Add a Text-Based Casino Game for FogOS

.gitignore

@@ -15,3 +15,4 @@ mkfs/mkfs
 kernel/kernel
 user/usys.S
 .gdbinit
+.DS_Store

user/textGame.c

@@ -0,0 +1,161 @@
+#include "kernel/types.h"
+#include "kernel/stat.h"
+#include "kernel/fs.h"
+#include "kernel/fcntl.h"
+#include "user/user.h"
+
+int LCG(int prev){// function that generates a psuedorandom number, using the previous value in the sequence, which starts at a seed
+
+    //https://www.ams.org/journals/mcom/1999-68-225/S0025-5718-99-00996-5/S0025-5718-99-00996-5.pdf has table of values
+    const long a = 530877178;
+    const long c = 0;//c = 0, since it is what the chart has
+    const long m = 536870909;// 2^29 -3
+    prev = prev % m;
+    return (a*prev+c)%m;
+}
+int isNonNegativeInt(char *inString){
+    if (inString[0] == '-'){//no negative bets allowed
+        return 0;
+    }
+    int i = 0;
+    while (inString[i] != '\0') {//loop over every char in string
+        if (inString[i] < '0' || inString[i] > '9'){// not a digit
+            return 0;
+        }
+        i++;
+    }
+    return 1;
+
+}
+void removeTrailingNewline(char *string){
+    int stringLength = strlen(string);
+    if (stringLength > 0 && string[stringLength-1] == '\n'){//if string has at least one character, and last char is newline
+        string[stringLength-1] = '\0';
+    }
+}
+
+int getInputAndCompare(char *userInput, char *comparisonString){
+    gets(userInput, 128);
+    removeTrailingNewline(userInput);
+    return (strcmp(userInput, comparisonString) == 0);//1 if they match, 0 otherwise
+}
+
+int shouldBuyOrSellStuff(char *responseInput, int isSelling){//isSelling is 1 if selling, 0 if buying
+    printf("would you like to %s\n", (isSelling ? "sell some of your stuff yes/no" : "buy some things yes/no"));//use ternary operator to change the print depending on if buying or selling
+    return getInputAndCompare(responseInput, "yes");
+}
+
+void performBuying(int *coinAmount, int *stuffAmount, char *responseInput){
+    printf("how many things would you like to buy for $50 each?\n");
+    gets(responseInput, 128);// get amount to buy in response var
+    removeTrailingNewline(responseInput);
+    while (!isNonNegativeInt(responseInput) || atoi(responseInput)<0 || 50*atoi(responseInput)>*coinAmount){//reuse bet handling to check if we can convert, and check we are buying positive amount, and that we have enough money
+        printf("invalid input. Make sure you input a positive int, and have enough money to buy that many.\n");
+        printf("how many things would you like to buy for $50 each?\n");
+        gets(responseInput, 128);// get amount to buy in response var
+        removeTrailingNewline(responseInput);
+    }
+    *stuffAmount = *stuffAmount + atoi(responseInput);//increase stuff
+    *coinAmount = *coinAmount - atoi(responseInput)*50;//decrease money
+
+}
+
+void performSelling(int *coinAmount, int *stuffAmount, int *randomNumber, int maxSalePrice, char *responseInput){
+    printf("how many things would you like to sell?\n");
+    gets(responseInput, 128);// get amount to sell in response var
+    removeTrailingNewline(responseInput);
+
+    while (!isNonNegativeInt(responseInput) || atoi(responseInput)>*stuffAmount){//reuse bet handling to check if we can convert, and check we have enough stuff
+        printf("invalid input. Make sure you input a non-negative integer, and you have enough stuff.\n");
+        printf("how many things would you like to sell?\n");
+        gets(responseInput, 128);// get amount to sell in response var
+        removeTrailingNewline(responseInput);
+
+    }
+    *stuffAmount = *stuffAmount - atoi(responseInput);
+    *randomNumber = LCG(*randomNumber);// get a new random val with LCG
+    int salePrice = *randomNumber%(maxSalePrice-1)+1;//random int from 1-maxSalePrice
+    printf("your stuff sold for $%d each\n", salePrice);
+    printf("you have %d things\n", *stuffAmount);
+    *coinAmount = *coinAmount + salePrice * atoi(responseInput);
+    printf("You now have $%d\n", *coinAmount);
+}
+
+int main() {// a reimplementation of a simple casino game I wrote in python a while ago
+    const int initialStuff = 12;// starting stuff amount
+    const int initialCoins = 100;// starting coins amount
+    int coins = initialCoins;//set coins var
+    int stuff = initialStuff;//set stuff var
+    char *betInput = malloc(128*sizeof(char));// a var for holding the bet
+    char *responseInput = malloc(128*sizeof(char));//a var for holding various responses
+    int randVal = uptime();// set seed for lcg as uptime
+    int roll = 0;//set roll var to 0;
+    while (coins >= 0){//keep going while coins <= 0, not < because allows you to sell stuff at 0
+        if (coins <= 0 && stuff <= 0){//stop if you are out of money and stuff(changed from equals zero, since if negative, also want to stop)
+            break;
+        }
+        printf("how much to bet (type leave to leave the casino)\n");
+        if (getInputAndCompare(betInput, "leave")){//handle input of leave
+            break;
+        }
+        //not leave, so now check if it is a valid bet
+        while (!isNonNegativeInt(betInput) || atoi(betInput)>coins){//make sure it is valid int input, if it is, also make sure we have enough coins
+            printf("invalid bet. make sure you give a positive integer, and have enough money.\n");
+            printf("how much to bet\n");
+            gets(betInput, 128);
+            removeTrailingNewline(betInput);
+        }
+        randVal = LCG(randVal);// get a new random val with LCG
+        roll = (randVal % 97) + 1; // get a roll from 1-98
+        if (roll == 1){// win more coins if roll is one
+            coins = coins + atoi(betInput)*48;//win 48 times your bet
+            printf("you won\n");
+            if (shouldBuyOrSellStuff(responseInput, 1)){//does the user want to sell
+                printf("you have %d things\n", stuff);// print out how much stuff we have, so the user knows
+                performSelling(&coins, &stuff, &randVal, 100, responseInput);
+            }
+            printf("would you like to leave yes/no\n");
+            if (getInputAndCompare(responseInput, "yes")){//said yes to leaving
+                break;
+            }
+        }
+        else if (roll == 2){//win stuff if roll is 2
+            stuff=stuff+(atoi(betInput));// win your bet in stuff
+            printf("you won %d things\n", atoi(betInput));
+            printf("you have %d things\n", stuff);
+            if (shouldBuyOrSellStuff(responseInput, 0)){//user wants to buy things
+                performBuying(&coins, &stuff, responseInput);
+
+            }
+        }
+        else{//you lose
+            coins=coins-atoi(betInput);// lose your bet
+            printf("you lose\n");
+
+        }
+        printf("you have $%d\n", coins);//print money after bet
+        //now allow the user to sell stuff if they are out of money.
+        if (coins <= 0){//not enough money
+            if (shouldBuyOrSellStuff(responseInput, 1)){//user wants to sell
+                if (stuff<=0){//out of money and stuff
+                    printf("not enough stuff\n");
+                    break;
+                }
+                else{//have at least some stuff
+                    printf("you have %d things\n", stuff);// print out how much stuff we have, so the user knows
+                    performSelling(&coins, &stuff, &randVal, 20, responseInput);
+                }
+            }
+        }
+        // allow user to buy stuff
+        if (shouldBuyOrSellStuff(responseInput, 0)){//user wants to buy things
+            performBuying(&coins, &stuff, responseInput);
+        }
+    }
+    printf("profit was $%d\n",coins-initialCoins);
+    printf("you gained %d things\n",stuff-initialStuff);
+
+    free(betInput);
+    free(responseInput);
+    return 0;
+}