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 org.apache.iceberg.parquet;
  
  import java.math.BigDecimal;
  import java.math.BigInteger;
  import java.nio.ByteBuffer;
  import java.nio.ByteOrder;
  import java.nio.charset.StandardCharsets;
  import java.util.UUID;
  import java.util.function.Function;
  import org.apache.iceberg.expressions.Literal;
  import org.apache.iceberg.types.Type;
  import org.apache.parquet.io.api.Binary;
  import org.apache.parquet.schema.LogicalTypeAnnotation;
  import org.apache.parquet.schema.LogicalTypeAnnotation.DecimalLogicalTypeAnnotation;
  import org.apache.parquet.schema.PrimitiveType;
  
  class ParquetConversions {
    private ParquetConversions() {}
  
    @SuppressWarnings("unchecked")
    static <T> Literal<T> fromParquetPrimitive(Type type, PrimitiveType parquetType, Object value) {
      switch (type.typeId()) {
        case BOOLEAN:
          return (Literal<T>) Literal.of((Boolean) value);
        case INTEGER:
        case DATE:
          return (Literal<T>) Literal.of((Integer) value);
        case LONG:
        case TIME:
        case TIMESTAMP:
          // time & timestamp/timestamptz are stored in microseconds
          // https://iceberg.apache.org/spec/#parquet
          var millis =
              (parquetType.getLogicalTypeAnnotation()
                      instanceof LogicalTypeAnnotation.TimestampLogicalTypeAnnotation t
                  && t.getUnit() == LogicalTypeAnnotation.TimeUnit.MILLIS);
          if (parquetType.getPrimitiveTypeName() == PrimitiveType.PrimitiveTypeName.INT32) { // uint32
            long v = ((Integer) value).longValue();
            return (Literal<T>) Literal.of(millis ? v * 1000L : v);
          }
          return (Literal<T>) Literal.of(millis ? (Long) value * 1000L : (Long) value);
        case FLOAT:
          return (Literal<T>) Literal.of((Float) value);
        case DOUBLE:
          return (Literal<T>) Literal.of((Double) value);
        case STRING:
          Function<Object, Object> stringConversion = converterFromParquet(parquetType);
          return (Literal<T>) Literal.of((CharSequence) stringConversion.apply(value));
        case UUID:
          Function<Object, Object> uuidConversion = converterFromParquet(parquetType);
          return (Literal<T>) Literal.of((UUID) uuidConversion.apply(value));
        case FIXED:
        case BINARY:
          Function<Object, Object> binaryConversion = converterFromParquet(parquetType);
          return (Literal<T>) Literal.of((ByteBuffer) binaryConversion.apply(value));
        case DECIMAL:
          Function<Object, Object> decimalConversion = converterFromParquet(parquetType);
          return (Literal<T>) Literal.of((BigDecimal) decimalConversion.apply(value));
        default:
          throw new IllegalArgumentException("Unsupported primitive type: " + type);
      }
    }
  
    static Function<Object, Object> converterFromParquet(
        PrimitiveType parquetType, Type icebergType) {
      Function<Object, Object> fromParquet = converterFromParquet(parquetType);
      if (icebergType != null) {
        if (icebergType.typeId() == Type.TypeID.LONG
            && parquetType.getPrimitiveTypeName() == PrimitiveType.PrimitiveTypeName.INT32) {
          return value -> ((Integer) fromParquet.apply(value)).longValue();
        } else if (icebergType.typeId() == Type.TypeID.DOUBLE
            && parquetType.getPrimitiveTypeName() == PrimitiveType.PrimitiveTypeName.FLOAT) {
          return value -> ((Float) fromParquet.apply(value)).doubleValue();
        }
      }
  
      return fromParquet;
    }
  
    static Function<Object, Object> converterFromParquet(PrimitiveType type) {
      if (type.getOriginalType() != null) {
        switch (type.getOriginalType()) {
          case ENUM:
          case UTF8:
            // decode to CharSequence to avoid copying into a new String
            return binary -> StandardCharsets.UTF_8.decode(((Binary) binary).toByteBuffer());
          case DECIMAL:
            DecimalLogicalTypeAnnotation decimal =
                (DecimalLogicalTypeAnnotation) type.getLogicalTypeAnnotation();
            int scale = decimal.getScale();
            switch (type.getPrimitiveTypeName()) {
              case INT32:
              case INT64:
                return num -> BigDecimal.valueOf(((Number) num).longValue(), scale);
              case FIXED_LEN_BYTE_ARRAY:
              case BINARY:
                return bin -> new BigDecimal(new BigInteger(((Binary) bin).getBytes()), scale);
              default:
                throw new IllegalArgumentException(
                    "Unsupported primitive type for decimal: " + type.getPrimitiveTypeName());
            }
          default:
        }
      }
  
      switch (type.getPrimitiveTypeName()) {
        case FIXED_LEN_BYTE_ARRAY:
        case BINARY:
          return binary -> ByteBuffer.wrap(((Binary) binary).getBytes());
        case INT96:
          return binary ->
              ParquetUtil.extractTimestampInt96(
                  ByteBuffer.wrap(((Binary) binary).getBytes()).order(ByteOrder.LITTLE_ENDIAN));
        default:
      }
  
      return obj -> obj;
    }
  }
  