lib/mtgox/value.rb
require 'bigdecimal'
# In the "old API", currency- and amount-values (price, volume,...)
# were given as float. These values are likely being deprecated and
# replaced by fields of the same name with "_int" as suffix. These are
# fixed-decimal, so you have to move the decimal point yourself
# (divide). The exponent differs based on the kind of the value.
module MtGox
module Value
# We assume here that any other currency than :jpy uses :usd
INT_MULTIPLIERS = {:btc => 100_000_000, :usd => 100_000, :jpy => 1000}
# Takes a hash return by the API and convert some value_int to a
# currency value using USD conversion rule. You can specify which
# key to convert
#
# @param value [Hash] a hash from the API
# params key [String] the key from the previous hash to convert, default to 'value_int'
# @authenticated false
# @return [Float]
def value_currency(value, key = 'value_int')
decimalify(value[key].to_i, :usd)
end
# Takes a hash return by the API and convert some value_int to
# [Float] BitCoin value . You can specify which key to convert
#
# @param value [Hash] a hash from the API
# params key [String] the key from the previous hash to convert, default to 'value_int'
# @authenticated false
# @return [Float] a float BTC value
def value_bitcoin(value, key = 'value_int')
decimalify(value[key], :btc)
end
# Convert a BigDecimal value to an int using the MtGox conversion rules.
#
# param decimal [BigDecimal] to convert
# param currency [Symbol] currency conversion rule to use amongst [:btc, :usd, :jpy]
# return an int
def intify(decimal, currency)
(decimal * INT_MULTIPLIERS[currency]).to_i
end
# Convert an int value to a decimal using the MtGox conversion rules.
#
# param int [Fixnum] to convert
# param currency [Symbol] currency conversion rule to use amongst [:btc, :usd, :jpy]
# return a [BigDecimal]
def decimalify(int, currency)
(BigDecimal(int.to_s) / INT_MULTIPLIERS[currency])
end
end
end