Refactored TrainingResource to use the Provider interface.

Playlists are now generated from a default playlist and regularly
merged with the default playlist to get updates.

Also adding the Question tests that got left out of a previous commit.

20 files changed, 648 insertions, 329 deletions

diff --git a/src/com/p4square/grow/backend/GrowBackend.java b/src/com/p4square/grow/backend/GrowBackend.java
index 45e0fa2..195554e 100644
--- a/src/com/p4square/grow/backend/GrowBackend.java
+++ b/src/com/p4square/grow/backend/GrowBackend.java
@@ -4,6 +4,8 @@
 
 package com.p4square.grow.backend;
 
+import java.io.IOException;
+
 import org.apache.log4j.Logger;
 
 import org.restlet.Application;
@@ -17,10 +19,15 @@ import com.p4square.grow.config.Config;
 import com.p4square.grow.backend.db.CassandraDatabase;
 import com.p4square.grow.backend.db.CassandraKey;
 import com.p4square.grow.backend.db.CassandraProviderImpl;
+import com.p4square.grow.backend.db.CassandraTrainingRecordProvider;
 
 import com.p4square.grow.model.Question;
+import com.p4square.grow.model.TrainingRecord;
+import com.p4square.grow.model.Playlist;
 
 import com.p4square.grow.provider.Provider;
+import com.p4square.grow.provider.ProvidesQuestions;
+import com.p4square.grow.provider.ProvidesTrainingRecords;
 import com.p4square.grow.provider.QuestionProvider;
 
 import com.p4square.grow.backend.resources.AccountResource;
@@ -35,7 +42,8 @@ import com.p4square.grow.backend.resources.TrainingResource;
  *
  * @author Jesse Morgan <jesse@jesterpm.net>
  */
-public class GrowBackend extends Application {
+public class GrowBackend extends Application
+        implements ProvidesQuestions, ProvidesTrainingRecords {
     private static final String DEFAULT_COLUMN = "value";
 
     private final static Logger LOG = Logger.getLogger(GrowBackend.class);
@@ -44,6 +52,7 @@ public class GrowBackend extends Application {
     private final CassandraDatabase mDatabase;
 
     private final Provider<String, Question> mQuestionProvider;
+    private final CassandraTrainingRecordProvider mTrainingRecordProvider;
 
     public GrowBackend() {
         this(new Config());
@@ -53,12 +62,14 @@ public class GrowBackend extends Application {
         mConfig = config;
         mDatabase = new CassandraDatabase();
 
-        mQuestionProvider = new QuestionProvider<CassandraKey>(new CassandraProviderImpl<Question>(mDatabase, "strings", Question.class)) {
+        mQuestionProvider = new QuestionProvider<CassandraKey>(new CassandraProviderImpl<Question>(mDatabase, Question.class)) {
             @Override
             public CassandraKey makeKey(String questionId) {
-                return new CassandraKey("/questions/" + questionId, DEFAULT_COLUMN);
+                return new CassandraKey("strings", "/questions/" + questionId, DEFAULT_COLUMN);
             }
         };
+
+        mTrainingRecordProvider = new CassandraTrainingRecordProvider(mDatabase);
     }
 
     @Override
@@ -120,10 +131,23 @@ public class GrowBackend extends Application {
         return mDatabase;
     }
 
+    @Override
     public Provider<String, Question> getQuestionProvider() {
         return mQuestionProvider;
     }
 
+    @Override
+    public Provider<String, TrainingRecord> getTrainingRecordProvider() {
+        return mTrainingRecordProvider;
+    }
+
+    /**
+     * @return the Default Playlist.
+     */
+    public Playlist getDefaultPlaylist() throws IOException {
+        return mTrainingRecordProvider.getDefaultPlaylist();
+    }
+
     /**
      * Stand-alone main for testing.
      */
diff --git a/src/com/p4square/grow/backend/db/CassandraKey.java b/src/com/p4square/grow/backend/db/CassandraKey.java
index 8e23087..853fe96 100644
--- a/src/com/p4square/grow/backend/db/CassandraKey.java
+++ b/src/com/p4square/grow/backend/db/CassandraKey.java
@@ -10,14 +10,20 @@ package com.p4square.grow.backend.db;
  * @author Jesse Morgan <jesse@jesterpm.net>
  */
 public class CassandraKey {
+    private final String mColumnFamily;
     private final String mId;
     private final String mColumn;
 
-    public CassandraKey(String id, String column) {
+    public CassandraKey(String columnFamily, String id, String column) {
+        mColumnFamily = columnFamily;
         mId = id;
         mColumn = column;
     }
 
+    public String getColumnFamily() {
+        return mColumnFamily;
+    }
+
     public String getId() {
         return mId;
     }
diff --git a/src/com/p4square/grow/backend/db/CassandraProviderImpl.java b/src/com/p4square/grow/backend/db/CassandraProviderImpl.java
index fb6e34e..c1f6e6d 100644
--- a/src/com/p4square/grow/backend/db/CassandraProviderImpl.java
+++ b/src/com/p4square/grow/backend/db/CassandraProviderImpl.java
@@ -6,10 +6,6 @@ package com.p4square.grow.backend.db;
 
 import java.io.IOException;
 
-import org.codehaus.jackson.map.DeserializationConfig;
-import org.codehaus.jackson.map.ObjectMapper;
-import org.codehaus.jackson.map.SerializationConfig;
-
 import com.p4square.grow.provider.JsonEncodedProvider;
 
 /**
@@ -19,24 +15,22 @@ import com.p4square.grow.provider.JsonEncodedProvider;
  */
 public class CassandraProviderImpl<V> extends JsonEncodedProvider<CassandraKey, V> {
     private final CassandraDatabase mDb;
-    private final String mColumnFamily;
 
-    public CassandraProviderImpl(CassandraDatabase db, String columnFamily, Class<V> clazz) {
+    public CassandraProviderImpl(CassandraDatabase db, Class<V> clazz) {
         super(clazz);
 
         mDb = db;
-        mColumnFamily = columnFamily;
     }
 
     @Override
     public V get(CassandraKey key) throws IOException {
-        String blob = mDb.getKey(mColumnFamily, key.getId(), key.getColumn());
+        String blob = mDb.getKey(key.getColumnFamily(), key.getId(), key.getColumn());
         return decode(blob);
     }
 
     @Override
     public void put(CassandraKey key, V obj) throws IOException {
         String blob = encode(obj);
-        mDb.putKey(mColumnFamily, key.getId(), key.getColumn(), blob);
+        mDb.putKey(key.getColumnFamily(), key.getId(), key.getColumn(), blob);
     }
 }
diff --git a/src/com/p4square/grow/backend/db/CassandraTrainingRecordProvider.java b/src/com/p4square/grow/backend/db/CassandraTrainingRecordProvider.java
new file mode 100644
index 0000000..4face52
--- /dev/null
+++ b/src/com/p4square/grow/backend/db/CassandraTrainingRecordProvider.java
@@ -0,0 +1,71 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.backend.db;
+
+import java.io.IOException;
+
+import com.p4square.grow.model.Playlist;
+import com.p4square.grow.model.TrainingRecord;
+
+import com.p4square.grow.provider.JsonEncodedProvider;
+import com.p4square.grow.provider.Provider;
+
+/**
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public class CassandraTrainingRecordProvider implements Provider<String, TrainingRecord> {
+    private static final CassandraKey DEFAULT_PLAYLIST_KEY = new CassandraKey("strings", "defaultPlaylist", "value");
+
+    private static final String COLUMN_FAMILY = "training";
+    private static final String PLAYLIST_KEY = "playlist";
+    private static final String LAST_VIDEO_KEY = "lastVideo";
+
+    private final CassandraDatabase mDb;
+    private final Provider<CassandraKey, Playlist> mPlaylistProvider;
+
+    public CassandraTrainingRecordProvider(CassandraDatabase db) {
+        mDb = db;
+        mPlaylistProvider = new CassandraProviderImpl<>(db, Playlist.class);
+    }
+
+    @Override
+    public TrainingRecord get(String userid) throws IOException {
+        Playlist playlist = mPlaylistProvider.get(new CassandraKey(COLUMN_FAMILY, userid, PLAYLIST_KEY));
+
+        if (playlist == null) {
+            // We consider no playlist to mean no record whatsoever.
+            return null;
+        }
+
+        TrainingRecord r = new TrainingRecord();
+        r.setPlaylist(playlist);
+        r.setLastVideo(mDb.getKey(COLUMN_FAMILY, userid, LAST_VIDEO_KEY));
+
+        return r;
+    }
+
+    @Override
+    public void put(String userid, TrainingRecord record) throws IOException {
+        String lastVideo = record.getLastVideo();
+        Playlist playlist = record.getPlaylist();
+
+        mDb.putKey(COLUMN_FAMILY, userid, LAST_VIDEO_KEY, lastVideo);
+        mPlaylistProvider.put(new CassandraKey(COLUMN_FAMILY, userid, PLAYLIST_KEY), playlist);
+    }
+
+    /**
+     * @return the default playlist stored in the database.
+     */
+    public Playlist getDefaultPlaylist() throws IOException {
+        Playlist playlist = mPlaylistProvider.get(DEFAULT_PLAYLIST_KEY);
+
+        if (playlist == null) {
+            playlist = new Playlist();
+        }
+
+        return playlist;
+    }
+}
diff --git a/src/com/p4square/grow/backend/resources/Playlist.java b/src/com/p4square/grow/backend/resources/Playlist.java
deleted file mode 100644
index f3d2f08..0000000
--- a/src/com/p4square/grow/backend/resources/Playlist.java
+++ /dev/null
@@ -1,134 +0,0 @@
-/*
- * Copyright 2013 Jesse Morgan
- */
-
-package com.p4square.grow.backend.resources;
-
-import java.io.IOException;
-
-import java.util.HashMap;
-import java.util.Map;
-
-import org.codehaus.jackson.map.ObjectMapper;
-import org.codehaus.jackson.type.TypeReference;
-
-import com.p4square.grow.backend.db.CassandraDatabase;
-
-/**
- * 
- * @author Jesse Morgan <jesse@jesterpm.net>
- */
-class Playlist {
-    private static final ObjectMapper MAPPER = new ObjectMapper();
-
-    /**
-     * Load a Playlist from the database.
-     */
-    public static Playlist load(CassandraDatabase db, String userId) throws IOException {
-        String playlistString = db.getKey("training", userId, "playlist");
-
-        if (playlistString == null) {
-            return null;
-        }
-
-        Map<String, Map<String, VideoRecord>> playlist =
-            MAPPER.readValue(playlistString, new TypeReference<Map<String, Map<String, VideoRecord>>>() { });
-
-        return new Playlist(playlist);
-
-    }
-
-    /**
-     * Persist the Playlist for the given user.
-     * @return The String serialization of the playlist.
-     */
-    public static String save(CassandraDatabase db, String userId, Playlist playlist) throws IOException {
-        String playlistString = MAPPER.writeValueAsString(playlist.mPlaylist);
-        db.putKey("training", userId, "playlist", playlistString);
-        return playlistString;
-    }
-
-
-    private Map<String, Map<String, VideoRecord>> mPlaylist;
-
-    /**
-     * Construct an empty playlist.
-     */
-    public Playlist() {
-        mPlaylist = new HashMap<String, Map<String, VideoRecord>>();
-    }
-
-    /**
-     * Constructor for database initialization.
-     */
-    private Playlist(Map<String, Map<String, VideoRecord>> playlist) {
-        mPlaylist = playlist;
-    }
-
-    public VideoRecord find(String videoId) {
-        for (Map<String, VideoRecord> chapter : mPlaylist.values()) {
-            VideoRecord r = chapter.get(videoId);
-
-            if (r != null) {
-                return r;
-            }
-        }
-
-        return null;
-    }
-
-    /**
-     * Add a video to the playlist.
-     */
-    public VideoRecord add(String chapter, String videoId) {
-        Map<String, VideoRecord> chapterMap = mPlaylist.get(chapter);
-
-        if (chapterMap == null) {
-            chapterMap = new HashMap<String, VideoRecord>();
-            mPlaylist.put(chapter, chapterMap);
-        }
-
-        VideoRecord r = new VideoRecord();
-        chapterMap.put(videoId, r);
-        return r;
-    }
-
-    /**
-     * @return The last chapter to be completed.
-     */
-    public Map<String, Boolean> getChapterStatuses() {
-        Map<String, Boolean> completed = new HashMap<String, Boolean>();
-
-        for (String chapter : mPlaylist.keySet()) {
-            completed.put(chapter, isChapterComplete(chapter));
-        }
-
-        return completed;
-    }
-
-    public boolean isChapterComplete(String chapterId) {
-        boolean complete = true;
-
-        Map<String, VideoRecord> chapter = mPlaylist.get(chapterId);
-        if (chapter != null) {
-            for (VideoRecord r : chapter.values()) {
-                if (r.getRequired() && !r.getComplete()) {
-                    return false;
-                }
-            }
-        }
-
-        return complete;
-    }
-
-    @Override
-    public String toString() {
-        try {
-            return MAPPER.writeValueAsString(mPlaylist);
-
-        } catch (IOException e) {
-            return super.toString();
-        }
-    }
-
-}
diff --git a/src/com/p4square/grow/backend/resources/SurveyResource.java b/src/com/p4square/grow/backend/resources/SurveyResource.java
index 83c4cad..497978f 100644
--- a/src/com/p4square/grow/backend/resources/SurveyResource.java
+++ b/src/com/p4square/grow/backend/resources/SurveyResource.java
@@ -9,7 +9,7 @@ import java.io.IOException;
 import java.util.Map;
 import java.util.HashMap;
 
-import org.codehaus.jackson.map.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectMapper;
 
 import org.restlet.data.MediaType;
 import org.restlet.data.Status;
diff --git a/src/com/p4square/grow/backend/resources/SurveyResultsResource.java b/src/com/p4square/grow/backend/resources/SurveyResultsResource.java
index 91d4d0f..e87126d 100644
--- a/src/com/p4square/grow/backend/resources/SurveyResultsResource.java
+++ b/src/com/p4square/grow/backend/resources/SurveyResultsResource.java
@@ -10,7 +10,7 @@ import java.util.HashMap;
 import com.netflix.astyanax.model.Column;
 import com.netflix.astyanax.model.ColumnList;
 
-import org.codehaus.jackson.map.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectMapper;
 
 import org.restlet.data.MediaType;
 import org.restlet.data.Status;
diff --git a/src/com/p4square/grow/backend/resources/TrainingRecordResource.java b/src/com/p4square/grow/backend/resources/TrainingRecordResource.java
index 6de9507..e42456e 100644
--- a/src/com/p4square/grow/backend/resources/TrainingRecordResource.java
+++ b/src/com/p4square/grow/backend/resources/TrainingRecordResource.java
@@ -14,7 +14,7 @@ import java.util.HashMap;
 import com.netflix.astyanax.model.Column;
 import com.netflix.astyanax.model.ColumnList;
 
-import org.codehaus.jackson.map.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectMapper;
 
 import org.restlet.data.MediaType;
 import org.restlet.data.Status;
@@ -22,11 +22,21 @@ import org.restlet.resource.ServerResource;
 import org.restlet.representation.Representation;
 import org.restlet.representation.StringRepresentation;
 
+import org.restlet.ext.jackson.JacksonRepresentation;
+
 import org.apache.log4j.Logger;
 
 import com.p4square.grow.backend.GrowBackend;
 import com.p4square.grow.backend.db.CassandraDatabase;
 
+import com.p4square.grow.model.Playlist;
+import com.p4square.grow.model.VideoRecord;
+import com.p4square.grow.model.TrainingRecord;
+
+import com.p4square.grow.provider.Provider;
+import com.p4square.grow.provider.ProvidesTrainingRecords;
+import com.p4square.grow.provider.JsonEncodedProvider;
+
 import com.p4square.grow.model.Score;
 
 /**
@@ -43,23 +53,41 @@ public class TrainingRecordResource extends ServerResource {
         SUMMARY, VIDEO
     }
 
-    private GrowBackend mBackend;
     private CassandraDatabase mDb;
+    private Provider<String, TrainingRecord> mTrainingRecordProvider;
 
     private RequestType mRequestType;
     private String mUserId;
     private String mVideoId;
+    private TrainingRecord mRecord;
 
     @Override
     public void doInit() {
         super.doInit();
 
-        mBackend = (GrowBackend) getApplication();
-        mDb = mBackend.getDatabase();
+        mDb = ((GrowBackend) getApplication()).getDatabase();
+        mTrainingRecordProvider = ((ProvidesTrainingRecords) getApplication()).getTrainingRecordProvider();
 
         mUserId = getAttribute("userId");
         mVideoId = getAttribute("videoId");
 
+        try {
+            Playlist defaultPlaylist = ((GrowBackend) getApplication()).getDefaultPlaylist();
+
+            mRecord = mTrainingRecordProvider.get(mUserId);
+            if (mRecord == null) {
+                mRecord = new TrainingRecord();
+                mRecord.setPlaylist(defaultPlaylist);
+            } else {
+                // Merge the playlist with the most recent version.
+                mRecord.getPlaylist().merge(defaultPlaylist);
+            }
+
+        } catch (IOException e) {
+            LOG.error("IOException loading TrainingRecord: " + e.getMessage(), e);
+            mRecord = null;
+        }
+
         mRequestType = RequestType.SUMMARY;
         if (mVideoId != null) {
             mRequestType = RequestType.VIDEO;
@@ -71,24 +99,35 @@ public class TrainingRecordResource extends ServerResource {
      */
     @Override
     protected Representation get() {
-        String result = null;
+        JacksonRepresentation<?> rep = null;
+
+        if (mRecord == null) {
+            setStatus(Status.SERVER_ERROR_INTERNAL);
+            return null;
+        }
 
         switch (mRequestType) {
             case VIDEO:
-                result = mDb.getKey("training", mUserId, mVideoId);
+                VideoRecord video = mRecord.getPlaylist().find(mVideoId);
+                if (video == null) {
+                    break; // Fall through and return 404
+                }
+                rep = new JacksonRepresentation<VideoRecord>(video);
                 break;
 
             case SUMMARY:
-                result = buildSummary();
+                rep = new JacksonRepresentation<TrainingRecord>(mRecord);
                 break;
         }
 
-        if (result == null) {
+        if (rep == null) {
             setStatus(Status.CLIENT_ERROR_NOT_FOUND);
             return null;
-        }
 
-        return new StringRepresentation(result);
+        } else {
+            rep.setObjectMapper(JsonEncodedProvider.MAPPER);
+            return rep;
+        }
     }
 
     /**
@@ -96,27 +135,37 @@ public class TrainingRecordResource extends ServerResource {
      */
     @Override
     protected Representation put(Representation entity) {
-        boolean success = false;
+        if (mRecord == null) {
+            setStatus(Status.SERVER_ERROR_INTERNAL);
+            return null;
+        }
 
         switch (mRequestType) {
             case VIDEO:
                 try {
-                    mDb.putKey("training", mUserId, mVideoId, entity.getText());
-                    mDb.putKey("training", mUserId, "lastVideo", mVideoId);
-
-                    Playlist playlist = Playlist.load(mDb, mUserId);
-                    if (playlist != null) {
-                        VideoRecord r = playlist.find(mVideoId);
-                        if (r != null && !r.getComplete()) {
-                            r.complete();
-                            Playlist.save(mDb, mUserId, playlist);
-                        }
+                    JacksonRepresentation<VideoRecord> representation = 
+                        new JacksonRepresentation<>(entity, VideoRecord.class);
+                    representation.setObjectMapper(JsonEncodedProvider.MAPPER);
+                    VideoRecord update = representation.getObject();
+                    VideoRecord video = mRecord.getPlaylist().find(mVideoId);
+
+                    if (video == null) {
+                        // TODO: Video isn't on their playlist...
+                        LOG.warn("Skipping video completion for video missing from playlist.");
+
+                    } else if (update.getComplete() && !video.getComplete()) {
+                        // Video was newly completed
+                        video.complete();
+                        mRecord.setLastVideo(mVideoId);
+
+                        mTrainingRecordProvider.put(mUserId, mRecord);
                     }
 
-                    success = true;
+                    setStatus(Status.SUCCESS_NO_CONTENT);
 
                 } catch (Exception e) {
                     LOG.warn("Caught exception updating training record: " + e.getMessage(), e);
+                    setStatus(Status.SERVER_ERROR_INTERNAL);
                 }
                 break;
 
@@ -124,116 +173,7 @@ public class TrainingRecordResource extends ServerResource {
                 setStatus(Status.CLIENT_ERROR_METHOD_NOT_ALLOWED);
         }
 
-        if (success) {
-            setStatus(Status.SUCCESS_NO_CONTENT);
-
-        } else {
-            setStatus(Status.SERVER_ERROR_INTERNAL);
-        }
-
         return null;
     }
 
-    /**
-     * This method compiles the summary of the training completed.
-     */
-    private String buildSummary() {
-        StringBuilder sb = new StringBuilder("{ ");
-
-        // Last watch video
-        final String lastVideo = mDb.getKey("training", mUserId, "lastVideo");
-        if (lastVideo != null) {
-            sb.append("\"lastVideo\": \"" + lastVideo + "\", ");
-        }
-
-        // Get the user's video history
-        sb.append("\"videos\": { ");
-        ColumnList<String> row = mDb.getRow("training", mUserId);
-        if (!row.isEmpty()) {
-            boolean first = true;
-            for (Column<String> c : row) {
-                if ("lastVideo".equals(c.getName()) ||
-                    "playlist".equals(c.getName())) {
-                    continue;
-                }
-
-                if (first) {
-                    sb.append("\"" + c.getName() + "\": ");
-                    first = false;
-                } else {
-                    sb.append(", \"" + c.getName() + "\": ");
-                }
-
-                sb.append(c.getStringValue());
-            }
-        }
-        sb.append(" }");
-
-        // Get the user's playlist
-        try {
-            Playlist playlist = Playlist.load(mDb, mUserId);
-            if (playlist == null) {
-                playlist = createInitialPlaylist();
-            }
-
-            sb.append(", \"playlist\": ");
-            sb.append(playlist.toString());
-
-            // Last Completed Section
-            Map<String, Boolean> chapters = playlist.getChapterStatuses();
-            String chaptersString = MAPPER.writeValueAsString(chapters);
-            sb.append(", \"chapters\":");
-            sb.append(chaptersString);
-
-
-        } catch (IOException e) {
-            LOG.warn("IOException loading playlist for user " + mUserId, e);
-        }
-
-
-        sb.append(" }");
-        return sb.toString();
-    }
-
-    /**
-     * Create the user's initial playlist.
-     *
-     * @return Returns the String representation of the initial playlist.
-     */
-    private Playlist createInitialPlaylist() throws IOException {
-        Playlist playlist = new Playlist();
-
-        // Get assessment score
-        String summaryString = mDb.getKey("assessments", mUserId, "summary");
-        if (summaryString == null) {
-            return null;
-        }
-        Map<?,?> summary = MAPPER.readValue(summaryString, Map.class);
-        double score = (Double) summary.get("score");
-
-        // Get videos for each section and build playlist
-        for (String chapter : CHAPTERS) {
-            boolean required;
-
-            if ("introduction".equals(chapter)) {
-                // Introduction chapter is always required
-                required = true;
-            } else {
-                // Chapter required if the floor of the score is <= the chapter's numeric value.
-                required = score < Score.numericScore(chapter) + 1;
-            }
-
-            ColumnList<String> row = mDb.getRow("strings", "/training/" + chapter);
-            if (!row.isEmpty()) {
-                for (Column<String> c : row) {
-                    VideoRecord r = playlist.add(chapter, c.getName());
-                    r.setRequired(required);
-                }
-            }
-        }
-
-        Playlist.save(mDb, mUserId, playlist);
-
-        return playlist;
-    }
 }
diff --git a/src/com/p4square/grow/frontend/ChapterCompletePage.java b/src/com/p4square/grow/frontend/ChapterCompletePage.java
index efcde38..f1871b9 100644
--- a/src/com/p4square/grow/frontend/ChapterCompletePage.java
+++ b/src/com/p4square/grow/frontend/ChapterCompletePage.java
@@ -23,6 +23,9 @@ import net.jesterpm.fmfacade.json.JsonResponse;
 import net.jesterpm.fmfacade.json.ClientException;
 
 import com.p4square.grow.config.Config;
+import com.p4square.grow.model.TrainingRecord;
+import com.p4square.grow.provider.TrainingRecordProvider;
+import com.p4square.grow.provider.Provider;
 
 /**
  * This resource displays the transitional page between chapters.
@@ -35,6 +38,7 @@ public class ChapterCompletePage extends FreeMarkerPageResource {
     private GrowFrontend mGrowFrontend;
     private Config mConfig;
     private JsonRequestClient mJsonClient;
+    private Provider<String, TrainingRecord> mTrainingRecordProvider;
 
     private String mUserId;
     private String mChapter;
@@ -47,6 +51,12 @@ public class ChapterCompletePage extends FreeMarkerPageResource {
         mConfig = mGrowFrontend.getConfig();
 
         mJsonClient = new JsonRequestClient(getContext().getClientDispatcher());
+        mTrainingRecordProvider = new TrainingRecordProvider<String>(new JsonRequestProvider<TrainingRecord>(getContext().getClientDispatcher(), TrainingRecord.class)) {
+            @Override
+            public String makeKey(String userid) {
+                return getBackendEndpoint() + "/accounts/" + userid + "/training";
+            }
+        };
 
         mUserId = getRequest().getClientInfo().getUser().getIdentifier();
 
@@ -69,17 +79,15 @@ public class ChapterCompletePage extends FreeMarkerPageResource {
             Map<String, Object> root = getRootObject();
 
             // Get the training summary
-            Map<String, Object> trainingRecord = null;
-            Map<String, Boolean> chapters = null;
-            {
-                JsonResponse response = backendGet("/accounts/" + mUserId + "/training");
-                if (response.getStatus().isSuccess()) {
-                    trainingRecord = response.getMap();
-                    chapters = (Map<String, Boolean>) trainingRecord.get("chapters");
-                }
+            TrainingRecord trainingRecord = mTrainingRecordProvider.get(mUserId);
+            if (trainingRecord == null) {
+                // Wait. What? Everyone has a training record...
+                setStatus(Status.SERVER_ERROR_INTERNAL);
+                return new ErrorPage("Could not retrieve your training record.");
             }
 
             // Verify they completed the chapter.
+            Map<String, Boolean> chapters = trainingRecord.getPlaylist().getChapterStatuses();
             Boolean completed = chapters.get(mChapter);
             if (completed == null || !completed) {
                 // Redirect back to training page...
diff --git a/src/com/p4square/grow/frontend/TrainingPageResource.java b/src/com/p4square/grow/frontend/TrainingPageResource.java
index 6a0fc10..f71f784 100644
--- a/src/com/p4square/grow/frontend/TrainingPageResource.java
+++ b/src/com/p4square/grow/frontend/TrainingPageResource.java
@@ -27,13 +27,18 @@ import net.jesterpm.fmfacade.json.JsonResponse;
 import net.jesterpm.fmfacade.FreeMarkerPageResource;
 
 import com.p4square.grow.config.Config;
+import com.p4square.grow.model.TrainingRecord;
+import com.p4square.grow.model.VideoRecord;
+import com.p4square.grow.model.Playlist;
+import com.p4square.grow.provider.TrainingRecordProvider;
+import com.p4square.grow.provider.Provider;
 
 /**
  * TrainingPageResource handles rendering the training page.
  *
  * This resource expects the user to be authenticated and the ClientInfo User object
  * to be populated.
- * 
+ *
  * @author Jesse Morgan <jesse@jesterpm.net>
  */
 public class TrainingPageResource extends FreeMarkerPageResource {
@@ -43,6 +48,8 @@ public class TrainingPageResource extends FreeMarkerPageResource {
     private Template mTrainingTemplate;
     private JsonRequestClient mJsonClient;
 
+    private Provider<String, TrainingRecord> mTrainingRecordProvider;
+
     // Fields pertaining to this request.
     private String mChapter;
     private String mUserId;
@@ -60,6 +67,12 @@ public class TrainingPageResource extends FreeMarkerPageResource {
         }
 
         mJsonClient = new JsonRequestClient(getContext().getClientDispatcher());
+        mTrainingRecordProvider = new TrainingRecordProvider<String>(new JsonRequestProvider<TrainingRecord>(getContext().getClientDispatcher(), TrainingRecord.class)) {
+            @Override
+            public String makeKey(String userid) {
+                return getBackendEndpoint() + "/accounts/" + userid + "/training";
+            }
+        };
 
         mChapter = getAttribute("chapter");
         mUserId = getRequest().getClientInfo().getUser().getIdentifier();
@@ -72,18 +85,15 @@ public class TrainingPageResource extends FreeMarkerPageResource {
     protected Representation get() {
         try {
             // Get the training summary
-            Map<String, Object> trainingRecord = null;
-            Map<String, Object> completedVideos = new HashMap<String, Object>();
-            Map<String, Boolean> chapters = null;
-            {
-                JsonResponse response = backendGet("/accounts/" + mUserId + "/training");
-                if (response.getStatus().isSuccess()) {
-                    trainingRecord = response.getMap();
-                    completedVideos = (Map<String, Object>) trainingRecord.get("videos");
-                    chapters = (Map<String, Boolean>) trainingRecord.get("chapters");
-                }
+            TrainingRecord trainingRecord = mTrainingRecordProvider.get(mUserId);
+            if (trainingRecord == null) {
+                setStatus(Status.SERVER_ERROR_INTERNAL);
+                return new ErrorPage("Could not retrieve TrainingRecord.");
             }
 
+            Playlist playlist = trainingRecord.getPlaylist();
+            Map<String, Boolean> chapters = playlist.getChapterStatuses();
+
             // Get the current chapter (the lowest, incomplete chapter)
             if (mChapter == null) {
                 int min = Integer.MAX_VALUE;
@@ -120,7 +130,13 @@ public class TrainingPageResource extends FreeMarkerPageResource {
             // Mark the completed videos as completed
             int chapterProgress = 0;
             for (Map<String, Object> video : videos) {
-                boolean completed = (null != completedVideos.get(video.get("id")));
+                boolean completed = false;
+                VideoRecord record = playlist.find((String) video.get("id"));
+                cLog.info("VideoId: " + video.get("id"));
+                if (record != null) {
+                    cLog.info("VideoRecord: " + record.getComplete());
+                    completed = record.getComplete();
+                }
                 video.put("completed", completed);
 
                 if (completed) {
@@ -133,7 +149,6 @@ public class TrainingPageResource extends FreeMarkerPageResource {
             root.put("chapter", mChapter);
             root.put("chapterProgress", chapterProgress);
             root.put("videos", videos);
-            root.put("completedVideos", completedVideos);
 
             return new TemplateRepresentation(mTrainingTemplate, root, MediaType.TEXT_HTML);
 
@@ -166,18 +181,6 @@ public class TrainingPageResource extends FreeMarkerPageResource {
         return response;
     }
 
-    private JsonResponse backendPut(final String uri, final Map data) {
-        cLog.debug("Sending backend PUT " + uri);
-
-        final JsonResponse response = mJsonClient.put(getBackendEndpoint() + uri, data);
-        final Status status = response.getStatus();
-        if (!status.isSuccess() && !Status.CLIENT_ERROR_NOT_FOUND.equals(status)) {
-            cLog.warn("Error making backend request for '" + uri + "'. status = " + response.getStatus().toString());
-        }
-
-        return response;
-    }
-
     int chapterIndex(String chapter) {
         if ("teacher".equals(chapter)) {
             return 4;
diff --git a/src/com/p4square/grow/frontend/VideosResource.java b/src/com/p4square/grow/frontend/VideosResource.java
index e85ecd4..957445d 100644
--- a/src/com/p4square/grow/frontend/VideosResource.java
+++ b/src/com/p4square/grow/frontend/VideosResource.java
@@ -83,7 +83,7 @@ public class VideosResource extends ServerResource {
     @Override
     protected Representation post(Representation entity) {
         Map<String, Object> data = new HashMap<String, Object>();
-        data.put("completed", "t");
+        data.put("complete", "true");
         JsonResponse response = backendPut("/accounts/" + mUserId + "/training/videos/" + mVideoId, data);
 
         if (!response.getStatus().isSuccess()) {
diff --git a/src/com/p4square/grow/model/Chapter.java b/src/com/p4square/grow/model/Chapter.java
new file mode 100644
index 0000000..4d59983
--- /dev/null
+++ b/src/com/p4square/grow/model/Chapter.java
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.model;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import com.fasterxml.jackson.annotation.JsonAnyGetter;
+import com.fasterxml.jackson.annotation.JsonAnySetter;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
+/**
+ * Chapter is a list of VideoRecords in a Playlist.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public class Chapter implements Cloneable {
+    private Map<String, VideoRecord> mVideos;
+
+    public Chapter() {
+        mVideos = new HashMap<String, VideoRecord>();
+    }
+
+    /**
+     * @return The VideoRecord for videoid or null if videoid is not in the chapter.
+     */
+    public VideoRecord getVideoRecord(String videoid) {
+        return mVideos.get(videoid);
+    }
+
+    /**
+     * @return A map of video ids to VideoRecords.
+     */
+    @JsonAnyGetter
+    public Map<String, VideoRecord> getVideos() {
+        return mVideos;
+    }
+
+    /**
+     * Set the VideoRecord for a video id.
+     * @param videoId the video id.
+     * @param video the VideoRecord.
+     */
+    @JsonAnySetter
+    public void setVideoRecord(String videoId, VideoRecord video) {
+        mVideos.put(videoId, video);
+    }
+
+    /**
+     * @return true if every required video has been completed.
+     */
+    @JsonIgnore
+    public boolean isComplete() {
+        boolean complete = true;
+
+        for (VideoRecord r : mVideos.values()) {
+            if (r.getRequired() && !r.getComplete()) {
+                return false;
+            }
+        }
+
+        return complete;
+    }
+
+    /**
+     * Deeply clone a chapter.
+     *
+     * @return a new Chapter object identical but independent of this one.
+     */
+    public Chapter clone() throws CloneNotSupportedException {
+        Chapter c = new Chapter();
+        for (Map.Entry<String, VideoRecord> videoEntry : mVideos.entrySet()) {
+            c.setVideoRecord(videoEntry.getKey(), videoEntry.getValue().clone());
+        }
+        return c;
+    }
+}
diff --git a/src/com/p4square/grow/model/Playlist.java b/src/com/p4square/grow/model/Playlist.java
new file mode 100644
index 0000000..79ce68e
--- /dev/null
+++ b/src/com/p4square/grow/model/Playlist.java
@@ -0,0 +1,171 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.model;
+
+import java.util.Date;
+import java.util.HashMap;
+import java.util.Map;
+
+import com.fasterxml.jackson.annotation.JsonAnyGetter;
+import com.fasterxml.jackson.annotation.JsonAnySetter;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
+/**
+ * Representation of a user's playlist.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public class Playlist {
+    /**
+     * Map of Chapter ID to map of Video ID to VideoRecord.
+     */
+    private Map<String, Chapter> mPlaylist;
+
+    private Date mLastUpdated;
+
+    /**
+     * Construct an empty playlist.
+     */
+    public Playlist() {
+        mPlaylist = new HashMap<String, Chapter>();
+        mLastUpdated = new Date(0); // Default to a prehistoric date if we don't have one.
+    }
+
+    /**
+     * Find the VideoRecord for a video id.
+     */
+    public VideoRecord find(String videoId) {
+        for (Chapter chapter : mPlaylist.values()) {
+            VideoRecord r = chapter.getVideoRecord(videoId);
+
+            if (r != null) {
+                return r;
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * @return The last modified date of the source playlist.
+     */
+    public Date getLastUpdated() {
+        return mLastUpdated;
+    }
+
+    /**
+     * Set the last updated date.
+     * @param date the new last updated date.
+     */
+    public void setLastUpdated(Date date) {
+        mLastUpdated = date;
+    }
+
+    /**
+     * Add a video to the playlist.
+     */
+    public VideoRecord add(String chapterId, String videoId) {
+        Chapter chapter = mPlaylist.get(chapterId);
+
+        if (chapter == null) {
+            chapter = new Chapter();
+            mPlaylist.put(chapterId, chapter);
+        }
+
+        VideoRecord r = new VideoRecord();
+        chapter.setVideoRecord(videoId, r);
+        return r;
+    }
+
+    /**
+     * Add a Chapter to the Playlist.
+     * @param chapterId The name of the chapter.
+     * @param chapter The Chapter object to add.
+     */
+    @JsonAnySetter
+    public void addChapter(String chapterId, Chapter chapter) {
+        mPlaylist.put(chapterId, chapter);
+    }
+
+    /**
+     * @return a map of chapter id to chapter.
+     */
+    @JsonAnyGetter
+    public Map<String, Chapter> getChaptersMap() {
+        return mPlaylist;
+    }
+
+    /**
+     * @return The last chapter to be completed.
+     */
+    @JsonIgnore
+    public Map<String, Boolean> getChapterStatuses() {
+        Map<String, Boolean> completed = new HashMap<String, Boolean>();
+
+        for (Map.Entry<String, Chapter> entry : mPlaylist.entrySet()) {
+            completed.put(entry.getKey(), entry.getValue().isComplete());
+        }
+
+        return completed;
+    }
+
+    /**
+     * @return true if all required videos in the chapter have been watched.
+     */
+    public boolean isChapterComplete(String chapterId) {
+        Chapter chapter = mPlaylist.get(chapterId);
+        if (chapter != null) {
+            return chapter.isComplete();
+        }
+
+        return false;
+    }
+
+    /**
+     * Merge a playlist into this playlist.
+     *
+     * Merge is accomplished by adding all missing Chapters and VideoRecords to
+     * this playlist.
+     */
+    public void merge(Playlist source) {
+        if (source.getLastUpdated().before(mLastUpdated)) {
+            // Already up to date.
+            return;
+        }
+
+        for (Map.Entry<String, Chapter> entry : source.getChaptersMap().entrySet()) {
+            String chapterName = entry.getKey();
+            Chapter theirChapter = entry.getValue();
+            Chapter myChapter = mPlaylist.get(entry.getKey());
+
+            if (myChapter == null) {
+                // Add entire chapter
+                try {
+                    mPlaylist.put(chapterName, theirChapter.clone());
+                } catch (CloneNotSupportedException e) {
+                    throw new RuntimeException(e); // Unexpected...
+                }
+
+            } else {
+                // Check chapter for missing videos
+                for (Map.Entry<String, VideoRecord> videoEntry : theirChapter.getVideos().entrySet()) {
+                    String videoId = videoEntry.getKey();
+                    VideoRecord myVideo = myChapter.getVideoRecord(videoId);
+
+                    if (myVideo == null) {
+                        try {
+                            myVideo = videoEntry.getValue().clone();
+                            myChapter.setVideoRecord(videoId, myVideo);
+                        } catch (CloneNotSupportedException e) {
+                            throw new RuntimeException(e); // Unexpected...
+                        }
+                    }
+                }
+            }
+        }
+
+        mLastUpdated = source.getLastUpdated();
+    }
+}
diff --git a/src/com/p4square/grow/model/Question.java b/src/com/p4square/grow/model/Question.java
index 37deffa..f4b9458 100644
--- a/src/com/p4square/grow/model/Question.java
+++ b/src/com/p4square/grow/model/Question.java
@@ -7,9 +7,9 @@ package com.p4square.grow.model;
 import java.util.HashMap;
 import java.util.Map;
 
-import org.codehaus.jackson.annotate.JsonSubTypes;
-import org.codehaus.jackson.annotate.JsonSubTypes.Type;
-import org.codehaus.jackson.annotate.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonSubTypes.Type;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
 
 /**
  * Model of an assessment question.
diff --git a/src/com/p4square/grow/model/TrainingRecord.java b/src/com/p4square/grow/model/TrainingRecord.java
new file mode 100644
index 0000000..bc3ffa9
--- /dev/null
+++ b/src/com/p4square/grow/model/TrainingRecord.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.model;
+
+/**
+ * Representation of a user's training record.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public class TrainingRecord {
+    private String mLastVideo;
+    private Playlist mPlaylist;
+
+    public TrainingRecord() {
+        mPlaylist = new Playlist();
+    }
+
+    /**
+     * @return Video id of the last video watched.
+     */
+    public String getLastVideo() {
+        return mLastVideo;
+    }
+
+    /**
+     * Set the video id for the last video watched.
+     * @param video The new video id.
+     */
+    public void setLastVideo(String video) {
+        mLastVideo = video;
+    }
+
+    /**
+     * @return the user's Playlist.
+     */
+    public Playlist getPlaylist() {
+        return mPlaylist;
+    }
+
+    /**
+     * Set the user's playlist.
+     * @param playlist The new playlist.
+     */
+    public void setPlaylist(Playlist playlist) {
+        mPlaylist = playlist;
+    }
+}
diff --git a/src/com/p4square/grow/backend/resources/VideoRecord.java b/src/com/p4square/grow/model/VideoRecord.java
index 2ba28c3..ec99d0d 100644
--- a/src/com/p4square/grow/backend/resources/VideoRecord.java
+++ b/src/com/p4square/grow/model/VideoRecord.java
@@ -2,27 +2,32 @@
  * Copyright 2013 Jesse Morgan
  */
 
-package com.p4square.grow.backend.resources;
+package com.p4square.grow.model;
 
 import java.util.Date;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
 /**
  * Simple bean containing video completion data.
  *
  * @author Jesse Morgan <jesse@jesterpm.net>
  */
-class VideoRecord {
-    private boolean mComplete;
-    private boolean mRequired;
+public class VideoRecord implements Cloneable {
+    private Boolean mComplete;
+    private Boolean mRequired;
     private Date mCompletionDate;
 
     public VideoRecord() {
-        mComplete = false;
-        mRequired = true;
+        mComplete = null;
+        mRequired = null;
         mCompletionDate = null;
     }
 
     public boolean getComplete() {
+        if (mComplete == null) {
+            return false;
+        }
         return mComplete;
     }
 
@@ -30,7 +35,15 @@ class VideoRecord {
         mComplete = complete;
     }
 
+    @JsonIgnore
+    public boolean isCompleteSet() {
+        return mComplete != null;
+    }
+
     public boolean getRequired() {
+        if (mRequired == null) {
+            return true;
+        }
         return mRequired;
     }
 
@@ -38,6 +51,11 @@ class VideoRecord {
         mRequired = complete;
     }
 
+    @JsonIgnore
+    public boolean isRequiredSet() {
+        return mRequired != null;
+    }
+
     public Date getCompletionDate() {
         return mCompletionDate;
     }
@@ -53,4 +71,15 @@ class VideoRecord {
         mComplete = true;
         mCompletionDate = new Date();
     }
+
+    /**
+     * @return an identical clone of this record.
+     */
+    public VideoRecord clone() throws CloneNotSupportedException {
+        VideoRecord r = (VideoRecord) super.clone();
+        r.mComplete = mComplete;
+        r.mRequired = mRequired;
+        r.mCompletionDate = mCompletionDate;
+        return r;
+    }
 }
diff --git a/src/com/p4square/grow/provider/JsonEncodedProvider.java b/src/com/p4square/grow/provider/JsonEncodedProvider.java
index 605b18c..655b531 100644
--- a/src/com/p4square/grow/provider/JsonEncodedProvider.java
+++ b/src/com/p4square/grow/provider/JsonEncodedProvider.java
@@ -6,9 +6,9 @@ package com.p4square.grow.provider;
 
 import java.io.IOException;
 
-import org.codehaus.jackson.map.DeserializationConfig;
-import org.codehaus.jackson.map.ObjectMapper;
-import org.codehaus.jackson.map.SerializationConfig;
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
 
 /**
  * Provider provides a simple interface for loading and persisting
@@ -19,9 +19,9 @@ import org.codehaus.jackson.map.SerializationConfig;
 public abstract class JsonEncodedProvider<K, V> implements Provider<K, V> {
     public static final ObjectMapper MAPPER = new ObjectMapper();
     static {
-        MAPPER.configure(SerializationConfig.Feature.WRITE_ENUMS_USING_TO_STRING, true);
-        MAPPER.configure(DeserializationConfig.Feature.READ_ENUMS_USING_TO_STRING, true);
-        MAPPER.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+        MAPPER.configure(SerializationFeature.WRITE_ENUMS_USING_TO_STRING, true);
+        MAPPER.configure(DeserializationFeature.READ_ENUMS_USING_TO_STRING, true);
+        MAPPER.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
     }
 
     private final Class<V> mClazz;
diff --git a/src/com/p4square/grow/provider/ProvidesQuestions.java b/src/com/p4square/grow/provider/ProvidesQuestions.java
new file mode 100644
index 0000000..b43f649
--- /dev/null
+++ b/src/com/p4square/grow/provider/ProvidesQuestions.java
@@ -0,0 +1,19 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.provider;
+
+import com.p4square.grow.model.Question;
+
+/**
+ * Indicates the ability to provide a Question Provider.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public interface ProvidesQuestions {
+    /**
+     * @return A Provider of Questions keyed by question id.
+     */
+    Provider<String, Question> getQuestionProvider();
+}
diff --git a/src/com/p4square/grow/provider/ProvidesTrainingRecords.java b/src/com/p4square/grow/provider/ProvidesTrainingRecords.java
new file mode 100644
index 0000000..27ffa3e
--- /dev/null
+++ b/src/com/p4square/grow/provider/ProvidesTrainingRecords.java
@@ -0,0 +1,19 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.provider;
+
+import com.p4square.grow.model.TrainingRecord;
+
+/**
+ * Indicates the ability to provide a TrainingRecord Provider.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public interface ProvidesTrainingRecords {
+    /**
+     * @return A Provider of Questions keyed by question id.
+     */
+    Provider<String, TrainingRecord> getTrainingRecordProvider();
+}
diff --git a/src/com/p4square/grow/provider/TrainingRecordProvider.java b/src/com/p4square/grow/provider/TrainingRecordProvider.java
new file mode 100644
index 0000000..44dba87
--- /dev/null
+++ b/src/com/p4square/grow/provider/TrainingRecordProvider.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.provider;
+
+import java.io.IOException;
+
+import com.p4square.grow.model.TrainingRecord;
+
+/**
+ * TrainingRecordProvider wraps an existing Provider to get and put TrainingRecords.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public abstract class TrainingRecordProvider<K> implements Provider<String, TrainingRecord> {
+
+    private Provider<K, TrainingRecord> mProvider;
+
+    public TrainingRecordProvider(Provider<K, TrainingRecord> provider) {
+        mProvider = provider;
+    }
+
+    @Override
+    public TrainingRecord get(String key) throws IOException {
+        return mProvider.get(makeKey(key));
+    }
+
+    @Override
+    public void put(String key, TrainingRecord obj) throws IOException {
+        mProvider.put(makeKey(key), obj);
+    }
+
+    /**
+     * Make a Key for a TrainingRecord..
+     *
+     * @param userId The user id.
+     * @return a key for the TrainingRecord of userid.
+     */
+    protected abstract K makeKey(String userId);
+}