package com.wasu.cs.widget;

import android.content.Context;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.ScrollView;

import com.wasu.module.log.WLog;

import cn.com.wasu.main.R;

/**
 * @author danxingxi created on 2016.6.7
 * 中国蓝 CS 模板 最外层容器控件
 */
public class ListScrollView extends ScrollView implements OnClickListener
{

	/**
	 * Item点击的回调
	 */
	private OnItemClickListener mListener;

	private Adapter mAdapter;
	/**
	 * 屏幕的高度
	 */
	private int mScreenHeight;
	/**
	 * 每个条目的高度
	 */
	private int mItemHeight = getResources().getDimensionPixelOffset(R.dimen.d_260dp);
	private ViewGroup mContainer;

	/**
	 * 条目总数
	 */
	private int mItemCount;

	private boolean flag = false;
	private final String TAG="ListScrollView";

	/**
	 * 适配器
	 * @author zhy
	 *
	 */
	public static abstract class Adapter
	{
		public abstract View getView(ListScrollView parent, int pos);

		public abstract int getCount();

	}

	/**
	 * 点击的回调
	 */
	public interface OnItemClickListener
	{
		void onItemClick(int pos, View view);
	}

	public ListScrollView(Context context, AttributeSet attrs)
	{
		super(context, attrs);
		// 计算屏幕的高度
		WindowManager wm = (WindowManager) context
				.getSystemService(Context.WINDOW_SERVICE);
		DisplayMetrics outMetrics = new DisplayMetrics();
		wm.getDefaultDisplay().getMetrics(outMetrics);
		mScreenHeight = outMetrics.heightPixels;
		mScreenHeight -= getStatusHeight(context);

	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
	{
//		notifyDataSetChanged();

		super.onMeasure(widthMeasureSpec, heightMeasureSpec);
	}

	public View getItemByIndex(int index){
		return mContainer.getChildAt(index);
	}

	public void addChildView(View view)
	{
		mContainer.addView(view);
	}

	/**
	 * 在容器末尾添加一个Item
	 * @param i
	 */
	private void addChildView(int i)
	{
		View item = mAdapter.getView(this, i);
		ViewGroup.LayoutParams lp = new ViewGroup.LayoutParams(
				ViewGroup.LayoutParams.MATCH_PARENT, mItemHeight);
		item.setLayoutParams(lp);//设置参数
		item.setTag(i);//设置Tag
		item.setOnClickListener(this);//添加事件
		mContainer.addView(item);
	}
	/**
	 * 在容器指定位置添加一个Item
	 * @param i
	 * @param index
	 */
	private void addChildView(int i, int index)
	{
		View item = mAdapter.getView(this, i);
		ViewGroup.LayoutParams lp = new ViewGroup.LayoutParams(
				ViewGroup.LayoutParams.MATCH_PARENT, mItemHeight);
		item.setLayoutParams(lp);
		item.setTag(i);
		item.setOnClickListener(this);
		mContainer.addView(item, index);
	}

/*	@Override
	public boolean onTouchEvent(MotionEvent ev)
	{
		flag = true;
		int action = ev.getAction();
		int scrollY = getScrollY();
		switch (action)
		{
		case MotionEvent.ACTION_MOVE:
			Log.e("TAG", "scrollY = " + scrollY);
			// 表示此时ScrollView的顶部已经达到屏幕顶部
			if (scrollY == 0)
			{
				addChildToFirst();
			}
			// ScrollView的顶部已经到达屏幕底部
			if (Math.abs(scrollY - mItemHeight) <= mItemCount)
			{
				addChildToLast();
			}

			break;
		case MotionEvent.ACTION_UP:
			checkForReset();
			return true;
		default:
			break;
		}
		return super.onTouchEvent(ev);
	}
	*/
	/**
	 * 在底部添加一个View，并移除第一个View
	 */
	private void addChildToLast()
	{
		Log.e("TAG", "addChildToLast");
		int pos = (Integer) mContainer.getChildAt(1).getTag();
		addChildView(pos);
		mContainer.removeViewAt(0);
		this.scrollTo(0, 0);
	}

	/**
	 * 在顶部添加一个View，并移除最后一个View
	 */
	protected void addChildToFirst()
	{
		Log.e("TAG", "addChildToFirst");
		int pos = (Integer) mContainer.getChildAt(mItemCount - 1).getTag();
		addChildView(pos, 0);
		mContainer.removeViewAt(mContainer.getChildCount() - 1);
		this.scrollTo(0, mItemHeight);
	}

	/**
	 * 检查当前getScrollY,显示完成Item，或者收缩此Item
	 */
	private void checkForReset()
	{
		int val = getScrollY() % mItemHeight;
		if (val >= mItemHeight / 2)
		{
			smoothScrollTo(0, mItemHeight);
		} else
		{
			smoothScrollTo(0, 0);
		}

	}

	/**
	 * 获得状态栏的高度
	 * 
	 * @param context
	 * @return
	 */
	public int getStatusHeight(Context context)
	{

		int statusHeight = -1;
		try
		{
			Class<?> clazz = Class.forName("com.android.internal.R$dimen");
			Object object = clazz.newInstance();
			int height = Integer.parseInt(clazz.getField("status_bar_height")
					.get(object).toString());
			statusHeight = context.getResources().getDimensionPixelSize(height);
		} catch (Exception e)
		{
			e.printStackTrace();
		}
		return statusHeight;
	}

	public void setAdapter(Adapter mAdapter)
	{
		WLog.d("danxx" ,"setAdapter");
		this.mAdapter = mAdapter;
		notifyDataSetChanged();
	}

	/**
	 * 设置item的高度  默认是280
	 * @param height
	 */
	public void setmItemHeight(int height){
		mItemHeight = height;
	}

	private void notifyDataSetChanged(){
		WLog.d("danxx" ,"notifyDataSetChanged");
		//防止多次调用
		if (!flag)
		{
			//根据Adapter的方法，为容器添加Item
			if (mAdapter != null)
			{
				mContainer = (ViewGroup) findViewById(R.id.layoutBody);
				mItemCount = mAdapter.getCount();
				//mItemHeight = mScreenHeight / mItemCount;
				WLog.d(TAG,"ItemHeight="+mItemHeight);
				//mItemHeight = 300;
				mContainer.removeAllViews();
				for (int i = 0,count =mAdapter.getCount(); i < count ; i++)
				{
					addChildView(i);
				}
			}
		}
	}

	public void setOnItemClickListener(OnItemClickListener mListener)
	{
		this.mListener = mListener;
	}

	@Override
	public void onClick(View v)
	{
		int pos = (Integer) v.getTag();
		if (mListener != null)
		{
			mListener.onItemClick(pos, v);
		}
	}

	@Override
	protected void onDetachedFromWindow() {
		super.onDetachedFromWindow();
		flag = true;
	}

	@Override
	protected int computeScrollDeltaToGetChildRectOnScreen(Rect rect) {
		if (getChildCount() == 0) return 0;

		int height = getHeight();
		int screenTop = getScrollY();
		int screenBottom = screenTop + height;
		/**增加提前滚动距离**/
		int fadingEdge = getVerticalFadingEdgeLength()+this.getResources().getDimensionPixelSize(
				cn.com.wasu.main.R.dimen.d_200dp);

		// leave room for top fading edge as long as rect isn't at very top
		if (rect.top > 0) {
			screenTop += fadingEdge;
		}

		// leave room for bottom fading edge as long as rect isn't at very bottom
		if (rect.bottom < getChildAt(0).getHeight()) {
			screenBottom -= fadingEdge;
		}

		int scrollYDelta = 0;

		if (rect.bottom > screenBottom && rect.top > screenTop) {
			// need to move down to get it in view: move down just enough so
			// that the entire rectangle is in view (or at least the first
			// screen size chunk).

			if (rect.height() > height) {
				// just enough to get screen size chunk on
				scrollYDelta += (rect.top - screenTop);
			} else {
				// get entire rect at bottom of screen
				scrollYDelta += (rect.bottom - screenBottom);
			}

			// make sure we aren't scrolling beyond the end of our content
			int bottom = getChildAt(0).getBottom();
			int distanceToBottom = bottom - screenBottom;
			scrollYDelta = Math.min(scrollYDelta, distanceToBottom);

		} else if (rect.top < screenTop && rect.bottom < screenBottom) {
			// need to move up to get it in view: move up just enough so that
			// entire rectangle is in view (or at least the first screen
			// size chunk of it).

			if (rect.height() > height) {
				// screen size chunk
				scrollYDelta -= (screenBottom - rect.bottom);
			} else {
				// entire rect at top
				scrollYDelta -= (screenTop - rect.top);
			}

			// make sure we aren't scrolling any further than the top our content
			scrollYDelta = Math.max(scrollYDelta, -getScrollY());
		}
		return scrollYDelta;
	}
}