/*-
 * ============LICENSE_START=======================================================
 * ONAP CLAMP
 * ================================================================================
 * Copyright (C) 2019 Nokia. All rights
 *                             reserved.
 * ================================================================================
 * Licensed 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.
 * ============LICENSE_END============================================
 * ===================================================================
 *
 */

package org.onap.clamp.clds.util.drawing;

import java.awt.BasicStroke;
import java.awt.Point;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.geom.Ellipse2D;
import java.util.UUID;

import org.apache.batik.svggen.SVGGraphics2D;

public class ImageBuilder {

    public static final int POLICY_LINE_RATIO = 2;
    public static final int COLLECTOR_LINE_RATIO = 6;
    public static final float MS_LINE_TO_HEIGHT_RATIO = 0.75f;
    public static final float ARROW_TO_BASELINE_RATIO = 0.75f;

    private Point currentPoint;
    private final int baseLength;
    private final int rectHeight;
    private final SVGGraphics2D g2d;
    private final DocumentBuilder documentBuilder;

    private static final int LINE_THICKNESS = 2;
    private static final int CIRCLE_RADIUS = 17;

    ImageBuilder(SVGGraphics2D svgGraphics2D, DocumentBuilder documentBuilder, Point startingPoint, int baseLength,
            int rectHeight) {
        this.g2d = svgGraphics2D;
        this.documentBuilder = documentBuilder;
        this.currentPoint = new Point(startingPoint);
        this.baseLength = baseLength;
        this.rectHeight = rectHeight;
    }

    ImageBuilder rectangle(String dataElementId, RectTypes rectType, String text) {
        Point next = new Point(currentPoint.x + baseLength, currentPoint.y);
        Point point = coordinatesForRectangle(currentPoint, next);

        handleBasedOnRectType(rectType, text, point, baseLength, rectHeight);

        documentBuilder.pushChangestoDocument(g2d, dataElementId);
        currentPoint = next;
        return this;
    }

    ImageBuilder arrow() {
        String dataElementId = "Arrow-" + UUID.randomUUID().toString();
        Point to = new Point(currentPoint.x + (int) (baseLength * ARROW_TO_BASELINE_RATIO), currentPoint.y);
        AwtUtils.drawArrow(g2d, currentPoint, to, LINE_THICKNESS);
        documentBuilder.pushChangestoDocument(g2d, dataElementId);
        currentPoint = to;
        return this;
    }

    ImageBuilder circle(String dataElementId, int lineThickness) {
        Shape circleStart = new Ellipse2D.Double(currentPoint.x, ((double) currentPoint.y) - CIRCLE_RADIUS,
                2.0 * CIRCLE_RADIUS, 2.0 * CIRCLE_RADIUS);

        Stroke oldStroke = g2d.getStroke();
        g2d.setStroke(new BasicStroke(lineThickness));
        g2d.draw(circleStart);
        g2d.setStroke(oldStroke);
        documentBuilder.pushChangestoDocument(g2d, dataElementId);
        Point to = new Point(currentPoint.x + 2 * CIRCLE_RADIUS, currentPoint.y);
        currentPoint = to;
        return this;
    }

    DocumentBuilder getDocumentBuilder() {
        return documentBuilder;
    }

    private void handleBasedOnRectType(RectTypes rectType, String text, Point point, int width, int height) {
        AwtUtils.rectWithText(g2d, text, point, width, height);
        switch (rectType) {
            case COLECTOR:
                drawVerticalLineForCollector(point, width, height);
                break;
            case MICROSERVICE:
                drawHorizontalLineForMicroService(point, width, height);
                break;
            case POLICY:
                drawDiagonalLineForPolicy(point, width, height);
                break;
            default:
        }
    }

    private void drawVerticalLineForCollector(Point point, int width, int height) {
        g2d.drawLine(point.x + width / COLLECTOR_LINE_RATIO, point.y, point.x + width / COLLECTOR_LINE_RATIO,
                point.y + height);
    }

    private void drawHorizontalLineForMicroService(Point point, int width, int height) {
        int pointY = calculateMsHorizontalLineYCoordinate(point, height);
        g2d.drawLine(point.x, pointY, point.x + width, pointY);
    }

    private void drawDiagonalLineForPolicy(Point point, int width, int height) {
        g2d.drawLine(point.x, point.y + height / POLICY_LINE_RATIO, point.x + width / POLICY_LINE_RATIO, point.y);
    }

    private int calculateMsHorizontalLineYCoordinate(Point point, int height) {
        return (int) (point.y * height * MS_LINE_TO_HEIGHT_RATIO);
    }

    private Point coordinatesForRectangle(Point from, Point next) {
        int pointX = from.x;
        int pointY = from.y - next.y + LINE_THICKNESS / 2;
        return new Point(pointX, pointY);
    }

}