package io.ebeaninternal.server.type;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import io.ebean.text.TextException;
import io.ebeanservice.docstore.api.mapping.DocPropertyType;

import javax.persistence.EnumType;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.sql.SQLException;
import java.sql.Types;
import java.util.EnumSet;
import java.util.LinkedHashSet;
import java.util.Set;

JPA standard based Enum scalar type.

Converts between bean Enum types to database string or integer columns.


The limitation of this class is that it converts the Enum to either the ordinal or string value
of the Enum. If you wish to convert the Enum to some other value then you should look at the
Ebean specific @EnumMapping.

/**
 * JPA standard based Enum scalar type.
 * <p>
 * Converts between bean Enum types to database string or integer columns.
 * </p>
 * <p>
 * The limitation of this class is that it converts the Enum to either the ordinal or string value
 * of the Enum. If you wish to convert the Enum to some other value then you should look at the
 * Ebean specific @EnumMapping.
 * </p>
 */
public class ScalarTypeEnumStandard {

  @SuppressWarnings({"rawtypes", "unchecked"})
  public static class StringEnum extends EnumBase implements ScalarTypeEnum {

    private final int length;

    
Create a ScalarTypeEnum.
/**
     * Create a ScalarTypeEnum.
     */
    public StringEnum(Class enumType) {
      super(enumType, false, Types.VARCHAR);
      this.length = maxValueLength(enumType);
    }

    @Override
    public boolean isCompatible(EnumType enumType) {
      return EnumType.STRING == enumType;
    }

    
Return the IN values for DB constraint construction.
/**
     * Return the IN values for DB constraint construction.
     */
    @Override
    public Set<String> getDbCheckConstraintValues() {

      LinkedHashSet<String> values = new LinkedHashSet<>();

      Object[] ea = enumType.getEnumConstants();
      for (Object anEa : ea) {
        Enum<?> e = (Enum<?>) anEa;
        values.add("'" + e.name() + "'");
      }
      return values;
    }

    private int maxValueLength(Class<?> enumType) {

      int maxLen = 0;

      Object[] ea = enumType.getEnumConstants();
      for (Object anEa : ea) {
        Enum<?> e = (Enum<?>) anEa;
        maxLen = Math.max(maxLen, e.name().length());
      }

      return maxLen;
    }

    @Override
    public int getLength() {
      return length;
    }

    @Override
    public void bind(DataBind b, Object value) throws SQLException {
      if (value == null) {
        b.setNull(Types.VARCHAR);
      } else {
        b.setString(format(value));
      }
    }

    @Override
    public Object read(DataReader dataReader) throws SQLException {

      String string = dataReader.getString();
      if (string == null) {
        return null;
      } else {
        return parse(string);
      }
    }

    
Convert the Boolean value to the db value.
/**
     * Convert the Boolean value to the db value.
     */
    @Override
    public Object toJdbcType(Object beanValue) {
      if (beanValue == null) {
        return null;
      }
      return format(beanValue);
    }

    @Override
    public Object toBeanType(Object dbValue) {
      if (dbValue == null || dbValue instanceof Enum<?>) {
        return dbValue;
      }
      return Enum.valueOf(enumType, (String) dbValue);
    }

  }

  @SuppressWarnings({"rawtypes", "unchecked"})
  public static class OrdinalEnum extends EnumBase implements ScalarTypeEnum {

    private final Object[] enumArray;

    
Create a ScalarTypeEnum.
/**
     * Create a ScalarTypeEnum.
     */
    public OrdinalEnum(Class enumType) {
      super(enumType, false, Types.INTEGER);
      this.enumArray = EnumSet.allOf(enumType).toArray();
    }

    @Override
    public boolean isCompatible(EnumType enumType) {
      return EnumType.ORDINAL == enumType;
    }

    
Return the IN values for DB constraint construction.
/**
     * Return the IN values for DB constraint construction.
     */
    @Override
    public Set<String> getDbCheckConstraintValues() {

      LinkedHashSet<String> values = new LinkedHashSet<>();
      for (Object anEnumArray : enumArray) {
        Enum<?> e = (Enum<?>) anEnumArray;
        values.add(Integer.toString(e.ordinal()));
      }
      return values;
    }

    @Override
    public void bind(DataBind b, Object value) throws SQLException {
      if (value == null) {
        b.setNull(Types.INTEGER);
      } else {
        b.setInt(((Enum<?>) value).ordinal());
      }
    }

    @Override
    public Object read(DataReader dataReader) throws SQLException {

      Integer ordinal = dataReader.getInt();
      if (ordinal == null) {
        return null;
      } else {
        if (ordinal < 0 || ordinal >= enumArray.length) {
          String m = "Unexpected ordinal [" + ordinal + "] out of range [" + enumArray.length + "]";
          throw new IllegalStateException(m);
        }
        return enumArray[ordinal];
      }
    }

    
Convert the Enum value to the db value.
/**
     * Convert the Enum value to the db value.
     */
    @Override
    public Object toJdbcType(Object beanValue) {
      if (beanValue == null) {
        return null;
      }
      return ((Enum<?>) beanValue).ordinal();
    }

    
Convert the db value to the Enum value.
/**
     * Convert the db value to the Enum value.
     */
    @Override
    public Object toBeanType(Object dbValue) {
      if (dbValue == null || dbValue instanceof Enum<?>) {
        return dbValue;
      }

      int ordinal = (Integer) dbValue;
      if (ordinal < 0 || ordinal >= enumArray.length) {
        String m = "Unexpected ordinal [" + ordinal + "] out of range [" + enumArray.length + "]";
        throw new IllegalStateException(m);
      }
      return enumArray[ordinal];
    }

  }

  @SuppressWarnings({"rawtypes", "unchecked"})
  public abstract static class EnumBase extends ScalarTypeBase {

    protected final Class enumType;

    public EnumBase(Class<?> type, boolean jdbcNative, int jdbcType) {
      super(type, jdbcNative, jdbcType);
      this.enumType = type;
    }

    @Override
    public String format(Object value) {
      return ((Enum<?>) value).name();
    }

    @Override
    public String formatValue(Object value) {
      return ((Enum<?>) value).name();
    }

    @Override
    public Object parse(String value) {
      return Enum.valueOf(enumType, value);
    }

    @Override
    public Object convertFromMillis(long systemTimeMillis) {
      throw new TextException("Not Supported");
    }

    @Override
    public boolean isDateTimeCapable() {
      return false;
    }

    @Override
    public Object jsonRead(JsonParser parser) throws IOException {
      if (parser.getCodec() != null) {
        return parser.readValueAs(enumType);
      } else {
        return parse(parser.getValueAsString());
      }
    }

    @Override
    public void jsonWrite(JsonGenerator writer, Object value) throws IOException {
      if (writer.getCodec() != null) {
        writer.writeObject(value);
      } else {
        writer.writeString(formatValue(value));
      }
    }

    @Override
    public DocPropertyType getDocType() {
      return DocPropertyType.ENUM;
    }

    @Override
    public Object readData(DataInput dataInput) throws IOException {
      if (!dataInput.readBoolean()) {
        return null;
      } else {
        return parse(dataInput.readUTF());
      }
    }

    @Override
    public void writeData(DataOutput dataOutput, Object value) throws IOException {
      if (value == null) {
        dataOutput.writeBoolean(false);
      } else {
        ScalarHelp.writeUTF(dataOutput, format(value));
      }
    }
  }
}