package io.github.vmzakharov.ecdataframe.dataframe;

import io.github.vmzakharov.ecdataframe.dsl.value.Value;

public interface DfColumnComputed
extends DfColumn
{
    @Override
    default boolean isStored() { return false; }

    String getExpressionAsString();

    @Override
    default void setObject(int rowIndex, Object anObject)
    {
        throw new RuntimeException("Cannot set a value on computed column '" + this.getName() + "'");
    }

    @Override
    default void addEmptyValue()
    {
        // no-op
    }

    @Override
    default void addValue(Value value)
    {
        this.throwUnmodifiableColumnException();
    }

    
a placeholder method for computed columns defined so that addRow() could be called on a data frame with computed columns. If any value other than null is passed the method throws an exception 
Params:
newObject – an object to add to the column, expected null for computed columns/**
     * a placeholder method for computed columns defined so that {@code addRow()} could be called on a data frame with
     * computed columns. If any value other than {@code null} is passed the method throws an exception
     * @param newObject an object to add to the column, expected {@code null} for computed columns
     */
    @Override
    default void addObject(Object newObject)
    {
        if (newObject != null)
        {
            this.throwUnmodifiableColumnException();
        }
    }

    @Override
    default void incrementFrom(int targetRowIndex, DfColumn sourceColumn, int sourceRowIndex)
    {
        throw new RuntimeException("Cannot increment a value of computed column '" + this.getName() + "'");
    }

    default void throwUnmodifiableColumnException()
    {
        throw new UnsupportedOperationException("Cannot modify computed column '" + this.getName() + "'");
    }
}