package com.tom_roush.pdfbox.pdmodel.interactive.form;

import com.tom_roush.pdfbox.cos.COSArray;
import com.tom_roush.pdfbox.cos.COSBase;
import com.tom_roush.pdfbox.cos.COSDictionary;
import com.tom_roush.pdfbox.cos.COSInteger;
import com.tom_roush.pdfbox.cos.COSName;
import com.tom_roush.pdfbox.pdmodel.common.COSArrayList;
import com.tom_roush.pdfbox.pdmodel.common.COSObjectable;
import com.tom_roush.pdfbox.pdmodel.fdf.FDFField;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

/**
 * A non terminal field in an interactive form.
 *
 * A non terminal field is a node in the fields tree node whose descendants
 * are fields.
 *
 * The attributes such as FT (field type) or V (field value) do not logically
 * belong to the non terminal field but are inheritable attributes
 * for descendant terminal fields.
 */
public class PDNonTerminalField extends PDField
{
    /**
     * Constructor.
     *
     * @param acroForm The form that this field is part of.
     */
    public PDNonTerminalField(PDAcroForm acroForm)
    {
        super(acroForm);
    }

    /**
     * Constructor.
     *
     * @param acroForm The form that this field is part of.
     * @param field the PDF object to represent as a field.
     * @param parent the parent node of the node to be created
     */
    public PDNonTerminalField(PDAcroForm acroForm, COSDictionary field, PDNonTerminalField parent)
    {
        super(acroForm, field, parent);
    }

    @Override
    public int getFieldFlags()
    {
        int retval = 0;
        COSInteger ff = (COSInteger) dictionary.getDictionaryObject(COSName.FF);
        if (ff != null)
        {
            retval = ff.intValue();
        }
        // There is no need to look up the parent hierarchy within a non terminal field
        return retval;
    }

    @Override
    void importFDF(FDFField fdfField) throws IOException
    {
        super.importFDF(fdfField);

        List<FDFField> fdfKids = fdfField.getKids();
        List<PDField> children = getChildren();
        for (int i = 0; fdfKids != null && i < fdfKids.size(); i++)
        {
            for (COSObjectable pdKid : children)
            {
                if (pdKid instanceof PDField)
                {
                    PDField pdChild = (PDField) pdKid;
                    FDFField fdfChild = fdfKids.get(i);
                    String fdfName = fdfChild.getPartialFieldName();
                    if (fdfName != null && fdfName.equals(pdChild.getPartialName()))
                    {
                        pdChild.importFDF(fdfChild);
                    }
                }
            }
        }
    }

    @Override
    FDFField exportFDF() throws IOException
    {
        FDFField fdfField = new FDFField();
        fdfField.setPartialFieldName(getPartialName());
        fdfField.setValue(getValue());

        List<PDField> children = getChildren();
        List<FDFField> fdfChildren = new ArrayList<FDFField>();
        for (PDField child : children)
        {
            fdfChildren.add(child.exportFDF());
        }
        fdfField.setKids(fdfChildren);

        return fdfField;
    }

    /**
     * Returns this field's children. These may be either terminal or non-terminal fields.
     *
     * @return he list of child fields.
     */
    public List<PDField> getChildren()
    {
        List<PDField> children = new ArrayList<PDField>();
        COSArray kids = (COSArray) dictionary.getDictionaryObject(COSName.KIDS);
        for (int i = 0; i < kids.size(); i++)
        {
            PDField field = PDField
                .fromDictionary(acroForm, (COSDictionary) kids.getObject(i), this);
            if (field != null)
            {
                children.add(field);
            }
        }
        return children;
    }

    /**
     * Sets the child fields.
     *
     * @param children The list of child fields.
     */
    public void setChildren(List<PDField> children)
    {
        COSArray kidsArray = COSArrayList.converterToCOSArray(children);
        dictionary.setItem(COSName.KIDS, kidsArray);
    }

    /**
     * {@inheritDoc}
     * <p><b>Note:</b> while non-terminal fields <b>do</b> inherit field values, this method returns
     * the local value, without inheritance.
     */
    @Override
    public String getFieldType()
    {
        return dictionary.getNameAsString(COSName.FT);
    }

    /**
     * {@inheritDoc}
     *
     * <p><b>Note:</b> while non-terminal fields <b>do</b> inherit field values, this method returns
     * the local value, without inheritance.
     */
    public COSBase getValue()
    {
        return dictionary.getDictionaryObject(COSName.V);
    }

    /**
     * {@inheritDoc}
     *
     * <p><b>Note:</b> while non-terminal fields <b>do</b> inherit field values, this method returns
     * the local value, without inheritance.
     */
    @Override
    public String getValueAsString()
    {
        COSBase fieldValue = dictionary.getDictionaryObject(COSName.V);
        return fieldValue != null ? fieldValue.toString() : "";
    }

    /**
     * Sets the value of this field. This may be of any kind which is valid for this field's
     * children.
     *
     * <p><b>Note:</b> while non-terminal fields <b>do</b> inherit field values, this method returns
     * the local value, without inheritance.
     */
    public void setValue(COSBase object) throws IOException
    {
        dictionary.setItem(COSName.V, object);
        // todo: propagate change event to children?
        // todo: construct appearances of children?
    }

    /**
     * Returns the default value of this field. This may be of any kind which is valid for this field's
     * children.
     *
     * <p><b>Note:</b> while non-terminal fields <b>do</b> inherit field values, this method returns
     * the local value, without inheritance.
     */
    public COSBase getDefaultValue()
    {
        return dictionary.getDictionaryObject(COSName.DV);
    }

    /**
     * Sets the default of this field. This may be of any kind which is valid for this field's
     * children.
     *
     * <p><b>Note:</b> while non-terminal fields <b>do</b> inherit field values, this method returns
     * the local value, without inheritance.
     */
    public void setDefaultValue(COSBase value)
    {
        dictionary.setItem(COSName.V, value);
    }
}