/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Android code.
 *
 * The Initial Developer of the Original Code is Mozilla Foundation.
 * Portions created by the Initial Developer are Copyright (C) 2009-2010
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Sriram Ramasubramanian <sriram@mozilla.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

package org.mozilla.gecko;

import java.util.*;

import android.content.ContentResolver;
import android.graphics.drawable.*;
import android.util.Log;

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

public class Tabs implements GeckoEventListener {
    private static final String LOGTAG = "GeckoTabs";

    private static int selectedTab = -1;
    private HashMap<Integer, Tab> tabs;
    private ArrayList<Tab> order;
    private ContentResolver resolver;

    private Tabs() {
        tabs = new HashMap<Integer, Tab>();
        order = new ArrayList<Tab>();
        GeckoAppShell.registerGeckoEventListener("SessionHistory:New", this);
        GeckoAppShell.registerGeckoEventListener("SessionHistory:Back", this);
        GeckoAppShell.registerGeckoEventListener("SessionHistory:Forward", this);
        GeckoAppShell.registerGeckoEventListener("SessionHistory:Goto", this);
        GeckoAppShell.registerGeckoEventListener("SessionHistory:Purge", this);
    }

    public int getCount() {
        return tabs.size();
    }

    public Tab addTab(JSONObject params) throws JSONException {
        int id = params.getInt("tabID");
        if (tabs.containsKey(id))
           return tabs.get(id);

        String url = params.getString("uri");
        Boolean external = params.getBoolean("external");
        int parentId = params.getInt("parentId");
        String title = params.getString("title");

        Tab tab = new Tab(id, url, external, parentId, title);
        tabs.put(id, tab);
        order.add(tab);
        Log.i(LOGTAG, "Added a tab with id: " + id + ", url: " + url);
        return tab;
    }

    public void removeTab(int id) {
        if (tabs.containsKey(id)) {
            order.remove(getTab(id));
            tabs.remove(id);
            Log.i(LOGTAG, "Removed a tab with id: " + id);
        }
    }

    public Tab selectTab(int id) {
        if (!tabs.containsKey(id))
            return null;
 
        selectedTab = id;
        return tabs.get(id);
    }

    public int getIndexOf(Tab tab) {
        return order.lastIndexOf(tab);
    }

    public Tab getTabAt(int index) {
        if (index >= 0 && index < order.size())
            return order.get(index);
        else
            return null;
    }

    public Tab getSelectedTab() {
        return tabs.get(selectedTab);
    }

    public int getSelectedTabId() {
        return selectedTab;
    }

    public boolean isSelectedTab(Tab tab) {
        return (tab.getId() == selectedTab);
    }

    public Tab getTab(int id) {
        if (getCount() == 0)
            return null;

        if (!tabs.containsKey(id))
           return null;

        return tabs.get(id);
    }

    /** Close tab and then select the default next tab */
    public void closeTab(Tab tab) {
        closeTab(tab, getNextTab(tab));
    }

    /** Close tab and then select nextTab */
    public void closeTab(Tab tab, Tab nextTab) {
        if (tab == null || nextTab == null)
            return;

        GeckoAppShell.sendEventToGecko(new GeckoEvent("Tab:Select", String.valueOf(nextTab.getId())));
        GeckoAppShell.sendEventToGecko(new GeckoEvent("Tab:Close", String.valueOf(tab.getId())));
    }

    /** Return the tab that will be selected by default after this one is closed */
    public Tab getNextTab(Tab tab) {
        Tab selectedTab = getSelectedTab();
        if (selectedTab != tab)
            return selectedTab;

        int index = getIndexOf(tab);
        Tab nextTab = getTabAt(index + 1);
        if (nextTab == null)
            nextTab = getTabAt(index - 1);

        Tab parent = getTab(tab.getParentId());
        if (parent != null) {
            // If the next tab is a sibling, switch to it. Otherwise go back to the parent.
            if (nextTab != null && nextTab.getParentId() == tab.getParentId())
                return nextTab;
            else
                return parent;
        }
        return nextTab;
    }

    public HashMap<Integer, Tab> getTabs() {
        if (getCount() == 0)
            return null;

        return tabs;
    }
    
    public ArrayList<Tab> getTabsInOrder() {
        if (getCount() == 0)
            return null;

        return order;
    }

    public void setContentResolver(ContentResolver resolver) {
        this.resolver = resolver;
    }

    public ContentResolver getContentResolver() {
        return resolver;
    }

    //Making Tabs a singleton class
    private static class TabsInstanceHolder {
        private static final Tabs INSTANCE = new Tabs();
    }

    public static Tabs getInstance() {
       return Tabs.TabsInstanceHolder.INSTANCE;
    }

    // GeckoEventListener implementation

    public void handleMessage(String event, JSONObject message) {
        try {
            if (event.startsWith("SessionHistory:")) {
                Tab tab = getTab(message.getInt("tabID"));
                if (tab != null) {
                    event = event.substring("SessionHistory:".length());
                    tab.handleSessionHistoryMessage(event, message);
                }
            }
        } catch (Exception e) { 
            Log.i(LOGTAG, "handleMessage throws " + e + " for message: " + event);
        }
    }

    public void refreshThumbnails() {
        Iterator<Tab> iterator = tabs.values().iterator();
        while (iterator.hasNext())
            GeckoApp.mAppContext.getAndProcessThumbnailForTab(iterator.next());
    }
}