#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<sys/resource.h>
#include<sys/utsname.h>
#include<sys/sysinfo.h>
#include<sys/types.h>
#include<unistd.h>
#include<time.h>

#define CPUINFO "/proc/cpuinfo"
#define CPUFREQ "/sys/devices/system/cpu/cpu0/cpufreq/"
#define REPOS "\033[H" // Re-positions the cursor to top left of screen
#define CLEAR "\033[2J"

typedef struct Chunk chunk;

struct Chunk {
    size_t size;
    char* mem;
};


size_t read_file(FILE* file, chunk* out) {
    char* block = malloc(500 * sizeof(char));
    if (!file) {
	return -1;
    }
    if (!block) {
	fclose(file);
	return -1;
    }
    size_t fileout = 0;
    size_t old = 0;
    fileout = fread(block, sizeof(char), 500, file);
    while (fileout != 0) {
	old = out->size;
	out->size = out->size + fileout;
	out->mem = realloc(out->mem, out->size);
	if (out->mem) {
	    fclose(file);
	    free(block);
	    return -1;
	}
	memcpy(&(out->mem[old]), block, fileout);
    }
    free(block);
    fclose(file);
    return fileout; 
}

void move(int row, int col) {
    printf("\x1b[%d;%df", row, col);
}

void repos() {
    printf("\033[H");
}

void die(const char* reason, int ret) {
}

int printcores(char* proc_data) {
    char* core_loc = strstr(proc_data, "siblings");
    char* freq_loc = strstr(proc_data, "cpu MHz");
    int core_num = atoi(core_loc);
    float core_freq = atof(freq_loc);
    for (int i = 0; i < core_num; i++) {
	;
    }
    return 0;
}

int printmemory() {
    return 0;
}

int printcpu() {
    return 0;
}

int main(int argc, char** argv) {
    short memory = 0;
    short cpu = 0;
    short cores = 0;
    int samples = 20;
    unsigned int tdelay = 500000;
    unsigned long prevtime;
    time_t sec;
    struct sysinfo* initial_readings = (struct sysinfo*)malloc(sizeof(struct sysinfo));
    chunk* proc_data = malloc(sizeof(chunk));
    if (!initial_readings || !proc_data) {
	die("Memory error!", 3);
    }
    proc_data->mem = malloc(1);
    if (!proc_data) {
	die("Memory error!", 3);
    }
    proc_data->size = 0;
    if (!sysinfo(initial_readings)) {
	free(initial_readings);
	die("Unable to get system info!", 2);
    }
    if (read_file(fopen(CPUINFO, "r"), proc_data) == -1) {
	die("Reading file error!", 4);
    }
    int start = 1;
    if ((atoi(argv[1]) != 0) || (strlen(argv[1]) == 1)) {
	samples = atoi(argv[1]);
	start++;
    }
    if ((argc >= 3) && ((atoi(argv[2]) != 0) || (strlen(argv[2]) == 1))) {
	tdelay = atoi(argv[2]);
	start++;
    }

    for (int i = start; i < argc ; i++) {
	if (strstr(argv[i], "--memory")) {
	    memory = 1;
	}
	else if (strstr(argv[i], "--cpu")) {
	    cpu = 1;
	}
	else if (strstr(argv[i], "--cores")) {
	    cores = 1;
	}
	else if (strstr(argv[i], "--samples=")) {
	    samples = atoi(argv[i] + 10);
	}
	else if (strstr(argv[i], "--tdelay=")) {
	    tdelay = atoi(strstr(argv[i], "--tdelay=") + 9);
	}
	else {
	    free(initial_readings);
	    free(proc_data->mem);
	    free(proc_data);
	    printf("Invalid argument!");
	    die("Invalid argument!", 1);
	    return 1;
	}
    }
    if (samples < 0 || tdelay < 0)
	die("Invalid argument!", 1);
    for (int i = 0; i < samples; i++) {
	printf("%s", CLEAR);
	prevtime = time(&sec);
	if (memory) {
	    printmemory();
	}
	if (cpu) {
	    printcpu();
	}
	while (1) {
	    if (prevtime - time(&sec) >= tdelay)
		break;
	}
    }
    if (cores)
	printcores(proc_data->mem);
    free(initial_readings);
    free(proc_data->mem);
    free(proc_data);
    return 0;
}