/*
 * Copyright (c) 2022-2023 Niko Bonnieure, Par le Peuple, NextGraph.org developers
 * All rights reserved.
 * Licensed under the Apache License, Version 2.0
 * <LICENSE-APACHE2 or http://www.apache.org/licenses/LICENSE-2.0>
 * or the MIT license <LICENSE-MIT or http://opensource.org/licenses/MIT>,
 * at your option. All files in the project carrying such
 * notice may not be copied, modified, or distributed except
 * according to those terms.
*/

use async_std::task;
use ed25519_dalek::*;
use futures::{channel::mpsc, select, Future, FutureExt, SinkExt};
pub use noise_protocol::U8Array;
use noise_protocol::DH;
pub use noise_rust_crypto::sensitive::Sensitive;
use p2p_repo::log::*;
use p2p_repo::types::PubKey;
use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};

#[cfg(target_arch = "wasm32")]
pub fn spawn_and_log_error<F>(fut: F) -> task::JoinHandle<()>
where
    F: Future<Output = ResultSend<()>> + 'static,
{
    task::spawn_local(async move {
        if let Err(e) = fut.await {
            log_err!("EXCEPTION {}", e)
        }
    })
}
#[cfg(target_arch = "wasm32")]
pub type ResultSend<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;

#[cfg(not(target_arch = "wasm32"))]
pub type ResultSend<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;

#[cfg(not(target_arch = "wasm32"))]
pub fn spawn_and_log_error<F>(fut: F) -> task::JoinHandle<()>
where
    F: Future<Output = ResultSend<()>> + Send + 'static,
{
    task::spawn(async move {
        if let Err(e) = fut.await {
            log_err!("{}", e)
        }
    })
}

pub type Sender<T> = mpsc::UnboundedSender<T>;
pub type Receiver<T> = mpsc::UnboundedReceiver<T>;

pub fn keypair_from_ed(secret: SecretKey, public: PublicKey) -> (Sensitive<[u8; 32]>, PubKey) {
    let ed_priv_key = secret.to_bytes();
    let ed_pub_key = public.to_bytes();
    //let priv_key = PrivKey::Ed25519PrivKey(ed_priv_key);
    let pub_key = PubKey::Ed25519PubKey(ed_pub_key);
    let priv_key = Sensitive::<[u8; 32]>::from_slice(&ed_priv_key);
    (priv_key, pub_key)
}

pub fn keys_from_bytes(secret_key: [u8; 32]) -> (Sensitive<[u8; 32]>, PubKey) {
    let sk = SecretKey::from_bytes(&secret_key).unwrap();
    let pk: PublicKey = (&sk).into();

    let pub_key = PubKey::Ed25519PubKey(pk.to_bytes());

    let priv_key = Sensitive::<[u8; 32]>::from_slice(&secret_key);
    (priv_key, pub_key)
}

pub fn gen_dh_keys() -> (Sensitive<[u8; 32]>, [u8; 32]) {
    let pri = noise_rust_crypto::X25519::genkey();
    let publ = noise_rust_crypto::X25519::pubkey(&pri);
    (pri, publ)
}

pub fn gen_ed_keys() -> (Sensitive<[u8; 32]>, PubKey) {
    let mut ed25519_priv = Sensitive::<[u8; 32]>::new();
    getrandom::getrandom(&mut *ed25519_priv).expect("getrandom failed");

    //TODO FIXME do not create a SecretKey or call into() on it, as this is not using Sensitive<>
    let secret = SecretKey::from_bytes(&ed25519_priv.as_slice()).unwrap();
    let ed25519_pub: PublicKey = (&secret).into();

    (ed25519_priv, PubKey::Ed25519PubKey(ed25519_pub.to_bytes()))
}

pub struct Dual25519Keys {
    pub x25519_priv: Sensitive<[u8; 32]>,
    pub x25519_public: [u8; 32],
    pub ed25519_priv: SecretKey,
    pub ed25519_pub: PublicKey,
}

pub fn from_ed_priv_to_dh_priv(private: Sensitive<[u8; 32]>) -> Sensitive<[u8; 32]> {
    let ed25519_priv = SecretKey::from_bytes(&private.as_slice()).unwrap();
    let exp: ExpandedSecretKey = (&ed25519_priv).into();
    let exp_bytes = exp.to_bytes();
    let mut bits = Sensitive::<[u8; 32]>::from_slice(&exp_bytes[0..32]);
    bits[0] &= 248;
    bits[31] &= 127;
    bits[31] |= 64;
    bits
}

impl Dual25519Keys {
    pub fn generate() -> Self {
        let mut x25519_priv = Sensitive::<[u8; 32]>::new();
        getrandom::getrandom(&mut *x25519_priv).expect("getrandom failed");

        let ed25519_priv = SecretKey::from_bytes(&x25519_priv.as_slice()).unwrap();
        let exp: ExpandedSecretKey = (&ed25519_priv).into();
        let exp_bytes = exp.to_bytes();
        let ed25519_pub: PublicKey = (&ed25519_priv).into();

        let mut bits = Sensitive::<[u8; 32]>::from_slice(&exp_bytes[0..32]);
        bits[0] &= 248;
        bits[31] &= 127;
        bits[31] |= 64;

        let x25519_public = noise_rust_crypto::X25519::pubkey(&bits);

        Self {
            x25519_priv: bits,
            x25519_public,
            ed25519_priv,
            ed25519_pub,
        }
    }
    pub fn from_sensitive(sensitive: Sensitive<[u8; 32]>) -> Self {
        let ed25519_priv = SecretKey::from_bytes(&sensitive.as_slice()).unwrap();
        let exp: ExpandedSecretKey = (&ed25519_priv).into();
        let exp_bytes = exp.to_bytes();
        let ed25519_pub: PublicKey = (&ed25519_priv).into();

        let mut bits = Sensitive::<[u8; 32]>::from_slice(&exp_bytes[0..32]);
        bits[0] &= 248;
        bits[31] &= 127;
        bits[31] |= 64;

        let x25519_public = noise_rust_crypto::X25519::pubkey(&bits);

        Self {
            x25519_priv: bits,
            x25519_public,
            ed25519_priv,
            ed25519_pub,
        }
    }
}

pub fn get_domain_without_port(domain: &String) -> String {
    let parts: Vec<&str> = domain.split(':').collect();
    parts[0].to_string()
}

pub fn get_domain_without_port_443(domain: &str) -> &str {
    let parts: Vec<&str> = domain.split(':').collect();
    if parts.len() > 1 && parts[1] == "443" {
        return parts[0];
    }
    domain
}

pub fn is_public_ipv4(ip: &Ipv4Addr) -> bool {
    // TODO, use core::net::Ipv6Addr.is_global when it will be stable
    return is_ipv4_global(ip);
}

pub fn is_public_ipv6(ip: &Ipv6Addr) -> bool {
    // TODO, use core::net::Ipv6Addr.is_global when it will be stable
    return is_ipv6_global(ip);
}

pub fn is_public_ip(ip: &IpAddr) -> bool {
    match ip {
        IpAddr::V4(v4) => is_public_ipv4(v4),
        IpAddr::V6(v6) => is_public_ipv6(v6),
    }
}

pub fn is_private_ip(ip: &IpAddr) -> bool {
    match ip {
        IpAddr::V4(v4) => is_ipv4_private(v4),
        IpAddr::V6(v6) => is_ipv6_private(v6),
    }
}

#[must_use]
#[inline]
pub const fn is_ipv4_shared(addr: &Ipv4Addr) -> bool {
    addr.octets()[0] == 100 && (addr.octets()[1] & 0b1100_0000 == 0b0100_0000)
}

#[must_use]
#[inline]
pub const fn is_ipv4_benchmarking(addr: &Ipv4Addr) -> bool {
    addr.octets()[0] == 198 && (addr.octets()[1] & 0xfe) == 18
}

#[must_use]
#[inline]
pub const fn is_ipv4_reserved(addr: &Ipv4Addr) -> bool {
    addr.octets()[0] & 240 == 240 && !addr.is_broadcast()
}

#[must_use]
#[inline]
pub const fn is_ipv4_private(addr: &Ipv4Addr) -> bool {
    addr.is_private() || addr.is_link_local()
}

#[must_use]
#[inline]
pub const fn is_ipv4_global(addr: &Ipv4Addr) -> bool {
    !(addr.octets()[0] == 0 // "This network"
            || addr.is_private()
            || is_ipv4_shared(addr)
            || addr.is_loopback()
            || addr.is_link_local()
            // addresses reserved for future protocols (`192.0.0.0/24`)
            ||(addr.octets()[0] == 192 && addr.octets()[1] == 0 && addr.octets()[2] == 0)
            || addr.is_documentation()
            || is_ipv4_benchmarking(addr)
            || is_ipv4_reserved(addr)
            || addr.is_broadcast())
}

#[must_use]
#[inline]
pub const fn is_ipv6_unique_local(addr: &Ipv6Addr) -> bool {
    (addr.segments()[0] & 0xfe00) == 0xfc00
}

#[must_use]
#[inline]
pub const fn is_ipv6_unicast_link_local(addr: &Ipv6Addr) -> bool {
    (addr.segments()[0] & 0xffc0) == 0xfe80
}

#[must_use]
#[inline]
pub const fn is_ipv6_documentation(addr: &Ipv6Addr) -> bool {
    (addr.segments()[0] == 0x2001) && (addr.segments()[1] == 0xdb8)
}

#[must_use]
#[inline]
pub const fn is_ipv6_private(addr: &Ipv6Addr) -> bool {
    is_ipv6_unique_local(addr)
}

#[must_use]
#[inline]
pub const fn is_ipv6_global(addr: &Ipv6Addr) -> bool {
    !(addr.is_unspecified()
        || addr.is_loopback()
        // IPv4-mapped Address (`::ffff:0:0/96`)
        || matches!(addr.segments(), [0, 0, 0, 0, 0, 0xffff, _, _])
        // IPv4-IPv6 Translat. (`64:ff9b:1::/48`)
        || matches!(addr.segments(), [0x64, 0xff9b, 1, _, _, _, _, _])
        // Discard-Only Address Block (`100::/64`)
        || matches!(addr.segments(), [0x100, 0, 0, 0, _, _, _, _])
        // IETF Protocol Assignments (`2001::/23`)
        || (matches!(addr.segments(), [0x2001, b, _, _, _, _, _, _] if b < 0x200)
            && !(
                // Port Control Protocol Anycast (`2001:1::1`)
                u128::from_be_bytes(addr.octets()) == 0x2001_0001_0000_0000_0000_0000_0000_0001
                // Traversal Using Relays around NAT Anycast (`2001:1::2`)
                || u128::from_be_bytes(addr.octets()) == 0x2001_0001_0000_0000_0000_0000_0000_0002
                // AMT (`2001:3::/32`)
                || matches!(addr.segments(), [0x2001, 3, _, _, _, _, _, _])
                // AS112-v6 (`2001:4:112::/48`)
                || matches!(addr.segments(), [0x2001, 4, 0x112, _, _, _, _, _])
                // ORCHIDv2 (`2001:20::/28`)
                || matches!(addr.segments(), [0x2001, b, _, _, _, _, _, _] if b >= 0x20 && b <= 0x2F)
            ))
        || is_ipv6_documentation(addr)
        || is_ipv6_unique_local(addr)
        || is_ipv6_unicast_link_local(addr))
}