package com.netfluke.sergey.plumbbob;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.util.Log;
import android.view.ViewGroup;

/**
 * This class draws the projection of a plumb bob on canvas. It assumes Portrait
 *    orientation, hard set on the activity in the Manifest. The y-axis of the
 *    sensor coordinate system is assumed to be parallel to the _long_ side
 *    of the phone, x-axis to the shorter one.
 *
 *    For allowing Landscape, the code would need to account for the fact that
 *    the sensor coordinate system remains the same no matter how the phone
 *    is flipped, but the screen coordinate system changes on flip.
 *
 *    For the Canvas/Paint drawing, see
 *      https://developer.android.com/training/custom-views/custom-drawing.html
 *    for a much more elaborate example
 */

public class Bob extends ViewGroup {

    RectF bounds;
    Paint paint, paint1;

    float cx, cy;  // centre of screen
    float dx, dy;  // displacement of bob's center from center
    float r = 100f;

    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        // Do nothing. Do not call the superclass method--that would start a layout pass
        // on this view's children. PieChart lays out its children in onSizeChanged().
    }

    /*
     * Needs a constructor.
     *   Class constructor taking only a context.
     */
    public Bob(Context context) {
        super(context);

        init();
    }

    /**
     * Class constructor taking a context and an attribute set. This constructor
     * is used by the layout engine to construct a {@link Bob} from a set of
     * XML attributes. Without this, you will get a runtime error about
     * not being able to create the Bob object from XML.
     *
     * @param context
     * @param attrs   An attribute set which can contain attributes from
     *                {@link <package_name>.R.styleable.Bob} as well as attributes inherited
     *                from {@link android.view.View}.
     */
    public Bob(Context context, AttributeSet attrs) {
        super(context, attrs);

        init();
    }

    private void init()
    {
        paint = new Paint();
        paint.setColor(Color.RED);
        paint.setAntiAlias(true);
        paint.setStrokeCap(Paint.Cap.BUTT);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeWidth(r/2);

        paint1 = new Paint();
        paint1.setColor(Color.BLUE);
        paint1.setAntiAlias(true);
        paint1.setStrokeCap(Paint.Cap.BUTT);
        paint1.setStyle(Paint.Style.STROKE);
        paint1.setStrokeWidth(2);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);


        // Draw the bob
        canvas.drawOval(bounds, paint);

        canvas.drawLine( cx, cy, cx + dx, cy + dy, paint1);

    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);

        Log.d("SIZE", "w: " + w + " h: " + h + " oldw: " + oldw + " oldh: " + oldh);

        cx = w/2.0f;
        cy = h/2.0f;

        // initial position: dead center
        bounds = new RectF(cx - r, cy - r, cx + r , cy + r );
        Log.d("RECT", "RectF: " + bounds);

        invalidate();
    }

    // x and y are on the scale from 0 to 10, and measure displacement from center
    public void repositionBob(float x, float y){

        float cm = Math.min( cx, cy ); // must ensure we are drawing with the same factor on X and Y axes
        dx = - cm * x/10f;  // must be negative: gravity vector points down, screen's X grows left-to-write
        dy = cm * y/10f;    // screen's Y grows from the top down, just the direction we want.
        bounds = new RectF(cx + dx - r, cy + dy - r, cx + dx + r , cy + dy + r );
        invalidate();
    }

}