/*
 * 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.pdfbox.pdmodel.interactive.annotation;

import java.io.IOException;
import java.util.Calendar;
import java.util.Objects;

import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.LogManager;
import org.apache.pdfbox.cos.COSArray;
import org.apache.pdfbox.cos.COSBase;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSInteger;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.cos.COSNumber;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.common.COSObjectable;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.pdmodel.documentinterchange.markedcontent.PDPropertyList;
import org.apache.pdfbox.pdmodel.graphics.color.PDColor;
import org.apache.pdfbox.pdmodel.graphics.color.PDColorSpace;
import org.apache.pdfbox.pdmodel.graphics.color.PDDeviceCMYK;
import org.apache.pdfbox.pdmodel.graphics.color.PDDeviceGray;
import org.apache.pdfbox.pdmodel.graphics.color.PDDeviceRGB;

/**
 * A PDF annotation.
 * 
 * @author Ben Litchfield
 */
public abstract class PDAnnotation implements COSObjectable
{
    /**
     * Log instance.
     */
    private static final Logger LOG = LogManager.getLogger(PDAnnotation.class);

    /**
     * An annotation flag.
     */
    private static final int FLAG_INVISIBLE = 1 << 0;
    /**
     * An annotation flag.
     */
    private static final int FLAG_HIDDEN = 1 << 1;
    /**
     * An annotation flag.
     */
    private static final int FLAG_PRINTED = 1 << 2;
    /**
     * An annotation flag.
     */
    private static final int FLAG_NO_ZOOM = 1 << 3;
    /**
     * An annotation flag.
     */
    private static final int FLAG_NO_ROTATE = 1 << 4;
    /**
     * An annotation flag.
     */
    private static final int FLAG_NO_VIEW = 1 << 5;
    /**
     * An annotation flag.
     */
    private static final int FLAG_READ_ONLY = 1 << 6;
    /**
     * An annotation flag.
     */
    private static final int FLAG_LOCKED = 1 << 7;
    /**
     * An annotation flag.
     */
    private static final int FLAG_TOGGLE_NO_VIEW = 1 << 8;
    /**
     * An annotation flag.
     * @see #setLockedContents(boolean)
     */
    private static final int FLAG_LOCKED_CONTENTS = 1 << 9;

    private final COSDictionary dictionary;

    /**
     * Create the correct annotation from the base COS object.
     *
     * @param base The COS object that is the annotation.
     * @return The correctly typed annotation object, never null.
     *
     * @throws IOException If the annotation type is unknown.
     */
    public static PDAnnotation createAnnotation(COSBase base) throws IOException
    {
        if (base instanceof COSDictionary)
        {
            COSDictionary annotDic = (COSDictionary) base;
            String subtype = annotDic.getNameAsString(COSName.SUBTYPE);
            if (null == subtype)
            {
                LOG.debug("Unknown annotation subtype");
                return new PDAnnotationUnknown(annotDic);
            }
            switch (subtype)
            {
                case PDAnnotationFileAttachment.SUB_TYPE:
                    return new PDAnnotationFileAttachment(annotDic);
                case PDAnnotationLine.SUB_TYPE:
                    return new PDAnnotationLine(annotDic);
                case PDAnnotationLink.SUB_TYPE:
                    return new PDAnnotationLink(annotDic);
                case PDAnnotationPopup.SUB_TYPE:
                    return new PDAnnotationPopup(annotDic);
                case PDAnnotationRubberStamp.SUB_TYPE:
                    return new PDAnnotationRubberStamp(annotDic);
                case PDAnnotationSquare.SUB_TYPE:
                    return new PDAnnotationSquare(annotDic);
                case PDAnnotationCircle.SUB_TYPE:
                    return new PDAnnotationCircle(annotDic);
                case PDAnnotationPolygon.SUB_TYPE:
                    return new PDAnnotationPolygon(annotDic);
                case PDAnnotationPolyline.SUB_TYPE:
                    return new PDAnnotationPolyline(annotDic);
                case PDAnnotationInk.SUB_TYPE:
                    return new PDAnnotationInk(annotDic);
                case PDAnnotationText.SUB_TYPE:
                    return new PDAnnotationText(annotDic);
                case PDAnnotationHighlight.SUB_TYPE:
                    return new PDAnnotationHighlight(annotDic);
                case PDAnnotationUnderline.SUB_TYPE:
                    return new PDAnnotationUnderline(annotDic);
                case PDAnnotationStrikeout.SUB_TYPE:
                    return new PDAnnotationStrikeout(annotDic);
                case PDAnnotationSquiggly.SUB_TYPE:
                    return new PDAnnotationSquiggly(annotDic);
                case PDAnnotationWidget.SUB_TYPE:
                    return new PDAnnotationWidget(annotDic);
                case PDAnnotationFreeText.SUB_TYPE:
                    return new PDAnnotationFreeText(annotDic);
                case PDAnnotationCaret.SUB_TYPE:
                    return new PDAnnotationCaret(annotDic);
                case PDAnnotationSound.SUB_TYPE:
                    return new PDAnnotationSound(annotDic);
                default:
                    // TODO not yet implemented:
                    // Movie, Screen, PrinterMark, TrapNet, Watermark, 3D, Redact
                    LOG.debug("Unknown or unsupported annotation subtype {}", subtype);
                    return new PDAnnotationUnknown(annotDic);
            }
        }
        else
        {
            throw new IOException("Error: Unknown annotation type " + base);
        }
    }

    /**
     * Constructor.
     */
    protected PDAnnotation()
    {
        dictionary = new COSDictionary();
        dictionary.setItem(COSName.TYPE, COSName.ANNOT);
    }

    /**
     * Constructor.
     * 
     * @param dict The annotations dictionary.
     */
    protected PDAnnotation(COSDictionary dict)
    {
        dictionary = dict;
        COSBase type = dict.getDictionaryObject(COSName.TYPE);
        if (type == null)
        {
            dictionary.setItem(COSName.TYPE, COSName.ANNOT);
        }
        else if (!COSName.ANNOT.equals(type))
        {
            LOG.warn("Annotation has type {}, further mayhem may follow", type);
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean equals (Object o)
    {
        if (o == this)
        {
            return true;
        }

        if (!(o instanceof PDAnnotation))
        {
            return false;
        }

        COSDictionary toBeCompared = ((PDAnnotation) o).getCOSObject();
        return toBeCompared.equals(getCOSObject());
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int hashCode()
    {
        return Objects.hash(dictionary);
    }


    /**
     * This will set the sub type (and hence appearance, AP taking precedence) For this annotation. See the SUB_TYPE_XXX
     * constants for valid values.
     *
     * @param subType The subtype of the annotation
     */
    protected final void setSubtype(String subType)
    {
        getCOSObject().setName(COSName.SUBTYPE, subType);
    }

    /**
     * This will retrieve the subtype of the annotation.
     *
     * @return The subtype of this annotation, see the SUB_TYPE_XXX constants.
     */
    public final String getSubtype()
    {
        return getCOSObject().getNameAsString(COSName.SUBTYPE);
    }

    /**
     * The annotation rectangle, defining the location of the annotation on the page in default user space units. This
     * is usually required and should not return null on valid PDF documents. But where this is a parent form field with
     * children, such as radio button collections then the rectangle will be null.
     * 
     * @return The Rect value of this annotation.
     */
    public PDRectangle getRectangle()
    {
        COSArray rectArray = dictionary.getCOSArray(COSName.RECT);
        PDRectangle rectangle = null;
        if (rectArray != null)
        {
            if (rectArray.size() == 4 && rectArray.getObject(0) instanceof COSNumber
                    && rectArray.getObject(1) instanceof COSNumber
                    && rectArray.getObject(2) instanceof COSNumber
                    && rectArray.getObject(3) instanceof COSNumber)
            {
                rectangle = new PDRectangle(rectArray);
            }
            else
            {
                LOG.warn("{} is not a rectangle array, returning null", rectArray);
            }
        }
        return rectangle;
    }

    /**
     * This will set the rectangle for this annotation.
     * 
     * @param rectangle The new rectangle values.
     */
    public void setRectangle(PDRectangle rectangle)
    {
        dictionary.setItem(COSName.RECT, rectangle.getCOSArray());
    }

    /**
     * This will get the flags for this field.
     * 
     * @return flags The set of flags.
     */
    public int getAnnotationFlags()
    {
        return getCOSObject().getInt(COSName.F, 0);
    }

    /**
     * This will set the flags for this field.
     * 
     * @param flags The new flags.
     */
    public void setAnnotationFlags(int flags)
    {
        getCOSObject().setInt(COSName.F, flags);
    }

    /**
     * Interface method for COSObjectable.
     * 
     * @return This object as a standard COS object.
     */
    @Override
    public COSDictionary getCOSObject()
    {
        return dictionary;
    }

    /**
     * Returns the annotations appearance state, which selects the applicable appearance stream from an appearance
     * subdictionary.
     * 
     * @return the annotations appearance state
     */
    public COSName getAppearanceState()
    {
        return getCOSObject().getCOSName(COSName.AS);
    }

    /**
     * This will set the annotations appearance state name.
     * 
     * @param as The name of the appearance stream.
     */
    public void setAppearanceState(String as)
    {
        getCOSObject().setName(COSName.AS, as);
    }

    /**
     * This will get the appearance dictionary associated with this annotation. This may return null.
     * 
     * @return This annotations appearance.
     */
    public PDAppearanceDictionary getAppearance()
    {
        COSDictionary appearance = dictionary.getCOSDictionary(COSName.AP);
        return appearance != null ? new PDAppearanceDictionary(appearance) : null;
    }

    /**
     * This will set the appearance associated with this annotation.
     * 
     * @param appearance The appearance dictionary for this annotation.
     */
    public void setAppearance(PDAppearanceDictionary appearance)
    {
        dictionary.setItem(COSName.AP, appearance);
    }

    /**
     * Returns the appearance stream for this annotation, if any. The annotation state is taken into account, if
     * present.
     * 
     * @return the appearance stream
     */
    public PDAppearanceStream getNormalAppearanceStream()
    {
        PDAppearanceDictionary appearanceDict = getAppearance();
        if (appearanceDict == null)
        {
            return null;
        }

        PDAppearanceEntry normalAppearance = appearanceDict.getNormalAppearance();
        if (normalAppearance == null)
        {
            return null;
        }

        if (normalAppearance.isSubDictionary())
        {
            COSName state = getAppearanceState();
            return normalAppearance.getSubDictionary().get(state);
        }
        else
        {
// PDAppearanceStream extends PDFormXObject, but does not reference the resource cache
            return normalAppearance.getAppearanceStream();
        }
    }

    /**
     * Get the invisible flag.
     * 
     * @return The invisible flag.
     */
    public boolean isInvisible()
    {
        return getCOSObject().getFlag(COSName.F, FLAG_INVISIBLE);
    }

    /**
     * Set the invisible flag.
     * 
     * @param invisible The new invisible flag.
     */
    public void setInvisible(boolean invisible)
    {
        getCOSObject().setFlag(COSName.F, FLAG_INVISIBLE, invisible);
    }

    /**
     * Get the hidden flag.
     * 
     * @return The hidden flag.
     */
    public boolean isHidden()
    {
        return getCOSObject().getFlag(COSName.F, FLAG_HIDDEN);
    }

    /**
     * Set the hidden flag.
     * 
     * @param hidden The new hidden flag.
     */
    public void setHidden(boolean hidden)
    {
        getCOSObject().setFlag(COSName.F, FLAG_HIDDEN, hidden);
    }

    /**
     * Get the printed flag.
     * 
     * @return The printed flag.
     */
    public boolean isPrinted()
    {
        return getCOSObject().getFlag(COSName.F, FLAG_PRINTED);
    }

    /**
     * Set the printed flag.
     * 
     * @param printed The new printed flag.
     */
    public void setPrinted(boolean printed)
    {
        getCOSObject().setFlag(COSName.F, FLAG_PRINTED, printed);
    }

    /**
     * Get the noZoom flag.
     * 
     * @return The noZoom flag.
     */
    public boolean isNoZoom()
    {
        return getCOSObject().getFlag(COSName.F, FLAG_NO_ZOOM);
    }

    /**
     * Set the noZoom flag.
     * 
     * @param noZoom The new noZoom flag.
     */
    public void setNoZoom(boolean noZoom)
    {
        getCOSObject().setFlag(COSName.F, FLAG_NO_ZOOM, noZoom);
    }

    /**
     * Get the noRotate flag.
     * 
     * @return The noRotate flag.
     */
    public boolean isNoRotate()
    {
        return getCOSObject().getFlag(COSName.F, FLAG_NO_ROTATE);
    }

    /**
     * Set the noRotate flag.
     * 
     * @param noRotate The new noRotate flag.
     */
    public void setNoRotate(boolean noRotate)
    {
        getCOSObject().setFlag(COSName.F, FLAG_NO_ROTATE, noRotate);
    }

    /**
     * Get the noView flag.
     * 
     * @return The noView flag.
     */
    public boolean isNoView()
    {
        return getCOSObject().getFlag(COSName.F, FLAG_NO_VIEW);
    }

    /**
     * Set the noView flag.
     * 
     * @param noView The new noView flag.
     */
    public void setNoView(boolean noView)
    {
        getCOSObject().setFlag(COSName.F, FLAG_NO_VIEW, noView);
    }

    /**
     * Get the readOnly flag.
     * 
     * @return The readOnly flag.
     */
    public boolean isReadOnly()
    {
        return getCOSObject().getFlag(COSName.F, FLAG_READ_ONLY);
    }

    /**
     * Set the readOnly flag.
     * 
     * @param readOnly The new readOnly flag.
     */
    public void setReadOnly(boolean readOnly)
    {
        getCOSObject().setFlag(COSName.F, FLAG_READ_ONLY, readOnly);
    }

    /**
     * Get the locked flag.
     * 
     * @return The locked flag.
     */
    public boolean isLocked()
    {
        return getCOSObject().getFlag(COSName.F, FLAG_LOCKED);
    }

    /**
     * Set the locked flag.
     * 
     * @param locked The new locked flag.
     */
    public void setLocked(boolean locked)
    {
        getCOSObject().setFlag(COSName.F, FLAG_LOCKED, locked);
    }

    /**
     * Get the toggleNoView flag.
     * 
     * @return The toggleNoView flag.
     */
    public boolean isToggleNoView()
    {
        return getCOSObject().getFlag(COSName.F, FLAG_TOGGLE_NO_VIEW);
    }

    /**
     * Set the toggleNoView flag.
     * 
     * @param toggleNoView The new toggleNoView flag.
     */
    public void setToggleNoView(boolean toggleNoView)
    {
        getCOSObject().setFlag(COSName.F, FLAG_TOGGLE_NO_VIEW, toggleNoView);
    }

    /**
     * Get the LockedContents flag.
     *
     * @return The LockedContents flag.
     * @see #setLockedContents(boolean)
     */
    public boolean isLockedContents()
    {
        return getCOSObject().getFlag(COSName.F, FLAG_LOCKED_CONTENTS);
    }

    /**
     * Set the LockedContents flag. If set, do not allow the contents of the annotation to be
     * modified by the user. This flag does not restrict deletion of the annotation or changes to
     * other annotation properties, such as position and size.
     *
     * @param lockedContents The new LockedContents flag value.
     * @see
     * <a href="https://www.adobe.com/content/dam/acom/en/devnet/acrobat/pdfs/PDF32000_2008.pdf#page=393">PDF
     * 32000-1:2008 12.5.3, Table 165</a>
     * @see #isLockedContents()
     * @see #FLAG_LOCKED_CONTENTS
     * @since PDF 1.7
     */
    public void setLockedContents(boolean lockedContents)
    {
        getCOSObject().setFlag(COSName.F, FLAG_LOCKED_CONTENTS, lockedContents);
    }

    /**
     * Get the "contents" of the field.
     * 
     * @return the value of the contents.
     */
    public String getContents()
    {
        return dictionary.getString(COSName.CONTENTS);
    }

    /**
     * Set the "contents" of the field.
     * 
     * @param value the value of the contents.
     */
    public void setContents(String value)
    {
        dictionary.setString(COSName.CONTENTS, value);
    }

    /**
     * This will retrieve the date and time the annotation was modified.
     * 
     * @return the modified date/time (often in date format, but can be an arbitrary string).
     */
    public String getModifiedDate()
    {
        return getCOSObject().getString(COSName.M);
    }

    /**
     * This will set the date and time the annotation was modified.
     *
     * @param m the date and time the annotation was created. Date values used in a PDF shall
     * conform to a standard date format, which closely follows that of the international standard
     * ASN.1 (Abstract Syntax Notation One), defined in ISO/IEC 8824. A date shall be a text string
     * of the form (D:YYYYMMDDHHmmSSOHH'mm). Alternatively, use
     * {@link #setModifiedDate(java.util.Calendar)}
     */
    public void setModifiedDate(String m)
    {
        getCOSObject().setString(COSName.M, m);
    }

    /**
     * This will set the date and time the annotation was modified.
     *
     * @param c the date and time the annotation was created.
     */
    public void setModifiedDate(Calendar c)
    {
        getCOSObject().setDate(COSName.M, c);
    }

    /**
     * This will get the name, a string intended to uniquely identify each annotation within a page. Not to be confused
     * with some annotations Name entry which impact the default image drawn for them.
     * 
     * @return The identifying name for the Annotation.
     */
    public String getAnnotationName()
    {
        return getCOSObject().getString(COSName.NM);
    }

    /**
     * This will set the name, a string intended to uniquely identify each annotation within a page. Not to be confused
     * with some annotations Name entry which impact the default image drawn for them.
     * 
     * @param nm The identifying name for the annotation.
     */
    public void setAnnotationName(String nm)
    {
        getCOSObject().setString(COSName.NM, nm);
    }

    /**
     * This will get the key of this annotation in the structural parent tree.
     *
     * @return the integer key of the annotation's entry in the structural parent tree or -1 if
     * there isn't any.
     */
    public int getStructParent()
    {
        return getCOSObject().getInt(COSName.STRUCT_PARENT);
    }

    /**
     * This will set the key for this annotation in the structural parent tree.
     * 
     * @param structParent The new key for this annotation.
     */
    public void setStructParent(int structParent)
    {
        getCOSObject().setInt(COSName.STRUCT_PARENT, structParent);
    }

    /**
     * This will get the optional content group or optional content membership dictionary for the
     * annotation.
     *
     * @return The optional content group or optional content membership dictionary or null if there
     * is none.
     */
    public PDPropertyList getOptionalContent()
    {
        COSDictionary optionalContent = getCOSObject().getCOSDictionary(COSName.OC);
        return optionalContent != null ? PDPropertyList.create(optionalContent) : null;
    }

    /**
     * Sets the optional content group or optional content membership dictionary for the annotation.
     *
     * @param oc The optional content group or optional content membership dictionary.
     */
    public void setOptionalContent(PDPropertyList oc)
    {
        getCOSObject().setItem(COSName.OC, oc);
    }

    /**
     * This will retrieve the border array. If none is available then it will create and return a
     * default array, which is [0 0 1]. The array consists of at least three numbers defining the
     * horizontal corner radius, vertical corner radius, and border width. The array may have a
     * fourth element, an optional dash array defining a pattern of dashes and gaps that shall be
     * used in drawing the border. If the array has less than three elements, the original array
     * will be copied and missing elements with value 0 will be added.
     *
     * @return the border array, never null.
     */
    public COSArray getBorder()
    {
        COSArray border = getCOSObject().getCOSArray(COSName.BORDER);
        if (border != null)
        {
            if (border.size() < 3)
            {
                // create a copy to avoid altering the PDF
                COSArray newBorder = new COSArray();
                newBorder.addAll(border);
                border = newBorder;
                // Adobe Reader behaves as if missing elements are 0.
                while (border.size() < 3)
                {
                    border.add(COSInteger.ZERO);
                }
            }
        }
        else
        {
            border = new COSArray();
            border.add(COSInteger.ZERO);
            border.add(COSInteger.ZERO);
            border.add(COSInteger.ONE);
        }
        return border;
    }
    
    /**
     * This will set the border array.
     * 
     * @param borderArray the border array to set.
     */
    public void setBorder(COSArray borderArray)
    {
        getCOSObject().setItem(COSName.BORDER, borderArray);
    }
    
    /**
     * This will set the color used in drawing various elements. As of PDF 1.6 these are : Background of icon when
     * closed Title bar of popup window Border of a link annotation
     * 
     * Colour is in DeviceRGB colourspace
     * 
     * @param c colour in the DeviceRGB colourspace
     * 
     */
    public void setColor(PDColor c)
    {
        getCOSObject().setItem(COSName.C, c.toCOSArray());
    }

    /**
     * This will retrieve the color used in drawing various elements. As of PDF 1.6 these are :
     * <ul>
     * <li>Background of icon when closed</li>
     * <li>Title bar of popup window</li>
     * <li>Border of a link annotation</li>
     * </ul>
     *
     * @return Color object representing the colour
     * 
     */
    public PDColor getColor()
    {
        return getColor(COSName.C);
    }

    protected PDColor getColor(COSName itemName)
    {
        COSArray cs = this.getCOSObject().getCOSArray(itemName);
        if (cs != null)
        {
            PDColorSpace colorSpace = null;
            switch (cs.size())
            {
            case 1:
                colorSpace = PDDeviceGray.INSTANCE;
                break;
            case 3:
                colorSpace = PDDeviceRGB.INSTANCE;
                break;
            case 4:
                colorSpace = PDDeviceCMYK.INSTANCE;
                break;
            default:
                break;
            }
            return new PDColor(cs, colorSpace);
        }
        return null;
    }

    /**
     * This will set the corresponding page for this annotation. This is optional but recommended.
     * Not doing it <a href="https://stackoverflow.com/questions/74836898/">can cause trouble when
     * PDFs get signed</a>.
     *
     * @param page is the corresponding page
     */
    public void setPage(PDPage page)
    {
        this.getCOSObject().setItem(COSName.P, page);
    }

    /**
     * This will retrieve the corresponding page of this annotation. See also
     * <a href="https://stackoverflow.com/a/36894982/535646">this answer</a> about what to do if
     * the page isn't available.
     *
     * @return The corresponding page or null if not available.
     */
    public PDPage getPage()
    {
        COSDictionary page = getCOSObject().getCOSDictionary(COSName.P);
        return page != null ? new PDPage(page) : null;
    }

    /**
     * Create the appearance entry for this annotation. Not having it may prevent display in some viewers. This method
     * is for overriding in subclasses, the default implementation does nothing.
     * 
     * @param document the related document
     */
    public void constructAppearances(PDDocument document)
    {
    }

    /**
     * Create the appearance entry for this annotation. Not having it may prevent display in some
     * viewers. This method is for overriding in subclasses, the default implementation does
     * nothing.
     * 
     */
    public void constructAppearances()
    {
    }

}
