/*
 * 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.google.zxing.client.android;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.DecodeHintType;
import com.google.zxing.Result;
import com.google.zxing.ResultMetadataType;
import com.google.zxing.ResultPoint;
import com.google.zxing.client.android.camera.CameraManager;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.preference.PreferenceManager;
import android.text.ClipboardManager;
import android.util.Log;
import android.util.TypedValue;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.WindowManager;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import java.io.IOException;
import java.text.DateFormat;
import java.util.Collection;
import java.util.Date;
import java.util.EnumSet;
import java.util.Map;
import java.util.Set;

/**
 * This activity opens the camera and does the actual scanning on a background thread. It draws a
 * viewfinder to help the user place the barcode correctly, shows feedback as the image processing
 * is happening, and then overlays the results when a scan is successful.
 *
 * @author dswitkin@google.com (Daniel Switkin)
 * @author Sean Owen
 */
public final class CaptureActivity extends Activity implements SurfaceHolder.Callback {

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

  private static final long DEFAULT_INTENT_RESULT_DURATION_MS = 1500L;
  private static final long BULK_MODE_SCAN_DELAY_MS = 1000L;

  private static final String PACKAGE_NAME = "com.google.zxing.client.android";
  private static final String PRODUCT_SEARCH_URL_PREFIX = "http://www.google";
  private static final String PRODUCT_SEARCH_URL_SUFFIX = "/m/products/scan";
  private static final String[] ZXING_URLS = { "http://zxing.appspot.com/scan", "zxing://scan/" };

  private static final Set<ResultMetadataType> DISPLAYABLE_METADATA_TYPES =
      EnumSet.of(ResultMetadataType.ISSUE_NUMBER,
                 ResultMetadataType.SUGGESTED_PRICE,
                 ResultMetadataType.ERROR_CORRECTION_LEVEL,
                 ResultMetadataType.POSSIBLE_COUNTRY);

  private CameraManager cameraManager;
  private CaptureActivityHandler handler;
  private Result savedResultToShow;
  private ViewfinderView viewfinderView;
  private TextView statusView;
  private View resultView;
  private Result lastResult;
  private boolean hasSurface;
  private IntentSource source;
  private String sourceUrl;
  private Collection<BarcodeFormat> decodeFormats;
  private Map<DecodeHintType,?> decodeHints;
  private String characterSet;
  private InactivityTimer inactivityTimer;
  private BeepManager beepManager;
  private AmbientLightManager ambientLightManager;

  ViewfinderView getViewfinderView() {
    return viewfinderView;
  }

  public Handler getHandler() {
    return handler;
  }

  CameraManager getCameraManager() {
    return cameraManager;
  }

  @Override
  public void onCreate(Bundle icicle) {
    super.onCreate(icicle);

    Window window = getWindow();
    window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
    setContentView(R.layout.zxing_capture);

    hasSurface = false;
    inactivityTimer = new InactivityTimer(this);
    beepManager = new BeepManager(this);
    ambientLightManager = new AmbientLightManager(this);

    PreferenceManager.setDefaultValues(this, R.xml.zxing_preferences, false);

    showHelpOnFirstLaunch();
  }

  @Override
  protected void onResume() {
    super.onResume();

    // CameraManager must be initialized here, not in onCreate(). This is necessary because we don't
    // want to open the camera driver and measure the screen size if we're going to show the help on
    // first launch. That led to bugs where the scanning rectangle was the wrong size and partially
    // off screen.
    cameraManager = new CameraManager(getApplication());

    viewfinderView = (ViewfinderView) findViewById(R.id.viewfinder_view);
    viewfinderView.setCameraManager(cameraManager);

    resultView = findViewById(R.id.result_view);
    statusView = (TextView) findViewById(R.id.status_view);

    handler = null;
    lastResult = null;

    resetStatusView();

    SurfaceView surfaceView = (SurfaceView) findViewById(R.id.preview_view);
    SurfaceHolder surfaceHolder = surfaceView.getHolder();
    if (hasSurface) {
      // The activity was paused but not stopped, so the surface still exists. Therefore
      // surfaceCreated() won't be called, so init the camera here.
      initCamera(surfaceHolder);
    } else {
      // Install the callback and wait for surfaceCreated() to init the camera.
      surfaceHolder.addCallback(this);
      surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    beepManager.updatePrefs();
    ambientLightManager.start(cameraManager);

    inactivityTimer.onResume();

    Intent intent = getIntent();

    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);

    source = IntentSource.NONE;
    decodeFormats = null;
    characterSet = null;

    if (intent != null) {

      String action = intent.getAction();
      String dataString = intent.getDataString();

      if (Intents.Scan.ACTION.equals(action)) {

        // Scan the formats the intent requested, and return the result to the calling activity.
        source = IntentSource.NATIVE_APP_INTENT;
        decodeFormats = DecodeFormatManager.parseDecodeFormats(intent);
        decodeHints = DecodeHintManager.parseDecodeHints(intent);

        if (intent.hasExtra(Intents.Scan.WIDTH) && intent.hasExtra(Intents.Scan.HEIGHT)) {
          int width = intent.getIntExtra(Intents.Scan.WIDTH, 0);
          int height = intent.getIntExtra(Intents.Scan.HEIGHT, 0);
          if (width > 0 && height > 0) {
            cameraManager.setManualFramingRect(width, height);
          }
        }
        
        String customPromptMessage = intent.getStringExtra(Intents.Scan.PROMPT_MESSAGE);
        if (customPromptMessage != null) {
          statusView.setText(customPromptMessage);
        }

      } else if (dataString != null &&
                 dataString.contains(PRODUCT_SEARCH_URL_PREFIX) &&
                 dataString.contains(PRODUCT_SEARCH_URL_SUFFIX)) {

        // Scan only products and send the result to mobile Product Search.
        source = IntentSource.PRODUCT_SEARCH_LINK;
        sourceUrl = dataString;
        decodeFormats = DecodeFormatManager.PRODUCT_FORMATS;

      } else if (isZXingURL(dataString)) {

        // Scan formats requested in query string (all formats if none specified).
        // If a return URL is specified, send the results there. Otherwise, handle it ourselves.
        source = IntentSource.ZXING_LINK;
        sourceUrl = dataString;
        Uri inputUri = Uri.parse(dataString);
        decodeFormats = DecodeFormatManager.parseDecodeFormats(inputUri);
        // Allow a sub-set of the hints to be specified by the caller.
        decodeHints = DecodeHintManager.parseDecodeHints(inputUri);

      }

      characterSet = intent.getStringExtra(Intents.Scan.CHARACTER_SET);

    }
  }
  
  private static boolean isZXingURL(String dataString) {
    if (dataString == null) {
      return false;
    }
    for (String url : ZXING_URLS) {
      if (dataString.startsWith(url)) {
        return true;
      }
    }
    return false;
  }

  @Override
  protected void onPause() {
    if (handler != null) {
      handler.quitSynchronously();
      handler = null;
    }
    inactivityTimer.onPause();
    ambientLightManager.stop();
    cameraManager.closeDriver();
    if (!hasSurface) {
      SurfaceView surfaceView = (SurfaceView) findViewById(R.id.preview_view);
      SurfaceHolder surfaceHolder = surfaceView.getHolder();
      surfaceHolder.removeCallback(this);
    }
    super.onPause();
  }

  @Override
  protected void onDestroy() {
    inactivityTimer.shutdown();
    super.onDestroy();
  }

  @Override
  public boolean onKeyDown(int keyCode, KeyEvent event) {
    switch (keyCode) {
      case KeyEvent.KEYCODE_BACK:
        if (source == IntentSource.NATIVE_APP_INTENT) {
          setResult(RESULT_CANCELED);
          finish();
          return true;
        }
        if ((source == IntentSource.NONE || source == IntentSource.ZXING_LINK) && lastResult != null) {
          restartPreviewAfterDelay(0L);
          return true;
        }
        break;
      case KeyEvent.KEYCODE_FOCUS:
      case KeyEvent.KEYCODE_CAMERA:
        // Handle these events so they don't launch the Camera app
        return true;
      // Use volume up/down to turn on light
      case KeyEvent.KEYCODE_VOLUME_DOWN:
        cameraManager.setTorch(false);
        return true;
      case KeyEvent.KEYCODE_VOLUME_UP:
        cameraManager.setTorch(true);
        return true;
    }
    return super.onKeyDown(keyCode, event);
  }

  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater menuInflater = getMenuInflater();
    menuInflater.inflate(R.menu.zxing_capture, menu);
    return super.onCreateOptionsMenu(menu);
  }

  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
    Intent intent = new Intent(Intent.ACTION_VIEW);
    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
    int itemId = item.getItemId();
    if(itemId == R.id.menu_help) {
      intent.setClassName(this, HelpActivity.class.getName());
      startActivity(intent);
    } else {
      return super.onOptionsItemSelected(item);
    }
    return true;
  }

  private void decodeOrStoreSavedBitmap(Bitmap bitmap, Result result) {
    // Bitmap isn't used yet -- will be used soon
    if (handler == null) {
      savedResultToShow = result;
    } else {
      if (result != null) {
        savedResultToShow = result;
      }
      if (savedResultToShow != null) {
        Message message = Message.obtain(handler, R.id.decode_succeeded, savedResultToShow);
        handler.sendMessage(message);
      }
      savedResultToShow = null;
    }
  }

  @Override
  public void surfaceCreated(SurfaceHolder holder) {
    if (holder == null) {
      Log.e(TAG, "*** WARNING *** surfaceCreated() gave us a null surface!");
    }
    if (!hasSurface) {
      hasSurface = true;
      initCamera(holder);
    }
  }

  @Override
  public void surfaceDestroyed(SurfaceHolder holder) {
    hasSurface = false;
  }

  @Override
  public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

  }

  /**
   * A valid barcode has been found, so give an indication of success and show the results.
   *
   * @param rawResult The contents of the barcode.
   * @param barcode   A greyscale bitmap of the camera data which was decoded.
   */
  public void handleDecode(Result rawResult, Bitmap barcode, float scaleFactor) {
    inactivityTimer.onActivity();
    lastResult = rawResult;

    boolean fromLiveScan = barcode != null;
    if (fromLiveScan) {
      // Then not from history, so beep/vibrate and we have an image to draw on
      beepManager.playBeepSoundAndVibrate();
      drawResultPoints(barcode, scaleFactor, rawResult);
    }

    handleDecodeExternally(rawResult, barcode);
  }

  /**
   * Superimpose a line for 1D or dots for 2D to highlight the key features of the barcode.
   *
   * @param barcode   A bitmap of the captured image.
   * @param scaleFactor amount by which thumbnail was scaled
   * @param rawResult The decoded results which contains the points to draw.
   */
  private void drawResultPoints(Bitmap barcode, float scaleFactor, Result rawResult) {
    ResultPoint[] points = rawResult.getResultPoints();
    if (points != null && points.length > 0) {
      Canvas canvas = new Canvas(barcode);
      Paint paint = new Paint();
      paint.setColor(getResources().getColor(R.color.result_points));
      if (points.length == 2) {
        paint.setStrokeWidth(4.0f);
        drawLine(canvas, paint, points[0], points[1], scaleFactor);
      } else if (points.length == 4 &&
                 (rawResult.getBarcodeFormat() == BarcodeFormat.UPC_A ||
                  rawResult.getBarcodeFormat() == BarcodeFormat.EAN_13)) {
        // Hacky special case -- draw two lines, for the barcode and metadata
        drawLine(canvas, paint, points[0], points[1], scaleFactor);
        drawLine(canvas, paint, points[2], points[3], scaleFactor);
      } else {
        paint.setStrokeWidth(10.0f);
        for (ResultPoint point : points) {
          if(point != null) {
            canvas.drawPoint(scaleFactor * point.getX(), scaleFactor * point.getY(), paint);
          }
        }
      }
    }
  }

  private static void drawLine(Canvas canvas, Paint paint, ResultPoint a, ResultPoint b, float scaleFactor) {
    if (a != null && b != null) {
      canvas.drawLine(scaleFactor * a.getX(), 
                      scaleFactor * a.getY(), 
                      scaleFactor * b.getX(), 
                      scaleFactor * b.getY(), 
                      paint);
    }
  }

  // Briefly show the contents of the barcode, then handle the result outside Barcode Scanner.
  private void handleDecodeExternally(Result rawResult, Bitmap barcode) {

    if (barcode != null) {
      viewfinderView.drawResultBitmap(barcode);
    }

    long resultDurationMS;
    if (getIntent() == null) {
      resultDurationMS = DEFAULT_INTENT_RESULT_DURATION_MS;
    } else {
      resultDurationMS = getIntent().getLongExtra(Intents.Scan.RESULT_DISPLAY_DURATION_MS,
                                                  DEFAULT_INTENT_RESULT_DURATION_MS);
    }

    if (source == IntentSource.NATIVE_APP_INTENT) {
      
      // Hand back whatever action they requested - this can be changed to Intents.Scan.ACTION when
      // the deprecated intent is retired.
      Intent intent = new Intent(getIntent().getAction());
      intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
      intent.putExtra(Intents.Scan.RESULT, rawResult.toString());
      intent.putExtra(Intents.Scan.RESULT_FORMAT, rawResult.getBarcodeFormat().toString());
      byte[] rawBytes = rawResult.getRawBytes();
      if (rawBytes != null && rawBytes.length > 0) {
        intent.putExtra(Intents.Scan.RESULT_BYTES, rawBytes);
      }
      Map<ResultMetadataType,?> metadata = rawResult.getResultMetadata();
      if (metadata != null) {
        if (metadata.containsKey(ResultMetadataType.UPC_EAN_EXTENSION)) {
          intent.putExtra(Intents.Scan.RESULT_UPC_EAN_EXTENSION,
                          metadata.get(ResultMetadataType.UPC_EAN_EXTENSION).toString());
        }
        Integer orientation = (Integer) metadata.get(ResultMetadataType.ORIENTATION);
        if (orientation != null) {
          intent.putExtra(Intents.Scan.RESULT_ORIENTATION, orientation.intValue());
        }
        String ecLevel = (String) metadata.get(ResultMetadataType.ERROR_CORRECTION_LEVEL);
        if (ecLevel != null) {
          intent.putExtra(Intents.Scan.RESULT_ERROR_CORRECTION_LEVEL, ecLevel);
        }
        Iterable<byte[]> byteSegments = (Iterable<byte[]>) metadata.get(ResultMetadataType.BYTE_SEGMENTS);
        if (byteSegments != null) {
          int i = 0;
          for (byte[] byteSegment : byteSegments) {
            intent.putExtra(Intents.Scan.RESULT_BYTE_SEGMENTS_PREFIX + i, byteSegment);
            i++;
          }
        }
      }
      sendReplyMessage(R.id.return_scan_result, intent, resultDurationMS);
      
    }
  }
  
  private void sendReplyMessage(int id, Object arg, long delayMS) {
    Message message = Message.obtain(handler, id, arg);
    if (delayMS > 0L) {
      handler.sendMessageDelayed(message, delayMS);
    } else {
      handler.sendMessage(message);
    }
  }

  /**
   * We want the help screen to be shown automatically the first time a new version of the app is
   * run. The easiest way to do this is to check android:versionCode from the manifest, and compare
   * it to a value stored as a preference.
   */
  private boolean showHelpOnFirstLaunch() {
    // Library project: we do not ever want to confuse the user with a help screen.
    return false;
  }

  private void initCamera(SurfaceHolder surfaceHolder) {
    if (surfaceHolder == null) {
      throw new IllegalStateException("No SurfaceHolder provided");
    }
    if (cameraManager.isOpen()) {
      Log.w(TAG, "initCamera() while already open -- late SurfaceView callback?");
      return;
    }
    try {
      cameraManager.openDriver(surfaceHolder);
      // Creating the handler starts the preview, which can also throw a RuntimeException.
      if (handler == null) {
        handler = new CaptureActivityHandler(this, decodeFormats, decodeHints, characterSet, cameraManager);
      }
      decodeOrStoreSavedBitmap(null, null);
    } catch (IOException ioe) {
      Log.w(TAG, ioe);
      displayFrameworkBugMessageAndExit();
    } catch (RuntimeException e) {
      // Barcode Scanner has seen crashes in the wild of this variety:
      // java.?lang.?RuntimeException: Fail to connect to camera service
      Log.w(TAG, "Unexpected error initializing camera", e);
      displayFrameworkBugMessageAndExit();
    }
  }

  private void displayFrameworkBugMessageAndExit() {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle(getString(R.string.zxing_app_name));
    builder.setMessage(getString(R.string.msg_camera_framework_bug));
    builder.setPositiveButton(R.string.button_ok, new FinishListener(this));
    builder.setOnCancelListener(new FinishListener(this));
    builder.show();
  }

  public void restartPreviewAfterDelay(long delayMS) {
    if (handler != null) {
      handler.sendEmptyMessageDelayed(R.id.restart_preview, delayMS);
    }
    resetStatusView();
  }

  private void resetStatusView() {
    resultView.setVisibility(View.GONE);
    statusView.setText(R.string.msg_default_status);
    statusView.setVisibility(View.VISIBLE);
    viewfinderView.setVisibility(View.VISIBLE);
    lastResult = null;
  }

  public void drawViewfinder() {
    viewfinderView.drawViewfinder();
  }
}