use std::time::{SystemTime, UNIX_EPOCH, Duration};
use rand::Rng;

// Base-62 encoding characters
const BASE62: &[u8] = b"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

// Convert a number to Base-62
fn to_base62(mut num: u64) -> String {
    let mut result = String::new();
    while num > 0 {
        result.insert(0, BASE62[(num % 62) as usize] as char);
        num /= 62;
    }
    result
}

// Generate an 8-character unique ID
fn generate_id() -> String {
    let epoch_start = UNIX_EPOCH + Duration::from_secs(1577836800); // 2020-01-01
    let now = SystemTime::now().duration_since(epoch_start).unwrap().as_millis();
    let random: u64 = rand::thread_rng().gen_range(0..1000); // 3-digit random number
    let id = now * 1000 + random; // Combine timestamp + randomness
    let base62_id = to_base62(id);
    format!("{:0>8}", base62_id)[..8].to_string() // Ensure 8 chars
}

fn main() {
    println!("{}", generate_id()); // Example output: "9XcF7Bv2"
}