package com.duben.microtribe.utils;

import android.content.Context;
import android.content.SharedPreferences;
import android.provider.Settings;
import android.telephony.TelephonyManager;

import com.duben.microtribe.MintsApplication;

import java.io.UnsupportedEncodingException;
import java.util.UUID;

/**
 * 描述：google生成android设备UUID
 * 作者：孟崔广
 * 时间：2018/5/9 20:03
 * 邮箱：mengcg@xiaojinqb.cn
 */
public class DeviceUuidFactory {
    protected static final String PREFS_FILE = "device_id.xml";
    protected static final String PREFS_DEVICE_ID = "device_id";

    protected static UUID uuid;

    public DeviceUuidFactory() {
        Context context= MintsApplication.getContext();
        if (uuid == null) {
            synchronized (DeviceUuidFactory.class) {
                if (uuid == null) {
                    final SharedPreferences prefs = context.getSharedPreferences(PREFS_FILE, 0);
                    final String id = prefs.getString(PREFS_DEVICE_ID, null);

                    if (id != null) {
                        // Use the ids previously computed and stored in the prefs file
                        uuid = UUID.fromString(id);

                    } else {

                        final String androidId = Settings.Secure.getString(context.getContentResolver(), Settings.Secure.ANDROID_ID);

                        // Use the Android ID unless it's broken, in which case fallback on deviceId,
                        // unless it's not available, then fallback on a random number which we store
                        // to a prefs file
                        try {
                            if (!"9774d56d682e549c".equals(androidId)) {
                                uuid = UUID.nameUUIDFromBytes(androidId.getBytes("utf8"));
                            } else {
                                final String deviceId = ((TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE)).getDeviceId();
                                uuid = deviceId != null ? UUID.nameUUIDFromBytes(deviceId.getBytes("utf8")) : UUID.randomUUID();
                            }
                        } catch (UnsupportedEncodingException e) {
                            throw new RuntimeException(e);
                        }

                        // Write the value out to the prefs file
                        prefs.edit().putString(PREFS_DEVICE_ID, uuid.toString()).commit();

                    }

                }
            }
        }

    }


    /**
     * Returns a unique UUID for the current android device.  As with all UUIDs, this unique ID is "very highly likely"
     * to be unique across all Android devices.  Much more so than ANDROID_ID is.
     * <p>
     * The UUID is generated by using ANDROID_ID as the base key if appropriate, falling back on
     * TelephonyManager.getDeviceID() if ANDROID_ID is known to be incorrect, and finally falling back
     * on a random UUID that's persisted to SharedPreferences if getDeviceID() does not return a
     * usable value.
     * <p>
     * In some rare circumstances, this ID may change.  In particular, if the device is factory reset a new device ID
     * may be generated.  In addition, if a user upgrades their phone from certain buggy implementations of Android 2.2
     * to a newer, non-buggy version of Android, the device ID may change.  Or, if a user uninstalls your app on
     * a device that has neither a proper Android ID nor a Device ID, this ID may change on reinstallation.
     * <p>
     * Note that if the code falls back on using TelephonyManager.getDeviceId(), the resulting ID will NOT
     * change after a factory reset.  Something to be aware of.
     * <p>
     * Works around a bug in Android 2.2 for many devices when using ANDROID_ID directly.
     *
     * @return a UUID that may be used to uniquely identify your device for most purposes.
     * @see //http://code.google.com/p/android/issues/detail?id=10603
     */
    public UUID getDeviceUuid() {
        return uuid;
    }
}
