// <Kira Installer - universal Linux installer.>
// Copyright (C) <2026>  <Kira Foundation>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

/*
   KiraSize struct implementation for work with base2 sizes.
*/

use std::ops::{Add, Sub};

#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
pub struct KiraSize {
    size_bytes: u64,
}

impl std::fmt::Display for KiraSize {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        if self.size_bytes < 1000 {
            write!(f, "{}B", self.size_bytes)
        } else {
            let mut s = self.size_bytes as f64;
            let mut idx = 0;
            for i in 0..5 {
                s = s / 1024.0;
                idx = i;
                if s < 1000.0 {
                    break;
                }
            }
            write!(f, "{:.2}{}", s, Self::SUFFIXS[idx])
        }
    }
}

impl KiraSize {
    pub const SUFFIXS: [&str; 5] = ["KB", "MB", "GB", "TB", "PB"];

    /// returns size in bytes suffixed with "B" character
    pub fn to_parted_bytes_str(&self)-> String {
        format!("{}B", self.size_bytes)
    }


    pub fn new_b(size:u64) -> Self {
        Self { size_bytes: size }
    }
    pub fn new_kb(size:u64) -> Self {
        Self { size_bytes: size * 1024 }
    }
    pub fn new_mb(size:u64) -> Self {
        Self { size_bytes: size * 1024u64.pow(2) }
    }
    pub fn new_gb(size:u64) -> Self {
        Self { size_bytes: size * 1024u64.pow(3) }
    }
    pub fn new_tb(size:u64) -> Self {
        Self { size_bytes: size * 1024u64.pow(4) }
    }
    pub fn new_pb(size:u64) -> Self {
        Self { size_bytes: size * 1024u64.pow(5) }
    }

    pub fn b(&self) -> u64 {
        self.size_bytes
    }
    pub fn kb(&self) -> u64 {
        self.size_bytes / 1024u64
    }
    pub fn mb(&self) -> u64 {
        self.size_bytes / 1024u64.pow(2)
    }
    pub fn gb(&self) -> u64 {
        self.size_bytes / 1024u64.pow(3)
    }
    pub fn tb(&self) -> u64 {
        self.size_bytes / 1024u64.pow(4)
    }
    pub fn pb(&self) -> u64 {
        self.size_bytes / 1024u64.pow(5)
    }

    pub fn from_str_bytes(s: &str) -> Option<Self> {
        Some(Self::new_b(u64::from_str_radix(s, 10).ok()?))
    }

    pub fn div_c(self, other: u64) -> Self {
        Self { size_bytes: self.size_bytes / other }
    }

    ///
    /// Panics if overflow accurs.
    /// 
    pub fn mul_c(self, other: u64) -> Self {
        Self { size_bytes: self.size_bytes.strict_mul(other) }
    }

}

impl Add for KiraSize {
    type Output = KiraSize;

    fn add(self, other: KiraSize) -> Self::Output {
        KiraSize {
            size_bytes: self.size_bytes + other.size_bytes,
        }
    }
}

impl Sub for KiraSize {
    type Output = KiraSize;

    /// Panics if overflow accors.
    fn sub(self, other: KiraSize) -> Self::Output {
        KiraSize {
            size_bytes: self.size_bytes.strict_sub(other.size_bytes),
        }
    }
}