code: /*
   * Copyright (c) 2019 the Eclipse Milo Authors
   *
   * This program and the accompanying materials are made
   * available under the terms of the Eclipse Public License 2.0
   * which is available at https://www.eclipse.org/legal/epl-2.0/
   *
   * SPDX-License-Identifier: EPL-2.0
   */
  
  package org.eclipse.milo.opcua.sdk.server.events.conversions;
  
  import java.text.DateFormat;
  import java.text.ParseException;
  import java.text.SimpleDateFormat;
  import java.util.Date;
  import java.util.TimeZone;
  import java.util.UUID;
  
  import org.eclipse.milo.opcua.stack.core.BuiltinDataType;
  import org.eclipse.milo.opcua.stack.core.types.builtin.DateTime;
  import org.eclipse.milo.opcua.stack.core.types.builtin.ExpandedNodeId;
  import org.eclipse.milo.opcua.stack.core.types.builtin.LocalizedText;
  import org.eclipse.milo.opcua.stack.core.types.builtin.NodeId;
  import org.eclipse.milo.opcua.stack.core.types.builtin.QualifiedName;
  import org.eclipse.milo.opcua.stack.core.types.builtin.unsigned.UByte;
  import org.eclipse.milo.opcua.stack.core.types.builtin.unsigned.UInteger;
  import org.eclipse.milo.opcua.stack.core.types.builtin.unsigned.ULong;
  import org.eclipse.milo.opcua.stack.core.types.builtin.unsigned.UShort;
  import org.jetbrains.annotations.NotNull;
  import org.jetbrains.annotations.Nullable;
  
  final class StringConversions {
  
      private static final DateFormat ISO_8601_UTC_DATE_FORMAT;
  
      static {
          ISO_8601_UTC_DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
          ISO_8601_UTC_DATE_FORMAT.setTimeZone(TimeZone.getTimeZone("UTC"));
      }
  
      private StringConversions() {}
  
      @Nullable
      static Boolean stringToBoolean(@NotNull String s) {
          if (s.equalsIgnoreCase("true") || s.equals("1")) {
              return true;
          } else if (s.equalsIgnoreCase("false") || s.equals("0")) {
              return false;
          } else {
              return null;
          }
      }
  
      @Nullable
      static UByte stringToByte(@NotNull String s) {
          try {
              return UByte.valueOf(s);
          } catch (NumberFormatException e) {
              return null;
          }
      }
  
      @Nullable
      static DateTime stringToDateTime(@NotNull String s) {
          try {
              Date date = iso8601UtcStringToDate(s);
  
              return new DateTime(date);
          } catch (ParseException e) {
              return null;
          }
      }
  
      @Nullable
      static Double stringToDouble(@NotNull String s) {
          try {
              return Double.valueOf(s);
          } catch (NumberFormatException e) {
              return null;
          }
      }
  
      @Nullable
      static ExpandedNodeId stringToExpandedNodeId(@NotNull String s) {
          try {
              return ExpandedNodeId.parse(s);
          } catch (Throwable t) {
              return null;
          }
      }
  
      @Nullable
      static Float stringToFloat(@NotNull String s) {
          try {
              return Float.valueOf(s);
          } catch (NumberFormatException e) {
              return null;
          }
      }
  
      @Nullable
      static UUID stringToGuid(@NotNull String s) {
          try {
              return UUID.fromString(s);
          } catch (IllegalArgumentException e) {
              return null;
          }
      }
  
      @Nullable
      static Short stringToInt16(@NotNull String s) {
          try {
              return Short.valueOf(s);
          } catch (NumberFormatException e) {
              return null;
          }
      }
  
      @Nullable
      static Integer stringToInt32(@NotNull String s) {
          try {
              return Integer.valueOf(s);
          } catch (NumberFormatException e) {
              return null;
          }
      }
  
      @Nullable
      static Long stringToInt64(@NotNull String s) {
          try {
              return Long.valueOf(s);
          } catch (NumberFormatException e) {
              return null;
          }
      }
  
      @Nullable
      static NodeId stringToNodeId(@NotNull String s) {
          try {
              return NodeId.parse(s);
          } catch (Throwable t) {
              return null;
          }
      }
  
  
      @Nullable
      static Byte stringToSByte(@NotNull String s) {
          try {
              return Byte.valueOf(s);
          } catch (NumberFormatException e) {
              return null;
          }
      }
  
      @NotNull
      static LocalizedText stringToLocalizedText(@NotNull String s) {
          return new LocalizedText("", s);
      }
  
      @NotNull
      static QualifiedName stringToQualifiedName(@NotNull String s) {
          return new QualifiedName(0, s);
      }
  
      @Nullable
      static UShort stringToUInt16(@NotNull String s) {
          try {
              return UShort.valueOf(s);
          } catch (NumberFormatException e) {
              return null;
          }
      }
  
      @Nullable
      static UInteger stringToUInt32(@NotNull String s) {
          try {
              return UInteger.valueOf(s);
          } catch (NumberFormatException e) {
              return null;
          }
      }
  
      @Nullable
      static ULong stringToUInt64(@NotNull String s) {
          try {
              return ULong.valueOf(s);
          } catch (NumberFormatException e) {
              return null;
          }
      }
  
      private static Date iso8601UtcStringToDate(String s) throws ParseException {
          synchronized (ISO_8601_UTC_DATE_FORMAT) {
              return ISO_8601_UTC_DATE_FORMAT.parse(s);
          }
      }
  
      @Nullable
      static Object convert(@NotNull Object o, BuiltinDataType targetType, boolean implicit) {
          if (o instanceof String) {
              String s = (String) o;
  
              return implicit ?
                  implicitConversion(s, targetType) :
                  explicitConversion(s, targetType);
          } else {
              return null;
          }
      }
  
      @Nullable
      static Object explicitConversion(@NotNull String s, BuiltinDataType targetType) {
          //@formatter:off
          switch (targetType) {
              case DateTime:          return stringToDateTime(s);
              case ExpandedNodeId:    return stringToExpandedNodeId(s);
              case NodeId:            return stringToNodeId(s);
              case LocalizedText:     return stringToLocalizedText(s);
              case QualifiedName:     return stringToQualifiedName(s);
              default:                return implicitConversion(s, targetType);
          }
          //@formatter:on
      }
  
      @Nullable
      static Object implicitConversion(@NotNull String s, BuiltinDataType targetType) {
          //@formatter:off
          switch (targetType) {
              case Boolean:   return stringToBoolean(s);
              case Byte:      return stringToByte(s);
              case Double:    return stringToDouble(s);
              case Float:     return stringToFloat(s);
              case Guid:      return stringToGuid(s);
              case Int16:     return stringToInt16(s);
              case Int32:     return stringToInt32(s);
              case Int64:     return stringToInt64(s);
              case SByte:     return stringToSByte(s);
              case UInt16:    return stringToUInt16(s);
              case UInt32:    return stringToUInt32(s);
              case UInt64:    return stringToUInt64(s);
              default:        return null;
          }
          //@formatter:on
      }
  
  }
  