# frozen_string_literal: true

#
# The System configuration. Various configuration items that can be updated/defined at run time
#
# Use of this class allows you to simply ask for the configuration parameter directly without
# first having to get an instance of it.
#
# SystemConfiguration.queue_impl #=> 'RedisQueue'
#
# This method only is allowed for accessors, you should NEVER set values on the SystemConfiguration
# unless you are updating via the Admin or Stack UI, or during testing to setup a specific configuration
# for that.
#
module CoreSystemConfiguration
  extend ActiveSupport::Concern

  def self.included(base)
    base.class_eval do
      #
      # Fields
      #
      field :environment, type: String, default: 'test'
      # SMTP configuration
      field :default_email, type: String, default: 'support@app47.com'
      field :support_email, type: String, default: 'support@app47.com'
      field :smtp_name, type: String
      field :smtp_address, type: String
      field :smtp_domain, type: String
      field :smtp_port, type: Integer, default: 587
      field :smtp_user_name, type: String
      field :smtp_password, type: String
      field :smtp_enable_starttls_auto, type: Boolean
      field :mailgun_api_key, type: String
      # Twillio support
      field :twilio_account_id, type: String
      field :twilio_auth_token, type: String
      field :twilio_phone_number, type: String
      # URLs
      field :base_url, type: String
      field :cdn_url, type: String
      # Slack support
      field :slack_api_url, type: String
      field :slack_support_channel, type: String, default: 'support'
      field :slack_sales_channel, type: String, default: 'sales'
      # Time Zone Support
      field :default_time_zone, type: String, default: 'US/Eastern'
      # AWS
      field :aws_region, type: String
      field :aws_access_key, type: String
      field :aws_access_secret, type: String
      field :aws_auto_scaling_group_name, type: String
      # Zendesk
      field :zendesk_token, type: String
      field :zendesk_base_url, type: String, default: 'https://app47.zendesk.com'
      field :zendesk_documentation_path, type: String, default: 'hc'
      field :zendesk_support_path, type: String, default: 'hc/en-us/requests'
      field :zendesk_updates_path, type: String, default: 'hc'
      # Switchboard
      field :switchboard_base_url, type: String, default: 'https://switchboard.app47.com'
      field :switchboard_stack_id, type: String
      field :switchboard_stack_api_token, type: String
      #
      # Validations
      #
      validates :environment, presence: true, uniqueness: true
      validates :slack_support_channel, presence: true
      validates :slack_sales_channel, presence: true
      validates :default_time_zone, presence: true
    end
    base.extend ClassMethods
  end

  module ClassMethods
    #
    # Fetch the system configuration based on environment name. First try the rails cache
    # if not there, then go to the database.
    #
    # Also, if an argument error is thrown, then just fetch from the database.
    #
    def configuration
      cache_key = "SystemConfiguration::#{Rails.env}"

      begin
        config = Rails.cache.fetch(cache_key, expires_in: 90.seconds) do
          SystemConfiguration.find_by(environment: Rails.env)
        end
      rescue StandardError
        # This seems to happen in testing relative to Country, when it does, remove
        # ourselves from the cache and return the DB entry.
        Rails.cache.delete cache_key
        config = SystemConfiguration.find_or_create_by!(environment: Rails.env)
      end

      config.nil? ? SystemConfiguration.create(environment: Rails.env) : config
    end

    def smtp_configuration
      output = {}
      config = configuration
      fields = %w[name address domain port user_name password enable_starttls_auto]
      fields.each do |field|
        field_name = "smtp_#{field}".to_sym
        output[field.to_sym] = config.send(field_name)
      end
      output
    end

    #
    # NOTE: Currently ignored Codacy issue: When using 'method_missing', fall back on 'super'
    #
    # rubocop:disable Style/MethodMissingSuper
    def method_missing(method, *args, &block)
      configuration.send method, *args
    end

    def respond_to?(method_name, _include_private = false)
      SystemConfiguration.fields.include?(method_name)
    end
    # rubocop:enable Style/MethodMissingSuper
  end

  #
  # Make sure the password doesn't get blanked out on an update
  #
  def secure_fields
    super + %i[smtp_password
               aws_access_secret
               mailgun_api_key
               switchboard_stack_api_token
               twilio_auth_token
               zendesk_token]
  end

  #
  # Determine if SMTP is configured
  #
  def smtp_configured?
    smtp_name.present? && smtp_address.present? && smtp_domain.present?
  end

  #
  # Determine if mailgun is configured
  #
  def mailgun_configured?
    smtp_configured? && mailgun_api_key.present?
  end

  #
  # Determine if AWS is configured
  #
  def aws_configured?
    [aws_region.present?, aws_access_key.present?, aws_access_secret.present?].all?
  end

  #
  # Determine if auto scaling group is configured
  #
  def aws_auto_scaling_configured?
    aws_configured? && aws_auto_scaling_group_name.present?
  end

  #
  # AWS client.
  #
  def aws_ec2_client
    return nil unless aws_configured?

    Aws::EC2::Client.new region: aws_region,
                         credentials: Aws::Credentials.new(aws_access_key, aws_access_secret)
  end

  #
  # Return the zendesk documentation URL
  #
  def zendesk_documentation_url(user = nil)
    zendesk_url(forward_to: zendesk_documentation_path, user: user)
  end

  #
  # Return the zendesk support URL
  #
  def zendesk_requests_url(user = nil)
    zendesk_url(forward_to: zendesk_support_path, user: user)
  end

  #
  # Return the zendesk support URL
  #
  def zendesk_new_request_url(user = nil)
    zendesk_url(forward_to: "#{zendesk_support_path}/new", user: user)
  end

  #
  # Return the zendesk update URL
  #
  def zendesk_updates_url(user = nil)
    zendesk_url(forward_to: zendesk_updates_path, user: user)
  end

  #
  # Generate a Zendesk URL
  #
  # If a user is passed in and Zendesk is configured then return a JWT enabled URL for
  # SSO authentication to Zendesk.
  #
  def zendesk_url(forward_to: zendesk_documentation_path, user: nil)
    config = SystemConfiguration.configuration
    path = if config.zendesk_configured? && user.present?
             time_now = Time.now.to_i
             jti = "#{time_now}/#{rand(36 ** 64).to_s(36)}"
             payload = { jwt: JWT.encode({ iat: time_now, # Seconds since epoch, determine when this token is stale
                                           jti: jti, # Unique token identifier, helps prevent replay attacks
                                           name: user.name,
                                           email: user.email }, config.zendesk_token),
                         return_to: CGI.escape([config.zendesk_base_url, forward_to].join('/')) }
             ['access/jwt', payload.to_query].join('?')
           else
             forward_to
           end
    [config.zendesk_base_url, path].join('/')
  end

  #
  # Is zendesk configured?
  #
  def zendesk_configured?
    [zendesk_token.present?,
     zendesk_base_url.present?,
     zendesk_documentation_path.present?,
     zendesk_support_path.present?].all?
  end

  #
  # Public: Determine if switchboard is configured
  #
  # Examples
  #
  #   switchboard_configured?
  #   # => true || false
  #
  def switchboard_configured?
    [switchboard_base_url.present?, switchboard_stack_api_token.present?, switchboard_stack_id.present?].all?
  end

  #
  # Determine if twillio is configured at a system configuration
  #
  # Examples
  #
  #   switchboard_configured?
  #   # => true || false
  #
  def twilio_configured?
    [twilio_account_id.present?, twilio_auth_token.present?, twilio_phone_number.present?].all?
  end

  #
  # Determine if Slack is configured
  #
  # Examples
  #
  #   switchboard_configured?
  #   # => true || false
  #
  def slack_configured?
    slack_api_url.present?
  end

  private

  #
  # Clear the cache when the object is saved
  #
  def clear_cache
    Rails.cache.delete "SystemConfiguration::#{Rails.env}"
  end
end