/*
    Program to caluclate the value of dirt depending on how many blocks a vendor has.

    Author: John Ginnane
    Date: 07 / 02 / 12
*/

#include <stdio.h>

main()
{
    // Initialising the variables.
    float dirtValue = 10;
    // A value of 1 means the block is worth 1 copper.
    // 1 gold = 10 silver
    // 1 silver = 10 copper

    float dirtStock = 10000;

    float trade = 0;

    /*
        The mode determines one thing: How sales go.
        If mode 1 then if you sell 100 blocks, the value goes down by 1% in total and you earn 5,000 copper. (50 gold)
        If mode 2 then if you sell 100 blocks, the value goes down as if you sold 1 block, but repeated 100 times so it decreases after each block, even if it's a single sale.
        */

    int mode = 1;

    // Display the initial value and number of stock.
    printf("The initial value of dirt: %0.4f\n", dirtValue);
    printf("The initial number of stock: %0.2f\n\n", dirtStock);
    printf("Enter the number of blocks you want to sell\n");
    printf("Enter a negative number to buy and a positive one to sell\n");

    if(mode == 1)
    {
        while(dirtStock > 0 && dirtValue > 0)
        {
            // Ask the user to enter how many blocks they want to buy or sell.
            printf("How many blocks would you like to buy/sell: ");
            scanf("%f", &trade);

            if(trade > 0)
            {
                printf("You have sold %0.2f blocks worth a total of %0.4f copper.\n\n", trade, trade * dirtValue);
            }

            if(trade < 0)
            {
                printf("You have purchased %0.2f blocks worth a total of %0.4f copper.\n\n", -trade, trade * dirtValue);
            }

            if(trade == 0)
            {
                printf("No blocks have been sold nor purchased\n\n");
            }

            dirtValue = dirtValue * (dirtStock / (dirtStock + trade));
            dirtStock = dirtStock + trade;

            printf("The value of dirt is now: %0.4f\n", dirtValue);
            printf("The number of stock is now: %0.2f\n\n", dirtStock);
        }
    }
}