// License: GPL. Copyright 2007 by Immanuel Scholz and others
package org.openstreetmap.josm.data;

import static org.openstreetmap.josm.tools.I18n.tr;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.StringReader;
import java.net.HttpURLConnection;
import java.net.URLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Collection;
import java.util.Collections;
import java.util.LinkedList;
import java.util.StringTokenizer;
import java.util.Map.Entry;

import javax.swing.JOptionPane;

import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.io.OsmConnection;
import org.openstreetmap.josm.io.XmlWriter;
import org.openstreetmap.josm.tools.Base64;
import org.openstreetmap.josm.tools.XmlObjectParser;

/**
 * This class tweak the Preferences class to provide server side preference settings, as example
 * used in the applet version.
 *
 * @author Imi
 */
public class ServerSidePreferences extends Preferences {

    private final Connection connection;

    private class Connection extends OsmConnection {
        URL serverUrl;
        public Connection(URL serverUrl) {
            this.serverUrl = serverUrl;
        }
        public String download() {
            try {
                System.out.println("reading preferences from "+serverUrl);
                URLConnection con = serverUrl.openConnection();
                if (con instanceof HttpURLConnection) addAuth((HttpURLConnection) con);
                con.connect();
                BufferedReader reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
                StringBuilder b = new StringBuilder();
                for (String line = reader.readLine(); line != null; line = reader.readLine()) {
                    b.append(line);
                    b.append("\n");
                }
                if (con instanceof HttpURLConnection) ((HttpURLConnection) con).disconnect();
                return b.toString();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }
        public void upload(String s) {
            try {
                URL u = new URL(getPreferencesDir());
                System.out.println("uploading preferences to "+u);
                HttpURLConnection con = (HttpURLConnection)u.openConnection();
                con.addRequestProperty("Authorization", "Basic "+Base64.encode(get("osm-server.username")+":"+get("osm-server.password")));
                con.setRequestMethod("POST");
                con.setDoOutput(true);
                con.connect();
                PrintWriter out = new PrintWriter(new OutputStreamWriter(con.getOutputStream()));
                out.println(s);
                out.close();
                con.getInputStream().close();
                con.disconnect();
                JOptionPane.showMessageDialog(Main.parent, tr("Preferences stored on {0}", u.getHost()));
            } catch (Exception e) {
                e.printStackTrace();
                JOptionPane.showMessageDialog(Main.parent, tr("Could not upload preferences. Reason: {0}", e.getMessage()));
            }
        }
    }

    public ServerSidePreferences(URL serverUrl) {
        Connection connection = null;
        try {
            connection = new Connection(new URL(serverUrl+"user/preferences"));
        } catch (MalformedURLException e) {
            e.printStackTrace();
            JOptionPane.showMessageDialog(Main.parent, tr("Could not load preferences from server."));
        }
        this.connection = connection;
    }

    @Override public String getPreferencesDir() {
        return connection.serverUrl.toString();
    }

    /**
     * Do nothing on load. Preferences are loaded with download().
     */
    @Override public void load() {
    }

    /**
     * Do nothing on save. Preferences are uploaded using upload().
     */
    @Override public void save() {
    }

    public static class Prop {
        public String key;
        public String value;
    }

    public void download(String userName, String password) {
        resetToDefault();
        if (!properties.containsKey("osm-server.username") && userName != null)
            properties.put("osm-server.username", userName);
        if (!properties.containsKey("osm-server.password") && password != null)
            properties.put("osm-server.password", password);
        String cont = connection.download();
        if (cont == null) return;
        Reader in = new StringReader(cont);
        try {
            XmlObjectParser.Uniform<Prop> parser = new XmlObjectParser.Uniform<Prop>(in, "tag", Prop.class);
            for (Prop p : parser)
                properties.put(p.key, p.value);
        } catch (RuntimeException e) {
            e.printStackTrace();
        }
    }

    /**
     * Use this instead of save() for the ServerSidePreferences, since uploads
     * are costly while save is called often.
     *
     * This is triggered by an explicit menu option.
     */
    public void upload() {
        StringBuilder b = new StringBuilder("<preferences>\n");
        for (Entry<String, String> p : properties.entrySet()) {
            if (p.getKey().equals("osm-server.password"))
                continue; // do not upload password. It would get stored in plain!
            b.append("<tag key='");
            b.append(XmlWriter.encode(p.getKey()));
            b.append("' value='");
            b.append(XmlWriter.encode(p.getValue()));
            b.append("' />\n");
        }
        b.append("</preferences>");
        connection.upload(b.toString());
    }

    @Override public Collection<Bookmark> loadBookmarks() {
        try {
            Collection<Bookmark> bookmarks;
            BufferedReader in = new BufferedReader(new InputStreamReader(new URL("http://"+connection.serverUrl.getHost()+"/josm/bookmarks").openStream()));
            bookmarks = new LinkedList<Bookmark>();
            for (String line = in.readLine(); line != null; line = in.readLine()) {
                StringTokenizer st = new StringTokenizer(line, ",");
                if (st.countTokens() < 5)
                    continue;
                Bookmark b = new Bookmark();
                b.name = st.nextToken();
                try {
                    for (int i = 0; i < b.latlon.length; ++i)
                        b.latlon[i] = Double.parseDouble(st.nextToken());
                    bookmarks.add(b);
                } catch (NumberFormatException x) {
                    // line not parsed
                }
            }
            in.close();
            return bookmarks;
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return Collections.emptyList();
    }

    @Override public void saveBookmarks(Collection<Bookmark> bookmarks) {
    }
}