# encoding: utf-8

module OneApm
  # We really don't want to send bad values to the collector, and it doesn't
  # accept types like Rational that have occasionally slipped into our data.
  #
  # These methods are intended to safely coerce things into the form we want,
  # to provide documentation of expected types on to_collector_array methods,
  # and to log failures if totally invalid data gets into outgoing data
  module Coerce
    def int(value, context=nil)
      Integer(value)
    rescue => error
      log_failure(value, Integer, context, error)
      0
    end

    def int_or_nil(value, context=nil)
      return nil if value.nil?
      Integer(value)
    rescue => error
      log_failure(value, Integer, context, error)
      nil
    end

    def float(value, context=nil)
      result = Float(value)
      raise "Value #{result.inspect} is not finite." unless result.finite?
      result
    rescue => error
      log_failure(value, Float, context, error)
      0.0
    end

    def string(value, context=nil)
      return value if value.nil?
      String(value)
    rescue => error
      log_failure(value.class, String, context, error)
      ""
    end

    # Convert a hash into a format acceptable to be included with Transaction
    # event data.
    #
    # We accept a hash and will return a new hash where all of the keys
    # have been converted to strings.  As values we only allow Strings,
    # Floats, Integers. Symbols are also allowed but are converted to strings.
    # Any values of other type (e.g. Hash, Array, any other class) are
    # discarded. Their keys are also removed from the results hash.
    def event_params(value, context=nil)
      unless value.is_a? Hash
        raise ArgumentError, "Expected Hash but got #{value.class}"
      end
      value.inject({}) do |memo, (key, val)|
        case val
        when String, Integer, TrueClass, FalseClass
          memo[key.to_s] = val
        when Float
          if val.finite?
            memo[key.to_s] = val
          else
            memo[key.to_s] = nil
          end
        when Symbol
          memo[key.to_s] = val.to_s
        end
        memo
      end
    rescue => error
      log_failure(value.class, 'valid event params', context, error)
      {}
    end

    def log_failure(value, type, context, error)
      msg = "Unable to convert '#{value}' to #{type}"
      msg += " in context '#{context}'" if context
      OneApm::Agent.logger.warn(msg, error)
    end
  end
end