use super::*;

use std::io;
use std::path::Path;

//////////////////////////////////////////////////////////////////////////////////////////////////////////////

#[macro_export]
macro_rules! assert_err {
    ($ex:expr) => {
        if let Ok(v) = $ex {
            panic!("assertion failed, expected Err(..), got {:?}", v);
        }
    };
}

#[macro_export]
macro_rules! io_error_other {
    ($msg:expr) => {
        io::Error::new(io::ErrorKind::Other, $msg.to_string())
    };
}

pub fn to_io_error_other<E: std::error::Error + Send + Sync + 'static>(x: E) -> io::Error {
    io::Error::new(io::ErrorKind::Other, x)
}

#[macro_export]
macro_rules! bail_io_error_other {
    ($msg:expr) => {
        return io::Result::Err(io::Error::new(io::ErrorKind::Other, $msg.to_string()))
    };
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////

pub fn system_boxed<'a, Out>(
    future: impl Future<Output = Out> + Send + 'a,
) -> SendPinBoxFutureLifetime<'a, Out> {
    Box::pin(future)
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////

cfg_if! {
    if #[cfg(target_arch = "wasm32")] {

        // xxx: for now until wasm threads are more stable, and/or we bother with web workers
        pub fn get_concurrency() -> u32 {
            1
        }

    } else {

        pub fn get_concurrency() -> u32 {
            std::thread::available_parallelism()
                .map(|x| x.get())
                .unwrap_or_else(|e| {
                    warn!("unable to get concurrency defaulting to single core: {}", e);
                    1
                }) as u32
        }

    }
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////

pub fn split_port(name: &str) -> EyreResult<(String, Option<u16>)> {
    if let Some(split) = name.rfind(':') {
        let hoststr = &name[0..split];
        let portstr = &name[split + 1..];
        let port: u16 = portstr.parse::<u16>().wrap_err("invalid port")?;

        Ok((hoststr.to_string(), Some(port)))
    } else {
        Ok((name.to_string(), None))
    }
}

pub fn prepend_slash(s: String) -> String {
    if s.starts_with('/') {
        return s;
    }
    let mut out = "/".to_owned();
    out.push_str(s.as_str());
    out
}

pub fn timestamp_to_secs(ts: u64) -> f64 {
    ts as f64 / 1000000.0f64
}

pub fn secs_to_timestamp(secs: f64) -> u64 {
    (secs * 1000000.0f64) as u64
}

pub fn ms_to_us(ms: u32) -> u64 {
    (ms as u64) * 1000u64
}

// Calculate retry attempt with logarhythmic falloff
pub fn retry_falloff_log(
    last_us: u64,
    cur_us: u64,
    interval_start_us: u64,
    interval_max_us: u64,
    interval_multiplier_us: f64,
) -> bool {
    //
    if cur_us < interval_start_us {
        // Don't require a retry within the first 'interval_start_us' microseconds of the reliable time period
        false
    } else if cur_us >= last_us + interval_max_us {
        // Retry at least every 'interval_max_us' microseconds
        true
    } else {
        // Exponential falloff between 'interval_start_us' and 'interval_max_us' microseconds
        last_us <= secs_to_timestamp(timestamp_to_secs(cur_us) / interval_multiplier_us)
    }
}

pub fn try_at_most_n_things<T, I, C, R>(max: usize, things: I, closure: C) -> Option<R>
where
    I: IntoIterator<Item = T>,
    C: Fn(T) -> Option<R>,
{
    let mut fails = 0usize;
    for thing in things.into_iter() {
        if let Some(r) = closure(thing) {
            return Some(r);
        }
        fails += 1;
        if fails >= max {
            break;
        }
    }
    None
}

pub async fn async_try_at_most_n_things<T, I, C, R, F>(
    max: usize,
    things: I,
    closure: C,
) -> Option<R>
where
    I: IntoIterator<Item = T>,
    C: Fn(T) -> F,
    F: Future<Output = Option<R>>,
{
    let mut fails = 0usize;
    for thing in things.into_iter() {
        if let Some(r) = closure(thing).await {
            return Some(r);
        }
        fails += 1;
        if fails >= max {
            break;
        }
    }
    None
}

pub trait CmpAssign {
    fn min_assign(&mut self, other: Self);
    fn max_assign(&mut self, other: Self);
}

impl<T> CmpAssign for T
where
    T: core::cmp::Ord,
{
    fn min_assign(&mut self, other: Self) {
        if &other < self {
            *self = other;
        }
    }
    fn max_assign(&mut self, other: Self) {
        if &other > self {
            *self = other;
        }
    }
}

pub fn compatible_unspecified_socket_addr(socket_addr: &SocketAddr) -> SocketAddr {
    match socket_addr {
        SocketAddr::V4(_) => SocketAddr::new(IpAddr::V4(Ipv4Addr::new(0, 0, 0, 0)), 0),
        SocketAddr::V6(_) => SocketAddr::new(IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0)), 0),
    }
}

pub fn listen_address_to_socket_addrs(listen_address: &str) -> EyreResult<Vec<SocketAddr>> {
    // If no address is specified, but the port is, use ipv4 and ipv6 unspecified
    // If the address is specified, only use the specified port and fail otherwise
    let ip_addrs = vec![
        IpAddr::V4(Ipv4Addr::UNSPECIFIED),
        IpAddr::V6(Ipv6Addr::UNSPECIFIED),
    ];

    Ok(if let Some(portstr) = listen_address.strip_prefix(':') {
        let port = portstr
            .parse::<u16>()
            .wrap_err("Invalid port format in udp listen address")?;
        ip_addrs.iter().map(|a| SocketAddr::new(*a, port)).collect()
    } else if let Ok(port) = listen_address.parse::<u16>() {
        ip_addrs.iter().map(|a| SocketAddr::new(*a, port)).collect()
    } else {
        cfg_if! {
            if #[cfg(target_arch = "wasm32")] {
                use core::str::FromStr;
                vec![SocketAddr::from_str(listen_address).map_err(|e| io_error_other!(e)).wrap_err("Unable to parse address")?]
            } else {
                listen_address
                    .to_socket_addrs()
                    .wrap_err("Unable to resolve address")?
                    .collect()
            }
        }
    })
}

pub trait Dedup<T: PartialEq + Clone> {
    fn remove_duplicates(&mut self);
}

impl<T: PartialEq + Clone> Dedup<T> for Vec<T> {
    fn remove_duplicates(&mut self) {
        let mut already_seen = Vec::new();
        self.retain(|item| match already_seen.contains(item) {
            true => false,
            _ => {
                already_seen.push(item.clone());
                true
            }
        })
    }
}

cfg_if::cfg_if! {
    if #[cfg(unix)] {
        use std::os::unix::fs::MetadataExt;
        use std::os::unix::prelude::PermissionsExt;
        use nix::unistd::{Uid, Gid};

        pub fn ensure_file_private_owner<P:AsRef<Path>>(path: P) -> EyreResult<()>
        {
            let path = path.as_ref();
            if !path.exists() {
                return Ok(());
            }

            let uid = Uid::effective();
            let gid = Gid::effective();
            let meta = std::fs::metadata(path).wrap_err("unable to get metadata for path")?;

            if meta.mode() != 0o600 {
                std::fs::set_permissions(path,std::fs::Permissions::from_mode(0o600)).wrap_err("unable to set correct permissions on path")?;
            }
            if meta.uid() != uid.as_raw() || meta.gid() != gid.as_raw() {
                bail!("path has incorrect owner/group");
            }
            Ok(())
        }
    } else if #[cfg(windows)] {
        //use std::os::windows::fs::MetadataExt;
        //use windows_permissions::*;

        pub fn ensure_file_private_owner<P:AsRef<Path>>(path: P) -> EyreResult<()>
        {
            let path = path.as_ref();
            if !path.exists() {
                return Ok(());
            }

            Ok(())
        }
    } else {
        pub fn ensure_file_private_owner<P:AsRef<Path>>(_path: P) -> Result<(), String>
        {
            Ok(())
        }
    }
}

#[repr(C, align(8))]
struct AlignToEight([u8; 8]);

pub unsafe fn aligned_8_u8_vec_uninit(n_bytes: usize) -> Vec<u8> {
    let n_units = (n_bytes + mem::size_of::<AlignToEight>() - 1) / mem::size_of::<AlignToEight>();
    let mut aligned: Vec<AlignToEight> = Vec::with_capacity(n_units);
    let ptr = aligned.as_mut_ptr();
    let cap_units = aligned.capacity();
    mem::forget(aligned);

    Vec::from_raw_parts(
        ptr as *mut u8,
        n_bytes,
        cap_units * mem::size_of::<AlignToEight>(),
    )
}
