1/*
2 * Copyright (C) 2017 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 */
16
17package com.android.settings;
18
19import android.content.Context;
20import android.support.annotation.VisibleForTesting;
21import android.util.Log;
22
23import com.android.settings.utils.AsyncLoader;
24
25import java.io.File;
26import java.util.ArrayList;
27import java.util.List;
28
29/**
30 * LicenseHtmlLoader is a loader which loads a license html file from default license xml files.
31 */
32class LicenseHtmlLoader extends AsyncLoader<File> {
33    private static final String TAG = "LicenseHtmlLoader";
34
35    private static final String[] DEFAULT_LICENSE_XML_PATHS = {
36                "/system/etc/NOTICE.xml.gz",
37                "/vendor/etc/NOTICE.xml.gz",
38                "/odm/etc/NOTICE.xml.gz",
39                "/oem/etc/NOTICE.xml.gz"};
40    private static final String NOTICE_HTML_FILE_NAME = "NOTICE.html";
41
42    private Context mContext;
43
44    public LicenseHtmlLoader(Context context) {
45        super(context);
46        mContext = context;
47    }
48
49    @Override
50    public File loadInBackground() {
51        return generateHtmlFromDefaultXmlFiles();
52    }
53
54    @Override
55    protected void onDiscardResult(File f) {
56    }
57
58    private File generateHtmlFromDefaultXmlFiles() {
59        final List<File> xmlFiles = getVaildXmlFiles();
60        if (xmlFiles.isEmpty()) {
61            Log.e(TAG, "No notice file exists.");
62            return null;
63        }
64
65        File cachedHtmlFile = getCachedHtmlFile();
66        if(!isCachedHtmlFileOutdated(xmlFiles, cachedHtmlFile) ||
67                generateHtmlFile(xmlFiles, cachedHtmlFile)) {
68            return cachedHtmlFile;
69        }
70
71        return null;
72    }
73
74    @VisibleForTesting
75    List<File> getVaildXmlFiles() {
76        final List<File> xmlFiles = new ArrayList();
77        for (final String xmlPath : DEFAULT_LICENSE_XML_PATHS) {
78            File file = new File(xmlPath);
79            if (file.exists() && file.length() != 0) {
80                xmlFiles.add(file);
81            }
82        }
83        return xmlFiles;
84    }
85
86    @VisibleForTesting
87    File getCachedHtmlFile() {
88        return new File(mContext.getCacheDir(), NOTICE_HTML_FILE_NAME);
89    }
90
91    @VisibleForTesting
92    boolean isCachedHtmlFileOutdated(List<File> xmlFiles, File cachedHtmlFile) {
93        boolean outdated = true;
94        if (cachedHtmlFile.exists() && cachedHtmlFile.length() != 0) {
95            outdated = false;
96            for (File file : xmlFiles) {
97                if (cachedHtmlFile.lastModified() < file.lastModified()) {
98                    outdated = true;
99                    break;
100                }
101            }
102        }
103        return outdated;
104    }
105
106    @VisibleForTesting
107    boolean generateHtmlFile(List<File> xmlFiles, File htmlFile) {
108        return LicenseHtmlGeneratorFromXml.generateHtml(xmlFiles, htmlFile);
109    }
110}
111