use std::{net::IpAddr, ptr};

use bitflags::bitflags;

#[cfg(target_os = "windows")]

use windows_sys::Win32::Networking::WinSock;

use crate::{

    Error,

    capture::{Active, Capture},

    cstr_to_string, cstr_to_string_lossy, raw,

};

bitflags! {

    /// Network device flags.

    #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]

    pub struct IfFlags: u32 {

        /// Set if the device is a loopback interface

        const LOOPBACK = raw::PCAP_IF_LOOPBACK;

        /// Set if the device is up

        const UP = raw::PCAP_IF_UP;

        /// Set if the device is running

        const RUNNING = raw::PCAP_IF_RUNNING;

        /// Set if the device is a wireless interface; this includes IrDA as well as radio-based

        /// networks such as IEEE 802.15.4 and IEEE 802.11, so it doesn't just mean Wi-Fi

        const WIRELESS = raw::PCAP_IF_WIRELESS;

    }

}

impl From<u32> for IfFlags {

}

#[derive(Debug, Clone, PartialEq, Eq)]

/// Indication of whether the adapter is connected or not; for wireless interfaces, "connected"

/// means "associated with a network".

pub enum ConnectionStatus {

    /// It's unknown whether the adapter is connected or not

    Unknown,

    /// The adapter is connected

    Connected,

    /// The adapter is disconnected

    Disconnected,

    /// The notion of "connected" and "disconnected" don't apply to this interface; for example, it

    /// doesn't apply to a loopback device

    NotApplicable,

}

impl From<u32> for ConnectionStatus {

            // DeviceFlags::CONNECTION_STATUS should be a 2-bit mask which means that the four

            // values should cover all the possibilities.

            // GRCOV_EXCL_START

            _ => unreachable!(),

            // GRCOV_EXCL_STOP

        }

}

#[derive(Debug, Clone)]

pub struct DeviceFlags {

    pub if_flags: IfFlags,

    pub connection_status: ConnectionStatus,

}

impl From<u32> for DeviceFlags {

}

impl DeviceFlags {

}

#[derive(Debug, Clone)]

/// A network device name and pcap's description of it.

pub struct Device {

    /// The name of the interface

    pub name: String,

    /// A textual description of the interface, if available

    pub desc: Option<String>,

    /// Addresses associated with this interface

    pub addresses: Vec<Address>,

    /// Interface flags

    pub flags: DeviceFlags,

}

impl Device {

    /// Opens a `Capture<Active>` on this device.

    /// Returns the default Device suitable for captures according to pcap_findalldevs,

    /// or an error from pcap. Note that there may be no suitable devices.

    ///

    /// A device whose name is not valid UTF-8 is passed over, as in `Device::list`.

        unsafe {

                }

        }

    /// Returns a vector of `Device`s known by pcap via pcap_findalldevs.

    ///

    /// A device whose name is not valid UTF-8 is left out, since that name is the only handle

    /// libpcap offers on it and it cannot be opened.

        unsafe {

                }

        }

    // Returns `None` when the name cannot be decoded, since the device cannot be opened without

    // it. The devices on either side of it are unaffected.

        ))

    {

}

impl From<&str> for Device {

}

#[derive(Debug, Clone)]

/// Address information for an interface

pub struct Address {

    /// The address

    pub addr: IpAddr,

    /// Network mask for this address

    pub netmask: Option<IpAddr>,

    /// Broadcast address for this address

    pub broadcast_addr: Option<IpAddr>,

    /// P2P destination address for this address

    pub dst_addr: Option<IpAddr>,

}

impl Address {

        }

        unsafe {

        }

    #[cfg(not(windows))]

        unsafe {

                libc::AF_INET => {

                }

                libc::AF_INET6 => {

                }

            }

        }

    #[cfg(windows)]

    unsafe fn convert_sockaddr(ptr: *const libc::sockaddr) -> Option<IpAddr> {

        if ptr.is_null() {

            return None;

        }

        unsafe {

            match (*ptr).sa_family {

                WinSock::AF_INET => {

                    let ptr: *const WinSock::SOCKADDR_IN = std::mem::transmute(ptr);

                    let addr: [u8; 4] = ((*ptr).sin_addr.S_un.S_addr).to_ne_bytes();

                    Some(IpAddr::from(addr))

                }

                WinSock::AF_INET6 => {

                    let ptr: *const WinSock::SOCKADDR_IN6 = std::mem::transmute(ptr);

                    let addr = (*ptr).sin6_addr.u.Byte;

                    Some(IpAddr::from(addr))

                }

                _ => None,

            }

        }

    }

}

#[cfg(test)]

mod tests {

    use std::ffi::CString;

    use crate::raw::testmod::{RAWMTX, as_pcap_t};

    use super::*;

    #[cfg(not(windows))]

    enum Sockaddr {

        SockaddrIn(libc::sockaddr_in),

        SockaddrIn6(libc::sockaddr_in6),

    }

    #[cfg(windows)]

    enum Sockaddr {

        SockaddrIn(WinSock::SOCKADDR_IN),

        SockaddrIn6(WinSock::SOCKADDR_IN6),

    }

    impl Sockaddr {

        fn as_mut_ptr(&mut self) -> *mut libc::sockaddr {

            match self {

                Sockaddr::SockaddrIn(sin) => sin as *mut _ as _,

                Sockaddr::SockaddrIn6(sin6) => sin6 as *mut _ as _,

            }

        }

        fn set_family(&mut self, family: u16) {

            // Annoyingly this differs between Linux (u16) and Mac (u8).

            #[cfg(not(windows))]

            let family = family as libc::sa_family_t;

            match self {

                Sockaddr::SockaddrIn(sin) => sin.sin_family = family,

                Sockaddr::SockaddrIn6(sin6) => sin6.sin6_family = family,

            }

        }

    }

    static IF1_NAME: &str = "if1";

    static IF2_NAME: &str = "if2";

    static IF1_DESC: &str = "if1 desc";

    static IF2_DESC: &str = "if2 desc";

    fn dev(name: &[u8], description: Option<&[u8]>) -> raw::pcap_if_t {

        raw::pcap_if_t {

            next: std::ptr::null_mut(),

            name: CString::new(name).unwrap().into_raw(),

            description: match description {

                Some(description) => CString::new(description).unwrap().into_raw(),

                None => std::ptr::null_mut(),

            },

            addresses: std::ptr::null_mut(),

            flags: 0,

        }

    }

    fn devs() -> Vec<raw::pcap_if_t> {

        let mut devs = vec![

            raw::pcap_if_t {

                next: std::ptr::null_mut(),

                name: CString::new(IF1_NAME).unwrap().into_raw(),

                description: CString::new(IF1_DESC).unwrap().into_raw(),

                addresses: std::ptr::null_mut(),

                flags: (raw::PCAP_IF_LOOPBACK | raw::PCAP_IF_UP),

            },

            raw::pcap_if_t {

                next: std::ptr::null_mut(),

                name: CString::new(IF2_NAME).unwrap().into_raw(),

                description: CString::new(IF2_DESC).unwrap().into_raw(),

                addresses: std::ptr::null_mut(),

                flags: 0,

            },

        ];

        devs[0].next = &mut devs[1];

        devs

    }

    trait InetAddressV4 {

        fn new() -> Self;

        fn set_addr(&mut self, addr: u32);

    }

    #[cfg(not(windows))]

    impl InetAddressV4 for libc::sockaddr_in {

        fn new() -> Self {

            let mut addr: Self = unsafe { std::mem::zeroed() };

            addr.sin_family = libc::AF_INET as libc::sa_family_t;

            addr

        }

        fn set_addr(&mut self, addr: u32) {

            self.sin_addr.s_addr = addr;

        }

    }

    #[cfg(windows)]

    impl InetAddressV4 for WinSock::SOCKADDR_IN {

        fn new() -> Self {

            let mut addr: Self = unsafe { std::mem::zeroed() };

            addr.sin_family = WinSock::AF_INET;

            addr

        }

        fn set_addr(&mut self, addr: u32) {

            self.sin_addr.S_un.S_addr = addr;

        }

    }

    fn sockaddr_ipv4() -> Sockaddr {

        #[cfg(not(windows))]

        let mut addr: libc::sockaddr_in = InetAddressV4::new();

        #[cfg(windows)]

        let mut addr: WinSock::SOCKADDR_IN = InetAddressV4::new();

        addr.sin_port = 1075;

        addr.set_addr(0x0A000042_u32.to_be());

        Sockaddr::SockaddrIn(addr)

    }

    trait InetAddressV6 {

        fn new() -> Self;

        fn set_octet(&mut self, index: usize, octet: u8);

    }

    #[cfg(not(windows))]

    impl InetAddressV6 for libc::sockaddr_in6 {

        fn new() -> Self {

            let mut addr: Self = unsafe { std::mem::zeroed() };

            addr.sin6_family = libc::AF_INET6 as libc::sa_family_t;

            addr.sin6_addr.s6_addr[0] = 0xFE;

            addr.sin6_addr.s6_addr[1] = 0x80;

            addr

        }

        fn set_octet(&mut self, index: usize, octet: u8) {

            self.sin6_addr.s6_addr[index] = octet;

        }

    }

    #[cfg(windows)]

    impl InetAddressV6 for WinSock::SOCKADDR_IN6 {

        fn new() -> Self {

            let mut addr: Self = unsafe { std::mem::zeroed() };

            addr.sin6_family = WinSock::AF_INET6;

            unsafe {

                addr.sin6_addr.u.Byte[0] = 0xFE;

                addr.sin6_addr.u.Byte[1] = 0x80;

            }

            addr

        }

        fn set_octet(&mut self, index: usize, octet: u8) {

            unsafe { self.sin6_addr.u.Byte[index] = octet };

        }

    }

    fn sockaddr_ipv6() -> Sockaddr {

        #[cfg(not(windows))]

        let mut addr: libc::sockaddr_in6 = InetAddressV6::new();

        #[cfg(windows)]

        let mut addr: WinSock::SOCKADDR_IN6 = InetAddressV6::new();

        addr.sin6_port = 1075;

        addr.set_octet(15, 0x42);

        Sockaddr::SockaddrIn6(addr)

    }

    impl From<&mut Sockaddr> for raw::pcap_addr_t {

        fn from(value: &mut Sockaddr) -> Self {

            raw::pcap_addr_t {

                next: std::ptr::null_mut(),

                addr: value.as_mut_ptr(),

                netmask: std::ptr::null_mut(),

                broadaddr: std::ptr::null_mut(),

                dstaddr: std::ptr::null_mut(),

            }

        }

    }

    #[test]

    fn test_device_flags() {

        let flags = DeviceFlags::from(

            raw::PCAP_IF_LOOPBACK | raw::PCAP_IF_UP | raw::PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,

        );

        assert!(flags.is_loopback());

        assert!(flags.is_up());

        assert!(flags.contains(IfFlags::LOOPBACK | IfFlags::UP));

        assert!(!flags.is_running());

        assert!(!flags.is_wireless());

        assert_ne!(flags.connection_status, ConnectionStatus::Unknown);

        assert_ne!(flags.connection_status, ConnectionStatus::Connected);

        assert_ne!(flags.connection_status, ConnectionStatus::Disconnected);

        assert_eq!(flags.connection_status, ConnectionStatus::NotApplicable);

        assert!(!format!("{flags:?}").is_empty());

    }

    #[test]

    fn test_connection_status() {

        let flags = raw::PCAP_IF_CONNECTION_STATUS_UNKNOWN;

        assert_eq!(ConnectionStatus::from(flags), ConnectionStatus::Unknown);

        let flags = raw::PCAP_IF_CONNECTION_STATUS_CONNECTED;

        assert_eq!(ConnectionStatus::from(flags), ConnectionStatus::Connected);

        let flags = raw::PCAP_IF_CONNECTION_STATUS_DISCONNECTED;

        assert_eq!(

            ConnectionStatus::from(flags),

            ConnectionStatus::Disconnected

        );

        let flags = raw::PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE;

        assert_eq!(

            ConnectionStatus::from(flags),

            ConnectionStatus::NotApplicable

        );

    }

    #[test]

    fn test_into_capture() {

        let _m = RAWMTX.lock();

        let mut dummy: isize = 777;

        let pcap = as_pcap_t(&mut dummy);

        let ctx = raw::pcap_create_context();

        ctx.expect().return_once_st(move |_, _, _| pcap);

        let ctx = raw::pcap_activate_context();

        ctx.expect()

            .withf_st(move |arg1| *arg1 == pcap)

            .return_once(|_| 0);

        let ctx = raw::pcap_close_context();

        ctx.expect()

            .withf_st(move |ptr| *ptr == pcap)

            .return_once(|_| {});

        let device: Device = "device".into();

        let _capture: Capture<Active> = device.clone().open().unwrap();

        assert!(!format!("{device:?}").is_empty());

    }

    #[test]

    fn test_lookup() {

        let _m = RAWMTX.lock();

        let ctx = raw::pcap_findalldevs_context();

        ctx.expect().return_once_st(move |_, arg1, _| {

            unsafe { *arg1 = std::ptr::null_mut() };

            0

        });

        let ctx = raw::pcap_freealldevs_context();

        ctx.expect().return_once(move |_| {});

        let device = Device::lookup().unwrap();

        assert!(device.is_none());

        let mut devs = devs();

        let mut addrs = sockaddr_ipv4();

        let mut pcap_addr = (&mut addrs).into();

        devs[0].addresses = &mut pcap_addr;

        let devs_ptr = devs.as_mut_ptr();

        let ctx = raw::pcap_findalldevs_context();

        ctx.checkpoint();

        ctx.expect().return_once_st(move |_, arg1, _| {

            unsafe { *arg1 = devs_ptr };

            0

        });

        let ctx = raw::pcap_freealldevs_context();

        ctx.checkpoint();

        ctx.expect().return_once(move |_| {});

        let device = Device::lookup().unwrap().unwrap();

        assert_eq!(&device.name, IF1_NAME);

        assert_eq!(&device.desc.unwrap(), IF1_DESC);

        assert_eq!(device.addresses.len(), 1);

        assert!(device.addresses[0].addr.is_ipv4());

        let ctx = raw::pcap_findalldevs_context();

        ctx.checkpoint();

        ctx.expect().return_once_st(move |_, _, _| -1);

        let ctx = raw::pcap_freealldevs_context();

        ctx.checkpoint();

        let result = Device::lookup();

        assert!(result.is_err());

    }

    #[test]

    fn test_list() {

        let _m = RAWMTX.lock();

        let ctx = raw::pcap_findalldevs_context();

        ctx.expect().return_once_st(move |_, arg1, _| {

            unsafe { *arg1 = std::ptr::null_mut() };

            0

        });

        let ctx = raw::pcap_freealldevs_context();

        ctx.expect().return_once(move |_| {});

        let devices = Device::list().unwrap();

        assert!(devices.is_empty());

        let mut devs = devs();

        let mut ipv4s = sockaddr_ipv4();

        let mut ipv6s = sockaddr_ipv6();

        let mut pcap_addr: raw::pcap_addr_t = (&mut ipv4s).into();

        let mut pcap_addr6: raw::pcap_addr_t = (&mut ipv6s).into();

        pcap_addr.next = &mut pcap_addr6;

        devs[1].addresses = &mut pcap_addr;

        let devs_ptr = devs.as_mut_ptr();

        let ctx = raw::pcap_findalldevs_context();

        ctx.checkpoint();

        ctx.expect().return_once_st(move |_, arg1, _| {

            unsafe { *arg1 = devs_ptr };

            0

        });

        let ctx = raw::pcap_freealldevs_context();

        ctx.checkpoint();

        ctx.expect().return_once(move |_| {});

        let devices = Device::list().unwrap();

        assert_eq!(devices.len(), devs.len());

        assert_eq!(&devices[0].name, IF1_NAME);

        assert_eq!(devices[0].desc.as_ref().unwrap(), IF1_DESC);

        assert_eq!(devices[0].addresses.len(), 0);

        assert_eq!(&devices[1].name, IF2_NAME);

        assert_eq!(devices[1].desc.as_ref().unwrap(), IF2_DESC);

        assert_eq!(devices[1].addresses.len(), 2);

        assert!(devices[1].addresses[0].addr.is_ipv4());

        assert!(devices[1].addresses[1].addr.is_ipv6());

        let ctx = raw::pcap_findalldevs_context();

        ctx.checkpoint();

        ctx.expect().return_once_st(move |_, _, _| -1);

        let ctx = raw::pcap_freealldevs_context();

        ctx.checkpoint();

        let result = Device::list();

        assert!(result.is_err());

    }

    #[test]

    fn test_list_bad_name() {

        let _m = RAWMTX.lock();

        let mut devs = vec![

            dev(IF1_NAME.as_bytes(), Some(IF1_DESC.as_bytes())),

            dev(b"d\xff\xfe0", Some(IF2_DESC.as_bytes())),

            dev(IF2_NAME.as_bytes(), Some(IF2_DESC.as_bytes())),

        ];

        devs[0].next = &mut devs[1];

        devs[1].next = &mut devs[2];

        let devs_ptr = devs.as_mut_ptr();

        let ctx = raw::pcap_findalldevs_context();

        ctx.expect().return_once_st(move |_, arg1, _| {

            unsafe { *arg1 = devs_ptr };

            0

        });

        let ctx = raw::pcap_freealldevs_context();

        ctx.expect().return_once(move |_| {});

        // The interface in the middle is gone, the ones either side of it are not.

        let devices = Device::list().unwrap();

        assert_eq!(devices.len(), 2);

        assert_eq!(&devices[0].name, IF1_NAME);

        assert_eq!(&devices[1].name, IF2_NAME);

    }

    #[test]

    fn test_lookup_bad_name() {

        let _m = RAWMTX.lock();

        let mut devs = vec![

            dev(b"d\xff\xfe0", Some(IF1_DESC.as_bytes())),

            dev(IF2_NAME.as_bytes(), Some(IF2_DESC.as_bytes())),

        ];

        devs[0].next = &mut devs[1];

        let devs_ptr = devs.as_mut_ptr();

        let ctx = raw::pcap_findalldevs_context();

        ctx.expect().return_once_st(move |_, arg1, _| {

            unsafe { *arg1 = devs_ptr };

            0

        });

        let ctx = raw::pcap_freealldevs_context();

        ctx.expect().return_once(move |_| {});

        let device = Device::lookup().unwrap().unwrap();

        assert_eq!(&device.name, IF2_NAME);

    }

    #[test]

    fn test_lookup_all_bad() {

        let _m = RAWMTX.lock();

        let mut devs = vec![dev(b"d\xff\xfe0", Some(IF1_DESC.as_bytes()))];

        let devs_ptr = devs.as_mut_ptr();

        let ctx = raw::pcap_findalldevs_context();

        ctx.expect().return_once_st(move |_, arg1, _| {

            unsafe { *arg1 = devs_ptr };

            0

        });

        let ctx = raw::pcap_freealldevs_context();

        ctx.expect().return_once(move |_| {});

        assert!(Device::lookup().unwrap().is_none());

    }

    #[test]

    fn test_list_descriptions() {

        let _m = RAWMTX.lock();

        let mut devs = vec![

            dev(IF1_NAME.as_bytes(), Some(b"caf\xe9")),

            dev(IF2_NAME.as_bytes(), None),

        ];

        devs[0].next = &mut devs[1];

        let devs_ptr = devs.as_mut_ptr();

        let ctx = raw::pcap_findalldevs_context();

        ctx.expect().return_once_st(move |_, arg1, _| {

            unsafe { *arg1 = devs_ptr };

            0

        });

        let ctx = raw::pcap_freealldevs_context();

        ctx.expect().return_once(move |_| {});

        // A description in some other encoding costs the caller a replacement character, no more.

        let devices = Device::list().unwrap();

        assert_eq!(devices.len(), 2);

        assert_eq!(devices[0].desc.as_deref(), Some("caf\u{fffd}"));

        assert_eq!(devices[1].desc, None);

    }

    #[test]

    fn test_address_ipv4() {

        let mut addr = sockaddr_ipv4();

        let pcap_addr: raw::pcap_addr_t = (&mut addr).into();

        let address = unsafe { Address::new(&pcap_addr) }.unwrap();

        assert!(address.addr.is_ipv4());

        assert_eq!(address.addr.to_string(), "10.0.0.66");

        assert!(address.netmask.is_none());

        assert!(address.broadcast_addr.is_none());

        assert!(address.dst_addr.is_none());

        assert!(!format!("{address:?}").is_empty());

    }

    #[test]

    fn test_address_family() {

        let mut addr = sockaddr_ipv4();

        #[cfg(not(windows))]

        addr.set_family(libc::AF_IPX as u16);

        #[cfg(windows)]

        addr.set_family(WinSock::AF_IPX);

        let pcap_addr: raw::pcap_addr_t = (&mut addr).into();

        let address = unsafe { Address::new(&pcap_addr) };

        assert!(address.is_none());

    }

    #[test]

    fn test_address_ipv6() {

        let mut addr = sockaddr_ipv6();

        let pcap_addr: raw::pcap_addr_t = (&mut addr).into();

        let address = unsafe { Address::new(&pcap_addr) }.unwrap();

        assert!(address.addr.is_ipv6());

        assert_eq!(address.addr.to_string(), "fe80::42");

        assert!(address.netmask.is_none());

        assert!(address.broadcast_addr.is_none());

        assert!(address.dst_addr.is_none());

        assert!(!format!("{address:?}").is_empty());

    }

}