use std::vec::IntoIter;

use peekmore::PeekMoreIterator;

use crate::Token;

#[derive(Debug)]
pub(crate) struct ParsedNumber {
    /// The full number excluding the decimal
    ///
    /// E.g. for `1.23`, this would be `"123"`
    pub num: String,

    /// The length of the decimal
    ///
    /// E.g. for `1.23`, this would be `2`
    pub dec_len: usize,

    /// The number following e in a scientific notated number
    ///
    /// E.g. for `1e23`, this would be `"23"`,
    /// for `1`, this would be an empty string
    // TODO: maybe we just return a bigint?
    pub times_ten: String,

    /// Whether or not `times_ten` is negative
    ///
    /// E.g. for `1e-23` this would be `true`,
    /// for `1e23` this would be `false`
    pub times_ten_is_postive: bool,
}

impl ParsedNumber {
    pub const fn new(
        num: String,
        dec_len: usize,
        times_ten: String,
        times_ten_is_postive: bool,
    ) -> Self {
        Self {
            num,
            dec_len,
            times_ten,
            times_ten_is_postive,
        }
    }
}

pub(crate) fn eat_whole_number(toks: &mut PeekMoreIterator<IntoIter<Token>>) -> String {
    let mut buf = String::new();
    while let Some(c) = toks.peek() {
        if !c.kind.is_ascii_digit() {
            break;
        }
        let tok = toks.next().unwrap();
        buf.push(tok.kind);
    }
    buf
}