/*
 * Copyright (C) 2008 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.zxing.camera;

import java.io.IOException;

import android.content.Context;
import android.graphics.PixelFormat;
import android.graphics.Point;
import android.graphics.Rect;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.os.Build;
import android.os.Handler;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.SurfaceHolder;

/**
 * This object wraps the Camera service object and expects to be the only one talking to it. The
 * implementation encapsulates the steps needed to take preview-sized images, which are used for
 * both preview and decoding.
 *
 */
public final class CameraManager {

	private static final String TAG = CameraManager.class.getSimpleName();

	private static final int MIN_FRAME_WIDTH = 240;
	private static final int MIN_FRAME_HEIGHT = 240;
	private static final int MAX_FRAME_WIDTH = 480;
	private static final int MAX_FRAME_HEIGHT = 360;

	private static CameraManager cameraManager;

	static final int SDK_INT; // Later we can use Build.VERSION.SDK_INT
	static {
		int sdkInt;
		try {
			sdkInt = Integer.parseInt(Build.VERSION.SDK);
		} catch (NumberFormatException nfe) {
			// Just to be safe
			sdkInt = 10000;
		}
		SDK_INT = sdkInt;
	}

	private final Context context;
	private final CameraConfigurationManager configManager;
	private Camera camera;
	private Rect framingRect;
	private Rect framingRectInPreview;
	private boolean initialized;
	private boolean previewing;
	private final boolean useOneShotPreviewCallback;
	/**
	 * Preview frames are delivered here, which we pass on to the registered handler. Make sure to
	 * clear the handler so it will only receive one message.
	 */
	private final PreviewCallback previewCallback;
	/** Autofocus callbacks arrive here, and are dispatched to the Handler which requested them. */
	private final AutoFocusCallback autoFocusCallback;

	/**
	 * Initializes this static object with the Context of the calling Activity.
	 *
	 * @param context The Activity which wants to use the camera.
	 */
	public static void init(Context context) {
		if (cameraManager == null) {
			cameraManager = new CameraManager(context);
		}
	}

	/**
	 * Gets the CameraManager singleton instance.
	 *
	 * @return A reference to the CameraManager singleton.
	 */
	public static CameraManager get() {
		return cameraManager;
	}

	private CameraManager(Context context) {

		this.context = context;
		this.configManager = new CameraConfigurationManager(context);

		// Camera.setOneShotPreviewCallback() has a race condition in Cupcake, so we use the older
		// Camera.setPreviewCallback() on 1.5 and earlier. For Donut and later, we need to use
		// the more efficient one shot callback, as the older one can swamp the system and cause it
		// to run out of memory. We can't use SDK_INT because it was introduced in the Donut SDK.
		//useOneShotPreviewCallback = Integer.parseInt(Build.VERSION.SDK) > Build.VERSION_CODES.CUPCAKE;
		useOneShotPreviewCallback = Integer.parseInt(Build.VERSION.SDK) > 3; // 3 = Cupcake

		previewCallback = new PreviewCallback(configManager, useOneShotPreviewCallback);
		autoFocusCallback = new AutoFocusCallback();
	}

	/**
	 * Opens the camera driver and initializes the hardware parameters.
	 *
	 * @param holder The surface object which the camera will draw preview frames into.
	 * @throws IOException Indicates the camera driver failed to open.
	 */
	public void openDriver(SurfaceHolder holder) throws IOException {
		if (camera == null) {
			camera = Camera.open();
			if (camera == null) {
				throw new IOException();
			}
			camera.setPreviewDisplay(holder);

			if (!initialized) {
				initialized = true;
				configManager.initFromCameraParameters(camera);
			}
			configManager.setDesiredCameraParameters(camera);

			//FIXME
			//     SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
			//�Ƿ�ʹ��ǰ��
			//      if (prefs.getBoolean(PreferencesActivity.KEY_FRONT_LIGHT, false)) {
			//        FlashlightManager.enableFlashlight();
			//      }
			FlashlightManager.enableFlashlight();
		}
	}

	
	//Lemon add <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
	private Parameters parameter;
	/**开关闪光灯
	 * @param open
	 * @return
	 */
	public boolean switchLight(boolean open) {
		parameter = camera.getParameters();  
		if (open) {
			parameter.setFlashMode(Parameters.FLASH_MODE_TORCH); 
			camera.setParameters(parameter);
			return true;
		} else {
			parameter.setFlashMode(Parameters.FLASH_MODE_OFF); 
			camera.setParameters(parameter);
			return false;
		}
	}
	//Lemon add >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
	
	/**
	 * Closes the camera driver if still in use.
	 */
	public void closeDriver() {
		if (camera != null) {
			FlashlightManager.disableFlashlight();
			camera.release();
			camera = null;
		}
	}

	/**
	 * Asks the camera hardware to begin drawing preview frames to the screen.
	 */
	public void startPreview() {
		if (camera != null && !previewing) {
			camera.startPreview();
			previewing = true;
		}
	}

	/**
	 * Tells the camera to stop drawing preview frames.
	 */
	public void stopPreview() {
		if (camera != null && previewing) {
			if (!useOneShotPreviewCallback) {
				camera.setPreviewCallback(null);
			}
			camera.stopPreview();
			previewCallback.setHandler(null, 0);
			autoFocusCallback.setHandler(null, 0);
			previewing = false;
		}
	}

	/**
	 * A single preview frame will be returned to the handler supplied. The data will arrive as byte[]
	 * in the message.obj field, with width and height encoded as message.arg1 and message.arg2,
	 * respectively.
	 *
	 * @param handler The handler to send the message to.
	 * @param message The what field of the message to be sent.
	 */
	public void requestPreviewFrame(Handler handler, int message) {
		if (camera != null && previewing) {
			previewCallback.setHandler(handler, message);
			if (useOneShotPreviewCallback) {
				camera.setOneShotPreviewCallback(previewCallback);
			} else {
				camera.setPreviewCallback(previewCallback);
			}
		}
	}

	/**
	 * Asks the camera hardware to perform an autofocus.
	 *
	 * @param handler The Handler to notify when the autofocus completes.
	 * @param message The message to deliver.
	 */
	public void requestAutoFocus(Handler handler, int message) {
		if (camera != null && previewing) {
			autoFocusCallback.setHandler(handler, message);
			//Log.d(TAG, "Requesting auto-focus callback");
			camera.autoFocus(autoFocusCallback);
		}
	}

	/**
	 * Calculates the framing rect which the UI should draw to show the user where to place the
	 * barcode. This target helps with alignment as well as forces the user to hold the device
	 * far enough away to ensure the image will be in focus.
	 *
	 * @return The rectangle to draw on screen in window coordinates.
	 */
	public Rect getFramingRect() {
		Point screenResolution = configManager.getScreenResolution();
		if (framingRect == null) {
			if (camera == null) {
				return null;
			}
			//Lemon 扫描框修改,解决拉伸<<<<<<<<<<<<<<<<<<<<<<<<<<<< 

			//      int width = screenResolution.x * 3 / 4;
			//      if (width < MIN_FRAME_WIDTH) {
			//        width = MIN_FRAME_WIDTH;
			//      } else if (width > MAX_FRAME_WIDTH) {
			//        width = MAX_FRAME_WIDTH;
			//      }
			//      int height = screenResolution.y * 3 / 4;
			//      if (height < MIN_FRAME_HEIGHT) {
			//        height = MIN_FRAME_HEIGHT;
			//      } else if (height > MAX_FRAME_HEIGHT) {
			//        height = MAX_FRAME_HEIGHT;
			//      }
			//      int leftOffset = (screenResolution.x - width) / 2;
			//      int topOffset = (screenResolution.y - height) / 2;
			//      framingRect = new Rect(leftOffset, topOffset, leftOffset + width, topOffset + height);
			//      Log.d(TAG, "Calculated framing rect: " + framingRect);

			//Lemon 扫描框修改,解决拉伸<<<<<<<<<<<<<<<<<<<<<<<<<<<< 
			DisplayMetrics metrics = context.getResources().getDisplayMetrics();  
			int width = (int) (metrics.widthPixels * 0.6);  
			int height = (int) (width * 0.9);  

			int leftOffset = (screenResolution.x - width) / 2;  
			int topOffset = (screenResolution.y - height) / 3;  
			framingRect = new Rect(leftOffset, topOffset, leftOffset + width,  
					topOffset + height);  
			Log.d(TAG, "Calculated framing rect: " + framingRect); 
			//Lemon 扫描框修改,解决拉伸>>>>>>>>>>>>>>>>>>>>>>>>>>>>

		}
		return framingRect;
	}

	/**
	 * Like {@link #getFramingRect} but coordinates are in terms of the preview frame,
	 * not UI / screen.
	 */
	public Rect getFramingRectInPreview() {
		if (framingRectInPreview == null) {
			Rect rect = new Rect(getFramingRect());
			Point cameraResolution = configManager.getCameraResolution();
			Point screenResolution = configManager.getScreenResolution();
			//modify here
			//      rect.left = rect.left * cameraResolution.x / screenResolution.x;
			//      rect.right = rect.right * cameraResolution.x / screenResolution.x;
			//      rect.top = rect.top * cameraResolution.y / screenResolution.y;
			//      rect.bottom = rect.bottom * cameraResolution.y / screenResolution.y;
			rect.left = rect.left * cameraResolution.y / screenResolution.x;
			rect.right = rect.right * cameraResolution.y / screenResolution.x;
			rect.top = rect.top * cameraResolution.x / screenResolution.y;
			rect.bottom = rect.bottom * cameraResolution.x / screenResolution.y;
			framingRectInPreview = rect;
		}
		return framingRectInPreview;
	}

	/**
	 * Converts the result points from still resolution coordinates to screen coordinates.
	 *
	 * @param points The points returned by the Reader subclass through Result.getResultPoints().
	 * @return An array of Points scaled to the size of the framing rect and offset appropriately
	 *         so they can be drawn in screen coordinates.
	 */
	/*
  public Point[] convertResultPoints(ResultPoint[] points) {
    Rect frame = getFramingRectInPreview();
    int count = points.length;
    Point[] output = new Point[count];
    for (int x = 0; x < count; x++) {
      output[x] = new Point();
      output[x].x = frame.left + (int) (points[x].getX() + 0.5f);
      output[x].y = frame.top + (int) (points[x].getY() + 0.5f);
    }
    return output;
  }
	 */

	/**
	 * A factory method to build the appropriate LuminanceSource object based on the format
	 * of the preview buffers, as described by Camera.Parameters.
	 *
	 * @param data A preview frame.
	 * @param width The width of the image.
	 * @param height The height of the image.
	 * @return A PlanarYUVLuminanceSource instance.
	 */
	public PlanarYUVLuminanceSource buildLuminanceSource(byte[] data, int width, int height) {
		Rect rect = getFramingRectInPreview();
		int previewFormat = configManager.getPreviewFormat();
		String previewFormatString = configManager.getPreviewFormatString();
		switch (previewFormat) {
		// This is the standard Android format which all devices are REQUIRED to support.
		// In theory, it's the only one we should ever care about.
		case PixelFormat.YCbCr_420_SP:
			// This format has never been seen in the wild, but is compatible as we only care
			// about the Y channel, so allow it.
		case PixelFormat.YCbCr_422_SP:
			return new PlanarYUVLuminanceSource(data, width, height, rect.left, rect.top,
					rect.width(), rect.height());
		default:
			// The Samsung Work incorrectly uses this variant instead of the 'sp' version.
			// Fortunately, it too has all the Y data up front, so we can read it.
			if ("yuv420p".equals(previewFormatString)) {
				return new PlanarYUVLuminanceSource(data, width, height, rect.left, rect.top,
						rect.width(), rect.height());
			}
		}
		throw new IllegalArgumentException("Unsupported picture format: " +
				previewFormat + '/' + previewFormatString);
	}

	public Context getContext() {
		return context;
	}

}
