/*
 * Copyright 2013 serso aka se.solovyev
 *
 * 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.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * Contact details
 *
 * Email: se.solovyev@gmail.com
 * Site:  http://se.solovyev.org
 */

package org.solovyev.android.calculator.plot;

import android.view.MotionEvent;
import android.view.VelocityTracker;

import org.solovyev.android.Views;

import javax.annotation.Nonnull;

class TouchHandler {

    @Nonnull
    private final VelocityTracker velocityTracker = VelocityTracker.obtain();
    private boolean afterZoom;
    @Nonnull
    private TouchHandlerListener listener;

    TouchHandler(@Nonnull TouchHandlerListener listener) {
        this.listener = listener;
    }

    public boolean handleTouchEvent(@Nonnull MotionEvent event) {
        // Calculator.log("touch " + event + ' ' + event.getPointerCount() + event.getPointerId(0));

        final int fullAction = event.getAction();
        final int action = fullAction & MotionEvent.ACTION_MASK;
        final int pointer = (fullAction & MotionEvent.ACTION_POINTER_ID_MASK) >> MotionEvent.ACTION_POINTER_ID_SHIFT;

        float x = event.getX();
        float y = event.getY();

        int pointerCount = Views.getPointerCountFromMotionEvent(event);

        switch (action) {
            case MotionEvent.ACTION_DOWN:
                afterZoom = false;
                velocityTracker.clear();
                velocityTracker.addMovement(event);
                listener.onTouchDown(x, y);
                break;

            case MotionEvent.ACTION_MOVE:
                if (pointerCount == 1) {
                    if (afterZoom) {
                        velocityTracker.clear();
                        listener.onTouchDown(x, y);
                        afterZoom = false;
                    }
                    velocityTracker.addMovement(event);
                    listener.onTouchMove(x, y);
                } else if (pointerCount == 2) {
                    listener.onTouchZoomMove(x, y, Views.getXFromMotionEvent(event, 1), Views.getYFromMotionEvent(event, 1));
                }
                break;

            case MotionEvent.ACTION_UP:
                velocityTracker.addMovement(event);
                velocityTracker.computeCurrentVelocity(1000);
                listener.onTouchUp(x, y);
                break;

            case MotionEvent.ACTION_POINTER_DOWN:
                if (pointerCount == 2) {
                    listener.onTouchZoomDown(x, y, Views.getXFromMotionEvent(event, 1), Views.getYFromMotionEvent(event, 1));
                }
                break;

            case MotionEvent.ACTION_POINTER_UP:
                if (pointerCount == 2) {
                    afterZoom = true;
                }
                break;
        }
        return true;
    }

    public float getXVelocity() {
        return velocityTracker.getXVelocity();
    }

    public float getYVelocity() {
        return velocityTracker.getYVelocity();
    }

    interface TouchHandlerListener {
        void onTouchDown(float x, float y);

        void onTouchMove(float x, float y);

        void onTouchUp(float x, float y);

        void onTouchZoomDown(float x1, float y1, float x2, float y2);

        void onTouchZoomMove(float x1, float y1, float x2, float y2);
    }
}
