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

require 'net/http'
require 'uri'

require_relative 'api/login'

module Compliance
  class ServerConfigurationMissing < StandardError; end

  # API Implementation does not hold any state by itself,
  # everything will be stored in local Configuration store
  class API
    extend Compliance::API::Login

    # return all compliance profiles available for the user
    # the user is either specified in the options hash or by default
    # the username of the account is used that is logged in
    def self.profiles(config)
      owner = config['owner'] || config['user']

      # Chef Compliance
      if is_compliance_server?(config)
        url = "#{config['server']}/user/compliance"
      # Chef Automate
      elsif is_automate_server?(config)
        url = "#{config['server']}/profiles/#{owner}"
      else
        raise ServerConfigurationMissing
      end

      headers = get_headers(config)
      response = Compliance::HTTP.get(url, headers, config['insecure'])
      data = response.body
      response_code = response.code
      case response_code
      when '200'
        msg = 'success'
        profiles = JSON.parse(data)
        # iterate over profiles
        if is_compliance_server?(config)
          mapped_profiles = []
          profiles.values.each { |org|
            mapped_profiles += org.values
          }
        # Chef Automate pre 0.8.0
        elsif is_automate_server_pre_080?(config)
          mapped_profiles = profiles.values.flatten
        else
          mapped_profiles = profiles.map { |e|
            e['owner_id'] = owner
            e
          }
        end
        return msg, mapped_profiles
      when '401'
        msg = '401 Unauthorized. Please check your token.'
        return msg, []
      else
        msg = "An unexpected error occurred (HTTP #{response_code}): #{response.message}"
        return msg, []
      end
    end

    # return the server api version
    # NB this method does not use Compliance::Configuration to allow for using
    # it before we know the version (e.g. oidc or not)
    def self.version(config)
      url = config['server']
      insecure = config['insecure']

      raise ServerConfigurationMissing if url.nil?

      headers = get_headers(config)
      response = Compliance::HTTP.get(url+'/version', headers, insecure)
      return {} if response.code == '404'

      data = response.body
      return {} if data.nil? || data.empty?

      parsed = JSON.parse(data)
      return {} unless parsed.key?('version') && !parsed['version'].empty?

      parsed
    end

    # verifies that a profile
    def self.exist?(config, profile)
      owner, id, ver = profile_split(profile)

      # ensure that we do not manipulate the configuration object
      user_config = config.dup
      user_config['owner'] = owner
      _msg, profiles = Compliance::API.profiles(user_config)

      if !profiles.empty?
        profiles.any? do |p|
          p['owner_id'] == owner &&
            p['name'] == id &&
            (ver.nil? || p['version'] == ver)
        end
      else
        false
      end
    end

    def self.upload(config, owner, profile_name, archive_path)
      # Chef Compliance
      if is_compliance_server?(config)
        url = "#{config['server']}/owners/#{owner}/compliance/#{profile_name}/tar"
      # Chef Automate pre 0.8.0
      elsif is_automate_server_pre_080?(config)
        url = "#{config['server']}/#{owner}"
      # Chef Automate
      else
        url = "#{config['server']}/profiles/#{owner}"
      end

      headers = get_headers(config)
      res = Compliance::HTTP.post_file(url, headers, archive_path, config['insecure'])
      [res.is_a?(Net::HTTPSuccess), res.body]
    end

    # Use username and refresh_token to get an API access token
    def self.get_token_via_refresh_token(url, refresh_token, insecure)
      uri = URI.parse("#{url}/login")
      req = Net::HTTP::Post.new(uri.path)
      req.body = { token: refresh_token }.to_json
      access_token = nil
      response = Compliance::HTTP.send_request(uri, req, insecure)
      data = response.body
      if response.code == '200'
        begin
          tokendata = JSON.parse(data)
          access_token = tokendata['access_token']
          msg = 'Successfully fetched API access token'
          success = true
        rescue JSON::ParserError => e
          success = false
          msg = e.message
        end
      else
        success = false
        msg = "Failed to authenticate to #{url} \n\
  Response code: #{response.code}\n  Body: #{response.body}"
      end

      [success, msg, access_token]
    end

    # Use username and password to get an API access token
    def self.get_token_via_password(url, username, password, insecure)
      uri = URI.parse("#{url}/login")
      req = Net::HTTP::Post.new(uri.path)
      req.body = { userid: username, password: password }.to_json
      access_token = nil
      response = Compliance::HTTP.send_request(uri, req, insecure)
      data = response.body
      if response.code == '200'
        access_token = data
        msg = 'Successfully fetched an API access token valid for 12 hours'
        success = true
      else
        success = false
        msg = "Failed to authenticate to #{url} \n\
  Response code: #{response.code}\n  Body: #{response.body}"
      end

      [success, msg, access_token]
    end

    def self.get_headers(config)
      token = get_token(config)
      if is_automate_server?(config)
        headers = { 'chef-delivery-enterprise' => config['automate']['ent'] }
        if config['automate']['token_type'] == 'dctoken'
          headers['x-data-collector-token'] = token
        else
          headers['chef-delivery-user'] = config['user']
          headers['chef-delivery-token'] = token
        end
      else
        headers = { 'Authorization' => "Bearer #{token}" }
      end
      headers
    end

    def self.get_token(config)
      return config['token'] unless config['refresh_token']
      _success, _msg, token = get_token_via_refresh_token(config['server'], config['refresh_token'], config['insecure'])
      token
    end

    def self.target_url(config, profile)
      owner, id, ver = profile_split(profile)

      return "#{config['server']}/owners/#{owner}/compliance/#{id}/tar" unless is_automate_server?(config)

      if ver.nil?
        "#{config['server']}/profiles/#{owner}/#{id}/tar"
      else
        "#{config['server']}/profiles/#{owner}/#{id}/version/#{ver}/tar"
      end
    end

    def self.profile_split(profile)
      owner, id = profile.split('/')
      id, version = id.split('#')
      [owner, id, version]
    end

    # returns a parsed url for `admin/profile` or `compliance://admin/profile`
    def self.sanitize_profile_name(profile)
      if URI(profile).scheme == 'compliance'
        uri = URI(profile)
      else
        uri = URI("compliance://#{profile}")
      end
      uri.to_s.sub(%r{^compliance:\/\/}, '')
    end

    def self.is_compliance_server?(config)
      config['server_type'] == 'compliance'
    end

    def self.is_automate_server_pre_080?(config)
      # Automate versions before 0.8.x do not have a valid version in the config
      return false unless config['server_type'] == 'automate'
      server_version_from_config(config).nil?
    end

    def self.is_automate_server_080_and_later?(config)
      # Automate versions 0.8.x and later will have a "version" key in the config
      # that is properly parsed out via server_version_from_config below
      return false unless config['server_type'] == 'automate'
      !server_version_from_config(config).nil?
    end

    def self.is_automate_server?(config)
      config['server_type'] == 'automate'
    end

    def self.server_version_from_config(config)
      # Automate versions 0.8.x and later will have a "version" key in the config
      # that looks like: "version":{"api":"compliance","version":"0.8.24"}
      return nil unless config.key?('version')
      return nil unless config['version'].is_a?(Hash)
      config['version']['version']
    end

    def self.determine_server_type(url, insecure)
      if target_is_automate_server?(url, insecure)
        :automate
      elsif target_is_compliance_server?(url, insecure)
        :compliance
      else
        Inspec::Log.debug('Could not determine server type using known endpoints')
        nil
      end
    end

    def self.target_is_automate_server?(url, insecure)
      automate_endpoint = '/compliance/version'
      response = Compliance::HTTP.get(url + automate_endpoint, nil, insecure)
      case response.code
      when '401'
        Inspec::Log.debug(
          "Received 401 from #{url}#{automate_endpoint} - " \
          'assuming target is a Chef Automate instance',
        )
        true
      when '200'
        # Chef Automate currently returns 401 for `/compliance/version` but some
        # versions of OpsWorks Chef Automate return 200 and a Chef Manage page
        # when unauthenticated requests are received.
        if response.body.include?('Are You Looking For the Chef Server?')
          Inspec::Log.debug(
            "Received 200 from #{url}#{automate_endpoint} - " \
            'assuming target is an OpsWorks Chef Automate instance',
          )
          true
        else
          Inspec::Log.debug(
            "Received 200 from #{url}#{automate_endpoint} " \
            'but did not receive the Chef Manage page - ' \
            'assuming target is not a Chef Automate instance',
          )
          false
        end
      else
        Inspec::Log.debug(
          "Received unexpected status code #{response.code} " \
          "from #{url}#{automate_endpoint} - " \
          'assuming target is not a Chef Automate instance',
        )
        false
      end
    end

    def self.target_is_compliance_server?(url, insecure)
      # All versions of Chef Compliance return 200 for `/api/version`
      compliance_endpoint = '/api/version'

      response = Compliance::HTTP.get(url + compliance_endpoint, nil, insecure)
      return false unless response.code == '200'

      Inspec::Log.debug(
        "Received 200 from #{url}#{compliance_endpoint} - " \
        'assuming target is a Compliance server',
      )
      true
    end
  end
end