use crate::FileTime;

use std::ffi::CString;

use std::fs;

use std::io;

use std::os::unix::prelude::*;

use std::path::Path;

fn get_times(

    atime: Option<FileTime>,

    mtime: Option<FileTime>,

    current: impl FnOnce() -> io::Result<fs::Metadata>,

) -> io::Result<Option<(FileTime, FileTime)>> {

    let pair = match (atime, mtime) {

        (Some(a), Some(b)) => (a, b),

        (None, None) => return Ok(None),

        (Some(a), None) => {

            let meta = current()?;

            (a, FileTime::from_last_modification_time(&meta))

        }

        (None, Some(b)) => {

            let meta = current()?;

            (FileTime::from_last_access_time(&meta), b)

        }

    };

    Ok(Some(pair))

}

#[allow(dead_code)]

pub fn set_symlink_file_times(p: &Path, atime: FileTime, mtime: FileTime) -> io::Result<()> {

    set_times(p, Some(atime), Some(mtime), true)

}

pub fn set_times(

    p: &Path,

    atime: Option<FileTime>,

    mtime: Option<FileTime>,

    symlink: bool,

) -> io::Result<()> {

    let (atime, mtime) = match get_times(atime, mtime, || p.metadata())? {

        Some(pair) => pair,

        None => return Ok(()),

    };

    let p = CString::new(p.as_os_str().as_bytes())?;

    let times = [to_timeval(&atime), to_timeval(&mtime)];

    let rc = unsafe {

        if symlink {

            libc::lutimes(p.as_ptr(), times.as_ptr())

        } else {

            libc::utimes(p.as_ptr(), times.as_ptr())

        }

    };

    return if rc == 0 {

        Ok(())

    } else {

        Err(io::Error::last_os_error())

    };

}

fn to_timeval(ft: &FileTime) -> libc::timeval {

    libc::timeval {

        tv_sec: ft.seconds() as libc::time_t,

        tv_usec: (ft.nanoseconds() / 1000) as libc::suseconds_t,

    }

}

#[cfg(target_env = "uclibc")]

fn to_timespec(ft: &FileTime) -> libc::timespec {

    libc::timespec {

        tv_sec: ft.seconds() as libc::time_t,

        #[cfg(all(target_arch = "x86_64", target_pointer_width = "32"))]

        tv_nsec: (ft.nanoseconds()) as i64,

        #[cfg(not(all(target_arch = "x86_64", target_pointer_width = "32")))]

        tv_nsec: (ft.nanoseconds()) as libc::c_long,

    }

}