package org.cao.optimization.util;

import java.io.File;

import org.cao.optimization.ConstantValue;

import android.graphics.Bitmap;
import android.os.Environment;

public class Image {
	// 图片ID
	private String id;
	// 图片对应bitmap对象
	private Bitmap bitmap;

	public Image(String id, Bitmap bitmap) {
		super();
		this.id = id;
		this.bitmap = bitmap;
	}

	public Image(String id) {
		this.id = id;
	}

	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public Bitmap getBitmap() {
		return bitmap;
	}

	public void setBitmap(Bitmap bitmap) {
		this.bitmap = bitmap;
	}

	/**
	 * @Title: hasFile
	 * @Description: 判断本地SD中是否有图片
	 * @param id
	 * @return
	 * @throws
	 */
	public static boolean hasFile(String id) {
		boolean result = false;
		// 判断本地SDCard中是否有相关文件
		if (Environment.getExternalStorageState().equals(
				Environment.MEDIA_MOUNTED)) {
			File externalStorageDirectory = Environment
					.getExternalStorageDirectory();
			String path = externalStorageDirectory.getAbsolutePath()
					+ ConstantValue.IMAGE_PATH;

			File dir = new File(path);
			File[] listFiles = dir.listFiles();
			if (listFiles != null && listFiles.length > 0) {
				for (int i = 0; i < listFiles.length; i++) {
					if (listFiles[i].getName().startsWith(id)) {
						result = true;
						break;
					}
				}
			}
		}
		return result;
	}

	/**
	 * @Title: getFileFromSDCard
	 * @Description: 从SD卡中获取图片
	 * @param id
	 * @param path
	 * @param extend
	 * @return
	 * @throws
	 */
	public static File getFileFromSDCard(String id, String path, String extend) {
		File result = null;
		if (Environment.getExternalStorageState().equals(
				Environment.MEDIA_MOUNTED)) {
			File externalStorageDirectory = Environment
					.getExternalStorageDirectory();
			path = externalStorageDirectory.getAbsolutePath() + path;
			result = new File(new File(path), id + extend);
		}

		return result;
	}

	/**
	 * @Title: getFileFromSDCard
	 * @Description: 从SD卡中获取图片
	 * @param id
	 * @return
	 * @throws
	 */
	public static File getFileFromSDCard(String id) {
		return getFileFromSDCard(id, ConstantValue.IMAGE_PATH,
				ConstantValue.PNG);
	}

}

/**
 * @ClassName: ImageCache
 * @author victor_freedom (x_freedom_reddevil@126.com)
 * @createddate 2015-1-30 下午4:49:56
 * @Description: Image对象高速缓存
 */
public class ImageCache {
	static private ImageCache cache;// 一个Cache实例
	private Hashtable<String, ImageRef> ImageRefs;// 用于Chche内容的存储
	private ReferenceQueue<Image> q;// 垃圾Reference的队列

	// 继承SoftReference，使得每一个实例都具有可识别的标识。
	private class ImageRef extends SoftReference<Image> {
		private String key = "";

		public ImageRef(Image im, ReferenceQueue<Image> q) {
			super(im, q);
			key = im.getId();
		}
	}

	// 构建一个缓存器实例
	private ImageCache() {
		ImageRefs = new Hashtable<String, ImageRef>();
		q = new ReferenceQueue<Image>();

	}

	// 取得缓存器实例

	public static ImageCache getInstance() {
		if (cache == null) {
			cache = new ImageCache();
		}
		return cache;

	}

	// 以软引用的方式对一个Image对象的实例进行引用并保存该引用
	public void cacheImage(Image im) {
		cleanCache();// 清除垃圾引用
		ImageRef ref = new ImageRef(im, q);
		ImageRefs.put(im.getId(), ref);
	}

	// 依据所指定的ID号，重新获取相应Image对象的实例
	public Image getImage(String id) {
		Image im = null;
		// 缓存中是否有该Image实例的软引用，如果有，从软引用中取得。
		if (ImageRefs.containsKey(id)) {
			ImageRef ref = (ImageRef) ImageRefs.get(id);
			im = (Image) ref.get();
		}

		// 如果没有软引用，或者从软引用中得到的实例是null，重新构建一个实例，
		// 并保存对这个新建实例的软引用

		if (im == null) {
			im = new Image(id);
			System.out.println("Retrieve From ImageInfoCenter. ID=" + id);
			this.cacheImage(im);
		}
		return im;
	}

	private void cleanCache() {
		ImageRef ref = null;
		while ((ref = (ImageRef) q.poll()) != null) {
			ImageRefs.remove(ref.key);
		}
	}

	// 清除Cache内的全部内容

	public void clearCache() {
		cleanCache();
		ImageRefs.clear();
		System.gc();
		System.runFinalization();
	}
}