package com.luciofm.ifican.app.widget;

import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.util.AttributeSet;
import android.view.Gravity;
import android.widget.ImageView;

import com.luciofm.ifican.app.R;


public class ForegroundImageView extends ImageView {

    private Drawable mForeground;

    private final Rect mSelfBounds = new Rect();
    private final Rect mOverlayBounds = new Rect();

    private int mForegroundGravity = Gravity.FILL;

    protected boolean mForegroundInPadding = true;

    boolean mForegroundBoundsChanged = false;

    public ForegroundImageView(Context context) {
        super(context);
    }

    public ForegroundImageView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public ForegroundImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

        TypedArray a = null;
        try {
            a = context.obtainStyledAttributes(attrs, R.styleable.ForegroundImageView,
                                                          defStyle, 0);

            mForegroundGravity = a.getInt(R.styleable.ForegroundImageView_android_foregroundGravity,
                                          mForegroundGravity);

            final Drawable d = a.getDrawable(R.styleable.ForegroundImageView_android_foreground);
            if (d != null) {
                setForeground(d);
            }

            mForegroundInPadding = a.getBoolean(R.styleable.ForegroundImageView_android_foregroundInsidePadding,
                                                true);
        } finally {
            if (a != null)
                a.recycle();
        }
    }

    /**
     * Describes how the foreground is positioned.
     *
     * @return foreground gravity.
     * @see #setForegroundGravity(int)
     */
    public int getForegroundGravity() {
        return mForegroundGravity;
    }

    /**
     * Describes how the foreground is positioned. Defaults to START and TOP.
     *
     * @param foregroundGravity See {@link android.view.Gravity}
     * @see #getForegroundGravity()
     */
    public void setForegroundGravity(int foregroundGravity) {
        if (mForegroundGravity != foregroundGravity) {
            if ((foregroundGravity & Gravity.RELATIVE_HORIZONTAL_GRAVITY_MASK) == 0) {
                foregroundGravity |= Gravity.START;
            }

            if ((foregroundGravity & Gravity.VERTICAL_GRAVITY_MASK) == 0) {
                foregroundGravity |= Gravity.TOP;
            }

            mForegroundGravity = foregroundGravity;


            if (mForegroundGravity == Gravity.FILL && mForeground != null) {
                Rect padding = new Rect();
                mForeground.getPadding(padding);
            }

            requestLayout();
        }
    }

    @Override
    protected boolean verifyDrawable(Drawable who) {
        return super.verifyDrawable(who) || (who == mForeground);
    }

    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
    @Override
    public void jumpDrawablesToCurrentState() {
        super.jumpDrawablesToCurrentState();
        if (mForeground != null) mForeground.jumpToCurrentState();
    }

    @Override
    protected void drawableStateChanged() {
        super.drawableStateChanged();
        if (mForeground != null && mForeground.isStateful()) {
            mForeground.setState(getDrawableState());
        }
    }

    /**
     * Supply a Drawable that is to be rendered on top of all of the child
     * views in the frame layout.  Any padding in the Drawable will be taken
     * into account by ensuring that the children are inset to be placed
     * inside of the padding area.
     *
     * @param drawable The Drawable to be drawn on top of the children.
     */
    public void setForeground(Drawable drawable) {
        if (mForeground != drawable) {
            if (mForeground != null) {
                mForeground.setCallback(null);
                unscheduleDrawable(mForeground);
            }

            mForeground = drawable;

            if (drawable != null) {
                setWillNotDraw(false);
                drawable.setCallback(this);
                if (drawable.isStateful()) {
                    drawable.setState(getDrawableState());
                }
                if (mForegroundGravity == Gravity.FILL) {
                    Rect padding = new Rect();
                    drawable.getPadding(padding);
                }
            } else {
                setWillNotDraw(true);
            }
            requestLayout();
            invalidate();
        }
    }

    /**
     * Returns the drawable used as the foreground of this FrameLayout. The
     * foreground drawable, if non-null, is always drawn on top of the children.
     *
     * @return A Drawable or null if no foreground was set.
     */
    public Drawable getForeground() {
        return mForeground;
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        mForegroundBoundsChanged = changed;
    }

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

    @Override
    public void draw(Canvas canvas) {
        super.draw(canvas);

        if (mForeground != null) {
            final Drawable foreground = mForeground;

            if (mForegroundBoundsChanged) {
                mForegroundBoundsChanged = false;
                final Rect selfBounds = mSelfBounds;
                final Rect overlayBounds = mOverlayBounds;

                final int w = getRight() - getLeft();
                final int h = getBottom() - getTop();

                if (mForegroundInPadding) {
                    selfBounds.set(0, 0, w, h);
                } else {
                    selfBounds.set(getPaddingLeft(), getPaddingTop(),
                                   w - getPaddingRight(), h - getPaddingBottom());
                }

                Gravity.apply(mForegroundGravity, foreground.getIntrinsicWidth(),
                              foreground.getIntrinsicHeight(), selfBounds, overlayBounds);
                foreground.setBounds(overlayBounds);
            }

            foreground.draw(canvas);
        }
    }
}