/*
 * Copyright 2009 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.ratebeer.android.gui;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Fragment;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * <p>A utility class which helps ease integration with Barcode Scanner via {@link Intent}s. This is a simple way to invoke barcode scanning and
 * receive the result, without any need to integrate, modify, or learn the project's source code.</p> <p> <h2>Initiating a barcode scan</h2> <p> <p>To
 * integrate, create an instance of {@code IntentIntegrator} and call {@link #initiateScan()} and wait for the result in your app.</p> <p> <p>It does
 * require that the Barcode Scanner (or work-alike) application is installed. The {@link #initiateScan()} method will prompt the user to download the
 * application, if needed.</p> <p> <p>There are a few steps to using this integration. First, your {@link Activity} must implement the method {@link
 * Activity#onActivityResult(int, int, Intent)} and include a line of code like this:</p> <p>
 * <pre>{@code
 * public void onActivityResult(int requestCode, int resultCode, Intent intent) {
 *   IntentResult scanResult = IntentIntegrator.parseActivityResult(requestCode, resultCode, intent);
 *   if (scanResult != null) {
 *     // handle scan result
 *   }
 *   // else continue with any other code you need in the method
 *   ...
 * }
 * }</pre>
 * <p> <p>This is where you will handle a scan result.</p> <p> <p>Second, just call this in response to a user action somewhere to begin the scan
 * process:</p> <p>
 * <pre>{@code
 * IntentIntegrator integrator = new IntentIntegrator(yourActivity);
 * integrator.initiateScan();
 * }</pre>
 * <p> <p>Note that {@link #initiateScan()} returns an {@link AlertDialog} which is non-null if the user was prompted to download the application.
 * This lets the calling app potentially manage the dialog. In particular, ideally, the app dismisses the dialog if it's still active in its {@link
 * Activity#onPause()} method.</p> <p> <p>You can use {@link #setTitle(String)} to customize the title of this download prompt dialog (or, use {@link
 * #setTitleByID(int)} to set the title by string resource ID.) Likewise, the prompt message, and yes/no button labels can be changed.</p> <p>
 * <p>Finally, you can use {@link #addExtra(String, Object)} to add more parameters to the Intent used to invoke the scanner. This can be used to set
 * additional options not directly exposed by this simplified API.</p> <p> <p>By default, this will only allow applications that are known to respond
 * to this intent correctly do so. The apps that are allowed to response can be set with {@link #setTargetApplications(List)}. For example, set to
 * {@link #TARGET_BARCODE_SCANNER_ONLY} to only target the Barcode Scanner app itself.</p> <p> <h2>Sharing text via barcode</h2> <p> <p>To share text,
 * encoded as a QR Code on-screen, similarly, see {@link #shareText(CharSequence)}.</p> <p> <p>Some code, particularly download integration, was
 * contributed from the Anobiit application.</p> <p> <h2>Enabling experimental barcode formats</h2> <p> <p>Some formats are not enabled by default
 * even when scanning with {@link #ALL_CODE_TYPES}, such as PDF417. Use {@link #initiateScan(java.util.Collection)} with a collection containing the
 * names of formats to scan for explicitly, like "PDF_417", to use such formats.</p>
 * @author Sean Owen
 * @author Fred Lin
 * @author Isaac Potoczny-Jones
 * @author Brad Drehmer
 * @author gcstang
 */
@SuppressWarnings("unused")
public final class BarcodeIntentIntegrator {

	public static final int REQUEST_CODE = 0x0000c0de; // Only use bottom 16 bits
	private static final String TAG = BarcodeIntentIntegrator.class.getSimpleName();

	public static final String DEFAULT_TITLE = "Install Barcode Scanner?";
	public static final String DEFAULT_MESSAGE = "This application requires Barcode Scanner. Would you like to install it?";
	public static final String DEFAULT_YES = "Yes";
	public static final String DEFAULT_NO = "No";

	private static final String BS_PACKAGE = "com.google.zxing.client.android";
	private static final String BSPLUS_PACKAGE = "com.srowen.bs.android";

	// supported barcode formats
	public static final Collection<String> PRODUCT_CODE_TYPES = list("UPC_A", "UPC_E", "EAN_8", "EAN_13", "RSS_14");
	public static final Collection<String> ONE_D_CODE_TYPES =
			list("UPC_A", "UPC_E", "EAN_8", "EAN_13", "CODE_39", "CODE_93", "CODE_128", "ITF", "RSS_14", "RSS_EXPANDED");
	public static final Collection<String> QR_CODE_TYPES = Collections.singleton("QR_CODE");
	public static final Collection<String> DATA_MATRIX_TYPES = Collections.singleton("DATA_MATRIX");

	public static final Collection<String> ALL_CODE_TYPES = null;

	public static final List<String> TARGET_BARCODE_SCANNER_ONLY = Collections.singletonList(BS_PACKAGE);
	public static final List<String> TARGET_ALL_KNOWN = list(BSPLUS_PACKAGE,             // Barcode Scanner+
			BSPLUS_PACKAGE + ".simple", // Barcode Scanner+ Simple
			BS_PACKAGE                  // Barcode Scanner
			// What else supports this intent?
	);

	private final Activity activity;
	private final Fragment fragment;

	private String title;
	private String message;
	private String buttonYes;
	private String buttonNo;
	private List<String> targetApplications;
	private final Map<String, Object> moreExtras = new HashMap<>(3);

	/**
	 * @param activity {@link Activity} invoking the integration
	 */
	public BarcodeIntentIntegrator(Activity activity) {
		this.activity = activity;
		this.fragment = null;
		initializeConfiguration();
	}

	/**
	 * @param fragment {@link Fragment} invoking the integration. {@link #startActivityForResult(Intent, int)} will be called on the {@link Fragment}
	 * instead of an {@link Activity}
	 */
	public BarcodeIntentIntegrator(Fragment fragment) {
		this.activity = fragment.getActivity();
		this.fragment = fragment;
		initializeConfiguration();
	}

	private void initializeConfiguration() {
		title = DEFAULT_TITLE;
		message = DEFAULT_MESSAGE;
		buttonYes = DEFAULT_YES;
		buttonNo = DEFAULT_NO;
		targetApplications = TARGET_ALL_KNOWN;
	}

	public String getTitle() {
		return title;
	}

	public void setTitle(String title) {
		this.title = title;
	}

	public void setTitleByID(int titleID) {
		title = activity.getString(titleID);
	}

	public String getMessage() {
		return message;
	}

	public void setMessage(String message) {
		this.message = message;
	}

	public void setMessageByID(int messageID) {
		message = activity.getString(messageID);
	}

	public String getButtonYes() {
		return buttonYes;
	}

	public void setButtonYes(String buttonYes) {
		this.buttonYes = buttonYes;
	}

	public void setButtonYesByID(int buttonYesID) {
		buttonYes = activity.getString(buttonYesID);
	}

	public String getButtonNo() {
		return buttonNo;
	}

	public void setButtonNo(String buttonNo) {
		this.buttonNo = buttonNo;
	}

	public void setButtonNoByID(int buttonNoID) {
		buttonNo = activity.getString(buttonNoID);
	}

	public Collection<String> getTargetApplications() {
		return targetApplications;
	}

	public final void setTargetApplications(List<String> targetApplications) {
		if (targetApplications.isEmpty()) {
			throw new IllegalArgumentException("No target applications");
		}
		this.targetApplications = targetApplications;
	}

	public void setSingleTargetApplication(String targetApplication) {
		this.targetApplications = Collections.singletonList(targetApplication);
	}

	public Map<String, ?> getMoreExtras() {
		return moreExtras;
	}

	public final void addExtra(String key, Object value) {
		moreExtras.put(key, value);
	}

	/**
	 * Initiates a scan for all known barcode types with the default camera.
	 * @return the {@link AlertDialog} that was shown to the user prompting them to download the app if a prompt was needed, or null otherwise.
	 */
	public final AlertDialog initiateScan() {
		return initiateScan(ALL_CODE_TYPES, -1);
	}

	/**
	 * Initiates a scan for all known barcode types with the specified camera.
	 * @param cameraId camera ID of the camera to use. A negative value means "no preference".
	 * @return the {@link AlertDialog} that was shown to the user prompting them to download the app if a prompt was needed, or null otherwise.
	 */
	public final AlertDialog initiateScan(int cameraId) {
		return initiateScan(ALL_CODE_TYPES, cameraId);
	}

	/**
	 * Initiates a scan, using the default camera, only for a certain set of barcode types, given as strings corresponding to their names in ZXing's
	 * {@code BarcodeFormat} class like "UPC_A". You can supply constants like {@link #PRODUCT_CODE_TYPES} for example.
	 * @param desiredBarcodeFormats names of {@code BarcodeFormat}s to scan for
	 * @return the {@link AlertDialog} that was shown to the user prompting them to download the app if a prompt was needed, or null otherwise.
	 */
	public final AlertDialog initiateScan(Collection<String> desiredBarcodeFormats) {
		return initiateScan(desiredBarcodeFormats, -1);
	}

	/**
	 * Initiates a scan, using the specified camera, only for a certain set of barcode types, given as strings corresponding to their names in ZXing's
	 * {@code BarcodeFormat} class like "UPC_A". You can supply constants like {@link #PRODUCT_CODE_TYPES} for example.
	 * @param desiredBarcodeFormats names of {@code BarcodeFormat}s to scan for
	 * @param cameraId camera ID of the camera to use. A negative value means "no preference".
	 * @return the {@link AlertDialog} that was shown to the user prompting them to download the app if a prompt was needed, or null otherwise
	 */
	public final AlertDialog initiateScan(Collection<String> desiredBarcodeFormats, int cameraId) {
		Intent intentScan = new Intent(BS_PACKAGE + ".SCAN");
		intentScan.addCategory(Intent.CATEGORY_DEFAULT);

		// check which types of codes to scan for
		if (desiredBarcodeFormats != null) {
			// set the desired barcode types
			StringBuilder joinedByComma = new StringBuilder();
			for (String format : desiredBarcodeFormats) {
				if (joinedByComma.length() > 0) {
					joinedByComma.append(',');
				}
				joinedByComma.append(format);
			}
			intentScan.putExtra("SCAN_FORMATS", joinedByComma.toString());
		}

		// check requested camera ID
		if (cameraId >= 0) {
			intentScan.putExtra("SCAN_CAMERA_ID", cameraId);
		}

		String targetAppPackage = findTargetAppPackage(intentScan);
		if (targetAppPackage == null) {
			return showDownloadDialog();
		}
		intentScan.setPackage(targetAppPackage);
		intentScan.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
		//noinspection deprecation
		intentScan.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
		attachMoreExtras(intentScan);
		startActivityForResult(intentScan, REQUEST_CODE);
		return null;
	}

	/**
	 * Start an activity. This method is defined to allow different methods of activity starting for newer versions of Android and for compatibility
	 * library.
	 * @param intent Intent to start.
	 * @param code Request code for the activity
	 * @see android.app.Activity#startActivityForResult(Intent, int)
	 * @see android.app.Fragment#startActivityForResult(Intent, int)
	 */
	protected void startActivityForResult(Intent intent, int code) {
		if (fragment == null) {
			activity.startActivityForResult(intent, code);
		} else {
			fragment.startActivityForResult(intent, code);
		}
	}

	private String findTargetAppPackage(Intent intent) {
		PackageManager pm = activity.getPackageManager();
		List<ResolveInfo> availableApps = pm.queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
		if (availableApps != null) {
			for (String targetApp : targetApplications) {
				if (contains(availableApps, targetApp)) {
					return targetApp;
				}
			}
		}
		return null;
	}

	private static boolean contains(Iterable<ResolveInfo> availableApps, String targetApp) {
		for (ResolveInfo availableApp : availableApps) {
			String packageName = availableApp.activityInfo.packageName;
			if (targetApp.equals(packageName)) {
				return true;
			}
		}
		return false;
	}

	private AlertDialog showDownloadDialog() {
		AlertDialog.Builder downloadDialog = new AlertDialog.Builder(activity);
		downloadDialog.setTitle(title);
		downloadDialog.setMessage(message);
		downloadDialog.setPositiveButton(buttonYes, (dialogInterface, i) -> {
			String packageName;
			if (targetApplications.contains(BS_PACKAGE)) {
				// Prefer to suggest download of BS if it's anywhere in the list
				packageName = BS_PACKAGE;
			} else {
				// Otherwise, first option:
				packageName = targetApplications.get(0);
			}
			Uri uri = Uri.parse("market://details?id=" + packageName);
			Intent intent = new Intent(Intent.ACTION_VIEW, uri);
			try {
				if (fragment == null) {
					activity.startActivity(intent);
				} else {
					fragment.startActivity(intent);
				}
			} catch (ActivityNotFoundException anfe) {
				// Hmm, market is not installed
				Log.w(TAG, "Google Play is not installed; cannot install " + packageName);
			}
		});
		downloadDialog.setNegativeButton(buttonNo, null);
		downloadDialog.setCancelable(true);
		return downloadDialog.show();
	}


	/**
	 * <p>Call this from your {@link Activity}'s {@link Activity#onActivityResult(int, int, Intent)} method.</p>
	 * @param requestCode request code from {@code onActivityResult()}
	 * @param resultCode result code from {@code onActivityResult()}
	 * @param intent {@link Intent} from {@code onActivityResult()}
	 * @return null if the event handled here was not related to this class, or else an {@link BarcodeIntentResult} containing the result of the scan.
	 * If the user cancelled scanning, the fields will be null.
	 */
	public static BarcodeIntentResult parseActivityResult(int requestCode, int resultCode, Intent intent) {
		if (requestCode == REQUEST_CODE) {
			if (resultCode == Activity.RESULT_OK) {
				String contents = intent.getStringExtra("SCAN_RESULT");
				String formatName = intent.getStringExtra("SCAN_RESULT_FORMAT");
				byte[] rawBytes = intent.getByteArrayExtra("SCAN_RESULT_BYTES");
				int intentOrientation = intent.getIntExtra("SCAN_RESULT_ORIENTATION", Integer.MIN_VALUE);
				Integer orientation = intentOrientation == Integer.MIN_VALUE ? null : intentOrientation;
				String errorCorrectionLevel = intent.getStringExtra("SCAN_RESULT_ERROR_CORRECTION_LEVEL");
				return new BarcodeIntentResult(contents, formatName, rawBytes, orientation, errorCorrectionLevel);
			}
			return new BarcodeIntentResult();
		}
		return null;
	}


	/**
	 * Defaults to type "TEXT_TYPE".
	 * @param text the text string to encode as a barcode
	 * @return the {@link AlertDialog} that was shown to the user prompting them to download the app if a prompt was needed, or null otherwise
	 * @see #shareText(CharSequence, CharSequence)
	 */
	public final AlertDialog shareText(CharSequence text) {
		return shareText(text, "TEXT_TYPE");
	}

	/**
	 * Shares the given text by encoding it as a barcode, such that another user can scan the text off the screen of the device.
	 * @param text the text string to encode as a barcode
	 * @param type type of data to encode. See {@code com.google.zxing.client.android.Contents.Type} constants.
	 * @return the {@link AlertDialog} that was shown to the user prompting them to download the app if a prompt was needed, or null otherwise
	 */
	public final AlertDialog shareText(CharSequence text, CharSequence type) {
		Intent intent = new Intent();
		intent.addCategory(Intent.CATEGORY_DEFAULT);
		intent.setAction(BS_PACKAGE + ".ENCODE");
		intent.putExtra("ENCODE_TYPE", type);
		intent.putExtra("ENCODE_DATA", text);
		String targetAppPackage = findTargetAppPackage(intent);
		if (targetAppPackage == null) {
			return showDownloadDialog();
		}
		intent.setPackage(targetAppPackage);
		intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
		//noinspection deprecation
		intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
		attachMoreExtras(intent);
		if (fragment == null) {
			activity.startActivity(intent);
		} else {
			fragment.startActivity(intent);
		}
		return null;
	}

	private static List<String> list(String... values) {
		return Collections.unmodifiableList(Arrays.asList(values));
	}

	private void attachMoreExtras(Intent intent) {
		for (Map.Entry<String, Object> entry : moreExtras.entrySet()) {
			String key = entry.getKey();
			Object value = entry.getValue();
			// Kind of hacky
			if (value instanceof Integer) {
				intent.putExtra(key, (Integer) value);
			} else if (value instanceof Long) {
				intent.putExtra(key, (Long) value);
			} else if (value instanceof Boolean) {
				intent.putExtra(key, (Boolean) value);
			} else if (value instanceof Double) {
				intent.putExtra(key, (Double) value);
			} else if (value instanceof Float) {
				intent.putExtra(key, (Float) value);
			} else if (value instanceof Bundle) {
				intent.putExtra(key, (Bundle) value);
			} else {
				intent.putExtra(key, value.toString());
			}
		}
	}

}