Hi,
I have an idea for developers of wallets
It will help people to make decisions in the world where a fiat money have a priority
Sometime we put bitcoins in wallet and sometime pay by bitcoin.
But we can remember how many bitcoins we put and what rate in our loved fiat currency was there and same for paying by bitcoins.
A wallet can take in account all these parts (bitcoin +rate) and always shows to user he loses fiat money or if not if he will pay some bitcoins.
For example, now user have:
Input in wallet - 0.5 BTC, to be inputted at 2014-05-02 by rate $430 for BTC
Input in wallet - 0.3 BTC, 2014-07-20, $620 for BTC
For example today (2014-08-20) user wants to pay $96, today rate is $480 for one BTC, It's 0.2 BTC (when bitcoin costs $480), the wallet should calculate best sum of losing/winning what happens if user will pay. So wallet take best price and part for best for user side - $620 and calculate before paying and shows:
0.2 BTC - $96 (480 * 0.2) - you win: $28 (630*0.2-96) [wallet will take a most costed part of bitcoins first]
Ok, the user thinks - super and and he pays. After in database we have two records:
0.5 BTC for $430
0.1 BTC for $620
Tomorrow for example BTC costs $520. The user decides to buy something again.
He opens the wallet, go to site and there price - $280. Now he has 0.6 BTC in wallet to be derived from 0.5*430 + 0.1*620.
The wallet calculate how many BTC he will pay now - 280/520 = 0.53846. Wallet calculate before paying and shows to user a following:
$280, 0.53846 BTC, you win $29.46 (how we got: 280-0.1*620+(0.53846-0.1)*430)
OK, user thinks - it's super, bitcoin is super and press "To pay" button.
Now he has in wallet 0.06154 for $430.
So if then he will go to pay a rest of bitcoins in next payment when the bitcoin will cost $520 he will see:
$32, 0.06154 BTC, you lost $5.54 (32-0.06154*430)
May be he will decide to pay by other payment system by fiat money.
So for this implementation a wallet should keep all parts of bitcoins (pairs as BTC + rate of bitcoin in day when its was put to wallet)
Really i think this will help people to make decisions in the world where a fiat money have a priority!
Thanks!
P.S. If you will realize it you can donate here - 1MtuNUZJ571Bcvre7VDpidDTR884n58rqS (there are 1 mBTC is mine
I cannot time and possibilities to make it
Perlover