/**
 * Copyright (C) 2013 Open Whisper Systems
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.thoughtcrime.securesms;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ProgressBar;

import org.thoughtcrime.securesms.crypto.DecryptingQueue;
import org.thoughtcrime.securesms.crypto.IdentityKeyUtil;
import org.thoughtcrime.securesms.notifications.MessageNotifier;
import org.thoughtcrime.securesms.util.Util;
import org.whispersystems.textsecure.crypto.MasterSecret;
import org.thoughtcrime.securesms.database.DatabaseFactory;
import org.thoughtcrime.securesms.util.VersionTracker;

import java.io.File;
import java.util.SortedSet;
import java.util.TreeSet;

public class DatabaseUpgradeActivity extends Activity {

  public static final int NO_MORE_KEY_EXCHANGE_PREFIX_VERSION  = 46;
  public static final int MMS_BODY_VERSION                     = 46;
  public static final int TOFU_IDENTITIES_VERSION              = 50;
  public static final int CURVE25519_VERSION                   = 63;
  public static final int ASYMMETRIC_MASTER_SECRET_FIX_VERSION = 73;
  public static final int NO_V1_VERSION                        = 83;

  private static final SortedSet<Integer> UPGRADE_VERSIONS = new TreeSet<Integer>() {{
    add(NO_MORE_KEY_EXCHANGE_PREFIX_VERSION);
    add(TOFU_IDENTITIES_VERSION);
    add(CURVE25519_VERSION);
    add(ASYMMETRIC_MASTER_SECRET_FIX_VERSION);
  }};

  private MasterSecret masterSecret;

  @Override
  public void onCreate(Bundle bundle) {
    super.onCreate(bundle);
    this.masterSecret = getIntent().getParcelableExtra("master_secret");

    if (needsUpgradeTask()) {
      Log.w("DatabaseUpgradeActivity", "Upgrading...");
      setContentView(R.layout.database_upgrade_activity);

      ProgressBar indeterminateProgress = (ProgressBar)findViewById(R.id.indeterminate_progress);
      ProgressBar determinateProgress   = (ProgressBar)findViewById(R.id.determinate_progress);

      new DatabaseUpgradeTask(indeterminateProgress, determinateProgress)
          .execute(VersionTracker.getLastSeenVersion(this));
    } else {
      VersionTracker.updateLastSeenVersion(this);
      DecryptingQueue.schedulePendingDecrypts(DatabaseUpgradeActivity.this, masterSecret);
      MessageNotifier.updateNotification(DatabaseUpgradeActivity.this, masterSecret);
      startActivity((Intent)getIntent().getParcelableExtra("next_intent"));
      finish();
    }
  }

  private boolean needsUpgradeTask() {
    int currentVersionCode = Util.getCurrentApkReleaseVersion(this);
    int lastSeenVersion    = VersionTracker.getLastSeenVersion(this);

    Log.w("DatabaseUpgradeActivity", "LastSeenVersion: " + lastSeenVersion);

    if (lastSeenVersion >= currentVersionCode)
      return false;

    for (int version : UPGRADE_VERSIONS) {
      Log.w("DatabaseUpgradeActivity", "Comparing: " + version);
      if (lastSeenVersion < version)
        return true;
    }

    return false;
  }

  public static boolean isUpdate(Context context) {
    try {
      int currentVersionCode  = context.getPackageManager().getPackageInfo(context.getPackageName(), 0).versionCode;
      int previousVersionCode = VersionTracker.getLastSeenVersion(context);

      return previousVersionCode < currentVersionCode;
    } catch (PackageManager.NameNotFoundException e) {
      throw new AssertionError(e);
    }
  }

  public interface DatabaseUpgradeListener {
    public void setProgress(int progress, int total);
  }

  private class DatabaseUpgradeTask extends AsyncTask<Integer, Double, Void>
      implements DatabaseUpgradeListener
  {

    private final ProgressBar indeterminateProgress;
    private final ProgressBar determinateProgress;

    public DatabaseUpgradeTask(ProgressBar indeterminateProgress, ProgressBar determinateProgress) {
      this.indeterminateProgress = indeterminateProgress;
      this.determinateProgress   = determinateProgress;
    }

    @Override
    protected Void doInBackground(Integer... params) {
      Context context = DatabaseUpgradeActivity.this.getApplicationContext();

      Log.w("DatabaseUpgradeActivity", "Running background upgrade..");
      DatabaseFactory.getInstance(DatabaseUpgradeActivity.this)
                     .onApplicationLevelUpgrade(context, masterSecret, params[0], this);

      if (params[0] < CURVE25519_VERSION) {
        if (!IdentityKeyUtil.hasCurve25519IdentityKeys(context)) {
          IdentityKeyUtil.generateCurve25519IdentityKeys(context, masterSecret);
        }
      }

      if (params[0] < NO_V1_VERSION) {
        File v1sessions = new File(context.getFilesDir(), "sessions");

        if (v1sessions.exists() && v1sessions.isDirectory()) {
          File[] contents = v1sessions.listFiles();

          if (contents != null) {
            for (File session : contents) {
              session.delete();
            }
          }

          v1sessions.delete();
        }
      }

      return null;
    }

    @Override
    protected void onProgressUpdate(Double... update) {
      indeterminateProgress.setVisibility(View.GONE);
      determinateProgress.setVisibility(View.VISIBLE);

      double scaler = update[0];
      determinateProgress.setProgress((int)Math.floor(determinateProgress.getMax() * scaler));
    }

    @Override
    protected void onPostExecute(Void result) {
      VersionTracker.updateLastSeenVersion(DatabaseUpgradeActivity.this);
      DecryptingQueue.schedulePendingDecrypts(DatabaseUpgradeActivity.this, masterSecret);
      MessageNotifier.updateNotification(DatabaseUpgradeActivity.this, masterSecret);

      startActivity((Intent)getIntent().getParcelableExtra("next_intent"));
      finish();
    }

    @Override
    public void setProgress(int progress, int total) {
      publishProgress(((double)progress / (double)total));
    }
  }

}