/**
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

package com.android.internal.policy.impl;

import android.content.Context;
import android.content.Intent;
import android.database.ContentObserver;
import android.database.Cursor;
import android.os.Handler;
import android.provider.Settings;
import android.util.Log;
import android.util.SparseArray;
import android.view.KeyCharacterMap;

import java.net.URISyntaxException;

/**
 * Manages quick launch shortcuts by:
 * <li> Keeping the local copy in sync with the database (this is an observer)
 * <li> Returning a shortcut-matching intent to clients
 */
class ShortcutManager extends ContentObserver {
    
    private static final String TAG = "ShortcutManager";
    
    private static final int COLUMN_SHORTCUT = 0;
    private static final int COLUMN_INTENT = 1;
    private static final String[] sProjection = new String[] {
        Settings.Bookmarks.SHORTCUT, Settings.Bookmarks.INTENT
    };

    private Context mContext;
    private Cursor mCursor;
    /** Map of a shortcut to its intent. */
    private SparseArray<Intent> mShortcutIntents;
    
    public ShortcutManager(Context context, Handler handler) {
        super(handler);
        
        mContext = context;
        mShortcutIntents = new SparseArray<Intent>();
    }

    /** Observes the provider of shortcut+intents */
    public void observe() {
        mCursor = mContext.getContentResolver().query(
                Settings.Bookmarks.CONTENT_URI, sProjection, null, null, null);
        mCursor.registerContentObserver(this);
        updateShortcuts();
    }

    @Override
    public void onChange(boolean selfChange) {
        updateShortcuts();
    }
    
    private void updateShortcuts() {
        Cursor c = mCursor;
        if (!c.requery()) {
            Log.e(TAG, "ShortcutObserver could not re-query shortcuts.");
            return;
        }

        mShortcutIntents.clear();
        while (c.moveToNext()) {
            int shortcut = c.getInt(COLUMN_SHORTCUT);
            if (shortcut == 0) continue;
            String intentURI = c.getString(COLUMN_INTENT);
            Intent intent = null;
            try {
                intent = Intent.getIntent(intentURI);
            } catch (URISyntaxException e) {
                Log.w(TAG, "Intent URI for shortcut invalid.", e);
            }
            if (intent == null) continue;
            mShortcutIntents.put(shortcut, intent);
        }
    }
    
    /**
     * Gets the shortcut intent for a given keycode+modifier. Make sure you
     * strip whatever modifier is used for invoking shortcuts (for example,
     * if 'Sym+A' should invoke a shortcut on 'A', you should strip the
     * 'Sym' bit from the modifiers before calling this method.
     * <p>
     * This will first try an exact match (with modifiers), and then try a
     * match without modifiers (primary character on a key).
     * 
     * @param keyCode The keycode of the key pushed.
     * @param modifiers The modifiers without any that are used for chording
     *            to invoke a shortcut.
     * @return The intent that matches the shortcut, or null if not found.
     */
    public Intent getIntent(int keyCode, int modifiers) {
        KeyCharacterMap kcm = KeyCharacterMap.load(KeyCharacterMap.BUILT_IN_KEYBOARD);
        // First try the exact keycode (with modifiers)
        int shortcut = kcm.get(keyCode, modifiers);
        Intent intent = shortcut != 0 ? mShortcutIntents.get(shortcut) : null; 
        if (intent != null) return intent;
        
        // Next try the keycode without modifiers (the primary character on that key)
        shortcut = Character.toLowerCase(kcm.get(keyCode, 0));
        return shortcut != 0 ? mShortcutIntents.get(shortcut) : null;
    }

}