/*
    * Copyright 2020-2023 The OSHI Project Contributors
    * SPDX-License-Identifier: MIT
    */
   package oshi.hardware.common;
   
   import static oshi.util.Memoizer.memoize;
   
   import java.net.InetAddress;
  import java.net.InterfaceAddress;
  import java.net.NetworkInterface;
  import java.net.SocketException;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.Enumeration;
  import java.util.List;
  import java.util.Locale;
  import java.util.Properties;
  import java.util.function.Supplier;
  import java.util.stream.Collectors;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import oshi.annotation.concurrent.ThreadSafe;
  import oshi.hardware.NetworkIF;
  import oshi.util.Constants;
  import oshi.util.FileUtil;
  import oshi.util.FormatUtil;
  import oshi.util.ParseUtil;
  
  /**
   * Network interfaces implementation.
   */
  @ThreadSafe
  public abstract class AbstractNetworkIF implements NetworkIF {
  
      private static final Logger LOG = LoggerFactory.getLogger(AbstractNetworkIF.class);
  
      private static final String OSHI_VM_MAC_ADDR_PROPERTIES = "oshi.vmmacaddr.properties";
  
      private NetworkInterface networkInterface;
      private String name;
      private String displayName;
      private int index;
      private long mtu;
      private String mac;
      private String[] ipv4;
      private Short[] subnetMasks;
      private String[] ipv6;
      private Short[] prefixLengths;
  
      private final Supplier<Properties> vmMacAddrProps = memoize(AbstractNetworkIF::queryVmMacAddrProps);
  
      /**
       * Construct a {@link NetworkIF} object backed by the specified {@link NetworkInterface}.
       *
       * @param netint The core java {@link NetworkInterface} backing this object.
       * @throws InstantiationException If a socket exception prevents access to the backing interface.
       */
      protected AbstractNetworkIF(NetworkInterface netint) throws InstantiationException {
          this(netint, netint.getDisplayName());
      }
  
      /**
       * Construct a {@link NetworkIF} object backed by the specified {@link NetworkInterface}.
       *
       * @param netint      The core java {@link NetworkInterface} backing this object.
       * @param displayName A string to use for the display name in preference to the {@link NetworkInterface} value.
       * @throws InstantiationException If a socket exception prevents access to the backing interface.
       */
      protected AbstractNetworkIF(NetworkInterface netint, String displayName) throws InstantiationException {
          this.networkInterface = netint;
          try {
              this.name = networkInterface.getName();
              this.displayName = displayName;
              this.index = networkInterface.getIndex();
              // Set MTU
              this.mtu = ParseUtil.unsignedIntToLong(networkInterface.getMTU());
              // Set MAC
              byte[] hwmac = networkInterface.getHardwareAddress();
              if (hwmac != null) {
                  List<String> octets = new ArrayList<>(6);
                  for (byte b : hwmac) {
                      octets.add(String.format(Locale.ROOT, "%02x", b));
                  }
                  this.mac = String.join(":", octets);
              } else {
                  this.mac = Constants.UNKNOWN;
              }
              // Set IP arrays
              ArrayList<String> ipv4list = new ArrayList<>();
              ArrayList<Short> subnetMaskList = new ArrayList<>();
              ArrayList<String> ipv6list = new ArrayList<>();
              ArrayList<Short> prefixLengthList = new ArrayList<>();
  
              for (InterfaceAddress interfaceAddress : networkInterface.getInterfaceAddresses()) {
                  InetAddress address = interfaceAddress.getAddress();
                 if (address.getHostAddress().length() > 0) {
                     if (address.getHostAddress().contains(":")) {
                         ipv6list.add(address.getHostAddress().split("%")[0]);
                         prefixLengthList.add(interfaceAddress.getNetworkPrefixLength());
                     } else {
                         ipv4list.add(address.getHostAddress());
                         subnetMaskList.add(interfaceAddress.getNetworkPrefixLength());
                     }
                 }
             }
 
             this.ipv4 = ipv4list.toArray(new String[0]);
             this.subnetMasks = subnetMaskList.toArray(new Short[0]);
             this.ipv6 = ipv6list.toArray(new String[0]);
             this.prefixLengths = prefixLengthList.toArray(new Short[0]);
         } catch (SocketException e) {
             throw new InstantiationException(e.getMessage());
         }
     }
 
     /**
      * Returns network interfaces on this machine.
      *
      * @param includeLocalInterfaces include local interfaces in the result
      * @return A list of network interfaces
      */
     protected static List<NetworkInterface> getNetworkInterfaces(boolean includeLocalInterfaces) {
         List<NetworkInterface> interfaces = getAllNetworkInterfaces();
 
         return includeLocalInterfaces ? interfaces
                 : getAllNetworkInterfaces().stream().parallel().filter(ni -> !isLocalInterface(ni))
                         .collect(Collectors.toList());
     }
 
     /**
      * Returns all network interfaces.
      *
      * @return A list of network interfaces
      */
     private static List<NetworkInterface> getAllNetworkInterfaces() {
         try {
             Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
             return interfaces == null ? Collections.emptyList() : Collections.list(interfaces);
         } catch (SocketException ex) {
             LOG.error("Socket exception when retrieving interfaces: {}", ex.getMessage());
         }
         return Collections.emptyList();
     }
 
     private static boolean isLocalInterface(NetworkInterface networkInterface) {
         try {
             // getHardwareAddress also checks for loopback
             return networkInterface.getHardwareAddress() == null;
         } catch (SocketException e) {
             LOG.error("Socket exception when retrieving interface information for {}: {}", networkInterface,
                     e.getMessage());
         }
         return false;
     }
 
     @Override
     public NetworkInterface queryNetworkInterface() {
         return this.networkInterface;
     }
 
     @Override
     public String getName() {
         return this.name;
     }
 
     @Override
     public int getIndex() {
         return this.index;
     }
 
     @Override
     public String getDisplayName() {
         return this.displayName;
     }
 
     @Override
     public long getMTU() {
         return this.mtu;
     }
 
     @Override
     public String getMacaddr() {
         return this.mac;
     }
 
     @Override
     public String[] getIPv4addr() {
         return Arrays.copyOf(this.ipv4, this.ipv4.length);
     }
 
     @Override
     public Short[] getSubnetMasks() {
         return Arrays.copyOf(this.subnetMasks, this.subnetMasks.length);
     }
 
     @Override
     public String[] getIPv6addr() {
         return Arrays.copyOf(this.ipv6, this.ipv6.length);
     }
 
     @Override
     public Short[] getPrefixLengths() {
         return Arrays.copyOf(this.prefixLengths, this.prefixLengths.length);
     }
 
     @Override
     public boolean isKnownVmMacAddr() {
         String oui = getMacaddr().length() > 7 ? getMacaddr().substring(0, 8) : getMacaddr();
         return this.vmMacAddrProps.get().containsKey(oui.toUpperCase(Locale.ROOT));
     }
 
     private static Properties queryVmMacAddrProps() {
         return FileUtil.readPropertiesFromFilename(OSHI_VM_MAC_ADDR_PROPERTIES);
     }
 
     @Override
     public String toString() {
         StringBuilder sb = new StringBuilder();
         sb.append("Name: ").append(getName());
         if (!getName().equals(getDisplayName())) {
             sb.append(" (").append(getDisplayName()).append(")");
         }
         if (!getIfAlias().isEmpty()) {
             sb.append(" [IfAlias=").append(getIfAlias()).append("]");
         }
         sb.append("\n");
         sb.append("  MAC Address: ").append(getMacaddr()).append("\n");
         sb.append("  MTU: ").append(getMTU()).append(", ").append("Speed: ").append(getSpeed()).append("\n");
         String[] ipv4withmask = getIPv4addr();
         if (this.ipv4.length == this.subnetMasks.length) {
             for (int i = 0; i < this.subnetMasks.length; i++) {
                 ipv4withmask[i] += "/" + this.subnetMasks[i];
             }
         }
         sb.append("  IPv4: ").append(Arrays.toString(ipv4withmask)).append("\n");
         String[] ipv6withprefixlength = getIPv6addr();
         if (this.ipv6.length == this.prefixLengths.length) {
             for (int j = 0; j < this.prefixLengths.length; j++) {
                 ipv6withprefixlength[j] += "/" + this.prefixLengths[j];
             }
         }
         sb.append("  IPv6: ").append(Arrays.toString(ipv6withprefixlength)).append("\n");
         sb.append("  Traffic: received ").append(getPacketsRecv()).append(" packets/")
                 .append(FormatUtil.formatBytes(getBytesRecv())).append(" (" + getInErrors() + " err, ")
                 .append(getInDrops() + " drop);");
         sb.append(" transmitted ").append(getPacketsSent()).append(" packets/")
                 .append(FormatUtil.formatBytes(getBytesSent())).append(" (" + getOutErrors() + " err, ")
                 .append(getCollisions() + " coll);");
         return sb.toString();
     }
 }