # becomes something like C:\somewhere\backslashes/spec/fixtures/work-dir on Windows, and then PMT barfs itself.
    # This has been reported as https://tickets.puppetlabs.com/browse/PUP-4884
    File.expand_path((ENV['MODULE_WORKING_DIR']) ? ENV['MODULE_WORKING_DIR'] : 'spec/fixtures/work-dir')
  end

  # returns the current thread count that is currently active
  # a status of false or nil means the thread completed
  # so when anything else we count that as a active thread
  # @return [Integer] - current thread count
  def current_thread_count(items)
    active_threads = items.find_all do |_item, opts|
      if opts[:thread]
        opts[:thread].status
      else
        false
      end
    end
    logger.debug "Current thread count #{active_threads.count}"
    active_threads.count
  end

  # @summary Set a limit on the amount threads used, defaults to 10
  #   MAX_FIXTURE_THREAD_COUNT can be used to set this limit
  # @return [Integer] - returns the max_thread_count
  def max_thread_limit
    @max_thread_limit ||= (ENV['MAX_FIXTURE_THREAD_COUNT'] || 10).to_i
  end

  # @param items [Hash] - a hash of either repositories or forge modules
  # @param [Block] - the method you wish to use to download the item
  def download_items(items)
    items.each do |remote, opts|
      # get the current active threads that are alive
      count = current_thread_count(items)
      if count < max_thread_limit
        logger.debug "New Thread started for #{remote}"
        # start up a new thread and store it in the opts hash
        opts[:thread] = Thread.new do
          yield(remote, opts)
        end
      else
        # the last thread started should be the longest wait
        item, item_opts = items.find_all { |_i, o| o.key?(:thread) }.last
        logger.debug "Waiting on #{item}"
        item_opts[:thread].join # wait for the thread to finish
        # now that we waited lets try again
        redo
      end
    end
    # wait for all the threads to finish
    items.each { |_remote, opts| opts[:thread].join }
  end

  # @param target [String] - the target directory
  # @param link [String] - the name of the link you wish to create
  # works on windows and linux
  def setup_symlink(target, link)
    link = link['target']
    return if File.symlink?(link)
    logger.info("Creating symlink from #{link} to #{target}")
    if windows?
      target = File.join(File.dirname(link), target) unless Pathname.new(target).absolute?
      if Dir.respond_to?(:create_junction)
        Dir.create_junction(link, target)
      else
        system("call mklink /J \"#{link.tr('/', '\\')}\" \"#{target.tr('/', '\\')}\"")
      end
    else
      FileUtils.ln_sf(target, link)
    end
  end

  # @return [Boolean] - returns true if the module was downloaded successfully, false otherwise
  # @param [String] - the remote url or namespace/name of the module to download
  # @param [Hash] - list of options such as version, branch, ref
  def download_repository(remote, opts)
    scm = 'git'
    target = opts['target']
    subdir = opts['subdir']
    ref = opts['ref']
    scm = opts['scm'] if opts['scm']
    branch = opts['branch'] if opts['branch']
    flags = opts['flags']
    if valid_repo?(scm, target, remote)
      update_repo(scm, target)
    else
      clone_repo(scm, remote, target, subdir, ref, branch, flags)
    end
    revision(scm, target, ref) if ref
    remove_subdirectory(target, subdir) if subdir
  end

  # @return [String] - the spec/fixtures/modules directory in the module root folder
  def module_target_dir
    @module_target_dir ||= File.expand_path('spec/fixtures/modules')
  end

  # @return [Boolean] - returns true if the module was downloaded successfully, false otherwise
  # @param [String] - the remote url or namespace/name of the module to download
  # @param [Hash] - list of options such as version
  def download_module(remote, opts)
    ref = ''
    flags = ''
    if opts.instance_of?(String)
      target = opts
    elsif opts.instance_of?(Hash)
      target = opts['target']
      ref = " --version #{opts['ref']}" unless opts['ref'].nil?
      flags = " #{opts['flags']}" if opts['flags']
    end

    return false if File.directory?(target)

    # The PMT cannot handle multi threaded runs due to cache directory collisons
    # so we randomize the directory instead.
    # Does working_dir even need to be passed?
    Dir.mktmpdir do |working_dir|
      command = 'puppet module install' + ref + flags + ' --ignore-dependencies' \
      ' --force' \
      " --module_working_dir \"#{working_dir}\"" \
      " --target-dir \"#{module_target_dir}\" \"#{remote}\""

      unless system(command)
        raise "Failed to install module #{remote} to #{module_target_dir}"
      end
    end
    $CHILD_STATUS.success?
  end
end

include PuppetlabsSpecHelper::Tasks::FixtureHelpers

desc 'Create the fixtures directory'
task :spec_prep do
  # Ruby only sets File::ALT_SEPARATOR on Windows and Rubys standard library
  # uses this to check for Windows
  if windows?
    begin
      require 'win32/dir'
    rescue LoadError
      $stderr.puts 'win32-dir gem not installed, falling back to executing mklink directly'
    end
  end

  # git has a race condition creating that directory, that would lead to aborted clone operations
  FileUtils.mkdir_p('spec/fixtures/modules')

  symlinks.each { |target, link| setup_symlink(target, link) }

  download_items(repositories) { |remote, opts| download_repository(remote, opts) }

  download_items(forge_modules) { |remote, opts| download_module(remote, opts) }

  FileUtils.mkdir_p('spec/fixtures/manifests')
  FileUtils.touch('spec/fixtures/manifests/site.pp')
end

desc 'Clean up the fixtures directory'
task :spec_clean do
  repositories.each do |_remote, opts|
    target = opts['target']
    FileUtils.rm_rf(target)
  end

  forge_modules.each do |_remote, opts|
    target = opts['target']
    FileUtils.rm_rf(target)
  end

  FileUtils.rm_rf(module_working_directory)

  Rake::Task[:spec_clean_symlinks].invoke

  if File.zero?('spec/fixtures/manifests/site.pp')
    FileUtils.rm_f('spec/fixtures/manifests/site.pp')
  end
end

desc 'Clean up any fixture symlinks'
task :spec_clean_symlinks do
  fixtures('symlinks').each do |_source, opts|
    target = opts['target']
    FileUtils.rm_f(target)
  end
end