package com.danding.yang800.View;

import java.util.LinkedList;
import java.util.List;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.os.Handler;
import android.os.Vibrator;
import android.util.AttributeSet;
import android.util.Log;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewTreeObserver;
import android.view.ViewTreeObserver.OnPreDrawListener;
import android.view.WindowManager;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.ListAdapter;

import com.danding.yang800.Adapter.DragGridBaseAdapter;
import com.nineoldandroids.animation.Animator;
import com.nineoldandroids.animation.AnimatorListenerAdapter;
import com.nineoldandroids.animation.AnimatorSet;
import com.nineoldandroids.animation.ObjectAnimator;

/**
 * @author xiaanming
 * @blog http://blog.csdn.net/xiaanming
 */
public class DragGridView extends GridView {
    /**
     * DragGridView��item������Ӧ��ʱ�䣬 Ĭ����1000���룬Ҳ������������
     */
    private long dragResponseMS = 500;

    /**
     * �Ƿ������ק��Ĭ�ϲ�����
     */
    private boolean isDrag = false;

    private int mDownX;
    private int mDownY;
    private int moveX;
    private int moveY;
    /**
     * ������ק��position
     */
    private int mDragPosition;

    /**
     * �տ�ʼ��ק��item��Ӧ��View
     */
    private View mStartDragItemView = null;

    /**
     * ������ק�ľ�������ֱ����һ��ImageView
     */
    private ImageView mDragImageView;

    /**
     * ����
     */
    private Vibrator mVibrator;

    private WindowManager mWindowManager;
    /**
     * item����Ĳ��ֲ���
     */
    private WindowManager.LayoutParams mWindowLayoutParams;

    /**
     * ������ק��item��Ӧ��Bitmap
     */
    private Bitmap mDragBitmap;

    /**
     * ���µĵ㵽����item���ϱ�Ե�ľ���
     */
    private int mPoint2ItemTop;

    /**
     * ���µĵ㵽����item�����Ե�ľ���
     */
    private int mPoint2ItemLeft;

    /**
     * DragGridView������Ļ������ƫ����
     */
    private int mOffset2Top;

    /**
     * DragGridView������Ļ��ߵ�ƫ����
     */
    private int mOffset2Left;

    /**
     * ״̬���ĸ߶�
     */
    private int mStatusHeight;

    /**
     * DragGridView�Զ����¹����ı߽�ֵ
     */
    private int mDownScrollBorder;

    /**
     * DragGridView�Զ����Ϲ����ı߽�ֵ
     */
    private int mUpScrollBorder;

    /**
     * DragGridView�Զ��������ٶ�
     */
    private static final int speed = 20;

    private boolean mAnimationEnd = true;

    private DragGridBaseAdapter mDragAdapter;
    private int mNumColumns;
    private int mColumnWidth;
    private boolean mNumColumnsSet;
    private int mHorizontalSpacing;

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

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

    public DragGridView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        mVibrator = (Vibrator) context
                .getSystemService(Context.VIBRATOR_SERVICE);
        mWindowManager = (WindowManager) context
                .getSystemService(Context.WINDOW_SERVICE);
        mStatusHeight = getStatusHeight(context); // ��ȡ״̬���ĸ߶�

        if (!mNumColumnsSet) {
            mNumColumns = AUTO_FIT;
        }

    }

    private Handler mHandler = new Handler();

    // ���������Ƿ�Ϊ������Runnable
    private Runnable mLongClickRunnable = new Runnable() {

        @Override
        public void run() {
            isDrag = true; // ���ÿ�����ק
            mVibrator.vibrate(50); // ��һ��
            mStartDragItemView.setVisibility(View.INVISIBLE);// ���ظ�item

            // �������ǰ��µĵ���ʾitem����
            createDragImage(mDragBitmap, mDownX, mDownY);
        }
    };

    @Override
    public void setAdapter(ListAdapter adapter) {
        super.setAdapter(adapter);

        if (adapter instanceof DragGridBaseAdapter) {
            mDragAdapter = (DragGridBaseAdapter) adapter;
        } else {
            throw new IllegalStateException(
                    "the adapter must be implements DragGridAdapter");
        }
    }

    @Override
    public void setNumColumns(int numColumns) {
        super.setNumColumns(numColumns);
        mNumColumnsSet = true;
        this.mNumColumns = numColumns;
    }

    @Override
    public void setColumnWidth(int columnWidth) {
        super.setColumnWidth(columnWidth);
        mColumnWidth = columnWidth;
    }

    @Override
    public void setHorizontalSpacing(int horizontalSpacing) {
        super.setHorizontalSpacing(horizontalSpacing);
        this.mHorizontalSpacing = horizontalSpacing;
    }

    /**
     * ������ΪAUTO_FIT�������ж�����
     */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        if (mNumColumns == AUTO_FIT) {
            int numFittedColumns;
            if (mColumnWidth > 0) {
                int gridWidth = Math.max(MeasureSpec.getSize(widthMeasureSpec)
                        - getPaddingLeft() - getPaddingRight(), 0);
                numFittedColumns = gridWidth / mColumnWidth;
                if (numFittedColumns > 0) {
                    while (numFittedColumns != 1) {
                        if (numFittedColumns * mColumnWidth
                                + (numFittedColumns - 1) * mHorizontalSpacing > gridWidth) {
                            numFittedColumns--;
                        } else {
                            break;
                        }
                    }
                } else {
                    numFittedColumns = 1;
                }
            } else {
                numFittedColumns = 2;
            }
            mNumColumns = numFittedColumns;
        }

        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    /**
     * ������Ӧ��ק�ĺ�������Ĭ����1000����
     *
     * @param dragResponseMS
     */
    public void setDragResponseMS(long dragResponseMS) {
        this.dragResponseMS = dragResponseMS;
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mDownX = (int) ev.getX();
                mDownY = (int) ev.getY();

                // ���ݰ��µ�X,Y�����ȡ�����item��position
                mDragPosition = pointToPosition(mDownX, mDownY);

                if (mDragPosition == AdapterView.INVALID_POSITION) {
                    return super.dispatchTouchEvent(ev);
                }

                // ʹ��Handler�ӳ�dragResponseMSִ��mLongClickRunnable
                mHandler.postDelayed(mLongClickRunnable, dragResponseMS);

                // ����position��ȡ��item����Ӧ��View
                mStartDragItemView = getChildAt(mDragPosition
                        - getFirstVisiblePosition());

                // �����⼸�������ҿ��Բο��ҵĲ��������ͼ�������
                mPoint2ItemTop = mDownY - mStartDragItemView.getTop();
                mPoint2ItemLeft = mDownX - mStartDragItemView.getLeft();

                mOffset2Top = (int) (ev.getRawY() - mDownY);
                mOffset2Left = (int) (ev.getRawX() - mDownX);

                // ��ȡDragGridView�Զ����Ϲ�����ƫ������С�����ֵ��DragGridView���¹���
                mDownScrollBorder = getHeight() / 5;
                // ��ȡDragGridView�Զ����¹�����ƫ�������������ֵ��DragGridView���Ϲ���
                mUpScrollBorder = getHeight() * 4 / 5;

                // ����mDragItemView��ͼ����
                mStartDragItemView.setDrawingCacheEnabled(true);
                // ��ȡmDragItemView�ڻ����е�Bitmap����
                mDragBitmap = Bitmap.createBitmap(mStartDragItemView
                        .getDrawingCache());
                // ��һ���ܹؼ����ͷŻ�ͼ���棬��������ظ��ľ���
                mStartDragItemView.destroyDrawingCache();

                break;
            case MotionEvent.ACTION_MOVE:
                int moveX = (int) ev.getX();
                int moveY = (int) ev.getY();

                // ��������ڰ��µ�item�����ƶ���ֻҪ������item�ı߽����ǾͲ��Ƴ�mRunnable
                if (!isTouchInItem(mStartDragItemView, moveX, moveY)) {
                    mHandler.removeCallbacks(mLongClickRunnable);
                }
                break;
            case MotionEvent.ACTION_UP:
                mHandler.removeCallbacks(mLongClickRunnable);
                mHandler.removeCallbacks(mScrollRunnable);
                break;
        }
        return super.dispatchTouchEvent(ev);
    }

    private boolean isTouchInItem(View dragView, int x, int y) {
        if (dragView == null) {
            return false;
        }
        int leftOffset = dragView.getLeft();
        int topOffset = dragView.getTop();
        if (x < leftOffset || x > leftOffset + dragView.getWidth()) {
            return false;
        }

        if (y < topOffset || y > topOffset + dragView.getHeight()) {
            return false;
        }
        return true;
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        if (isDrag && mDragImageView != null) {
            switch (ev.getAction()) {
                case MotionEvent.ACTION_MOVE:
                    moveX = (int) ev.getX();
                    moveY = (int) ev.getY();

                    // �϶�item
                    onDragItem(moveX, moveY);
                    break;
                case MotionEvent.ACTION_UP:
                    onStopDrag();
                    isDrag = false;
                    break;
            }
            return true;
        }
        return super.onTouchEvent(ev);
    }

    /**
     * �����϶��ľ���
     *
     * @param bitmap
     * @param downX  ���µĵ���Ը��ؼ���X����
     * @param downY  ���µĵ���Ը��ؼ���X����
     */
    private void createDragImage(Bitmap bitmap, int downX, int downY) {
        mWindowLayoutParams = new WindowManager.LayoutParams();
        mWindowLayoutParams.format = PixelFormat.TRANSLUCENT; // ͼƬ֮��������ط�͸��
        mWindowLayoutParams.gravity = Gravity.TOP | Gravity.LEFT;
        mWindowLayoutParams.x = downX - mPoint2ItemLeft + mOffset2Left;
        mWindowLayoutParams.y = downY - mPoint2ItemTop + mOffset2Top
                - mStatusHeight;
        mWindowLayoutParams.alpha = 0.55f; // ͸����
        mWindowLayoutParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
        mWindowLayoutParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
        mWindowLayoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
                | WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;

        mDragImageView = new ImageView(getContext());
        mDragImageView.setImageBitmap(bitmap);
        mWindowManager.addView(mDragImageView, mWindowLayoutParams);
    }

    /**
     * �ӽ��������ƶ��϶�����
     */
    private void removeDragImage() {
        if (mDragImageView != null) {
            mWindowManager.removeView(mDragImageView);
            mDragImageView = null;
        }
    }

    private void onDragItem(int moveX, int moveY) {
        mWindowLayoutParams.x = moveX - mPoint2ItemLeft + mOffset2Left;
        mWindowLayoutParams.y = moveY - mPoint2ItemTop + mOffset2Top
                - mStatusHeight;
        mWindowManager.updateViewLayout(mDragImageView, mWindowLayoutParams); // ���¾����λ��
        onSwapItem(moveX, moveY);

        // GridView�Զ�����
        mHandler.post(mScrollRunnable);
    }

    /**
     * ��moveY��ֵ�������Ϲ����ı߽�ֵ������GridView�Զ����Ϲ���
     * ��moveY��ֵС�����¹����ı߽�ֵ������GridView�Զ����¹��� ���򲻽��й���
     */
    private Runnable mScrollRunnable = new Runnable() {

        @Override
        public void run() {
            int scrollY;
            if (getFirstVisiblePosition() == 0
                    || getLastVisiblePosition() == getCount() - 1) {
                mHandler.removeCallbacks(mScrollRunnable);
            }

            if (moveY > mUpScrollBorder) {
                scrollY = speed;
                mHandler.postDelayed(mScrollRunnable, 25);
            } else if (moveY < mDownScrollBorder) {
                scrollY = -speed;
                mHandler.postDelayed(mScrollRunnable, 25);
            } else {
                scrollY = 0;
                mHandler.removeCallbacks(mScrollRunnable);
            }

            smoothScrollBy(scrollY, 10);
        }
    };

    /**
     * ����item,���ҿ���item֮�����ʾ������Ч��
     *
     * @param moveX
     * @param moveY
     */
    private void onSwapItem(int moveX, int moveY) {
        // ��ȡ������ָ�ƶ������Ǹ�item��position
        final int tempPosition = pointToPosition(moveX, moveY);

        // ����tempPosition �ı��˲���tempPosition������-1,����н���
        if (tempPosition != mDragPosition
                && tempPosition != AdapterView.INVALID_POSITION
                && mAnimationEnd) {
            mDragAdapter.reorderItems(mDragPosition, tempPosition);
            mDragAdapter.setHideItem(tempPosition);

            final ViewTreeObserver observer = getViewTreeObserver();
            observer.addOnPreDrawListener(new OnPreDrawListener() {

                @Override
                public boolean onPreDraw() {
                    observer.removeOnPreDrawListener(this);
                    animateReorder(mDragPosition, tempPosition);
                    mDragPosition = tempPosition;
                    return true;
                }
            });

        }
    }

    /**
     * �����ƶ�����
     *
     * @param view
     * @param startX
     * @param endX
     * @param startY
     * @param endY
     * @return
     */
    private AnimatorSet createTranslationAnimations(View view, float startX,
                                                    float endX, float startY, float endY) {
        ObjectAnimator animX = ObjectAnimator.ofFloat(view, "translationX",
                startX, endX);
        ObjectAnimator animY = ObjectAnimator.ofFloat(view, "translationY",
                startY, endY);
        AnimatorSet animSetXY = new AnimatorSet();
        animSetXY.playTogether(animX, animY);
        return animSetXY;
    }

    /**
     * item�Ľ�������Ч��
     *
     * @param oldPosition
     * @param newPosition
     */
    private void animateReorder(final int oldPosition, final int newPosition) {
        boolean isForward = newPosition > oldPosition;
        List<Animator> resultList = new LinkedList<Animator>();
        if (isForward) {
            for (int pos = oldPosition; pos < newPosition; pos++) {
                View view = getChildAt(pos - getFirstVisiblePosition());
                System.out.println(pos);

                if ((pos + 1) % mNumColumns == 0) {
                    resultList.add(createTranslationAnimations(view,
                            -view.getWidth() * (mNumColumns - 1), 0,
                            view.getHeight(), 0));
                } else {
                    resultList.add(createTranslationAnimations(view,
                            view.getWidth(), 0, 0, 0));
                }
            }
        } else {
            for (int pos = oldPosition; pos > newPosition; pos--) {
                View view = getChildAt(pos - getFirstVisiblePosition());
                Log.e("MainActivity", view + "adas" + getFirstVisiblePosition());
                if ((pos + mNumColumns) % mNumColumns == 0) {
                    resultList.add(createTranslationAnimations(view,
                            view.getWidth() * (mNumColumns - 1), 0,
                            -view.getHeight(), 0));
                } else {
                    resultList.add(createTranslationAnimations(view,
                            -view.getWidth(), 0, 0, 0));
                }
            }
        }

        AnimatorSet resultSet = new AnimatorSet();
        resultSet.playTogether(resultList);
        resultSet.setDuration(300);
        resultSet.setInterpolator(new AccelerateDecelerateInterpolator());
        resultSet.addListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationStart(Animator animation) {
                mAnimationEnd = false;
            }

            @Override
            public void onAnimationEnd(Animator animation) {
                mAnimationEnd = true;
            }
        });
        resultSet.start();
    }

    /**
     * ֹͣ��ק���ǽ�֮ǰ���ص�item��ʾ���������������Ƴ�
     */
    private void onStopDrag() {
        View view = getChildAt(mDragPosition - getFirstVisiblePosition());
        if (view != null) {
            view.setVisibility(View.VISIBLE);
        }
        mDragAdapter.setHideItem(-1);
        removeDragImage();
    }

    /**
     * ��ȡ״̬���ĸ߶�
     *
     * @param context
     * @return
     */
    private static int getStatusHeight(Context context) {
        int statusHeight = 0;
        Rect localRect = new Rect();
        ((Activity) context).getWindow().getDecorView()
                .getWindowVisibleDisplayFrame(localRect);
        statusHeight = localRect.top;
        if (0 == statusHeight) {
            Class<?> localClass;
            try {
                localClass = Class.forName("com.android.internal.R$dimen");
                Object localObject = localClass.newInstance();
                int i5 = Integer.parseInt(localClass
                        .getField("status_bar_height").get(localObject)
                        .toString());
                statusHeight = context.getResources().getDimensionPixelSize(i5);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return statusHeight;
    }

}
