/*
 * Copyright (C) 2012-2014 Dominik Schürmann <dominik@dominikschuermann.de>
 * Copyright (C) 2010-2014 Thialfihar <thi@thialfihar.org>
 *
 * 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.sufficientlysecure.keychain.helper;

import android.content.Context;
import android.content.SharedPreferences;

import org.spongycastle.bcpg.CompressionAlgorithmTags;
import org.spongycastle.bcpg.HashAlgorithmTags;
import org.spongycastle.openpgp.PGPEncryptedData;
import org.sufficientlysecure.keychain.Constants;

import java.util.Vector;

/**
 * Singleton Implementation of a Preference Helper
 */
public class Preferences {
    private static Preferences sPreferences;
    private SharedPreferences mSharedPreferences;

    public static synchronized Preferences getPreferences(Context context) {
        return getPreferences(context, false);
    }

    public static synchronized Preferences getPreferences(Context context, boolean forceNew) {
        if (sPreferences == null || forceNew) {
            sPreferences = new Preferences(context);
        }
        return sPreferences;
    }

    private Preferences(Context context) {
        mSharedPreferences = context.getSharedPreferences("APG.main", Context.MODE_PRIVATE);
    }

    public String getLanguage() {
        return mSharedPreferences.getString(Constants.Pref.LANGUAGE, "");
    }

    public void setLanguage(String value) {
        SharedPreferences.Editor editor = mSharedPreferences.edit();
        editor.putString(Constants.Pref.LANGUAGE, value);
        editor.commit();
    }

    public long getPassphraseCacheTtl() {
        int ttl = mSharedPreferences.getInt(Constants.Pref.PASSPHRASE_CACHE_TTL, 180);
        // fix the value if it was set to "never" in previous versions, which currently is not
        // supported
        if (ttl == 0) {
            ttl = 180;
        }
        return (long) ttl;
    }

    public void setPassphraseCacheTtl(int value) {
        SharedPreferences.Editor editor = mSharedPreferences.edit();
        editor.putInt(Constants.Pref.PASSPHRASE_CACHE_TTL, value);
        editor.commit();
    }

    public int getDefaultEncryptionAlgorithm() {
        return mSharedPreferences.getInt(Constants.Pref.DEFAULT_ENCRYPTION_ALGORITHM,
                PGPEncryptedData.AES_256);
    }

    public void setDefaultEncryptionAlgorithm(int value) {
        SharedPreferences.Editor editor = mSharedPreferences.edit();
        editor.putInt(Constants.Pref.DEFAULT_ENCRYPTION_ALGORITHM, value);
        editor.commit();
    }

    public int getDefaultHashAlgorithm() {
        return mSharedPreferences.getInt(Constants.Pref.DEFAULT_HASH_ALGORITHM,
                HashAlgorithmTags.SHA512);
    }

    public void setDefaultHashAlgorithm(int value) {
        SharedPreferences.Editor editor = mSharedPreferences.edit();
        editor.putInt(Constants.Pref.DEFAULT_HASH_ALGORITHM, value);
        editor.commit();
    }

    public int getDefaultMessageCompression() {
        return mSharedPreferences.getInt(Constants.Pref.DEFAULT_MESSAGE_COMPRESSION,
                CompressionAlgorithmTags.ZLIB);
    }

    public void setDefaultMessageCompression(int value) {
        SharedPreferences.Editor editor = mSharedPreferences.edit();
        editor.putInt(Constants.Pref.DEFAULT_MESSAGE_COMPRESSION, value);
        editor.commit();
    }

    public int getDefaultFileCompression() {
        return mSharedPreferences.getInt(Constants.Pref.DEFAULT_FILE_COMPRESSION,
                CompressionAlgorithmTags.UNCOMPRESSED);
    }

    public void setDefaultFileCompression(int value) {
        SharedPreferences.Editor editor = mSharedPreferences.edit();
        editor.putInt(Constants.Pref.DEFAULT_FILE_COMPRESSION, value);
        editor.commit();
    }

    public boolean getDefaultAsciiArmor() {
        return mSharedPreferences.getBoolean(Constants.Pref.DEFAULT_ASCII_ARMOR, false);
    }

    public void setDefaultAsciiArmor(boolean value) {
        SharedPreferences.Editor editor = mSharedPreferences.edit();
        editor.putBoolean(Constants.Pref.DEFAULT_ASCII_ARMOR, value);
        editor.commit();
    }

    public boolean isFirstTime() {
        return mSharedPreferences.getBoolean(Constants.Pref.FIRST_TIME, true);
    }

    public void setFirstTime(boolean value) {
        SharedPreferences.Editor editor = mSharedPreferences.edit();
        editor.putBoolean(Constants.Pref.FIRST_TIME, value);
        editor.commit();
    }

    public String[] getKeyServers() {
        String rawData = mSharedPreferences.getString(Constants.Pref.KEY_SERVERS,
                Constants.Defaults.KEY_SERVERS);
        Vector<String> servers = new Vector<String>();
        String chunks[] = rawData.split(",");
        for (String c : chunks) {
            String tmp = c.trim();
            if (tmp.length() > 0) {
                servers.add(tmp);
            }
        }
        return servers.toArray(chunks);
    }

    public void setKeyServers(String[] value) {
        SharedPreferences.Editor editor = mSharedPreferences.edit();
        String rawData = "";
        for (String v : value) {
            String tmp = v.trim();
            if (tmp.length() == 0) {
                continue;
            }
            if (!"".equals(rawData)) {
                rawData += ",";
            }
            rawData += tmp;
        }
        editor.putString(Constants.Pref.KEY_SERVERS, rawData);
        editor.commit();
    }

    public void updatePreferences() {
        // migrate keyserver to hkps
        if (mSharedPreferences.getInt(Constants.Pref.KEY_SERVERS_DEFAULT_VERSION, 0) !=
                Constants.Defaults.KEY_SERVERS_VERSION) {
            String[] servers = getKeyServers();
            for (int i = 0; i < servers.length; i++) {
                if (servers[i].equals("pool.sks-keyservers.net")) {
                    servers[i] = "hkps://hkps.pool.sks-keyservers.net";
                } else if (servers[i].equals("pgp.mit.edu")) {
                    servers[i] = "hkps://pgp.mit.edu";
                }
            }
            setKeyServers(servers);
            mSharedPreferences.edit()
                    .putInt(Constants.Pref.KEY_SERVERS_DEFAULT_VERSION, Constants.Defaults.KEY_SERVERS_VERSION)
                    .commit();
        }

        // migrate old uncompressed constant to new one
        if (mSharedPreferences.getInt(Constants.Pref.DEFAULT_FILE_COMPRESSION, 0) == 0x21070001) {
            setDefaultFileCompression(CompressionAlgorithmTags.UNCOMPRESSED);
        }
    }

    public void setConcealPgpApplication(boolean conceal) {
        SharedPreferences.Editor editor = mSharedPreferences.edit();
        editor.putBoolean(Constants.Pref.CONCEAL_PGP_APPLICATION, conceal);
        editor.commit();
    }

    public boolean getConcealPgpApplication() {
        return mSharedPreferences.getBoolean(Constants.Pref.CONCEAL_PGP_APPLICATION, false);
    }
}