use rand::Rng;

pub const ID_CHARSET: &[u8] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
pub const ID_RAND_LEN: u32 = 26;
pub const TOKEN_CHARSET: &[u8] =
    b"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_";
pub const TOKEN_RAND_LEN: u32 = 43;

#[macro_export]
macro_rules! randid {
    (id) => {
        $crate::id::random_with_charset($crate::id::ID_RAND_LEN, $crate::id::ID_CHARSET)
    };
    (id $p:expr) => {
        format!(
            "{}-{}",
            $p,
            $crate::id::random_with_charset($crate::id::ID_RAND_LEN, $crate::id::ID_CHARSET)
        )
    };
    (token) => {
        random_with_charset($crate::id::TOKEN_RAND_LEN, $crate::id::TOKEN_CHARSET)
    };
    (token $p:expr) => {
        format!(
            "{}-{}",
            $p,
            $crate::id::random_with_charset($crate::id::TOKEN_RAND_LEN, $crate::id::TOKEN_CHARSET)
        )
    };
}

pub fn random_with_charset(len: u32, charset: &[u8]) -> String {
    (0..len)
        .map(|_| {
            let idx = rand::thread_rng().gen_range(0..charset.len());
            charset[idx] as char
        })
        .collect()
}