1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16package com.android.mail.utils;
17
18import android.content.Context;
19import android.content.pm.PackageInfo;
20import android.content.pm.PackageManager;
21import android.net.Uri;
22import android.text.TextUtils;
23
24import java.util.Locale;
25
26/**
27 * Constructs the URL for the context sensitive help page for this mail application. The URL will be
28 * specific to the user's language, application, application version and topic. For example:
29 *
30 * <p>http://support.example.com/email/?hl=en-us&p=androidhelp&version=1 for the top level english
31 * help page for version 1 of the mail application</p>
32 * <p>http://support.example.com/email/?hl=fr-fr&p=email_compose&version=2 for the compose email
33 * french help page for version 2 of the mail application</p>
34 */
35public final class HelpUrl {
36    private static final String LOG_TAG = LogTag.getLogTag();
37
38    private HelpUrl() {}
39
40    /**
41     * Constructs the URL for the context sensitive help page for this mail application.
42     *
43     * @param context a context from which to read resources
44     * @param topic describes the help topic to display; this String cannot be empty.
45     * @return Url for the Help page that is specific to a language, application, version and topic
46     */
47    public static Uri getHelpUrl(final Context context, Uri helpUri, String topic) {
48        if (TextUtils.isEmpty(topic)) {
49            throw new IllegalArgumentException("topic must be non-empty");
50        }
51
52        // %locale% is a special variable encoded in the Uri that should be replaced if it exists
53        if (helpUri.toString().contains("%locale%")) {
54            helpUri = Uri.parse(helpUri.toString().replace("%locale%", getLocale()));
55        }
56
57        final Uri.Builder builder = helpUri.buildUpon();
58        builder.appendQueryParameter("p", topic);
59        builder.appendQueryParameter("version", getVersion(context));
60
61        return builder.build();
62    }
63
64    private static String getLocale() {
65        final Locale locale = Locale.getDefault();
66        return locale.getLanguage() + "-" + locale.getCountry().toLowerCase();
67    }
68
69    private static String getVersion(final Context context) {
70        final String packageName = context.getApplicationInfo().packageName;
71        try {
72            final PackageInfo pi = context.getPackageManager().getPackageInfo(packageName, 0);
73            return String.valueOf(pi.versionCode);
74        } catch (PackageManager.NameNotFoundException e) {
75            LogUtils.e(LOG_TAG, "Error finding package name for application" + packageName);
76            throw new IllegalStateException("unable to determine package name for application");
77        }
78    }
79}
80