/*
 * 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.
 */

/* $Id$ */

package org.apache.fop.render.ps;

import java.awt.Color;
import java.awt.Point;
import java.io.IOException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.apache.xmlgraphics.ps.PSGenerator;

import org.apache.fop.fo.Constants;
import org.apache.fop.render.intermediate.ArcToBezierCurveTransformer;
import org.apache.fop.render.intermediate.BezierCurvePainter;
import org.apache.fop.render.intermediate.BorderPainter;
import org.apache.fop.render.intermediate.GraphicsPainter;
import org.apache.fop.traits.RuleStyle;
import org.apache.fop.util.ColorUtil;

/**
 * PostScript-specific implementation of the {@link BorderPainter}.
 */
public class PSGraphicsPainter implements GraphicsPainter, BezierCurvePainter {

    /** logging instance */
    private static Log log = LogFactory.getLog(PSGraphicsPainter.class);

    private final PSGenerator generator;

    /** Used for drawing arcs since PS does not natively support drawing elliptic curves */
    private final ArcToBezierCurveTransformer arcToBezierCurveTransformer;

    /**
     * Creates a new border painter for PostScript.
     * @param generator the PostScript generator
     */
    public PSGraphicsPainter(PSGenerator generator) {
        this.generator = generator;
        this.arcToBezierCurveTransformer = new ArcToBezierCurveTransformer(this);
    }

    /** {@inheritDoc} */
    public void drawBorderLine(int x1, int y1, int x2, int y2, boolean horz,
            boolean startOrBefore, int style, Color col) throws IOException {
        drawBorderLine(generator, toPoints(x1), toPoints(y1), toPoints(x2), toPoints(y2),
                horz, startOrBefore, style, col);
    }

    private static void drawLine(PSGenerator gen,
            float startx, float starty, float endx, float endy) throws IOException {
        gen.writeln(gen.formatDouble(startx) + " "
                + gen.formatDouble(starty) + " " + gen.mapCommand("moveto") + " "
                + gen.formatDouble(endx) + " "
                + gen.formatDouble(endy) + " " + gen.mapCommand("lineto") + " "
                + gen.mapCommand("stroke") + " " + gen.mapCommand("newpath"));
    }

    /** {@inheritDoc} */
    public static void drawBorderLine(PSGenerator gen,
            float x1, float y1, float x2, float y2, boolean horz,
            boolean startOrBefore, int style, Color col) throws IOException {
        float w = x2 - x1;
        float h = y2 - y1;
        if ((w < 0) || (h < 0)) {
            log.error("Negative extent received. Border won't be painted.");
            return;
        }
        switch (style) {
        case Constants.EN_DASHED:
            gen.useColor(col);
            if (horz) {
                float dashWidth = BorderPainter.dashWidthCalculator(w, h);
                if (dashWidth != 0) {
                    gen.useDash("[" + dashWidth + " " + BorderPainter.DASHED_BORDER_SPACE_RATIO
                            * dashWidth + "] 0");
                }
                gen.useLineCap(0);
                gen.useLineWidth(h);
                float ym = y1 + (h / 2);
                drawLine(gen, x1, ym, x2, ym);
            } else {
                float dashWidth = BorderPainter.dashWidthCalculator(h, w);
                if (dashWidth != 0) {
                    gen.useDash("[" + dashWidth + " " + BorderPainter.DASHED_BORDER_SPACE_RATIO
                            * dashWidth + "] 0");
                }
                gen.useLineCap(0);
                gen.useLineWidth(w);
                float xm = x1 + (w / 2);
                drawLine(gen, xm, y1, xm, y2);
            }
            break;
        case Constants.EN_DOTTED:
            gen.useColor(col);
            gen.useLineCap(1); //Rounded!
            if (horz) {
                float unit = Math.abs(2 * h);
                int rep = (int) (w / unit);
                if (rep % 2 == 0) {
                    rep++;
                }
                unit = w / rep;
                gen.useDash("[0 " + unit + "] 0");
                gen.useLineWidth(h);
                float ym = y1 + (h / 2);
                drawLine(gen, x1, ym, x2, ym);
            } else {
                float unit = Math.abs(2 * w);
                int rep = (int) (h / unit);
                if (rep % 2 == 0) {
                    rep++;
                }
                unit = h / rep;
                gen.useDash("[0 " + unit + "] 0");
                gen.useLineWidth(w);
                float xm = x1 + (w / 2);
                drawLine(gen, xm, y1, xm, y2);
            }
            break;
        case Constants.EN_DOUBLE:
            gen.useColor(col);
            gen.useDash(null);
            if (horz) {
                float h3 = h / 3;
                gen.useLineWidth(h3);
                float ym1 = y1 + (h3 / 2);
                float ym2 = ym1 + h3 + h3;
                drawLine(gen, x1, ym1, x2, ym1);
                drawLine(gen, x1, ym2, x2, ym2);
            } else {
                float w3 = w / 3;
                gen.useLineWidth(w3);
                float xm1 = x1 + (w3 / 2);
                float xm2 = xm1 + w3 + w3;
                drawLine(gen, xm1, y1, xm1, y2);
                drawLine(gen, xm2, y1, xm2, y2);
            }
            break;
        case Constants.EN_GROOVE:
        case Constants.EN_RIDGE:
            float colFactor = (style == Constants.EN_GROOVE ? 0.4f : -0.4f);
            gen.useDash(null);
            if (horz) {
                Color uppercol = ColorUtil.lightenColor(col, -colFactor);
                Color lowercol = ColorUtil.lightenColor(col, colFactor);
                float h3 = h / 3;
                gen.useLineWidth(h3);
                float ym1 = y1 + (h3 / 2);
                gen.useColor(uppercol);
                drawLine(gen, x1, ym1, x2, ym1);
                gen.useColor(col);
                drawLine(gen, x1, ym1 + h3, x2, ym1 + h3);
                gen.useColor(lowercol);
                drawLine(gen, x1, ym1 + h3 + h3, x2, ym1 + h3 + h3);
            } else {
                Color leftcol = ColorUtil.lightenColor(col, -colFactor);
                Color rightcol = ColorUtil.lightenColor(col, colFactor);
                float w3 = w / 3;
                gen.useLineWidth(w3);
                float xm1 = x1 + (w3 / 2);
                gen.useColor(leftcol);
                drawLine(gen, xm1, y1, xm1, y2);
                gen.useColor(col);
                drawLine(gen, xm1 + w3, y1, xm1 + w3, y2);
                gen.useColor(rightcol);
                drawLine(gen, xm1 + w3 + w3, y1, xm1 + w3 + w3, y2);
            }
            break;
        case Constants.EN_INSET:
        case Constants.EN_OUTSET:
            colFactor = (style == Constants.EN_OUTSET ? 0.4f : -0.4f);
            gen.useDash(null);
            if (horz) {
                Color c = ColorUtil.lightenColor(col, (startOrBefore ? 1 : -1) * colFactor);
                gen.useLineWidth(h);
                float ym1 = y1 + (h / 2);
                gen.useColor(c);
                drawLine(gen, x1, ym1, x2, ym1);
            } else {
                Color c = ColorUtil.lightenColor(col, (startOrBefore ? 1 : -1) * colFactor);
                gen.useLineWidth(w);
                float xm1 = x1 + (w / 2);
                gen.useColor(c);
                drawLine(gen, xm1, y1, xm1, y2);
            }
            break;
        case Constants.EN_HIDDEN:
            break;
        default:
            gen.useColor(col);
            gen.useDash(null);
            gen.useLineCap(0);
            if (horz) {
                gen.useLineWidth(h);
                float ym = y1 + (h / 2);
                drawLine(gen, x1, ym, x2, ym);
            } else {
                gen.useLineWidth(w);
                float xm = x1 + (w / 2);
                drawLine(gen, xm, y1, xm, y2);
            }
        }
    }

    /** {@inheritDoc} */
    public void drawLine(Point start, Point end,
            int width, Color color, RuleStyle style) throws IOException {
        if (start.y != end.y) {
            //TODO Support arbitrary lines if necessary
            throw new UnsupportedOperationException(
                    "Can only deal with horizontal lines right now");
        }

        saveGraphicsState();
        int half = width / 2;
        int starty = start.y - half;
        //Rectangle boundingRect = new Rectangle(start.x, start.y - half, end.x - start.x, width);

        switch (style.getEnumValue()) {
        case Constants.EN_SOLID:
        case Constants.EN_DASHED:
        case Constants.EN_DOUBLE:
            drawBorderLine(start.x, starty, end.x, starty + width,
                    true, true, style.getEnumValue(), color);
            break;
        case Constants.EN_DOTTED:
            clipRect(start.x, starty, end.x - start.x, width);
            //This displaces the dots to the right by half a dot's width
            //TODO There's room for improvement here
            generator.concatMatrix(1, 0, 0, 1, toPoints(half), 0);
            drawBorderLine(start.x, starty, end.x, starty + width,
                    true, true, style.getEnumValue(), color);
            break;
        case Constants.EN_GROOVE:
        case Constants.EN_RIDGE:
            generator.useColor(ColorUtil.lightenColor(color, 0.6f));
            moveTo(start.x, starty);
            lineTo(end.x, starty);
            lineTo(end.x, starty + 2 * half);
            lineTo(start.x, starty + 2 * half);
            closePath();
            generator.write(" " + generator.mapCommand("fill"));
            generator.writeln(" " + generator.mapCommand("newpath"));
            generator.useColor(color);
            if (style == RuleStyle.GROOVE) {
                moveTo(start.x, starty);
                lineTo(end.x, starty);
                lineTo(end.x, starty + half);
                lineTo(start.x + half, starty + half);
                lineTo(start.x, starty + 2 * half);
            } else {
                moveTo(end.x, starty);
                lineTo(end.x, starty + 2 * half);
                lineTo(start.x, starty + 2 * half);
                lineTo(start.x, starty + half);
                lineTo(end.x - half, starty + half);
            }
            closePath();
            generator.write(" " + generator.mapCommand("fill"));
            generator.writeln(" " + generator.mapCommand("newpath"));
            break;
        default:
            throw new UnsupportedOperationException("rule style not supported");
        }

        restoreGraphicsState();

    }

    private static float toPoints(int mpt) {
        return mpt / 1000f;
    }

    /** {@inheritDoc} */
    public void moveTo(int x, int y) throws IOException {
        generator.writeln(generator.formatDouble(toPoints(x)) + " "
                + generator.formatDouble(toPoints(y)) + " " + generator.mapCommand("moveto"));
    }

    /** {@inheritDoc} */
    public void lineTo(int x, int y) throws IOException {
        generator.writeln(generator.formatDouble(toPoints(x)) + " "
                + generator.formatDouble(toPoints(y)) + " " + generator.mapCommand("lineto"));
    }

    /** {@inheritDoc} */
    public void arcTo(final double startAngle, final double endAngle, final int cx, final int cy,
            final int width, final int height) throws IOException {
        arcToBezierCurveTransformer.arcTo(startAngle, endAngle, cx, cy, width, height);
    }

    /** {@inheritDoc} */
    public void closePath() throws IOException {
        generator.writeln("cp");
    }

    private void clipRect(int x, int y, int width, int height) throws IOException {
        generator.defineRect(toPoints(x), toPoints(y), toPoints(width), toPoints(height));
        clip();
    }

    /** {@inheritDoc} */
    public void clip() throws IOException {
        generator.writeln(generator.mapCommand("clip") + " " + generator.mapCommand("newpath"));
    }

    /** {@inheritDoc} */
    public void saveGraphicsState() throws IOException {
        generator.saveGraphicsState();
    }

    /** {@inheritDoc} */
    public void restoreGraphicsState() throws IOException {
        generator.restoreGraphicsState();
    }

    /** {@inheritDoc} */
    public void rotateCoordinates(double angle) throws IOException {
        StringBuffer sb = new StringBuffer()
                .append(generator.formatDouble(angle * 180d / Math.PI))
                .append("  rotate ");
        generator.writeln(sb.toString());
    }

    /** {@inheritDoc} */
    public void translateCoordinates(int xTranslate, int yTranslate) throws IOException {
        StringBuffer sb = new StringBuffer()
                .append(generator.formatDouble(toPoints(xTranslate)))
                .append(" ")
                .append(generator.formatDouble(toPoints(yTranslate)))
                .append("  translate ");
        generator.writeln(sb.toString());
    }

    /** {@inheritDoc} */
    public void scaleCoordinates(float xScale, float yScale) throws IOException {
        StringBuffer sb = new StringBuffer()
                .append(generator.formatDouble(xScale))
                .append(" ")
                .append(generator.formatDouble(yScale))
                .append("  scale ");
        generator.writeln(sb.toString());
    }

    /** {@inheritDoc} */
    public void cubicBezierTo(int p1x, int p1y, int p2x, int p2y, int p3x, int p3y)
            throws IOException {
        StringBuffer sb = new StringBuffer()
                .append(generator.formatDouble(toPoints(p1x)))
                .append(" ")
                .append(generator.formatDouble(toPoints(p1y)))
                .append(" ")
                .append(generator.formatDouble(toPoints(p2x)))
                .append(" ")
                .append(generator.formatDouble(toPoints(p2y)))
                .append(" ")
                .append(generator.formatDouble(toPoints(p3x)))
                .append(" ")
                .append(generator.formatDouble(toPoints(p3y)))
                .append(" curveto ");
        generator.writeln(sb.toString());
    }

}
