1/*
2 * Copyright (C) 2012 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.app.DownloadManager;
19import android.content.Context;
20import android.net.ConnectivityManager;
21import android.net.NetworkInfo;
22import android.os.Bundle;
23import android.os.ParcelFileDescriptor;
24import android.os.SystemClock;
25import android.text.TextUtils;
26
27import com.android.mail.R;
28import com.android.mail.providers.Attachment;
29import com.google.common.collect.ImmutableMap;
30
31import java.io.File;
32import java.io.FileInputStream;
33import java.io.FileNotFoundException;
34import java.io.FileOutputStream;
35import java.io.IOException;
36import java.io.InputStream;
37import java.text.DecimalFormat;
38import java.text.SimpleDateFormat;
39import java.util.Date;
40import java.util.Map;
41
42public class AttachmentUtils {
43    private static final String LOG_TAG = LogTag.getLogTag();
44
45    private static final int KILO = 1024;
46    private static final int MEGA = KILO * KILO;
47
48    /** Any IO reads should be limited to this timeout */
49    private static final long READ_TIMEOUT = 3600 * 1000;
50
51    private static final float MIN_CACHE_THRESHOLD = 0.25f;
52    private static final int MIN_CACHE_AVAILABLE_SPACE_BYTES = 100 * 1024 * 1024;
53
54    /**
55     * Singleton map of MIME->friendly description
56     * @see #getMimeTypeDisplayName(Context, String)
57     */
58    private static Map<String, String> sDisplayNameMap;
59
60    /**
61     * @return A string suitable for display in bytes, kilobytes or megabytes
62     *         depending on its size.
63     */
64    public static String convertToHumanReadableSize(Context context, long size) {
65        final String count;
66        if (size == 0) {
67            return "";
68        } else if (size < KILO) {
69            count = String.valueOf(size);
70            return context.getString(R.string.bytes, count);
71        } else if (size < MEGA) {
72            count = String.valueOf(size / KILO);
73            return context.getString(R.string.kilobytes, count);
74        } else {
75            DecimalFormat onePlace = new DecimalFormat("0.#");
76            count = onePlace.format((float) size / (float) MEGA);
77            return context.getString(R.string.megabytes, count);
78        }
79    }
80
81    /**
82     * Return a friendly localized file type for this attachment, or the empty string if
83     * unknown.
84     * @param context a Context to do resource lookup against
85     * @return friendly file type or empty string
86     */
87    public static String getDisplayType(final Context context, final Attachment attachment) {
88        if ((attachment.flags & Attachment.FLAG_DUMMY_ATTACHMENT) != 0) {
89            // This is a dummy attachment, display blank for type.
90            return "";
91        }
92
93        // try to get a friendly name for the exact mime type
94        // then try to show a friendly name for the mime family
95        // finally, give up and just show the file extension
96        final String contentType = attachment.getContentType();
97        String displayType = getMimeTypeDisplayName(context, contentType);
98        int index = !TextUtils.isEmpty(contentType) ? contentType.indexOf('/') : -1;
99        if (displayType == null && index > 0) {
100            displayType = getMimeTypeDisplayName(context, contentType.substring(0, index));
101        }
102        if (displayType == null) {
103            String extension = Utils.getFileExtension(attachment.getName());
104            // show '$EXTENSION File' for unknown file types
105            if (extension != null && extension.length() > 1 && extension.indexOf('.') == 0) {
106                displayType = context.getString(R.string.attachment_unknown,
107                        extension.substring(1).toUpperCase());
108            }
109        }
110        if (displayType == null) {
111            // no extension to display, but the map doesn't accept null entries
112            displayType = "";
113        }
114        return displayType;
115    }
116
117    /**
118     * Returns a user-friendly localized description of either a complete a MIME type or a
119     * MIME family.
120     * @param context used to look up localized strings
121     * @param type complete MIME type or just MIME family
122     * @return localized description text, or null if not recognized
123     */
124    public static synchronized String getMimeTypeDisplayName(final Context context,
125            String type) {
126        if (sDisplayNameMap == null) {
127            String docName = context.getString(R.string.attachment_application_msword);
128            String presoName = context.getString(R.string.attachment_application_vnd_ms_powerpoint);
129            String sheetName = context.getString(R.string.attachment_application_vnd_ms_excel);
130
131            sDisplayNameMap = new ImmutableMap.Builder<String, String>()
132                .put("image", context.getString(R.string.attachment_image))
133                .put("audio", context.getString(R.string.attachment_audio))
134                .put("video", context.getString(R.string.attachment_video))
135                .put("text", context.getString(R.string.attachment_text))
136                .put("application/pdf", context.getString(R.string.attachment_application_pdf))
137
138                // Documents
139                .put("application/msword", docName)
140                .put("application/vnd.openxmlformats-officedocument.wordprocessingml.document",
141                        docName)
142
143                // Presentations
144                .put("application/vnd.ms-powerpoint",
145                        presoName)
146                .put("application/vnd.openxmlformats-officedocument.presentationml.presentation",
147                        presoName)
148
149                // Spreadsheets
150                .put("application/vnd.ms-excel", sheetName)
151                .put("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
152                        sheetName)
153
154                .build();
155        }
156        return sDisplayNameMap.get(type);
157    }
158
159    /**
160     * Cache the file specified by the given attachment.  This will attempt to use any
161     * {@link ParcelFileDescriptor} in the Bundle parameter
162     * @param context
163     * @param attachment  Attachment to be cached
164     * @param attachmentFds optional {@link Bundle} containing {@link ParcelFileDescriptor} if the
165     *        caller has opened the files
166     * @return String file path for the cached attachment
167     */
168    // TODO(pwestbro): Once the attachment has a field for the cached path, this method should be
169    // changed to update the attachment, and return a boolean indicating that the attachment has
170    // been cached.
171    public static String cacheAttachmentUri(Context context, Attachment attachment,
172            Bundle attachmentFds) {
173        final File cacheDir = context.getCacheDir();
174
175        final long totalSpace = cacheDir.getTotalSpace();
176        if (attachment.size > 0) {
177            final long usableSpace = cacheDir.getUsableSpace() - attachment.size;
178            if (isLowSpace(totalSpace, usableSpace)) {
179                LogUtils.w(LOG_TAG, "Low memory (%d/%d). Can't cache attachment %s",
180                        usableSpace, totalSpace, attachment);
181                return null;
182            }
183        }
184        InputStream inputStream = null;
185        FileOutputStream outputStream = null;
186        File file = null;
187        try {
188            final SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd-kk:mm:ss");
189            file = File.createTempFile(dateFormat.format(new Date()), ".attachment", cacheDir);
190            final ParcelFileDescriptor fileDescriptor = attachmentFds != null
191                    && attachment.contentUri != null ? (ParcelFileDescriptor) attachmentFds
192                    .getParcelable(attachment.contentUri.toString())
193                    : null;
194            if (fileDescriptor != null) {
195                // Get the input stream from the file descriptor
196                inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
197            } else {
198                if (attachment.contentUri == null) {
199                    // The contentUri of the attachment is null.  This can happen when sending a
200                    // message that has been previously saved, and the attachments had been
201                    // uploaded.
202                    LogUtils.d(LOG_TAG, "contentUri is null in attachment: %s", attachment);
203                    throw new FileNotFoundException("Missing contentUri in attachment");
204                }
205                // Attempt to open the file
206                inputStream = context.getContentResolver().openInputStream(attachment.contentUri);
207            }
208            outputStream = new FileOutputStream(file);
209            final long now = SystemClock.elapsedRealtime();
210            final byte[] bytes = new byte[1024];
211            while (true) {
212                int len = inputStream.read(bytes);
213                if (len <= 0) {
214                    break;
215                }
216                outputStream.write(bytes, 0, len);
217                if (SystemClock.elapsedRealtime() - now > READ_TIMEOUT) {
218                    throw new IOException("Timed out reading attachment data");
219                }
220            }
221            outputStream.flush();
222            String cachedFileUri = file.getAbsolutePath();
223            LogUtils.d(LOG_TAG, "Cached %s to %s", attachment.contentUri, cachedFileUri);
224
225            final long usableSpace = cacheDir.getUsableSpace();
226            if (isLowSpace(totalSpace, usableSpace)) {
227                file.delete();
228                LogUtils.w(LOG_TAG, "Low memory (%d/%d). Can't cache attachment %s",
229                        usableSpace, totalSpace, attachment);
230                cachedFileUri = null;
231            }
232
233            return cachedFileUri;
234        } catch (IOException e) {
235            // Catch any exception here to allow for unexpected failures during caching se we don't
236            // leave app in inconsistent state as we call this method outside of a transaction for
237            // performance reasons.
238            LogUtils.e(LOG_TAG, e, "Failed to cache attachment %s", attachment);
239            if (file != null) {
240                file.delete();
241            }
242            return null;
243        } finally {
244            try {
245                if (inputStream != null) {
246                    inputStream.close();
247                }
248                if (outputStream != null) {
249                    outputStream.close();
250                }
251            } catch (IOException e) {
252                LogUtils.w(LOG_TAG, e, "Failed to close stream");
253            }
254        }
255    }
256
257    private static boolean isLowSpace(long totalSpace, long usableSpace) {
258        // For caching attachments we want to enable caching if there is
259        // more than 100MB available, or if 25% of total space is free on devices
260        // where the cache partition is < 400MB.
261        return usableSpace <
262                Math.min(totalSpace * MIN_CACHE_THRESHOLD, MIN_CACHE_AVAILABLE_SPACE_BYTES);
263    }
264
265    /**
266     * Checks if the attachment can be downloaded with the current network
267     * connection.
268     *
269     * @param attachment the attachment to be checked
270     * @return true if the attachment can be downloaded.
271     */
272    public static boolean canDownloadAttachment(Context context, Attachment attachment) {
273        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(
274                Context.CONNECTIVITY_SERVICE);
275        NetworkInfo info = connectivityManager.getActiveNetworkInfo();
276        if (info == null) {
277            return false;
278        } else if (info.isConnected()) {
279            if (info.getType() != ConnectivityManager.TYPE_MOBILE) {
280                // not mobile network
281                return true;
282            } else {
283                // mobile network
284                Long maxBytes = DownloadManager.getMaxBytesOverMobile(context);
285                return maxBytes == null || attachment == null || attachment.size <= maxBytes;
286            }
287        } else {
288            return false;
289        }
290    }
291}
292