#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
#include "clog.h"

enum { MAX_ROOM_NUM_SIZE=16 };

// You would think sizeof(Point) would be 1 + 4 + 4 + 16, but compiler may add padding to make data
// align with multiples of 4 in memory.  By default, the above type will occupy 28 bytes, not 25.
//
#pragma pack(1)  // This means pack fields to align by multiples of 1 byte (in other words, NO PADDING ALLOWED).

typedef struct {
    char c;
    int x;
    int y;
    char name[MAX_ROOM_NUM_SIZE];  // fixed string length limits cause major security holes
} Point;

// G

void print_point(Point p) {
    printf("p.x == %d    p.y == %d    p.name == \"%s\"\n", p.x, p.y, p.name);
}

void write_point_to_file(const char* path, Point p) {
    FILE* fp = fopen(path, "w");
    fwrite(&p, sizeof(p), 1, fp);  // copy bytes from memory to disk
    fclose(fp);
}

Point read_point_from_file(const char* path) {
    Point p;
    FILE* fp = fopen(path, "r");
    fread(&p, sizeof(p), 1, fp);  // copy bytes from disk to memory
    fclose(fp);
    return p;
}


int main(int argc, char* argv[]) {
    Point here = { .x = 0xba, .y=0x88, .name="MATH 175" };
    print_point(here);
    write_point_to_file("here.bin", here);  // file extensions are just a convention
    log_addr(&here);


    Point there = read_point_from_file("here.bin");
    print_point(there);
    log_addr(&there);
    
    printf("sizeof(there) == %zd\n", sizeof(there));
    
    return EXIT_SUCCESS;
}
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