import * as os from "node:os";
import * as net from "node:net";

export class IpUtil {

    // 常见虚拟机网络地址范围
    private static readonly VM_NETWORKS = [
        '192.168.56.0/24',  // VirtualBox Host-Only
        '192.168.122.0/24', // KVM
        '172.16.0.0/12',    // VMware NAT
        '192.168.99.0/24',  // Docker Machine
        '192.168.65.0/24',  // Docker Desktop
        '192.168.250.0/24', // Parallels
        '192.168.131.0/24'  // Hyper-V
    ];

    public static async getLocalIp(): Promise<string> {
        return new Promise((resolve, reject) => {
            const addressArray = IpUtil.getActiveIPv4Addresses()
            if (addressArray && addressArray.length > 0) {
                resolve(addressArray[0])
            }
            reject('未找到可用的IP地址')
        })
    }

    private static getActiveIPv4Addresses() {
        const interfaces = os.networkInterfaces()
        const addresses: Array<string> = []

        for (const interfaceName in interfaces) {
            const interfaceInfo = interfaces[interfaceName]
            // @ts-ignore
            for (const info of interfaceInfo) {
                // 过滤条件：IPv4、不是内部地址、不是回环地址、不是虚拟机IP
                if (info.family === 'IPv4' &&
                    !info.internal &&
                    net.isIPv4(info.address) &&
                    !IpUtil.isVMIP(info.address)) {
                    addresses.push(info.address)
                }
            }
        }
        return addresses
    }

    private static isVMIP(ip) {
        const ipLong = ip.split('.').reduce((acc, octet) => (acc << 8) + parseInt(octet, 10), 0)

        return IpUtil.VM_NETWORKS.some(range => {
            const [base, maskBits] = range.split('/')
            const mask = ~(0xFFFFFFFF >>> parseInt(maskBits, 10));
            const baseLong = base.split('.').reduce((acc, octet) => (acc << 8) + parseInt(octet, 10), 0)
            return (ipLong & mask) === (baseLong & mask)
        });
    }
}