content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.datastax.oss.driver.internal.core.type.codec;
  
  import static java.lang.Long.parseLong;
  
  import com.datastax.oss.driver.api.core.ProtocolVersion;
  import com.datastax.oss.driver.api.core.type.DataType;
  import com.datastax.oss.driver.api.core.type.DataTypes;
  import com.datastax.oss.driver.api.core.type.codec.TypeCodec;
  import com.datastax.oss.driver.api.core.type.codec.TypeCodecs;
  import com.datastax.oss.driver.api.core.type.reflect.GenericType;
  import com.datastax.oss.driver.internal.core.util.Strings;
  import edu.umd.cs.findbugs.annotations.NonNull;
  import edu.umd.cs.findbugs.annotations.Nullable;
  import java.nio.ByteBuffer;
  import java.time.LocalDate;
  import java.time.format.DateTimeFormatter;
  import java.time.temporal.ChronoUnit;
  import net.jcip.annotations.ThreadSafe;
  
  @ThreadSafe
  public class DateCodec implements TypeCodec<LocalDate> {
  
    private static final LocalDate EPOCH = LocalDate.of(1970, 1, 1);
  
    @NonNull
    @Override
    public GenericType<LocalDate> getJavaType() {
      return GenericType.LOCAL_DATE;
    }
  
    @NonNull
    @Override
    public DataType getCqlType() {
      return DataTypes.DATE;
    }
  
    @Override
    public boolean accepts(@NonNull Object value) {
      return value instanceof LocalDate;
    }
  
    @Override
    public boolean accepts(@NonNull Class<?> javaClass) {
      return javaClass == LocalDate.class;
    }
  
    @Nullable
    @Override
    public ByteBuffer encode(@Nullable LocalDate value, @NonNull ProtocolVersion protocolVersion) {
      if (value == null) {
        return null;
      }
      long days = ChronoUnit.DAYS.between(EPOCH, value);
      int unsigned = signedToUnsigned((int) days);
      return TypeCodecs.INT.encodePrimitive(unsigned, protocolVersion);
    }
  
    @Nullable
    @Override
    public LocalDate decode(@Nullable ByteBuffer bytes, @NonNull ProtocolVersion protocolVersion) {
      if (bytes == null || bytes.remaining() == 0) {
        return null;
      }
      int unsigned = TypeCodecs.INT.decodePrimitive(bytes, protocolVersion);
      int signed = unsignedToSigned(unsigned);
      return EPOCH.plusDays(signed);
    }
  
    @NonNull
    @Override
    public String format(@Nullable LocalDate value) {
      return (value == null) ? "NULL" : Strings.quote(DateTimeFormatter.ISO_LOCAL_DATE.format(value));
    }
  
    @Nullable
    @Override
    public LocalDate parse(@Nullable String value) {
      if (value == null || value.isEmpty() || value.equalsIgnoreCase("NULL")) {
        return null;
      }
  
      // single quotes are optional for long literals, mandatory for date patterns
      // strip enclosing single quotes, if any
      if (Strings.isQuoted(value)) {
        value = Strings.unquote(value);
      }
  
      if (Strings.isLongLiteral(value)) {
        long raw;
        try {
          raw = parseLong(value);
        } catch (NumberFormatException e) {
          throw new IllegalArgumentException(
              String.format("Cannot parse date value from \"%s\"", value));
        }
        int days;
        try {
          days = cqlDateToDaysSinceEpoch(raw);
        } catch (IllegalArgumentException e) {
          throw new IllegalArgumentException(
              String.format("Cannot parse date value from \"%s\"", value));
        }
        return EPOCH.plusDays(days);
      }
  
      try {
        return LocalDate.parse(value, DateTimeFormatter.ISO_LOCAL_DATE);
      } catch (RuntimeException e) {
        throw new IllegalArgumentException(
            String.format("Cannot parse date value from \"%s\"", value));
      }
    }
  
    private static int signedToUnsigned(int signed) {
      return signed - Integer.MIN_VALUE;
    }
  
    private static int unsignedToSigned(int unsigned) {
      return unsigned + Integer.MIN_VALUE; // this relies on overflow for "negative" values
    }
  
    /**
     * Converts a raw CQL long representing a numeric DATE literal to the number of days since the
     * Epoch. In CQL, numeric DATE literals are longs (unsigned integers actually) between 0 and 2^32
     * - 1, with the epoch in the middle; this method re-centers the epoch at 0.
     */
    private static int cqlDateToDaysSinceEpoch(long raw) {
      if (raw < 0 || raw > MAX_CQL_LONG_VALUE)
        throw new IllegalArgumentException(
            String.format(
                "Numeric literals for DATE must be between 0 and %d (got %d)",
                MAX_CQL_LONG_VALUE, raw));
      return (int) (raw - EPOCH_AS_CQL_LONG);
    }
  
    private static final long MAX_CQL_LONG_VALUE = ((1L << 32) - 1);
    private static final long EPOCH_AS_CQL_LONG = (1L << 31);
  }
  