#include "config.h"

#include <assert.h>
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "logerr.h"
#include "util.h"

#include "random.h"



struct Random {
	FILE *const file_handle;
};



int
urandom_bytes(const size_t n, uint8_t (*const addr)[]) {
	int rc = -1;

	uint8_t *ret = NULL;
	FILE *f = NULL;

	ret = malloc(n);
	if (ret == NULL) {
		logerr("malloc(): %s", strerror(errno));
		goto out;
	}

	f = fopen("/dev/urandom", "r");
	if (f == NULL) {
		logerr("fopen(): %s", strerror(errno));
		goto out;
	}

	const size_t read_count = fread(ret, 1U, n, f);
	if (ferror(f)) {
		logerr("fread(): %s", strerror(errno));
		goto out;
	}
	assert(read_count == n);

	if (fclose(f)) {
		logerr("fclose(): %s", strerror(errno));
		goto out;
	}
	f = NULL;

	memcpy(addr, ret, n);
	rc = 0;
out:
	if (f != NULL) {
		if (fclose(f)) {
			logerr("fclose(): %s", strerror(errno));
			rc = -1;
		}
	}
	if (ret != NULL) {
		freeit((void *)&ret);
	}
	return rc;
}

int
random_generate(
	const struct Random *const r,
	const size_t length,
	uint8_t (*const out)[]
) {
	int rc = -1;

	const size_t read_count = fread(out, 1U, length, r->file_handle);
	if (ferror(r->file_handle)) {
		logerr("fread(): %s", strerror(errno));
		goto out;
	}
	assert(read_count == length);

	rc = 0;
out:
	return rc;
}

int
random_new(const struct Random **const out) {
	int rc = -1;

	const struct Random *ret = NULL;
	FILE *f = NULL;

	ret = malloc(sizeof(*ret));
	if (ret == NULL) {
		logerr("malloc(): %s", strerror(errno));
		goto out;
	}

	f = fopen("/dev/urandom", "r");
	if (f == NULL) {
		logerr("fopen(): %s", strerror(errno));
		goto out;
	}

	memcpy((void *)ret, &(struct Random) {
		.file_handle = f,
	}, sizeof(*ret));
	*out = ret;
	rc = 0;
out:
	if (rc) {
		random_free(&ret);
	}
	return rc;
}

int
random_free(const struct Random **const r) {
	if (r == NULL) {
		return 0;
	}

	if (*r == NULL) {
		return 0;
	}

	int rc = -1;
	if (fclose((*r)->file_handle)) {
		logerr("fclose(): %s", strerror(errno));
		goto out;
	}

	rc = 0;
out:
	freeit((void *)r);
	return rc;
}