#include <stdio.h>
#include <stdlib.h>
#include <time.h>

typedef struct __page{
	int size, pSize, pid;
}page;

enum stat{unallocated, fragmentation, freeP};

int main(int argc, char **argv){
	if(argc != 3){
		fprintf(stderr, "Usage: %s <slices> <algorithm>\n", argv[0]);
		exit(EXIT_FAILURE);
	}
	time_t t;
	srand((unsigned) time(&t));

	int i, pSize, pid = 0, v, v_id;
	int slices = atoi(argv[1]);
	char fit = argv[2][0];
	page *memory = (page *) malloc(slices * sizeof(page));
	int stats[3] = {0, 0, 0};
	stats[2] = slices;

	switch(fit){
			case 'f':
				printf("First fit algorithm\n\n");
			break;
			case 'b':
				printf("Best fit algorithm\n\n");
			break;
			case 'w':
				printf("Worst fit algorithm\n\n");
			break;
			default:
				printf("algorithm not found!\n");
			exit(EXIT_FAILURE);			
	}

	for(i = 0; i < slices; i++){
		memory[i].size = 100 * (rand() % 8 + 1);
		memory[i].pSize = -1;
		memory[i].pid = -1;
		printf("page %d - size: %d\n", i, memory[i].size);
	}
	printf("\n");

	while(1){
		v_id = -1;
		v = -1;
		printf("process %d size: ", pid);
		scanf("%d", &pSize);
		if(pSize == 0)
			break;
		switch(fit){
			case 'f':
				for(v_id = 0; v_id < slices; v_id++)
					if(memory[v_id].pSize == -1 && memory[v_id].size >= pSize){	
						break;
					}
			break;

			case 'b':
				for(i = 0; i < slices; i++)
					if(memory[i].pSize == -1 && memory[i].size >= pSize){
						v_id = i;
						v = memory[i].size;
						break;
					}
				for(; i < slices; i++)
					if(memory[i].pSize == -1 && memory[i].size >= pSize && memory[i].size < v){
						v_id = i;
						v = memory[i].size;
					}
			break;

			case 'w':
				for(i = 0; i < slices; i++)
					if(memory[i].pSize == -1 && memory[i].size >= pSize){
						printf("a:%d\n", i);
						v_id = i;
						v = memory[i].size;
						break;
					}
				for(; i < slices; i++)
					if(memory[i].pSize == -1 && memory[i].size >= pSize && memory[i].size > v){
						printf("b:%d\n", i);
						v_id = i;
						v = memory[i].size;
					}
			break;
		}
		if(v_id == slices){
			printf("process %d could not be allocated\n", pid);
			printf("\tprocess size: %d\n\n",pSize);
			stats[0]++;
		}
		else{
			memory[v_id].pSize = pSize;
			memory[v_id].pid = pid;
			printf("process %d allocated in page %d\n", pid, v_id);
			printf("\tprocess size: %d\n", pSize);
			printf("\tpage size: %d\n", memory[v_id].size);
			printf("\tinternal fragmentation: %d\n\n", memory[v_id].size - memory[v_id].pSize);
			stats[1] += memory[v_id].size - memory[v_id].pSize;
			stats[2]--;
		}
		pid++;
	}

	printf("Unallocated processes: %d\n", stats[unallocated]);
	printf("Total internal fragmentation: %d\n", stats[fragmentation]);
	printf("free pages: %d\n", stats[freeP]);

	free(memory);
	return 0;
}