#!/usr/bin/env fun

/*
 * This file is part of the Fun programming language.
 * https://fun-lang.xyz/
 *
 * Copyright 2025 Johannes Findeisen <you@hanez.org>
 * Licensed under the terms of the Apache-2.0 license.
 * https://opensource.org/license/apache-2-0
 *
 * Added: 2025-12-12
 */

/*
 * Example: Using OS-based random_number(len) builtin
 * This generates cryptographically strong random bytes and returns them
 * hex-encoded as a string of length 2*len (since each byte -> two hex chars).
 */

#include <hex.fun>

print("--- random_number(len) demo ---")

len_bytes = 16
hexstr = random_number(len_bytes)
print("Requested bytes:")
print(to_string(len_bytes))
print("Hex string:")
print(hexstr)
print("Hex bytes array:")
print(to_string(hex_to_bytes(hexstr)))
echo("Hex dump to bytes:")
print(hex_to_bytes(hexstr))
print("Hex as decimal (first 4 bytes):")
print(to_string(hex_to_dec(substr(hexstr, 0, 8))))
print("Hex as decimal (all bytes):")
print(to_string(hex_to_dec(hexstr)))
print("Hex length (should be 2*bytes = 32):")
print(to_string(len(hexstr)))

// Zero length returns empty string
empty = random_number(0)
print("Empty (0 bytes) -> length: " + to_string(len(empty)) + " value: " + to_string(empty))

// You can request longer values as needed, e.g., 32 bytes -> 64 hex chars
hex64 = random_number(32)
print("32 bytes -> " + to_string(len(hex64)) + " hex chars")

/* Possible output:
--- random_number(len) demo ---
Requested bytes:
16
Hex string:
50a76f143d67ce173962cd2eea5a86a4
Hex bytes array:
[array n=16]
Hex dump to bytes:[80, 167, 111, 20, 61, 103, 206, 23, 57, 98, 205, 46, 234, 90, 134, 164]
Hex as decimal (first 4 bytes):
1353150228
Hex as decimal (all bytes):
4135093009263527588
Hex length (should be 2*bytes = 32):
32
Empty (0 bytes) -> length: 0 value: 
32 bytes -> 64 hex chars
*/