/*
 * 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.
 */

/* $Id: PDFTextPainter.java 1805173 2017-08-16 10:50:04Z ssteiner $ */

package org.apache.fop.svg;

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.geom.AffineTransform;
import java.awt.geom.GeneralPath;
import java.awt.geom.Point2D;
import java.io.IOException;

import org.apache.batik.gvt.text.TextPaintInfo;

import org.apache.fop.fonts.Font;
import org.apache.fop.fonts.FontInfo;
import org.apache.fop.svg.font.FOPGVTFont;
import org.apache.fop.svg.font.FOPGVTGlyphVector;

Renders the attributed character iterator of a TextNode. This class draws the text directly into the PDFGraphics2D so that the text is not drawn using shapes which makes the PDF files larger. If the text is simple enough to draw then it sets the font and calls drawString. If the text is complex or the cannot be translated into a simple drawString the StrokingTextPainter is used instead. 
Version:
$Id: PDFTextPainter.java 1805173 2017-08-16 10:50:04Z ssteiner $/**
 * Renders the attributed character iterator of a {@link org.apache.batik.bridge.TextNode}.
 * This class draws the text directly into the PDFGraphics2D so that
 * the text is not drawn using shapes which makes the PDF files larger.
 * If the text is simple enough to draw then it sets the font and calls
 * drawString. If the text is complex or the cannot be translated
 * into a simple drawString the StrokingTextPainter is used instead.
 *
 * @version $Id: PDFTextPainter.java 1805173 2017-08-16 10:50:04Z ssteiner $
 */
class PDFTextPainter extends NativeTextPainter {

    private PDFGraphics2D pdf;

    private PDFTextUtil textUtil;

    private double prevVisibleGlyphWidth;

    private boolean repositionNextGlyph;

    
Create a new PDF text painter with the given font information.
Params:
fi – the font info/**
     * Create a new PDF text painter with the given font information.
     *
     * @param fi the font info
     */
    public PDFTextPainter(FontInfo fi) {
        super(fi);
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override
    protected boolean isSupported(Graphics2D g2d) {
        return g2d instanceof PDFGraphics2D;
    }

    @Override
    protected void preparePainting(Graphics2D g2d) {
        pdf = (PDFGraphics2D) g2d;
    }

    @Override
    protected void saveGraphicsState() {
        pdf.saveGraphicsState();
    }

    @Override
    protected void restoreGraphicsState() {
        pdf.restoreGraphicsState();
    }

    @Override
    protected void setInitialTransform(AffineTransform transform) {
        createTextUtil();
        textUtil.concatMatrix(transform);
    }

    private void createTextUtil() {
        textUtil = new PDFTextUtil(pdf.fontInfo) {
            protected void write(String code) {
                pdf.currentStream.write(code);
            }
            protected void write(StringBuffer code) {
                pdf.currentStream.append(code);
            }
        };
    }

    @Override
    protected void clip(Shape clip) {
        pdf.writeClip(clip);
    }

    private static int[] paZero = new int[4];

    protected void writeGlyphs(FOPGVTGlyphVector gv, GeneralPath debugShapes) throws IOException {
        if (gv.getGlyphPositionAdjustments() == null) {
            super.writeGlyphs(gv, debugShapes);
        } else {
            FOPGVTFont gvtFont = (FOPGVTFont) gv.getFont();
            String fk = gvtFont.getFontKey();
            Font f = gvtFont.getFont();
            Point2D initialPos = gv.getGlyphPosition(0);
            if (f.isMultiByte()) {
                int         fs              = f.getFontSize();
                float       fsPoints        = fs / 1000f;
                double      xc              = 0f;
                double      yc              = 0f;
                double      xoLast          = 0f;
                double      yoLast          = 0f;
                textUtil.writeTextMatrix(new AffineTransform(1, 0, 0, -1, initialPos.getX(), initialPos.getY()));
                textUtil.updateTf(fk, fsPoints, true, false);
                int[][] dp = gv.getGlyphPositionAdjustments();
                for (int i = 0, n = gv.getNumGlyphs(); i < n; i++) {
                    int     gc              = gv.getGlyphCode(i);
                    int[]   pa              = ((i > dp.length) || (dp[i] == null)) ? paZero : dp[i];
                    double  xo              = xc + pa[0];
                    double  yo              = yc + pa[1];
                    double  xa              = f.getWidth(gc);
                    double  ya              = 0;
                    double  xd              = (xo - xoLast) / 1000f;
                    double  yd              = (yo - yoLast) / 1000f;
                    textUtil.writeTd(xd, yd);
                    textUtil.writeTj((char) gc, true, false);
                    xc += xa + pa[2];
                    yc += ya + pa[3];
                    xoLast = xo;
                    yoLast = yo;
                }
            }
        }
    }

    @Override
    protected void beginTextObject() {
        applyColorAndPaint(tpi);
        textUtil.beginTextObject();
        boolean stroke = (tpi.strokePaint != null) && (tpi.strokeStroke != null);
        textUtil.setTextRenderingMode(tpi.fillPaint != null, stroke, false);
    }

    @Override
    protected void endTextObject() {
        textUtil.writeTJ();
        textUtil.endTextObject();
    }

    private void applyColorAndPaint(TextPaintInfo tpi) {
        Paint fillPaint = tpi.fillPaint;
        Paint strokePaint = tpi.strokePaint;
        Stroke stroke = tpi.strokeStroke;
        int fillAlpha = PDFGraphics2D.OPAQUE;
        if (fillPaint instanceof Color) {
            Color col = (Color) fillPaint;
            pdf.applyColor(col, true);
            fillAlpha = col.getAlpha();
        }
        if (strokePaint instanceof Color) {
            Color col = (Color) strokePaint;
            pdf.applyColor(col, false);
        }
        pdf.applyPaint(fillPaint, true);
        pdf.applyStroke(stroke);
        if (strokePaint != null) {
            pdf.applyPaint(strokePaint, false);
        }
        pdf.applyAlpha(fillAlpha, PDFGraphics2D.OPAQUE);
    }

    @Override
    protected void positionGlyph(Point2D prevPos, Point2D glyphPos, boolean reposition) {
        // TODO Glyph transforms could be refined so not every char has to be painted
        // with its own TJ command (stretch/squeeze case could be optimized)
        repositionNextGlyph = (prevPos == null
                || prevPos.getY() != glyphPos.getY()
                || reposition);
        if (!repositionNextGlyph) {
            double xdiff = glyphPos.getX() - prevPos.getX();
            //Width of previous character
            double cw = prevVisibleGlyphWidth;
            double effxdiff = (1000 * xdiff) - cw;
            if (effxdiff != 0) {
                double adjust = (-effxdiff / font.getFontSize());
                textUtil.adjustGlyphTJ(adjust * 1000);
            }
        }
    }

    @Override
    protected void writeGlyph(char glyph, AffineTransform transform) {
        prevVisibleGlyphWidth = font.getWidth(glyph);
        boolean encodingChanging = false; // used for single byte
        if (!textUtil.isMultiByteFont(font.getFontName())) {
            int encoding = glyph / 256;
            glyph = (char) (glyph % 256);
            if (textUtil.getCurrentEncoding() != encoding) {
                textUtil.setCurrentEncoding(encoding);
                encodingChanging = true;
            }
        }
        if (repositionNextGlyph || encodingChanging) {
            textUtil.writeTJ();
            if (font != textUtil.getCurrentFont() || encodingChanging) {
                textUtil.setCurrentFont(font);
                textUtil.writeTf(font);
            }
            textUtil.writeTextMatrix(transform);
        }
        textUtil.writeTJMappedChar(glyph);
    }

}