1 files changed, 98 insertions, 0 deletions
diff --git a/src/com/android/messaging/util/YouTubeUtil.java b/src/com/android/messaging/util/YouTubeUtil.java
new file mode 100644
index 0000000..203a666
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+++ b/src/com/android/messaging/util/YouTubeUtil.java
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+/*
+ * Copyright (C) 2015 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.messaging.util;
+
+import android.net.Uri;
+import android.text.TextUtils;
+
+public class YouTubeUtil {
+    private static final String YOUTUBE_HOST_1 = "www.youtube.com";
+    private static final String YOUTUBE_HOST_2 = "youtube.com";
+    private static final String YOUTUBE_HOST_3 = "m.youtube.com";
+    private static final String YOUTUBE_HOST_4 = "youtube.googleapis.com";
+    private static final String YOUTUBE_HOST_5 = "youtu.be";
+
+    private static final String YOUTUBE_PATH_1 = "/watch";
+    private static final String YOUTUBE_PATH_2 = "/embed/";
+    private static final String YOUTUBE_PATH_3 = "/v/";
+    private static final String YOUTUBE_PATH_4 = "/apiplayer";
+
+    public static final String YOUTUBE_STATIC_THUMBNAIL_PREFIX = "https://img.youtube.com/vi/";
+    public static final String YOUTUBE_STATIC_THUMBNAIL_END = "/hqdefault.jpg";
+
+    public static String getYoutubePreviewImageLink(String urlString) {
+        // Types of youtube urls:
+        // 1.) http://www.youtube.com/watch?v=VIDEOID
+        // 2.) http://www.youtube.com/embed/VIDEOID
+        // 3.) http://www.youtube.com/v/VIDEOID
+        // 3a.) https://youtube.googleapis.com/v/VIDEOID
+        // 4.) http://www.youtube.com/apiplayer?video_id=VIDEO_ID
+        // 5.) http://youtu.be/VIDEOID
+        if (!urlString.startsWith("http")) {
+            // Apparently the url is not an RFC 2396 compliant uri without the port
+            urlString = "http://" + urlString;
+        }
+        final Uri uri = Uri.parse(urlString);
+        final String host = uri.getHost();
+        if (YOUTUBE_HOST_1.equalsIgnoreCase(host)
+                || YOUTUBE_HOST_2.equalsIgnoreCase(host)
+                || YOUTUBE_HOST_3.equalsIgnoreCase(host)
+                || YOUTUBE_HOST_4.equalsIgnoreCase(host)
+                || YOUTUBE_HOST_5.equalsIgnoreCase(host)) {
+            final String videoId = getYouTubeVideoId(uri);
+            if (!TextUtils.isEmpty(videoId)) {
+                return YOUTUBE_STATIC_THUMBNAIL_PREFIX + videoId + YOUTUBE_STATIC_THUMBNAIL_END;
+            }
+            return null;
+        }
+        return null;
+    }
+
+    private static String getYouTubeVideoId(Uri uri) {
+        final String urlPath = uri.getPath();
+
+        if (TextUtils.isEmpty(urlPath)) {
+            // There is no path so no need to continue.
+            return null;
+        }
+        // Case 1
+        if (urlPath.startsWith(YOUTUBE_PATH_1)) {
+            return uri.getQueryParameter("v");
+        }
+        // Case 2
+        if (urlPath.startsWith(YOUTUBE_PATH_2)) {
+            return getVideoIdFromPath(YOUTUBE_PATH_2, urlPath);
+        }
+        // Case 3
+        if (urlPath.startsWith(YOUTUBE_PATH_3)) {
+            return getVideoIdFromPath(YOUTUBE_PATH_3, urlPath);
+        }
+        // Case 4
+        if (urlPath.startsWith(YOUTUBE_PATH_4)) {
+            return uri.getQueryParameter("video_id");
+        }
+        // Case 5
+        if (YOUTUBE_HOST_5.equalsIgnoreCase(uri.getHost())) {
+            return getVideoIdFromPath("/", urlPath);
+        }
+        return null;
+    }
+
+    private static String getVideoIdFromPath(String prefixSubstring, String urlPath) {
+        return urlPath.substring(prefixSubstring.length());
+    }
+
+}