use crate::common::Result;
use crate::{Exceptions, Point};

use super::{Direction, RegressionLineTrait};

#[inline(always)]
pub fn intersect<T: RegressionLineTrait, T2: RegressionLineTrait>(
    l1: &T,
    l2: &T2,
) -> Result<Point> {
    if !(l1.isValid() && l2.isValid()) {
        return Err(Exceptions::ILLEGAL_STATE);
    }
    let d = l1.a() * l2.b() - l1.b() * l2.a();
    let x = (l1.c() * l2.b() - l1.b() * l2.c()) / d;
    let y = (l1.a() * l2.c() - l1.c() * l2.a()) / d;
    Ok(Point { x, y })
}

#[allow(dead_code)]
#[inline(always)]
pub fn opposite(dir: Direction) -> Direction {
    if dir == Direction::Left {
        Direction::Right
    } else {
        Direction::Left
    }
}

#[inline(always)]
pub fn UpdateMinMax<T: Ord + Copy>(min: &mut T, max: &mut T, val: T) {
    *min = std::cmp::min(*min, val);
    *max = std::cmp::max(*max, val);
}

#[inline(always)]
pub fn UpdateMinMaxFloat(min: &mut f64, max: &mut f64, val: f64) {
    *min = f64::min(*min, val);
    *max = f64::max(*max, val);
}

// template<typename T, typename = std::enable_if_t<std::is_integral_v<T>>>
pub fn ToString<T: Into<usize>>(val: T, len: usize) -> Result<String> {
    let mut len = len;
    let mut val = val.into();

    let mut result: String = vec!['0'; len].iter().collect();
    len -= 1;
    // std::string result(len--, '0');
    if (val < 0) {
        return Err(Exceptions::format_with("Invalid value"));
    }
    while len >= 0 && val != 0 {
        result.replace_range(len..len, &char::from(b'0' + (val % 10) as u8).to_string());

        len -= 1;
        val /= 10;
    }
    // for (; len >= 0 && val != 0; --len, val /= 10) {
    // 	result[len] = '0' + val % 10;}
    if (val != 0) {
        return Err(Exceptions::format_with("Invalid value"));
    }

    Ok(result)
}