/*
 * Copyright 2010, 2011, 2012, 2013 mapsforge.org
 * Copyright 2014 Ludwig M Brinckmann
 * Copyright 2014-2018 devemux86
 * Copyright 2015 Andreas Schildbach
 * Copyright 2018 mikes222
 *
 * This program is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.mapsforge.map.android.view;

import android.content.Context;
import android.graphics.Canvas;
import android.os.Handler;
import android.os.Looper;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.view.ViewGroup;

import org.mapsforge.core.graphics.GraphicFactory;
import org.mapsforge.core.model.BoundingBox;
import org.mapsforge.core.model.Dimension;
import org.mapsforge.core.model.LatLong;
import org.mapsforge.core.model.Point;
import org.mapsforge.map.android.graphics.AndroidGraphicFactory;
import org.mapsforge.map.android.input.MapZoomControls;
import org.mapsforge.map.android.input.TouchGestureHandler;
import org.mapsforge.map.controller.FrameBufferController;
import org.mapsforge.map.controller.LayerManagerController;
import org.mapsforge.map.controller.MapViewController;
import org.mapsforge.map.layer.Layer;
import org.mapsforge.map.layer.LayerManager;
import org.mapsforge.map.layer.TileLayer;
import org.mapsforge.map.layer.labels.LabelStore;
import org.mapsforge.map.layer.renderer.TileRendererLayer;
import org.mapsforge.map.model.Model;
import org.mapsforge.map.model.common.Observer;
import org.mapsforge.map.scalebar.DefaultMapScaleBar;
import org.mapsforge.map.scalebar.MapScaleBar;
import org.mapsforge.map.util.MapPositionUtil;
import org.mapsforge.map.util.MapViewProjection;
import org.mapsforge.map.view.FpsCounter;
import org.mapsforge.map.view.FrameBuffer;
import org.mapsforge.map.view.FrameBufferHA2;
import org.mapsforge.map.view.InputListener;

import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;

public class MapView extends ViewGroup implements org.mapsforge.map.view.MapView, Observer {

    /**
     * Child view Layout information associated with MapView.
     */
    public static class LayoutParams extends ViewGroup.LayoutParams {

        /**
         * Special values for the alignment requested by child views.
         */
        public enum Alignment {
            TOP_LEFT, TOP_CENTER, TOP_RIGHT, CENTER_LEFT, CENTER, CENTER_RIGHT, BOTTOM_LEFT, BOTTOM_CENTER, BOTTOM_RIGHT
        }

        /**
         * The location of the child view within the map view.
         */
        public LatLong latLong;

        /**
         * The alignment of the view compared to the location.
         */
        public Alignment alignment;

        public LayoutParams(Context c, AttributeSet attrs) {
            super(c, attrs);
            this.alignment = LayoutParams.Alignment.BOTTOM_CENTER;
        }

        /**
         * Creates a new set of layout parameters for a child view of MapView.
         *
         * @param width     the width of the child, either {@link #MATCH_PARENT}, {@link #WRAP_CONTENT} or a fixed size in pixels.
         * @param height    the height of the child, either {@link #MATCH_PARENT}, {@link #WRAP_CONTENT} or a fixed size in pixels.
         * @param latLong   the location of the child within the map view.
         * @param alignment the alignment of the view compared to the location.
         */
        public LayoutParams(int width, int height, LatLong latLong, Alignment alignment) {
            super(width, height);
            this.latLong = latLong;
            this.alignment = alignment;
        }

        public LayoutParams(ViewGroup.LayoutParams source) {
            super(source);
        }
    }

    private static final GraphicFactory GRAPHIC_FACTORY = AndroidGraphicFactory.INSTANCE;

    private final FpsCounter fpsCounter;
    private final FrameBuffer frameBuffer;
    private final FrameBufferController frameBufferController;
    private final GestureDetector gestureDetector;
    private GestureDetector gestureDetectorExternal;
    private final List<InputListener> inputListeners = new CopyOnWriteArrayList<>();
    private final LayerManager layerManager;
    private final Handler layoutHandler = new Handler();
    private MapScaleBar mapScaleBar;
    private final MapViewProjection mapViewProjection;
    private final MapZoomControls mapZoomControls;
    private final Model model;
    private final ScaleGestureDetector scaleGestureDetector;
    private final TouchGestureHandler touchGestureHandler;

    public MapView(Context context) {
        this(context, null);
    }

    public MapView(Context context, AttributeSet attributeSet) {
        super(context, attributeSet);

        setDescendantFocusability(FOCUS_BLOCK_DESCENDANTS);
        setWillNotDraw(false);

        this.model = new Model();

        this.fpsCounter = new FpsCounter(GRAPHIC_FACTORY, this.model.displayModel);
        this.frameBuffer = new FrameBufferHA2(this.model.frameBufferModel, this.model.displayModel, GRAPHIC_FACTORY);
        this.frameBufferController = FrameBufferController.create(this.frameBuffer, this.model);

        this.layerManager = new LayerManager(this, this.model.mapViewPosition, GRAPHIC_FACTORY);
        this.layerManager.start();
        LayerManagerController.create(this.layerManager, this.model);

        MapViewController.create(this, this.model);

        this.touchGestureHandler = new TouchGestureHandler(this);
        this.gestureDetector = new GestureDetector(context, touchGestureHandler);
        this.scaleGestureDetector = new ScaleGestureDetector(context, touchGestureHandler);

        this.mapZoomControls = new MapZoomControls(context, this);
        this.addView(this.mapZoomControls, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
        this.mapScaleBar = new DefaultMapScaleBar(this.model.mapViewPosition, this.model.mapViewDimension,
                GRAPHIC_FACTORY, this.model.displayModel);
        this.mapViewProjection = new MapViewProjection(this);

        model.mapViewPosition.addObserver(this);
    }

    public void addInputListener(InputListener listener) {
        if (listener == null) {
            throw new IllegalArgumentException("listener must not be null");
        } else if (this.inputListeners.contains(listener)) {
            throw new IllegalArgumentException("listener is already registered: " + listener);
        }
        this.inputListeners.add(listener);
    }

    @Override
    public void addLayer(Layer layer) {
        this.layerManager.getLayers().add(layer);
    }

    @Override
    protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
        return (p instanceof MapView.LayoutParams);
    }

    /**
     * Clear map view.
     */
    @Override
    public void destroy() {
        this.touchGestureHandler.destroy();
        this.layoutHandler.removeCallbacksAndMessages(null);
        this.layerManager.finish();
        this.frameBufferController.destroy();
        this.frameBuffer.destroy();
        if (this.mapScaleBar != null) {
            this.mapScaleBar.destroy();
        }
        this.mapZoomControls.destroy();
        this.getModel().mapViewPosition.destroy();
    }

    /**
     * Clear all map view elements.<br/>
     * i.e. layers, tile cache, label store, map view, resources, etc.
     */
    @Override
    public void destroyAll() {
        for (Layer layer : this.layerManager.getLayers()) {
            this.layerManager.getLayers().remove(layer);
            layer.onDestroy();
            if (layer instanceof TileLayer) {
                ((TileLayer<?>) layer).getTileCache().destroy();
            }
            if (layer instanceof TileRendererLayer) {
                LabelStore labelStore = ((TileRendererLayer) layer).getLabelStore();
                if (labelStore != null) {
                    labelStore.clear();
                }
            }
        }
        destroy();
    }

    @Override
    protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
        return new MapView.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT,
                null, MapView.LayoutParams.Alignment.BOTTOM_CENTER);
    }

    @Override
    public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) {
        return new MapView.LayoutParams(getContext(), attrs);
    }

    @Override
    protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
        return new MapView.LayoutParams(p);
    }

    @Override
    public BoundingBox getBoundingBox() {
        return MapPositionUtil.getBoundingBox(this.model.mapViewPosition.getMapPosition(),
                getDimension(), this.model.displayModel.getTileSize());
    }

    @Override
    public Dimension getDimension() {
        return new Dimension(getWidth(), getHeight());
    }

    @Override
    public FpsCounter getFpsCounter() {
        return this.fpsCounter;
    }

    @Override
    public FrameBuffer getFrameBuffer() {
        return this.frameBuffer;
    }

    @Override
    public LayerManager getLayerManager() {
        return this.layerManager;
    }

    @Override
    public MapScaleBar getMapScaleBar() {
        return this.mapScaleBar;
    }

    @Override
    public MapViewProjection getMapViewProjection() {
        return this.mapViewProjection;
    }

    /**
     * @return the zoom controls instance which is used in this MapView.
     */
    public MapZoomControls getMapZoomControls() {
        return this.mapZoomControls;
    }

    @Override
    public Model getModel() {
        return this.model;
    }

    public TouchGestureHandler getTouchGestureHandler() {
        return touchGestureHandler;
    }

    @Override
    public void onChange() {
        // Request layout for child views (besides zoom controls)
        int count = getChildCount();
        for (int i = 0; i < count; i++) {
            View child = getChildAt(i);
            if (!child.equals(this.mapZoomControls)) {
                layoutHandler.post(new Runnable() {
                    @Override
                    public void run() {
                        requestLayout();
                    }
                });
                break;
            }
        }
    }

    @Override
    protected void onDraw(Canvas androidCanvas) {
        org.mapsforge.core.graphics.Canvas graphicContext = AndroidGraphicFactory.createGraphicContext(androidCanvas);
        this.frameBuffer.draw(graphicContext);
        if (this.mapScaleBar != null) {
            this.mapScaleBar.draw(graphicContext);
        }
        this.fpsCounter.draw(graphicContext);
        graphicContext.destroy();
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        // Zoom controls
        if (this.mapZoomControls.getVisibility() != View.GONE) {
            int childGravity = this.mapZoomControls.getZoomControlsGravity();
            int childWidth = this.mapZoomControls.getMeasuredWidth();
            int childHeight = this.mapZoomControls.getMeasuredHeight();

            int childLeft;
            switch (childGravity & Gravity.HORIZONTAL_GRAVITY_MASK) {
                case Gravity.LEFT:
                    childLeft = left;
                    break;
                case Gravity.CENTER_HORIZONTAL:
                    childLeft = left + (right - left - childWidth) / 2;
                    break;
                case Gravity.RIGHT:
                default:
                    childLeft = right - childWidth;
                    break;
            }

            int childTop;
            switch (childGravity & Gravity.VERTICAL_GRAVITY_MASK) {
                case Gravity.TOP:
                    childTop = top;
                    break;
                case Gravity.CENTER_VERTICAL:
                    childTop = top + (bottom - top - childHeight) / 2;
                    break;
                case Gravity.BOTTOM:
                default:
                    childTop = bottom - childHeight;
                    break;
            }

            this.mapZoomControls.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
        }

        // Child views (besides zoom controls)
        int count = getChildCount();
        for (int i = 0; i < count; i++) {
            View child = getChildAt(i);
            if (child.equals(this.mapZoomControls)) {
                continue;
            }
            if (child.getVisibility() != View.GONE && checkLayoutParams(child.getLayoutParams())) {
                MapView.LayoutParams params = (MapView.LayoutParams) child.getLayoutParams();
                int childWidth = child.getMeasuredWidth();
                int childHeight = child.getMeasuredHeight();
                Point point = mapViewProjection.toPixels(params.latLong);
                if (point != null) {
                    int childLeft = getPaddingLeft() + (int) Math.round(point.x);
                    int childTop = getPaddingTop() + (int) Math.round(point.y);
                    switch (params.alignment) {
                        case TOP_LEFT:
                            break;
                        case TOP_CENTER:
                            childLeft -= childWidth / 2;
                            break;
                        case TOP_RIGHT:
                            childLeft -= childWidth;
                            break;
                        case CENTER_LEFT:
                            childTop -= childHeight / 2;
                            break;
                        case CENTER:
                            childLeft -= childWidth / 2;
                            childTop -= childHeight / 2;
                            break;
                        case CENTER_RIGHT:
                            childLeft -= childWidth;
                            childTop -= childHeight / 2;
                            break;
                        case BOTTOM_LEFT:
                            childTop -= childHeight;
                            break;
                        case BOTTOM_CENTER:
                            childLeft -= childWidth / 2;
                            childTop -= childHeight;
                            break;
                        case BOTTOM_RIGHT:
                            childLeft -= childWidth;
                            childTop -= childHeight;
                            break;
                    }
                    child.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
                }
            }
        }
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        measureChildren(widthMeasureSpec, heightMeasureSpec);
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    /**
     * This method is called by internal programs only. The underlying mapView implementation will
     * notify registered {@link InputListener} about the start of a manual move.
     * Note that this method may be called multiple times while the move has been started.
     * Also note that only manual moves get notified.
     */
    public void onMoveEvent() {
        for (InputListener listener : inputListeners) {
            listener.onMoveEvent();
        }
    }

    @Override
    protected void onSizeChanged(int width, int height, int oldWidth, int oldHeight) {
        this.model.mapViewDimension.setDimension(new Dimension(width, height));
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (!isClickable()) {
            return false;
        }

        this.mapZoomControls.onMapViewTouchEvent(event);
        if (this.gestureDetectorExternal != null && this.gestureDetectorExternal.onTouchEvent(event)) {
            return true;
        }

        boolean retVal = this.scaleGestureDetector.onTouchEvent(event);
        if (!this.scaleGestureDetector.isInProgress()) {
            retVal = this.gestureDetector.onTouchEvent(event);
        }
        return retVal;
    }

    /**
     * This method is called by internal programs only. The underlying mapView implementation will
     * notify registered {@link InputListener} about the start of a manual zoom.
     * Note that this method may be called multiple times while the zoom has been started.
     * Also note that only manual zooms get notified.
     */
    public void onZoomEvent() {
        for (InputListener listener : inputListeners) {
            listener.onZoomEvent();
        }
    }

    public void removeInputListener(InputListener listener) {
        if (listener == null) {
            throw new IllegalArgumentException("listener must not be null");
        } else if (!this.inputListeners.contains(listener)) {
            throw new IllegalArgumentException("listener is not registered: " + listener);
        }
        this.inputListeners.remove(listener);
    }

    @Override
    public void repaint() {
        if (Thread.currentThread() == Looper.getMainLooper().getThread()) {
            invalidate();
        } else {
            postInvalidate();
        }
    }

    /**
     * Sets the visibility of the zoom controls.
     *
     * @param showZoomControls true if the zoom controls should be visible, false otherwise.
     */
    public void setBuiltInZoomControls(boolean showZoomControls) {
        this.mapZoomControls.setShowMapZoomControls(showZoomControls);
    }

    @Override
    public void setCenter(LatLong center) {
        this.model.mapViewPosition.setCenter(center);
    }

    public void setGestureDetector(GestureDetector gestureDetector) {
        this.gestureDetectorExternal = gestureDetector;
    }

    @Override
    public void setMapScaleBar(MapScaleBar mapScaleBar) {
        if (this.mapScaleBar != null) {
            this.mapScaleBar.destroy();
        }
        this.mapScaleBar = mapScaleBar;
    }

    @Override
    public void setZoomLevel(byte zoomLevel) {
        this.model.mapViewPosition.setZoomLevel(zoomLevel);
    }

    @Override
    public void setZoomLevelMax(byte zoomLevelMax) {
        this.model.mapViewPosition.setZoomLevelMax(zoomLevelMax);
        this.mapZoomControls.setZoomLevelMax(zoomLevelMax);
    }

    @Override
    public void setZoomLevelMin(byte zoomLevelMin) {
        this.model.mapViewPosition.setZoomLevelMin(zoomLevelMin);
        this.mapZoomControls.setZoomLevelMin(zoomLevelMin);
    }
}
