module SoarAuditorApi
  class AuditorAPI
    DEBUG_PREFIX = "debug:" unless defined? DEBUG_PREFIX; DEBUG_PREFIX.freeze
    INFO_PREFIX  = "info:"  unless defined? INFO_PREFIX;  INFO_PREFIX.freeze
    WARN_PREFIX  = "warn:"  unless defined? WARN_PREFIX;  WARN_PREFIX.freeze
    ERROR_PREFIX = "error:" unless defined? ERROR_PREFIX; ERROR_PREFIX.freeze
    FATAL_PREFIX = "fatal:" unless defined? FATAL_PREFIX; FATAL_PREFIX.freeze

    def initialize
      @configuration = nil
      @minimum_audit_level = :info
      @audit_levels  = [:debug, :info, :warn, :error, :fatal]
    end

    def configure(configuration = nil)
      raise ArgumentError, "Invalid configuration provided" unless configuration_is_valid(configuration)
      @configuration = configuration
    end

    def set_audit_level(minimum_audit_level)
      raise ArgumentError, "Invalid audit level specified" unless @audit_levels.include?(minimum_audit_level)
      @minimum_audit_level = minimum_audit_level
    end

    def debug(data)
      audit(DEBUG_PREFIX + data.to_s) if audit_filtered(:debug)
    end

    def <<(data)
      audit(INFO_PREFIX + data.to_s) if audit_filtered(:info)
    end

    def info(data)
      audit(INFO_PREFIX + data.to_s) if audit_filtered(:info)
    end

    def warn(data)
      audit(WARN_PREFIX + data.to_s) if audit_filtered(:warn)
    end

    def error(data)
      audit(ERROR_PREFIX + data.to_s) if audit_filtered(:error)
    end

    def fatal(data)
      audit(FATAL_PREFIX + data.to_s) if audit_filtered(:fatal)
    end

    #Safety to ensure that the Auditor that extends this API implements this IOC method
    def configuration_is_valid(configuration)
      raise NotImplementedError, "Method must implement configuration_is_valid method in Auditor extending the API"
    end

    #Safety to ensure that the Auditor that extends this API implements this IOC method
    def audit(data)
      raise NotImplementedError, "Method must implement audit method in Auditor extending the API"
    end

    private

    def audit_filtered(audit_level)
      return @audit_levels.index(@minimum_audit_level) <= @audit_levels.index(audit_level)
    end
  end
end