exercise08.c

// C Primer Plus
// Chapter 17 Exercise 8:

// Modify the Pet Club program so that all pets with the same name are stored
// in a list in the same node. When the user chooses to find a pet, the
// program should request the pet name and then list all pets (along with their
// kinds) having that name.

// compile with pettree.c

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include "pettree.h"

char menu(void);
void addpet(Tree * pt);
void printpet(Pet pet);
void droppet(Tree * pt);
void showpets(const Tree * pt);
void findpet(const Tree * pt);
void uppercase(char * str);
char * get(char * st, int n);

int main(void) {
	Tree pets;
	char choice;
	InitializeTree(&pets);

	while ((choice = menu()) != 'q') {
		puts("");
		if (choice == 'a') {
			addpet(&pets);
		} else if (choice == 'l') {
			showpets(&pets);
		} else if (choice == 'f') {
			findpet(&pets);
		} else if (choice == 'n') {
			printf("%d pets in club\n", TreeItemCount(pets));
		} else if (choice == 'd') {
			droppet(&pets);
		} else {
			printf("Not a valid option.\n");
		}
		puts("");
	}
	DeleteAll(&pets);
	puts("Bye.");

	return 0;
}

char menu(void) {
	int ch;

	puts("Nerfville Pet Club Membership Program");
	puts("Enter the letter corresponding to your choice:");
	puts("a) add a pet 			l) show list of pets");
	puts("n) number of pets		f) find pets");
	puts("d) delete a pet 		q) quit");
	while ((ch = getchar()) != EOF) {
		while (getchar() != '\n')
			continue;
		ch = tolower(ch);
		if (strchr("alfndq", ch) == NULL)
			puts("Please enter an a, l, f, n, d or q:");
		else
			break;
	}
	if (ch == EOF)
		ch = 'q';

	return ch;
}

void addpet(Tree * pt) {
	Pet * ppet = (Pet *) malloc(sizeof(Pet));
	if (ppet == NULL) {
		fprintf(stderr, "Could not allocate memory.\n");
		return;
	}

	if (TreeIsFull(pt)) {
		puts("No room in the club!");
	}
	else {
		puts("Please enter name of pet:");
		get(ppet->name, STRLEN);
		puts("Please enter pet kind:");
		get(ppet->type, STRLEN);
		uppercase(ppet->name);
		uppercase(ppet->type);
		ppet->next = NULL;
		AddPet(ppet, pt);
	}
}

void droppet(Tree * pt) {
	Pet temp;

	if (TreeIsEmpty(pt)) {
		printf("No entries!\n");
		return;
	}

	puts("Please enter name of pet you wish to delete:");
	get(temp.name, STRLEN);
	puts("Please enter type of pet:");
	get(temp.type, STRLEN);
	uppercase(temp.name);
	uppercase(temp.type);
	printf("%s the %s ", temp.name, temp.type);
	if (DeletePet(&temp, pt))
		printf("is dropped from the club.\n");
	else
		printf("is not a member.\n");
}

void showpets(const Tree * pt) {
	if (TreeIsEmpty(pt))
		puts("No entries!");
	else
		TraverseTree(pt, printpet);
}

void printpet(Pet pet) {
	printf("Pet: %-19s Kind: %-19s\n", pet.name, pet.type);
}

void findpet(const Tree * pt) {
	Pet temp;

	if (TreeIsEmpty(pt)) {
		puts("No entries.");
		return;
	}

	puts("Please enter name of pet you wish to find:");
	get(temp.name, STRLEN);
	uppercase(temp.name);
	printf("Here are all pets named %s:\n", temp.name);
	ApplyToNode(&temp, pt, printpet);
}

void uppercase(char * str) {
	for (; *str != '\0'; str++)
		*str = toupper(*str);
}

char * get(char * string, int n) {
	// wrapper for fgets - read from stdin and replace
	// first newline with null character

	char * retval = fgets(string, n, stdin);

	for (; *string != '\0'; string++) {
		if (*string == '\n') {
			*string = '\0';
			break;
		}
	}
	return retval;
}