// SPDX-FileCopyrightText: 2026 Qyriad <qyriad@qyriad.me>
//
// SPDX-License-Identifier: EUPL-1.1

use std::num::NonZeroU64;

#[allow(unused_imports)]
use crate::prelude::*;

#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct Line(pub u64);

/// Constructors.
impl Line {
    pub const fn from_index(index: u64) -> Self {
        Self(index)
    }

    pub const fn from_linenr(linenr: NonZeroU64) -> Self {
        Self(linenr.get() - 1)
    }

    pub const fn next(self) -> Self {
        Self::from_index(self.index() + 1)
    }

    /// Panics if self is line index 0.
    pub const fn prev(self) -> Self {
        Self::from_index(self.index() - 1)
    }
}

/// Getters.
impl Line {
    /// 0-indexed
    pub const fn index(self) -> u64 {
        self.0
    }

    #[cfg(target_pointer_width = "64")]
    pub const fn index_usize(self) -> usize {
        self.0 as usize
    }

    /// 1-indexed
    pub const fn linenr(self) -> u64 {
        self.0 + 1
    }
}

/// [Alternate](Formatter::alternate) flag capitalizes "line".
///
/// ```
/// # use dynix::Line;
/// let line = Line::from_index(22);
/// assert_eq!(format!("{line}"), "line 23");
/// assert_eq!(format!("{line:#}"), "Line 23");
/// ```
impl Display for Line {
    fn fmt(&self, f: &mut Formatter) -> FmtResult {
        if f.alternate() {
            write!(f, "Line {}", self.linenr())?;
        } else {
            write!(f, "line {}", self.linenr())?;
        }

        Ok(())
    }
}