use etherparse::ether_type::ARP;
use etherparse::{Ethernet2Header, IpHeaders};
use sdlan_sn_rs::config::SDLAN_DEFAULT_TTL;
use sdlan_sn_rs::utils::{
    aes_encrypt, ip_to_string, is_multi_broadcast, net_bit_len_to_mask, BROADCAST_MAC,
};
use std::io::{Error, ErrorKind};
use std::os::windows::process::CommandExt;
use std::process::Command;
use std::sync::atomic::Ordering;
use std::sync::Arc;
use tracing::{debug, error, info};
use wintun;

use crate::get_edge;
use crate::network::{
    ARP_REPLY, ARP_REQUEST, ArpHdr, ArpRequestInfo, ArpResponse, DNS_IP, add_to_arp_wait_list, arp_arrived, form_ethernet_packet, generate_arp_request, send_arp_request, send_packet_to_net
};
use crate::pb::{encode_to_udp_message, SdlData};
use crate::tcp::PacketType;
use crate::utils::mac_to_string;

use super::device::{DeviceConfig, Mode};
use super::TunTapPacketHandler;

pub struct Iface {
    if_idx: u32,
    name: String,
    _adapter: Arc<wintun::Adapter>,
    session: Arc<wintun::Session>,
}

impl Iface {
    pub fn recv(&self, buf: &mut [u8]) -> std::io::Result<usize> {
        let Ok(pkt) = self.session.receive_blocking() else {
            return Err(Error::new(ErrorKind::Other, "failed to receive"));
        };
        let content = pkt.bytes();
        let length = content.len();
        if content.len() > buf.len() {
            return Err(Error::new(ErrorKind::Other, "length not enough"));
        }
        for i in 0..content.len() {
            buf[i] = content[i];
        }
        Ok(length)
    }

    pub fn send(&self, content: &[u8]) -> std::io::Result<usize> {
        let mut pkt = self
            .session
            .allocate_send_packet(content.len() as u16)
            .unwrap();
        let buf: &mut [u8] = pkt.bytes_mut();
        buf.copy_from_slice(content);
        self.session.send_packet(pkt);
        Ok(content.len())
    }

    pub fn reload_config(&self, device_config: &DeviceConfig, network_domain: &str) {
        let netbit = device_config.get_net_bit();
        let ip = device_config.get_ip();
        if netbit == 0 || ip == 0 {
            error!("reload config's ip is 0");
            return;
        }

        let mask = net_bit_len_to_mask(netbit);
        let mut default_gw = (ip & mask) + 1;
        if default_gw == ip {
            default_gw += 1;
        }
        let ip = ip_to_string(&ip);

        let netbit = ip_to_string(&net_bit_len_to_mask(netbit));

        let mut cmd = Command::new("netsh");
        debug!("name={}, addr={}, mask={}", self.name, ip, netbit);
        let command = cmd
            .creation_flags(0x08000000)
            .arg("interface")
            .arg("ip")
            .arg("set")
            .arg("address")
            .arg(&format!("name=\"{}\"", self.name))
            .arg("source=static")
            .arg(&format!("addr={}", ip))
            .arg(&format!("mask={}", netbit));

        let res = command.output();

        match res {
            Ok(r) => {
                debug!("netsh ok: [{:?}]", String::from_utf8_lossy(&r.stdout));
            }
            Err(e) => {
                error!("failed to run netsh: {}", e.to_string());
            }
        }

        let mut cmd = Command::new("netsh");
        let command = cmd
            .creation_flags(0x08000000)
            .arg("interface")
            .arg("ipv4")
            .arg("set")
            .arg("subinterface")
            .arg(&format!("\"{}\"", self.name))
            .arg(format!("mtu={}", device_config.mtu))
            .arg("store=persistent");

        let res = command.output();

        match res {
            Ok(r) => {
                debug!("netsh2 ok: [{:?}]", String::from_utf8_lossy(&r.stdout));
            }
            Err(e) => {
                error!("failed to run netsh2: {}", e.to_string());
            }
        }

        let gw = ip_to_string(&default_gw);
        println!("gw = {}", gw);
        if let Err(e) = set_dns(&self.name, network_domain, &gw, self.if_idx) {
            println!("failed to set dns: {:?}", e);
        } else {
            println!("set dns ok");
        }

    }
}

impl TunTapPacketHandler for Iface {
    async fn handle_packet_from_net(&self, data: &[u8], key: &[u8]) -> std::io::Result<()> {
        // got layer 2 frame
        match Ethernet2Header::from_slice(&data) {
            Ok((hdr, rest)) => {
                if rest.len() < 4 {
                    error!("payload length error");
                    return Ok(());
                }
                // let crc_code = &rest[(rest.len() - 4)..rest.len()];

                // let rest = &rest[..(rest.len() - 4)];

                // let crc_hash: crc::Crc<u32> = crc::Crc::<u32>::new(&crc::CRC_32_CKSUM);
                // let ck = CRC_HASH.checksum(&data[..(data.len()) - 4]);
                // let sent_ck = u32::from_be_bytes(crc_code.try_into().unwrap());
                // debug!("ck = {}, sent_ck = {}", ck, sent_ck);

                debug!("ip size is {}", rest.len());
                let edge = get_edge();
                let self_mac = edge.device_config.get_mac();

                if hdr.destination != self_mac && hdr.destination != BROADCAST_MAC {
                    error!(
                        "packet to [{:?}] not direct to us",
                        mac_to_string(&hdr.destination)
                    );
                    return Ok(());
                }

                if hdr.ether_type == ARP {
                    let mut arp = ArpHdr::from_slice(&data);
                    let self_ip = edge.device_config.get_ip();

                    debug!("self_ip: {:?}", self_ip.to_be_bytes());
                    let from_ip = ((arp.sipaddr[0] as u32) << 16) + arp.sipaddr[1] as u32;
                    debug!("from_ip: {:?}", from_ip.to_be_bytes());
                    let dest_ip = ((arp.dipaddr[0] as u32) << 16) + arp.dipaddr[1] as u32;
                    debug!("dest_ip: {:?}", dest_ip.to_be_bytes());

                    match arp.opcode {
                        ARP_REQUEST => {
                            // handle ARP REQUEST
                            debug!("got ARP REQUEST");
                            if arp.ethhdr.dest != [0xff; 6] {
                                debug!("ARP REQUEST not broadcast");
                                return Ok(());
                            }
                            if dest_ip == self_ip {
                                send_arp_request(ArpRequestInfo::Set {
                                    ip: from_ip,
                                    mac: arp.shwaddr,
                                })
                                .await;
                                // target to us
                                arp.opcode = ARP_REPLY;
                                arp.dhwaddr = arp.shwaddr;
                                arp.shwaddr = self_mac;
                                arp.ethhdr.src = self_mac;
                                arp.ethhdr.dest = arp.dhwaddr;

                                arp.dipaddr = arp.sipaddr;

                                arp.sipaddr =
                                    [((self_ip >> 16) & 0xffff) as u16, (self_ip & 0xffff) as u16];

                                let data = arp.marshal_to_bytes();
                                let Ok(encrypted) = aes_encrypt(key, &data) else {
                                    error!("failed to encrypt arp reply");
                                    return Ok(());
                                };

                                let data = SdlData {
                                    is_p2p: true,
                                    ttl: 2,
                                    network_id: edge.network_id.load(Ordering::Relaxed),
                                    src_mac: Vec::from(self_mac),
                                    dst_mac: Vec::from(arp.dhwaddr),
                                    data: encrypted,
                                };

                                let v = encode_to_udp_message(Some(data), PacketType::Data as u8)
                                    .unwrap();
                                debug!(
                                    "xxxx send arp reply to [{}], selfmac=[{}]",
                                    mac_to_string(&arp.dhwaddr),
                                    mac_to_string(&self_mac)
                                );
                                send_packet_to_net(edge, arp.dhwaddr, &v, 0).await;
                                // send_to_sock(edge, &v, from_sock);
                                // edge.sock.send(v).await;
                            }
                        }
                        ARP_REPLY => {

                            debug!("mac {:?} is at {:?}", arp.shwaddr, from_ip.to_be_bytes());
                            if dest_ip == self_ip {
                                send_arp_request(ArpRequestInfo::Set {
                                    ip: from_ip,
                                    mac: arp.shwaddr,
                                })
                                .await;
                                arp_arrived(from_ip, arp.shwaddr).await;
                            }
                        }
                        _other => {
                            error!("unknown arp type info");
                        }
                    }
                } else {
                    match IpHeaders::from_slice(rest) {
                        Ok((iphdr, _)) => {
                            let Some(ipv4) = iphdr.ipv4() else {
                                error!("not ipv4, dropping");
                                return Ok(());
                            };
                            let ip = u32::from_be_bytes(ipv4.0.source);
                            let mac = hdr.source;
                            if !is_multi_broadcast(&mac) {
                                send_arp_request(ArpRequestInfo::Set { ip, mac }).await;
                            }
                        }
                        Err(_) => {
                            error!("failed to parse ip header, dropping");
                            return Ok(());
                        }
                    }

                    match edge.device.send(rest) {
                        Ok(size) => {
                            debug!("send to tun {} bytes", size);
                        }
                        Err(e) => {
                            error!("failed to send to device: {}", e.to_string());
                        }
                    }
                    // edge.tun.send_data_to_tun(Vec::from(hdr.1)).await;
                }
            }
            Err(e) => {
                error!("failed to parse tap packet: {}", e);
                return Ok(());
            }
        }

        Ok(())
    }

    async fn handle_packet_from_device(
        &self,
        data: Vec<u8>,
        encrypt_key: &[u8],
    ) -> std::io::Result<()> {
        let eee = get_edge();

        let src_mac = eee.device_config.get_mac();

        match IpHeaders::from_slice(&data) {
            Ok((iphdr, _payload)) => {
                let Some(ipv4hdr) = iphdr.ipv4() else {
                    debug!("ipv6 packet ignored");
                    return Ok(());
                };
                let dstip = u32::from_be_bytes(ipv4hdr.0.destination);
                debug!("packet dst ip: {:?}", ipv4hdr.0.destination);
                let src = u32::from_be_bytes(ipv4hdr.0.source);
                debug!("packet src ip: {:?}", ipv4hdr.0.source);
                // packet should be sent to dev
                debug!("got {} bytes from tun", data.len());
                if (!eee.config.allow_routing) && (src != eee.device_config.get_ip()) {
                    info!("dropping routed packet");
                    return Ok(());
                }
                if !eee.is_authorized() {
                    debug!("drop tun packet due to not authed");
                    return Ok(());
                }
                if dstip == DNS_IP {
                    // println!("request for dns");
                    let addr = format!("{}:15353", eee.server_ip);
                    // println!("send dns to {}", addr);
                    if let Err(e) = eee.udp_sock_for_dns.send_to(&data, &addr).await {
                        error!("failed to send request to 15353: {}", e);
                    }
                    return Ok(());
                }
                match send_arp_request(ArpRequestInfo::Lookup { ip: dstip }).await {
                    ArpResponse::LookupResp {
                        mac,
                        ip,
                        do_arp_request,
                    } => {
                        if do_arp_request {
                            add_to_arp_wait_list(dstip, data);

                            info!(
                                "find ip: {:?} => {:?}",
                                src.to_be_bytes(),
                                dstip.to_be_bytes()
                            );
                            let arp_msg =
                                generate_arp_request(src_mac, ip, eee.device_config.get_ip());
                            let Ok(encrypted) = aes_encrypt(&encrypt_key, &arp_msg) else {
                                error!("failed to encrypt arp request");
                                return Ok(());
                            };
                            // println!("arp_msg: {:?}", arp_msg);
                            let data = SdlData {
                                network_id: eee.network_id.load(Ordering::Relaxed),
                                src_mac: Vec::from(src_mac),
                                dst_mac: Vec::from([0xff; 6]),
                                is_p2p: true,
                                ttl: SDLAN_DEFAULT_TTL as u32,
                                data: encrypted,
                            };
                            let data =
                                encode_to_udp_message(Some(data), PacketType::Data as u8).unwrap();
                            debug!("sending arp");
                            // let data = marshal_message(&data);
                            send_packet_to_net(eee, BROADCAST_MAC, &data, arp_msg.len() as u64)
                                .await;
                            // edge.sock.send(data).await;
                            // println!("should send arp");
                            return Ok(());
                        }

                        let packet = form_ethernet_packet(src_mac, mac, &data);
                        // prepend the ether header
                        /*
                        let mut etherheader = Ethernet2Header::default();
                        etherheader.destination = mac;
                        etherheader.ether_type = etherparse::EtherType::IPV4;
                        etherheader.source = src_mac;
                        let mut packet = Vec::with_capacity(14 + data.len() + 4);
                        packet.extend_from_slice(&etherheader.to_bytes()[..]);
                        packet.extend_from_slice(&data);
                        */
                        // let crc = CRC_HASH.checksum(&packet);
                        // packet.extend_from_slice(&crc.to_be_bytes());

                        let pkt_size = packet.len();
                        // println!("sending data with mac");

                        let Ok(encrypted) = aes_encrypt(&encrypt_key, &packet) else {
                            error!("failed to encrypt packet request");
                            return Ok(());
                        };
                        let data = SdlData {
                            is_p2p: true,
                            network_id: eee.network_id.load(Ordering::Relaxed),
                            ttl: SDLAN_DEFAULT_TTL as u32,
                            src_mac: Vec::from(src_mac),
                            dst_mac: Vec::from(mac),
                            data: Vec::from(encrypted),
                        };
                        let msg =
                            encode_to_udp_message(Some(data), PacketType::Data as u8).unwrap();
                        let size = msg.len();
                        send_packet_to_net(eee, mac, &msg, pkt_size as u64).await;
                        // let dstip = u32::from_be_bytes(ipv4hdr.0.destination);
                    }
                    _ => {}
                }
            }
            Err(e) => {
                error!("failed to parse ip packet: {}", e.to_string());
            }
        }
        Ok(())
    }
}

fn create_wintun(path: &str, name: &str) -> Iface {
    let wt = unsafe { wintun::load_from_path(path) }.expect("failed to load wintun");

    let adapter = match wintun::Adapter::open(&wt, name) {
        Ok(a) => a,
        Err(_e) => wintun::Adapter::create(&wt, name, "Example", None)
            .expect("failed to create tun adapter"),
    };
    let idx = adapter.get_adapter_index().expect("failed to get adapter index");
    println!("idx = {}", idx);
    let session = Arc::new(adapter.start_session(wintun::MAX_RING_CAPACITY).unwrap());
    Iface {
        if_idx: idx,
        _adapter: adapter,
        session,
        name: name.to_owned(),
    }
}

pub fn new_iface(name: &str, _mode: Mode) -> Iface {
    create_wintun("./wintun.dll", name)
    // Ok(Box::new(create_wintun("/path/to/file")))
}

pub fn get_install_channel() -> String {
    "windows".to_owned()
}

pub fn set_dns(name: &str, _network_domain: &str, gw: &str, ifidx: u32) -> std::io::Result<()>{
    let res = Command::new("ROUTE")
        .arg("ADD")
        .arg("100.100.100.100")
        .arg("MASK")
        .arg("255.255.255.255")
        .arg(gw)
        .arg("IF")
        .arg(ifidx.to_string())
        .creation_flags(0x08000000)
        .output()?;

    println!("res1: {}", res.status.success());

    println!("route set ok");
    let res = Command::new("netsh")
        .arg("dnsclient")
        .arg("set")
        .arg("dnsserver")
        .arg(&format!("name={}", name))
        .arg("source=static")
        .arg("address=100.100.100.100")
        .arg("validate=no")
        .creation_flags(0x08000000)
        .output()?;
    println!("res2: {}", res.status.success());

    println!("netsh set ok");

    Ok(())
}

pub fn restore_dns() {

}