import Foundation
import Libclash
import NetworkExtension
import UserNotifications
#if canImport(CoreWLAN)
    import CoreWLAN
#endif

public class ExtensionPlatformInterface: NSObject, LibclashPlatformInterfaceProtocol{
    private let tunnel: ExtensionProvider
    private var networkSettings: NEPacketTunnelNetworkSettings?

    init(_ tunnel: ExtensionProvider) {
        self.tunnel = tunnel
    }

    public func openTun(_ options: LibclashTunOptionsProtocol?, ret0_: UnsafeMutablePointer<Int32>?) throws {
        try runBlocking { [self] in
            try await openTun0(options, ret0_)
        }
    }

    public func findConnectionOwner(_: Int32, sourceAddress _: String?, sourcePort _: Int32, destinationAddress _: String?, destinationPort _: Int32, ret0_ _: UnsafeMutablePointer<Int32>?) throws {
        throw NSError(domain: "not implemented", code: 0)
    }

    public func packageName(byUid _: Int32, error _: NSErrorPointer) -> String {
        ""
    }
    
    private func openTun0(_ options: LibclashTunOptionsProtocol?, _ ret0_: UnsafeMutablePointer<Int32>?) async throws {
        guard let options else {
            throw NSError(domain: "nil options", code: 0)
        }
        guard let ret0_ else {
            throw NSError(domain: "nil return pointer", code: 0)
        }

        // let autoRouteUseSubRangesByDefault = autoRouteUseSubRangesByDefault
        // let excludeAPNs = excludeAPNsRoute

        let settings = NEPacketTunnelNetworkSettings(tunnelRemoteAddress: "127.0.0.1")
        if options.getAutoRoute() {
            settings.mtu = NSNumber(value: options.getMTU())

            let dnsServer = try options.getDNSServerAddress()
            let dnsSettings = NEDNSSettings(servers: [dnsServer.value])
            dnsSettings.matchDomains = [""]
            dnsSettings.matchDomainsNoSearch = true
            settings.dnsSettings = dnsSettings

            var ipv4Address: [String] = []
            var ipv4Mask: [String] = []
            let ipv4AddressIterator = options.getInet4Address()!
            while ipv4AddressIterator.hasNext() {
                let ipv4Prefix = ipv4AddressIterator.next()!
                ipv4Address.append(ipv4Prefix.address())
                ipv4Mask.append(ipv4Prefix.mask())
            }

            let ipv4Settings = NEIPv4Settings(addresses: ipv4Address, subnetMasks: ipv4Mask)
            var ipv4Routes: [NEIPv4Route] = []
            var ipv4ExcludeRoutes: [NEIPv4Route] = []

            let inet4RouteAddressIterator = options.getInet4RouteAddress()!
            if inet4RouteAddressIterator.hasNext() {
                while inet4RouteAddressIterator.hasNext() {
                    let ipv4RoutePrefix = inet4RouteAddressIterator.next()!
                    ipv4Routes.append(NEIPv4Route(destinationAddress: ipv4RoutePrefix.address(), subnetMask: ipv4RoutePrefix.mask()))
                }
            } /* else if autoRouteUseSubRangesByDefault {
                 ipv4Routes.append(NEIPv4Route(destinationAddress: "1.0.0.0", subnetMask: "255.0.0.0"))
                 ipv4Routes.append(NEIPv4Route(destinationAddress: "2.0.0.0", subnetMask: "254.0.0.0"))
                 ipv4Routes.append(NEIPv4Route(destinationAddress: "4.0.0.0", subnetMask: "252.0.0.0"))
                 ipv4Routes.append(NEIPv4Route(destinationAddress: "8.0.0.0", subnetMask: "248.0.0.0"))
                 ipv4Routes.append(NEIPv4Route(destinationAddress: "16.0.0.0", subnetMask: "240.0.0.0"))
                 ipv4Routes.append(NEIPv4Route(destinationAddress: "32.0.0.0", subnetMask: "224.0.0.0"))
                 ipv4Routes.append(NEIPv4Route(destinationAddress: "64.0.0.0", subnetMask: "192.0.0.0"))
                 ipv4Routes.append(NEIPv4Route(destinationAddress: "128.0.0.0", subnetMask: "128.0.0.0"))
             } */ else
            {
                ipv4Routes.append(NEIPv4Route.default())
            }

            let inet4RouteExcludeAddressIterator = options.getInet4RouteExcludeAddress()!
            while inet4RouteExcludeAddressIterator.hasNext() {
                let ipv4RoutePrefix = inet4RouteExcludeAddressIterator.next()!
                ipv4ExcludeRoutes.append(NEIPv4Route(destinationAddress: ipv4RoutePrefix.address(), subnetMask: ipv4RoutePrefix.mask()))
            }
            /* if await excludeDefaultRoute.get(), !ipv4Routes.isEmpty {
                 if !ipv4ExcludeRoutes.contains(where: { it in
                     it.destinationAddress == "0.0.0.0" && it.destinationSubnetMask == "255.255.255.254"
                 }) {
                     ipv4ExcludeRoutes.append(NEIPv4Route(destinationAddress: "0.0.0.0", subnetMask: "255.255.255.254"))
                 }
             }
             if excludeAPNs, !ipv4Routes.isEmpty {
                 if !ipv4ExcludeRoutes.contains(where: { it in
                     it.destinationAddress == "17.0.0.0" && it.destinationSubnetMask == "255.0.0.0"
                 }) {
                     ipv4ExcludeRoutes.append(NEIPv4Route(destinationAddress: "17.0.0.0", subnetMask: "255.0.0.0"))
                 }
             } */

            ipv4Settings.includedRoutes = ipv4Routes
            ipv4Settings.excludedRoutes = ipv4ExcludeRoutes
            settings.ipv4Settings = ipv4Settings

            var ipv6Address: [String] = []
            var ipv6Prefixes: [NSNumber] = []
            let ipv6AddressIterator = options.getInet6Address()!
            while ipv6AddressIterator.hasNext() {
                let ipv6Prefix = ipv6AddressIterator.next()!
                ipv6Address.append(ipv6Prefix.address())
                ipv6Prefixes.append(NSNumber(value: ipv6Prefix.prefix()))
            }
            let ipv6Settings = NEIPv6Settings(addresses: ipv6Address, networkPrefixLengths: ipv6Prefixes)
            var ipv6Routes: [NEIPv6Route] = []
            var ipv6ExcludeRoutes: [NEIPv6Route] = []

            let inet6RouteAddressIterator = options.getInet6RouteAddress()!
            if inet6RouteAddressIterator.hasNext() {
                while inet6RouteAddressIterator.hasNext() {
                    let ipv6RoutePrefix = inet6RouteAddressIterator.next()!
                    ipv6Routes.append(NEIPv6Route(destinationAddress: ipv6RoutePrefix.address(), networkPrefixLength: NSNumber(value: ipv6RoutePrefix.prefix())))
                }
            } /* else if autoRouteUseSubRangesByDefault {
                 ipv6Routes.append(NEIPv6Route(destinationAddress: "100::", networkPrefixLength: 8))
                 ipv6Routes.append(NEIPv6Route(destinationAddress: "200::", networkPrefixLength: 7))
                 ipv6Routes.append(NEIPv6Route(destinationAddress: "400::", networkPrefixLength: 6))
                 ipv6Routes.append(NEIPv6Route(destinationAddress: "800::", networkPrefixLength: 5))
                 ipv6Routes.append(NEIPv6Route(destinationAddress: "1000::", networkPrefixLength: 4))
                 ipv6Routes.append(NEIPv6Route(destinationAddress: "2000::", networkPrefixLength: 3))
                 ipv6Routes.append(NEIPv6Route(destinationAddress: "4000::", networkPrefixLength: 2))
                 ipv6Routes.append(NEIPv6Route(destinationAddress: "8000::", networkPrefixLength: 1))
             } */ else
            {
                ipv6Routes.append(NEIPv6Route.default())
            }

            let inet6RouteExcludeAddressIterator = options.getInet6RouteExcludeAddress()!
            while inet6RouteExcludeAddressIterator.hasNext() {
                let ipv6RoutePrefix = inet6RouteExcludeAddressIterator.next()!
                ipv6ExcludeRoutes.append(NEIPv6Route(destinationAddress: ipv6RoutePrefix.address(), networkPrefixLength: NSNumber(value: ipv6RoutePrefix.prefix())))
            }

            ipv6Settings.includedRoutes = ipv6Routes
            ipv6Settings.excludedRoutes = ipv6ExcludeRoutes
            settings.ipv6Settings = ipv6Settings
        }

        if options.isHTTPProxyEnabled() {
            let proxySettings = NEProxySettings()
            let proxyServer = NEProxyServer(address: options.getHTTPProxyServer(), port: Int(options.getHTTPProxyServerPort()))
            proxySettings.httpServer = proxyServer
            proxySettings.httpsServer = proxyServer
            proxySettings.httpEnabled = true
            proxySettings.httpsEnabled = true

            var bypassDomains: [String] = []
            let bypassDomainIterator = options.getHTTPProxyBypassDomain()!
            while bypassDomainIterator.hasNext() {
                bypassDomains.append(bypassDomainIterator.next())
            }
            /* if excludeAPNs {
                 if !bypassDomains.contains(where: { it in
                     it == "push.apple.com"
                 }) {
                     bypassDomains.append("push.apple.com")
                 }
             } */
            if !bypassDomains.isEmpty {
                proxySettings.exceptionList = bypassDomains
            }
            var matchDomains: [String] = []
            let matchDomainIterator = options.getHTTPProxyMatchDomain()!
            while matchDomainIterator.hasNext() {
                matchDomains.append(matchDomainIterator.next())
            }
            if !matchDomains.isEmpty {
                proxySettings.matchDomains = matchDomains
            }
            settings.proxySettings = proxySettings
        }

        networkSettings = settings
        try await tunnel.setTunnelNetworkSettings(settings)
        if let tunFd = tunnel.packetFlow.value(forKeyPath: "socket.fileDescriptor") as? Int32 {
            ret0_.pointee = tunFd
            return
        }
        guard let tun_fd = getTunnelFd() else {
            throw NSError(domain: "missing file descriptor", code: 0)
        }
        ret0_.pointee = tun_fd
    }
    
    public func protectFd(_ fd: Int32) {
        
    }
    
    func getTunnelFd() -> Int32? {
        var buf = [CChar](repeating: 0, count: Int(IFNAMSIZ))
        for fd: Int32 in 0 ... 1024 {
            var len = socklen_t(buf.count)
            if getsockopt(fd, 2 /* IGMP */, 2, &buf, &len) == 0 && String(cString: buf).hasPrefix("utun") {
                return fd
            }
        }
        return tunnel.packetFlow.value(forKeyPath: "socket.fileDescriptor") as? Int32
    }
}
