/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * 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.
 */

package android.support.v4.widget;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RadialGradient;
import android.graphics.Shader;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.OvalShape;
import android.support.v4.view.ViewCompat;
import android.view.animation.Animation;
import android.widget.ImageView;

/**
 * Private class created to work around issues with AnimationListeners being
 * called before the animation is actually complete and support shadows on older platforms.
 */
class CircleImageView extends ImageView {

    private static final int KEY_SHADOW_COLOR = 0x1E000000;
    private static final int FILL_SHADOW_COLOR = 0x3D000000;
    // PX
    private static final float X_OFFSET = 0f;
    private static final float Y_OFFSET = 1.75f;
    private static final float SHADOW_RADIUS = 3.5f;
    private static final int SHADOW_ELEVATION = 4;

    private Animation.AnimationListener mListener;

    public CircleImageView(Context context, int color, final float radius) {
        super(context);
        final float density = getContext().getResources().getDisplayMetrics().density;
        final int diameter = (int) (radius * density * 2);
        final int shadowRadius = (int) (density * SHADOW_RADIUS);
        final int shadowYOffset = (int) (density * Y_OFFSET);
        final int shadowXOffset = (int) (density * X_OFFSET);
        ShapeDrawable circle;
        if (android.os.Build.VERSION.CODENAME.equals("L")
                || android.os.Build.VERSION.SDK_INT > 21) {
            circle = new ShapeDrawable(new OvalShape());
            ViewCompat.setElevation(this, SHADOW_ELEVATION * density);
        } else {
            OvalShape oval = new OvalShape() {
                Paint shadowPaint = new Paint();
                RadialGradient gradient;

                @Override
                public void draw(Canvas canvas, Paint paint) {
                    if (gradient == null) {
                        gradient = new RadialGradient(diameter/2, diameter/2, shadowRadius,
                                new int[]{FILL_SHADOW_COLOR, 0x00000000},
                                null, Shader.TileMode.CLAMP);
                        shadowPaint.setShader(gradient);
                    }
                    canvas.drawCircle(diameter / 2, diameter / 2, (diameter / 2), shadowPaint);
                    canvas.drawCircle(diameter / 2, diameter / 2, (diameter / 2 - shadowRadius),
                            paint);
                }
            };
            circle = new ShapeDrawable(oval);
            ViewCompat.setLayerType(this, ViewCompat.LAYER_TYPE_SOFTWARE, circle.getPaint());
            circle.getPaint().setShadowLayer(shadowRadius, shadowXOffset, shadowYOffset, KEY_SHADOW_COLOR);
            final int padding = (int) (shadowRadius / 2);
            // set padding so the inner image sits correctly within the shadow.
            setPadding(padding, padding, padding, padding);
        }
        circle.getPaint().setColor(color);
        setBackgroundDrawable(circle);
    }

    public void setAnimationListener(Animation.AnimationListener listener) {
        mListener = listener;
    }

    @Override
    public void onAnimationStart() {
        super.onAnimationStart();
        if (mListener != null) {
            mListener.onAnimationStart(getAnimation());
        }
    }

    @Override
    public void onAnimationEnd() {
        super.onAnimationEnd();
        if (mListener != null) {
            mListener.onAnimationEnd(getAnimation());
        }
    }

    /**
     * Update the background color of the circle image view.
     */
    public void setBackgroundColor(int colorRes) {
        if (getBackground() instanceof ShapeDrawable) {
            final Resources res = getResources();
            ((ShapeDrawable) getBackground()).getPaint().setColor(res.getColor(colorRes));
        }
    }
}