# Copyright 2016 Shawn Neal <sneal@sneal.net>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

require "securerandom" unless defined?(SecureRandom)

module WinRM
  # WinRM connection options, provides defaults and validation.
  class ConnectionOpts < Hash
    DEFAULT_OPERATION_TIMEOUT = 60
    DEFAULT_RECEIVE_TIMEOUT = DEFAULT_OPERATION_TIMEOUT + 10
    DEFAULT_MAX_ENV_SIZE = 153600
    DEFAULT_LOCALE = "en-US".freeze
    DEFAULT_RETRY_DELAY = 10
    DEFAULT_RETRY_LIMIT = 3
    DEFAULT_USER_AGENT = "Ruby WinRM Client".freeze

    class << self
      def create_with_defaults(overrides)
        config = default.merge(overrides)
        config = ensure_receive_timeout_is_greater_than_operation_timeout(config)
        config.validate
        config
      end

      private

      def ensure_receive_timeout_is_greater_than_operation_timeout(config)
        if config[:receive_timeout] < config[:operation_timeout]
          config[:receive_timeout] = config[:operation_timeout] + 10
        end
        config
      end

      def default
        config = ConnectionOpts.new
        config[:session_id] = SecureRandom.uuid.to_s.upcase
        config[:transport] = :negotiate
        config[:locale] = DEFAULT_LOCALE
        config[:max_envelope_size] = DEFAULT_MAX_ENV_SIZE
        config[:operation_timeout] = DEFAULT_OPERATION_TIMEOUT
        config[:receive_timeout] = DEFAULT_RECEIVE_TIMEOUT
        config[:retry_delay] = DEFAULT_RETRY_DELAY
        config[:retry_limit] = DEFAULT_RETRY_LIMIT
        config[:user_agent] = DEFAULT_USER_AGENT
        config
      end
    end

    def validate
      validate_required_fields
      validate_data_types
    end

    private

    def validate_required_fields
      raise "endpoint is a required option" unless self[:endpoint]

      if self[:client_cert]
        raise "path to client key is required" unless self[:client_key]
      elsif self[:transport] == :kerberos
        raise "realm is a required option" unless self[:realm]
        raise "service is a required option" unless self[:service]
      else
        raise "user is a required option" unless self[:user]
        raise "password is a required option" unless self[:password]
      end
    end

    def validate_data_types
      validate_integer(:retry_limit)
      validate_integer(:retry_delay)
      validate_integer(:max_envelope_size)
      validate_integer(:operation_timeout)
      validate_integer(:receive_timeout, self[:operation_timeout])
    end

    def validate_integer(key, min = 0)
      value = self[key]
      raise "#{key} must be a Integer" unless value && value.is_a?(Integer)
      raise "#{key} must be greater than #{min}" unless value > min
    end
  end
end
