diff --git a/src/js/picasa.js b/src/js/picasa.js
new file mode 100644
index 0000000..e6343a8
--- /dev/null
+++ b/src/js/picasa.js
@@ -0,0 +1,237 @@
+(function() {
+  const ALBUM_NAME = 'Screen Capture';
+  const CLIENT_ID = '368358534491.apps.googleusercontent.com';
+  const AUTH_URL = 'https://accounts.google.com/o/oauth2/auth';
+  const REDIRECT_URI = 'https://picasaweb.google.com';
+  const SCOPE = 'https://picasaweb.google.com/data/';
+  const RESPONSE_TYPE = 'token';
+  const ALBUM_URL = 'https://picasaweb.google.com/data/feed/api/user/' +
+    'default';
+  const CREATE_ALBUM_URL = 'https://picasaweb.google.com/data/feed/api/user/' +
+    'default';
+  const UPLOAD_BASE_URL = 'https://picasaweb.google.com/data/feed/api/user/' +
+    'default/albumid/';
+  const LOGOUT_URL = 'https://picasaweb.google.com/bye?continue=' +
+    'https://www.google.com/accounts/Logout?continue=' +
+    'https://picasaweb.google.com';
+
+  // var picasa = window.Picasa = new Site('picasa');
+  var picasa = window.Picasa = {
+    siteId: 'picasa',
+    currentUserId: null,
+    redirectUrl: REDIRECT_URI,
+    accessTokenCallback: null,
+    
+    getAccessToken: function(callback) {
+      picasa.accessTokenCallback = callback;
+      var url = AUTH_URL + '?client_id=' + CLIENT_ID + '&redirect_uri=' +
+        REDIRECT_URI + '&scope=' + SCOPE + '&response_type=' + RESPONSE_TYPE;
+      chrome.tabs.create({ url: url});
+    },
+
+    parseRedirectUrl: function(url) {
+      var result = false;
+      if (url.indexOf(REDIRECT_URI) == 0) {
+        var hash = url.split('#')[1];
+        if (hash) {
+          var params = hash.split('&');
+          var paramMap = {};
+          params.forEach(function(param) {
+            paramMap[param.split('=')[0]] = param.split('=')[1];
+          });
+
+          var accessToken = paramMap['access_token'];
+          var expires = paramMap['expires_in'];
+          if (accessToken && expires) {
+            result = {
+              accessToken: accessToken,
+              expires: expires
+            };
+          } else {
+            result = 'bad_redirect_url'; // Should never happened.
+          }
+        } else {
+          var search = url.split('?')[1];
+          if (search == 'error=access_denied')
+            result = 'access_denied';
+        }
+      }
+      return result;
+    },
+    
+    isRedirectUrl: function(url) {
+      return picasa.parseRedirectUrl(url) != false;
+    },
+    
+    parseAccessToken: function(redirectUrl) {
+      var parsedResult = picasa.parseRedirectUrl(redirectUrl);
+      if (parsedResult && typeof parsedResult == 'object') {
+        var user = new User({
+          accessToken: parsedResult.accessToken,
+          expires: new Date().getTime() + parsedResult.expires * 1000
+        });
+        picasa.accessTokenCallback('success', user);
+      } else {
+        picasa.accessTokenCallback('failure', 'user_denied');
+      }
+      picasa.accessTokenCallback = null;
+    },
+    
+    getUserInfo: function(user, callback) {
+      ajax({
+        url: ALBUM_URL,
+        parameters: {
+          fields: 'title,gphoto:nickname,entry/title,entry/gphoto:id',
+          alt: 'json',
+          access_token: user.accessToken
+        },
+        success: function(res) {
+          var userId = res.feed.title.$t;
+          var userName = res.feed.gphoto$nickname.$t;
+          user.id = userId;
+          user.name = userName;
+          
+          var albums = res.feed.entry;
+          if (albums) {
+            var length = albums.length;
+
+            // Check if user has created album "Screen Capture".
+            for (var i = 0; i < length; i++) {
+              var albumName = albums[i].title.$t;
+              if (albumName == ALBUM_NAME) {
+                user.albumId = albums[i].gphoto$id.$t;
+                break;
+              }
+            }
+          }
+
+          // Create album "Screen Capture" and retrieve album id.
+          if (!user.albumId) {
+            picasa.createAlbum(user.accessToken, function(result,
+                                                          albumIdOrMessage) {
+              if (result == 'success') {
+                user.albumId = albumIdOrMessage;
+                callback('success', user);
+              } else {
+                callback('failure', albumIdOrMessage);
+              }
+            });
+          } else {
+            callback('success', user);
+          }
+        },
+        status: {
+          404: function() {
+            callback('failure', 'failed_to_get_user_info');
+          }
+        }
+      });
+    },
+
+    createAlbum: function(accessToken, callback) {
+      var data = '<entry xmlns="http://www.w3.org/2005/Atom" ' +
+        'xmlns:media="http://search.yahoo.com/mrss/" ' +
+        'xmlns:gphoto="http://schemas.google.com/photos/2007">' +
+        '<title type="text">' + ALBUM_NAME +
+        '</title><category scheme="http://schemas.google.com/g/2005#kind" ' +
+        'term="http://schemas.google.com/photos/2007#album"></category>' +
+        '</entry>';
+
+      ajax({
+        method: 'POST',
+        url: CREATE_ALBUM_URL,
+        parameters: {
+          alt: 'json'
+        },
+        data: data,
+        headers: {
+          'GData-Version': 2,
+          'Content-Type': 'application/atom+xml',
+          'Authorization': 'OAuth ' + accessToken
+        },
+        complete: function(statusCode, album) {
+          if (statusCode == 201) {
+            var albumId = album.entry.gphoto$id.$t;
+            callback('success', albumId);
+          } else {
+            callback('failure', 'failure_to_create_album')
+          }
+        }
+      });
+    },
+
+    upload: function(user, caption, imageData, callback) {
+      caption = ajax.convertEntityString(caption);
+      caption = ajax.encodeForBinary(caption);
+
+      var imageFile = new Date().getTime() + '.png';
+      var headers = {
+        'GData-Version': 2,
+        'Content-Type': 'multipart/related; boundary=' +
+          MULTIPART_FORMDATA_BOUNDARY,
+        'Authorization': 'OAuth ' + user.accessToken
+      };
+
+      var captionData = '<entry xmlns="http://www.w3.org/2005/Atom">' +
+        '<title>' + imageFile + '</title>' +
+        '<summary>' + caption + '</summary>' +
+        '<category scheme="http://schemas.google.com/g/2005#kind" ' +
+        'term="http://schemas.google.com/photos/2007#photo"/></entry>';
+
+      var dataPart1 = {
+        contentType: 'application/atom+xml',
+        data: captionData
+      };
+      var dataPart2 = {
+        contentType: 'image/png',
+        data: imageData
+      };
+      var multipartData = {
+        boundary: MULTIPART_FORMDATA_BOUNDARY,
+        dataList: [dataPart1, dataPart2]
+      };
+
+      ajax({
+        url: UPLOAD_BASE_URL + user.albumId + '?alt=json',
+        headers: headers,
+        multipartData: multipartData,
+        complete: function(statusCode, res) {
+          if (statusCode == 201) {
+            var link = res.entry.link;
+            callback('success', link);
+          } else {
+            var message = 'failed_to_upload_image';
+            if (statusCode == 403) {
+              // bad access token
+              message = 'bad_access_token';
+            } else if (statusCode == 404 && res == 'No album found.') {
+              // Invalid album id.
+              message = 'invalid_album_id'
+            }
+            callback('failure', message);
+          }
+        }
+      });
+    },
+
+    getPhotoLink: function(user, photolinks, callback) {
+      for (var i = 0; i < photolinks.length; i++) {
+        var link = photolinks[i];
+        if (link.type == 'text/html' &&
+            link.rel == 'http://schemas.google.com/photos/2007#canonical') {
+          callback('success', link.href);
+          break;
+        }
+      }
+    },
+
+    logout: function(callback) {
+      ajax({
+        url: LOGOUT_URL,
+        success: function() {
+          callback();
+        }
+      });
+    }
+  };
+})();
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