/**
 * Copyright (c) 2013 LEAP Encryption Access Project and contributers
 *
 * 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 se.leap.bitmaskclient.eip;

import com.google.gson.Gson;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.IOException;

import de.blinkt.openvpn.VpnProfile;
import de.blinkt.openvpn.core.ConfigParser;

import static se.leap.bitmaskclient.Constants.LOCATION;
import static se.leap.bitmaskclient.Constants.LOCATIONS;
import static se.leap.bitmaskclient.Constants.NAME;
import static se.leap.bitmaskclient.Constants.OPENVPN_CONFIGURATION;
import static se.leap.bitmaskclient.Constants.TIMEZONE;
import static se.leap.bitmaskclient.Constants.VERSION;

/**
 * Gateway provides objects defining gateways and their metadata.
 * Each instance contains a VpnProfile for OpenVPN specific data and member
 * variables describing capabilities and location (name)
 *
 * @author Sean Leonard <meanderingcode@aetherislands.net>
 * @author Parménides GV <parmegv@sdf.org>
 * @author cyberta
 */
public class Gateway {

    public final static String TAG = Gateway.class.getSimpleName();
    public final static String KEY_N_CLOSEST_GATEWAY = "N_CLOSEST_GATEWAY";

    private JSONObject generalConfiguration;
    private JSONObject secrets;
    private JSONObject gateway;

    private String name;
    private int timezone;
    private int apiVersion;
    private VpnProfile vpnProfile;

    /**
     * Build a gateway object from a JSON OpenVPN gateway definition in eip-service.json
     * and create a VpnProfile belonging to it.
     */
    public Gateway(JSONObject eipDefinition, JSONObject secrets, JSONObject gateway) {

        this.gateway = gateway;
        this.secrets = secrets;

        generalConfiguration = getGeneralConfiguration(eipDefinition);
        timezone = getTimezone(eipDefinition);
        name = locationAsName(eipDefinition);
        apiVersion = getApiVersion(eipDefinition);
        vpnProfile = createVPNProfile();
        if (vpnProfile != null) {
            vpnProfile.mName = name;
        }
    }

    private JSONObject getGeneralConfiguration(JSONObject eipDefinition) {
        try {
            return eipDefinition.getJSONObject(OPENVPN_CONFIGURATION);
        } catch (JSONException e) {
            return new JSONObject();
        }
    }

    private int getTimezone(JSONObject eipDefinition) {
        JSONObject location = getLocationInfo(eipDefinition);
        return location.optInt(TIMEZONE);
    }

    private int getApiVersion(JSONObject eipDefinition) {
        return eipDefinition.optInt(VERSION);
    }

    private String locationAsName(JSONObject eipDefinition) {
        JSONObject location = getLocationInfo(eipDefinition);
        return location.optString(NAME);
    }

    private JSONObject getLocationInfo(JSONObject eipDefinition) {
        try {
            JSONObject locations = eipDefinition.getJSONObject(LOCATIONS);

            return locations.getJSONObject(gateway.getString(LOCATION));
        } catch (JSONException e) {
            return new JSONObject();
        }
    }

    /**
     * Create and attach the VpnProfile to our gateway object
     */
    private VpnProfile createVPNProfile() {
        try {
            VpnConfigGenerator vpnConfigurationGenerator = new VpnConfigGenerator(generalConfiguration, secrets, gateway, apiVersion);
            return vpnConfigurationGenerator.generateVpnProfile();
        } catch (ConfigParser.ConfigParseError | IOException | CloneNotSupportedException | JSONException e) {
            // FIXME We didn't get a VpnProfile!  Error handling! and log level
            e.printStackTrace();
            return null;
        }
    }

    public String getName() {
        return name;
    }

    public VpnProfile getProfile() {
        return vpnProfile;
    }

    public int getTimezone() {
        return timezone;
    }

    @Override
    public String toString() {
        return new Gson().toJson(this, Gateway.class);
    }

    @Override
    public boolean equals(Object obj) {
        return obj instanceof Gateway &&
                (this.mVpnProfile != null &&
                        ((Gateway) obj).mVpnProfile != null &&
                        this.mVpnProfile.mConnections != null &&
                        ((Gateway) obj).mVpnProfile != null &&
                        this.mVpnProfile.mConnections.length > 0 &&
                        ((Gateway) obj).mVpnProfile.mConnections.length > 0 &&
                        this.mVpnProfile.mConnections[0].mServerName != null &&
                        this.mVpnProfile.mConnections[0].mServerName.equals(((Gateway) obj).mVpnProfile.mConnections[0].mServerName)) ||
                        this.mVpnProfile == null && ((Gateway) obj).mVpnProfile == null;
    }
}