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

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

import java.util.Collection;
import java.util.LinkedList;

import javax.swing.JOptionPane;

import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.data.osm.OsmPrimitive;
import org.openstreetmap.josm.data.osm.visitor.NameVisitor;

/**
 * Class that uploads all changes to the osm server.
 *
 * This is done like this: - All objects with id = 0 are uploaded as new, except
 * those in deleted, which are ignored - All objects in deleted list are
 * deleted. - All remaining objects with modified flag set are updated.
 */
public class OsmServerWriter {

    /**
     * This list contains all successfully processed objects. The caller of
     * upload* has to check this after the call and update its dataset.
     *
     * If a server connection error occurs, this may contain fewer entries
     * than where passed in the list to upload*.
     */
    public Collection<OsmPrimitive> processed;

    private OsmApi api = new OsmApi();
    
    private static final int MSECS_PER_SECOND = 1000;
    private static final int SECONDS_PER_MINUTE = 60;
    private static final int MSECS_PER_MINUTE = MSECS_PER_SECOND * SECONDS_PER_MINUTE;

    long uploadStartTime;

    public String timeLeft(int progress, int list_size) {
        long now = System.currentTimeMillis();
        long elapsed = now - uploadStartTime;
        if (elapsed == 0)
            elapsed = 1;
        float uploads_per_ms = (float)progress / elapsed;
        float uploads_left = list_size - progress;
        int ms_left = (int)(uploads_left / uploads_per_ms);
        int minutes_left = ms_left / MSECS_PER_MINUTE;
        int seconds_left = (ms_left / MSECS_PER_SECOND) % SECONDS_PER_MINUTE ;
        String time_left_str = Integer.toString(minutes_left) + ":";
        if (seconds_left < 10)
            time_left_str += "0";
        time_left_str += Integer.toString(seconds_left);
        return time_left_str;
    }

    /**
     * Send the dataset to the server. 
     * @param the_version version of the data set
     * @param list list of objects to send
     */
    public void uploadOsm(String the_version, Collection<OsmPrimitive> list) {
        processed = new LinkedList<OsmPrimitive>();
        api.initialize();

        Main.pleaseWaitDlg.progress.setMaximum(list.size());
        Main.pleaseWaitDlg.progress.setValue(0);

        boolean useChangesets = api.hasChangesetSupport();
        
        // controls whether or not we try and upload the whole bunch in one go
        boolean useDiffUploads = Main.pref.getBoolean("osm-server.atomic-upload",
            "0.6".equals(api.getVersion()));

        // solicit commit comment from user
        String comment = null;
        while (useChangesets && comment == null) {
            comment = JOptionPane.showInputDialog(Main.parent,
                 tr("Provide a brief comment for the changes you are uploading:"),
                 tr("Commit comment"), JOptionPane.QUESTION_MESSAGE);
            if (comment == null)
                return;
            // Don't let people just hit enter
            if (comment.trim().length() >= 3)
                break;
            comment = null;
        }
        
        // create changeset if required
        try {
            if (useChangesets) api.createChangeset(comment);
        } catch (OsmTransferException ex) {
            dealWithTransferException(ex);
            return;
        }

        try {
            if (useDiffUploads) {
                // all in one go
                processed.addAll(api.uploadDiff(list));
            } else {
                // upload changes individually (90% of code is for the status display...)
                NameVisitor v = new NameVisitor();
                uploadStartTime = System.currentTimeMillis();
                for (OsmPrimitive osm : list) {
                    osm.visit(v);
                    int progress = Main.pleaseWaitDlg.progress.getValue();
                    String time_left_str = timeLeft(progress, list.size());
                    Main.pleaseWaitDlg.currentAction.setText(
                            tr("{0}% ({1}/{2}), {3} left. Uploading {4}: {5} (id: {6})",
                                    Math.round(100.0*progress/list.size()), progress,
                                    list.size(), time_left_str, tr(v.className), v.name, osm.id));
                    makeApiRequest(osm);
                    processed.add(osm);
                    Main.pleaseWaitDlg.progress.setValue(progress+1);
                }
            }
            if (useChangesets) api.stopChangeset();
        } catch (OsmTransferException e) {
            try {
                if (useChangesets) api.stopChangeset();
            } catch (Exception ee) {
                // ignore nested exception
            }
            dealWithTransferException(e);
        }
    }

    void makeApiRequest(OsmPrimitive osm) throws OsmTransferException {
        if (osm.deleted) {
            api.deletePrimitive(osm);
        } else if (osm.id == 0) {
            api.createPrimitive(osm);
        } else {
            api.modifyPrimitive(osm);
        }
    }

    private void dealWithTransferException (OsmTransferException e) {
        Main.pleaseWaitDlg.currentAction.setText(tr("Transfer aborted due to error (will wait for 5 seconds):") + e.getMessage());
        try {
            Thread.sleep(5000);
        }
        catch (InterruptedException ex) {}
    }
}