# encoding: utf-8
# author: Christoph Hartmann
# author: Dominik Richter

require 'uri'
require 'inspec/fetcher'
require 'inspec/errors'

# InSpec Target Helper for Chef Compliance
# reuses UrlHelper, but it knows the target server and the access token already
# similar to `inspec exec http://localhost:2134/owners/%base%/compliance/%ssh%/tar --user %token%`
module Compliance
  class Fetcher < Fetchers::Url
    name 'compliance'
    priority 500
    attr_reader :upstream_sha256

    def initialize(target, opts)
      super(target, opts)
      if target.is_a?(Hash) && target.key?(:url)
        @target = target[:url]
        @upstream_sha256 = target[:sha256]
      elsif target.is_a?(String)
        @target = target
        @upstream_sha256 = ''
      end
    end

    def sha256
      upstream_sha256.empty? ? super : upstream_sha256
    end

    def self.check_compliance_token(config)
      if config['token'].nil? && config['refresh_token'].nil?
        if config['server_type'] == 'automate'
          server = 'automate'
          msg = 'inspec compliance login https://your_automate_server --user USER --ent ENT --dctoken DCTOKEN or --token USERTOKEN'
        elsif config['server_type'] == 'automate2'
          server = 'automate2'
          msg = 'inspec compliance login https://your_automate2_server --user USER --token APITOKEN'
        else
          server = 'compliance'
          msg = "inspec compliance login https://your_compliance_server --user admin --insecure --token 'PASTE TOKEN HERE' "
        end
        raise Inspec::FetcherFailure, <<~EOF

          Cannot fetch #{uri} because your #{server} token has not been
          configured.

          Please login using

              #{msg}
        EOF
      end
    end

    def self.get_target_uri(target)
      if target.is_a?(String) && URI(target).scheme == 'compliance'
        URI(target)
      elsif target.respond_to?(:key?) && target.key?(:compliance)
        URI("compliance://#{target[:compliance]}")
      end
    end

    def self.resolve(target)
      uri = get_target_uri(target)
      return nil if uri.nil?

      config = Compliance::Configuration.new
      profile = Compliance::API.sanitize_profile_name(uri)
      profile_fetch_url = Compliance::API.target_url(config, profile)
      # we have detailed information available in our lockfile, no need to ask the server
      if target.respond_to?(:key?) && target.key?(:sha256)
        profile_checksum = target[:sha256]
      else
        check_compliance_token(config)
        # verifies that the target e.g base/ssh exists
        # Call profiles directly instead of exist? to capture the results
        # so we can access the upstream sha256 from the results.
        _msg, profile_result = Compliance::API.profiles(config, profile)
        if profile_result.empty?
          raise Inspec::FetcherFailure, "The compliance profile #{profile} was not found on the configured compliance server"
        else
          # Guarantee sorting by verison and grab the latest.
          # If version was specified, it will be the first and only result.
          # Note we are calling the sha256 as a string, not a symbol since
          # it was returned as json from the Compliance API.
          profile_info = profile_result.sort_by { |x| Gem::Version.new(x['version']) }[0]
          profile_checksum = profile_info.key?('sha256') ? profile_info['sha256'] : ''
        end
      end
      # We need to pass the token to the fetcher
      config['token'] = Compliance::API.get_token(config)

      # Needed for automate2 post request
      profile_stub = profile || target[:compliance]
      config['profile'] = Compliance::API.profile_split(profile_stub)

      new({ url: profile_fetch_url, sha256: profile_checksum }, config)
    rescue URI::Error => _e
      nil
    end

    # We want to save compliance: in the lockfile rather than url: to
    # make sure we go back through the Compliance API handling.
    def resolved_source
      @resolved_source ||= {
        compliance: compliance_profile_name,
        url: @target,
        sha256: sha256,
      }
    end

    def to_s
      'Chef Compliance Profile Loader'
    end

    private

    # determine the owner_id and the profile name from the url
    def compliance_profile_name
      m = if Compliance::API.is_automate_server_pre_080?(@config)
            %r{^#{@config['server']}/(?<owner>[^/]+)/(?<id>[^/]+)/tar$}
          elsif Compliance::API.is_automate_server_080_and_later?(@config)
            %r{^#{@config['server']}/profiles/(?<owner>[^/]+)/(?<id>[^/]+)/tar$}
          else
            %r{^#{@config['server']}/owners/(?<owner>[^/]+)/compliance/(?<id>[^/]+)/tar$}
          end.match(@target)

      if Compliance::API.is_automate2_server?(@config)
        m = {}
        m[:owner] = @config['profile'][0]
        m[:id] = @config['profile'][1]
      end

      raise 'Unable to determine compliance profile name. This can be caused by ' \
        'an incorrect server in your configuration. Try to login to compliance ' \
        'via the `inspec compliance login` command.' if m.nil?

      "#{m[:owner]}/#{m[:id]}"
    end
  end
end