Adding the feed backend support.

9 files changed, 554 insertions, 1 deletions

diff --git a/src/com/p4square/grow/backend/GrowBackend.java b/src/com/p4square/grow/backend/GrowBackend.java
index 195554e..f844feb 100644
--- a/src/com/p4square/grow/backend/GrowBackend.java
+++ b/src/com/p4square/grow/backend/GrowBackend.java
@@ -19,12 +19,16 @@ 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.CassandraCollectionProvider;
 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.model.MessageThread;
+import com.p4square.grow.model.Message;
 
+import com.p4square.grow.provider.CollectionProvider;
 import com.p4square.grow.provider.Provider;
 import com.p4square.grow.provider.ProvidesQuestions;
 import com.p4square.grow.provider.ProvidesTrainingRecords;
@@ -37,13 +41,17 @@ import com.p4square.grow.backend.resources.SurveyResultsResource;
 import com.p4square.grow.backend.resources.TrainingRecordResource;
 import com.p4square.grow.backend.resources.TrainingResource;
 
+import com.p4square.grow.backend.feed.FeedDataProvider;
+import com.p4square.grow.backend.feed.ThreadResource;
+import com.p4square.grow.backend.feed.TopicResource;
+
 /**
  * Main class for the backend application.
  *
  * @author Jesse Morgan <jesse@jesterpm.net>
  */
 public class GrowBackend extends Application
-        implements ProvidesQuestions, ProvidesTrainingRecords {
+        implements ProvidesQuestions, ProvidesTrainingRecords, FeedDataProvider {
     private static final String DEFAULT_COLUMN = "value";
 
     private final static Logger LOG = Logger.getLogger(GrowBackend.class);
@@ -54,6 +62,9 @@ public class GrowBackend extends Application
     private final Provider<String, Question> mQuestionProvider;
     private final CassandraTrainingRecordProvider mTrainingRecordProvider;
 
+    private final CollectionProvider<String, String, MessageThread> mFeedThreadProvider;
+    private final CollectionProvider<String, String, Message> mFeedMessageProvider;
+
     public GrowBackend() {
         this(new Config());
     }
@@ -69,6 +80,11 @@ public class GrowBackend extends Application
             }
         };
 
+        mFeedThreadProvider = new CassandraCollectionProvider<MessageThread>(mDatabase,
+                "feedthreads", MessageThread.class);
+        mFeedMessageProvider = new CassandraCollectionProvider<Message>(mDatabase,
+                "feedmessages", Message.class);
+
         mTrainingRecordProvider = new CassandraTrainingRecordProvider(mDatabase);
     }
 
@@ -97,6 +113,11 @@ public class GrowBackend extends Application
         // Misc.
         router.attach("/banner", BannerResource.class);
 
+        // Feed
+        router.attach("/feed/{topic}", TopicResource.class);
+        router.attach("/feed/{topic}/{thread}", ThreadResource.class);
+        //router.attach("/feed/{topic/{thread}/{message}", MessageResource.class);
+
         return router;
     }
 
@@ -148,6 +169,16 @@ public class GrowBackend extends Application
         return mTrainingRecordProvider.getDefaultPlaylist();
     }
 
+    @Override
+    public CollectionProvider<String, String, MessageThread> getThreadProvider() {
+        return mFeedThreadProvider;
+    }
+
+    @Override
+    public CollectionProvider<String, String, Message> getMessageProvider() {
+        return mFeedMessageProvider;
+    }
+
     /**
      * Stand-alone main for testing.
      */
diff --git a/src/com/p4square/grow/backend/db/CassandraCollectionProvider.java b/src/com/p4square/grow/backend/db/CassandraCollectionProvider.java
new file mode 100644
index 0000000..cc11828
--- /dev/null
+++ b/src/com/p4square/grow/backend/db/CassandraCollectionProvider.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.backend.db;
+
+import java.io.IOException;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import com.netflix.astyanax.model.Column;
+import com.netflix.astyanax.model.ColumnList;
+
+import com.p4square.grow.provider.CollectionProvider;
+import com.p4square.grow.provider.JsonEncodedProvider;
+
+/**
+ * CollectionProvider implementation backed by a Cassandra ColumnFamily.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public class CassandraCollectionProvider<V> implements CollectionProvider<String, String, V> {
+    private final CassandraDatabase mDb;
+    private final String mCF;
+    private final Class<V> mClazz;
+
+    public CassandraCollectionProvider(CassandraDatabase db, String columnFamily, Class<V> clazz) {
+        mDb = db;
+        mCF = columnFamily;
+        mClazz = clazz;
+    }
+
+    @Override
+    public V get(String collection, String key) throws IOException {
+        String blob = mDb.getKey(mCF, collection, key);
+        return decode(blob);
+    }
+
+    @Override
+    public Map<String, V> query(String collection) throws IOException {
+        return query(collection, -1);
+    }
+
+    @Override
+    public Map<String, V> query(String collection, int limit) throws IOException {
+        Map<String, V> result = new HashMap<>();
+
+        ColumnList<String> row = mDb.getRow(mCF, collection);
+        if (!row.isEmpty()) {
+            int count = 0;
+            for (Column<String> c : row) {
+                String key = c.getName();
+                String blob = c.getStringValue();
+                V obj = decode(blob);
+
+                result.put(key, obj);
+
+                if (limit >= 0 && ++count > limit) {
+                    break; // Limit reached.
+                }
+            }
+        }
+
+        return Collections.unmodifiableMap(result);
+    }
+
+    @Override
+    public void put(String collection, String key, V obj) throws IOException {
+        String blob = encode(obj);
+        mDb.putKey(mCF, collection, key, blob);
+    }
+
+    /**
+     * Encode the object as JSON.
+     *
+     * @param obj The object to encode.
+     * @return The JSON encoding of obj.
+     * @throws IOException if the object cannot be encoded.
+     */
+    protected String encode(V obj) throws IOException {
+        return JsonEncodedProvider.MAPPER.writeValueAsString(obj);
+    }
+
+    /**
+     * Decode the JSON string as an object.
+     *
+     * @param blob The JSON data to decode.
+     * @return The decoded object or null if blob is null.
+     * @throws IOException If an object cannot be decoded.
+     */
+    protected V decode(String blob) throws IOException {
+        if (blob == null) {
+            return null;
+        }
+
+        V obj = JsonEncodedProvider.MAPPER.readValue(blob, mClazz);
+        return obj;
+    }
+}
diff --git a/src/com/p4square/grow/backend/feed/FeedDataProvider.java b/src/com/p4square/grow/backend/feed/FeedDataProvider.java
new file mode 100644
index 0000000..41b2dfa
--- /dev/null
+++ b/src/com/p4square/grow/backend/feed/FeedDataProvider.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.backend.feed;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+
+import com.p4square.grow.model.MessageThread;
+import com.p4square.grow.model.Message;
+import com.p4square.grow.provider.CollectionProvider;
+
+/**
+ * Implementing this interface indicates you can provide a data source for the Feed.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public interface FeedDataProvider {
+    public static final Collection<String> TOPICS = Collections.unmodifiableCollection(
+            Arrays.asList(new String[] { "seeker", "believer", "disciple", "teacher" }));
+
+    /**
+     * @return a CollectionProvider of Threads.
+     */
+    CollectionProvider<String, String, MessageThread> getThreadProvider();
+
+    /**
+     * @return a CollectionProvider of Messages.
+     */
+    CollectionProvider<String, String, Message> getMessageProvider();
+}
diff --git a/src/com/p4square/grow/backend/feed/ThreadResource.java b/src/com/p4square/grow/backend/feed/ThreadResource.java
new file mode 100644
index 0000000..32a2f64
--- /dev/null
+++ b/src/com/p4square/grow/backend/feed/ThreadResource.java
@@ -0,0 +1,102 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.backend.feed;
+
+import java.io.IOException;
+
+import java.util.Map;
+import java.util.UUID;
+
+import org.restlet.data.Status;
+import org.restlet.resource.ServerResource;
+import org.restlet.representation.Representation;
+
+import org.restlet.ext.jackson.JacksonRepresentation;
+
+import org.apache.log4j.Logger;
+
+import com.p4square.grow.model.Message;
+
+/**
+ * ThreadResource manages the messages that make up a thread.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public class ThreadResource extends ServerResource {
+    private static final Logger LOG = Logger.getLogger(ThreadResource.class);
+
+    private FeedDataProvider mBackend;
+    private String mTopic;
+    private String mThreadId;
+
+    @Override
+    public void doInit() {
+        super.doInit();
+
+        mBackend = (FeedDataProvider) getApplication();
+        mTopic = getAttribute("topic");
+        mThreadId = getAttribute("thread");
+    }
+
+    /**
+     * GET a list of messages in a thread.
+     */
+    @Override
+    protected Representation get() {
+        // If the topic or threadId are missing, return a 404.
+        if (mTopic == null || mTopic.length() == 0 ||
+                mThreadId == null || mThreadId.length() == 0) {
+            setStatus(Status.CLIENT_ERROR_NOT_FOUND);
+            return null;
+        }
+
+        // TODO: Support limit query parameter.
+
+        try {
+            String collectionKey = mTopic + "/" + mThreadId;
+            Map<String, Message> messages = mBackend.getMessageProvider().query(collectionKey);
+            return new JacksonRepresentation(messages.values());
+
+        } catch (IOException e) {
+            LOG.error("Unexpected exception: " + e.getMessage(), e);
+            setStatus(Status.SERVER_ERROR_INTERNAL);
+            return null;
+        }
+    }
+
+    /**
+     * POST a new thread to the topic.
+     */
+    @Override
+    protected Representation post(Representation entity) {
+        // If the topic and thread are not provided, respond with not allowed.
+        // TODO: Check if the thread exists.
+        if (mTopic == null || !mBackend.TOPICS.contains(mTopic) ||
+                mThreadId == null || mThreadId.length() == 0) {
+            setStatus(Status.CLIENT_ERROR_METHOD_NOT_ALLOWED);
+            return null;
+        }
+
+        try {
+            JacksonRepresentation<Message> jsonRep = new JacksonRepresentation<Message>(entity, Message.class);
+            Message message = jsonRep.getObject();
+
+            // Force the thread id and message to be what we expect.
+            message.setThreadId(mThreadId);
+            message.setId(String.format("%x-%s", System.currentTimeMillis(), UUID.randomUUID().toString()));
+
+            String collectionKey = mTopic + "/" + mThreadId;
+            mBackend.getMessageProvider().put(collectionKey, message.getId(), message);
+
+            setLocationRef(mThreadId + "/" + message.getId());
+            return new JacksonRepresentation(message);
+
+        } catch (IOException e) {
+            LOG.error("Unexpected exception: " + e.getMessage(), e);
+            setStatus(Status.SERVER_ERROR_INTERNAL);
+            return null;
+        }
+    }
+}
diff --git a/src/com/p4square/grow/backend/feed/TopicResource.java b/src/com/p4square/grow/backend/feed/TopicResource.java
new file mode 100644
index 0000000..0904baa
--- /dev/null
+++ b/src/com/p4square/grow/backend/feed/TopicResource.java
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.backend.feed;
+
+import java.io.IOException;
+
+import java.util.Map;
+
+import org.restlet.data.Status;
+import org.restlet.resource.ServerResource;
+import org.restlet.representation.Representation;
+
+import org.restlet.ext.jackson.JacksonRepresentation;
+
+import org.apache.log4j.Logger;
+
+import com.p4square.grow.model.MessageThread;
+
+/**
+ * TopicResource manages the threads contained in a topic.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public class TopicResource extends ServerResource {
+    private static final Logger LOG = Logger.getLogger(TopicResource.class);
+
+    private FeedDataProvider mBackend;
+    private String mTopic;
+
+    @Override
+    public void doInit() {
+        super.doInit();
+
+        mBackend = (FeedDataProvider) getApplication();
+        mTopic = getAttribute("topic");
+    }
+
+    /**
+     * GET a list of threads in the topic.
+     */
+    @Override
+    protected Representation get() {
+        // If no topic is provided, return a list of topics.
+        if (mTopic == null || mTopic.length() == 0) {
+            return new JacksonRepresentation(FeedDataProvider.TOPICS);
+        }
+
+        // TODO: Support limit query parameter.
+
+        try {
+            Map<String, MessageThread> threads = mBackend.getThreadProvider().query(mTopic);
+            return new JacksonRepresentation(threads.values());
+
+        } catch (IOException e) {
+            LOG.error("Unexpected exception: " + e.getMessage(), e);
+            setStatus(Status.SERVER_ERROR_INTERNAL);
+            return null;
+        }
+    }
+
+    /**
+     * POST a new thread to the topic.
+     */
+    @Override
+    protected Representation post(Representation entity) {
+        // If no topic is provided, respond with not allowed.
+        if (mTopic == null || !mBackend.TOPICS.contains(mTopic)) {
+            setStatus(Status.CLIENT_ERROR_METHOD_NOT_ALLOWED);
+            return null;
+        }
+
+        try {
+            MessageThread newThread = MessageThread.createNew();
+            mBackend.getThreadProvider().put(mTopic, newThread.getId(), newThread);
+
+            setStatus(Status.SUCCESS_NO_CONTENT);
+            setLocationRef(mTopic + "/" + newThread.getId());
+            return null;
+
+        } catch (IOException e) {
+            LOG.error("Unexpected exception: " + e.getMessage(), e);
+            setStatus(Status.SERVER_ERROR_INTERNAL);
+            return null;
+        }
+    }
+}
diff --git a/src/com/p4square/grow/frontend/TrainingPageResource.java b/src/com/p4square/grow/frontend/TrainingPageResource.java
index adad68c..0f2b284 100644
--- a/src/com/p4square/grow/frontend/TrainingPageResource.java
+++ b/src/com/p4square/grow/frontend/TrainingPageResource.java
@@ -209,6 +209,7 @@ public class TrainingPageResource extends FreeMarkerPageResource {
             root.put("overallProgress", overallProgress);
             root.put("videos", videos);
             root.put("allowUserToSkip", allowUserToSkip);
+            root.put("showfeed", getQueryValue("showfeed") != null);
 
             return new TemplateRepresentation(mTrainingTemplate, root, MediaType.TEXT_HTML);
 
diff --git a/src/com/p4square/grow/model/Message.java b/src/com/p4square/grow/model/Message.java
new file mode 100644
index 0000000..6e07150
--- /dev/null
+++ b/src/com/p4square/grow/model/Message.java
@@ -0,0 +1,95 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.model;
+
+import java.util.Date;
+
+/**
+ * A feed message.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public class Message {
+    private String mThreadId;
+    private String mId;
+    private String mAuthor;
+    private Date mCreated;
+    private String mMessage;
+
+    /**
+     * @return The id of the thread that the message belongs to.
+     */
+    public String getThreadId() {
+        return mThreadId;
+    }
+
+    /**
+     * Set the id of the thread that the message belongs to.
+     * @param id The new thread id.
+     */
+    public void setThreadId(String id) {
+        mThreadId = id;
+    }
+
+    /**
+     * @return The id the message.
+     */
+    public String getId() {
+        return mId;
+    }
+
+    /**
+     * Set the id of the message.
+     * @param id The new message id.
+     */
+    public void setId(String id) {
+        mId = id;
+    }
+
+    /**
+     * @return The author of the message.
+     */
+    public String getAuthor() {
+        return mAuthor;
+    }
+
+    /**
+     * Set the author of the message.
+     * @param author The new author.
+     */
+    public void setAuthor(String author) {
+        mAuthor = author;
+    }
+
+    /**
+     * @return The Date the message was created.
+     */
+    public Date getCreated() {
+        return mCreated;
+    }
+
+    /**
+     * Set the Date the message was created.
+     * @param date The new creation date.
+     */
+    public void setCreated(Date date) {
+        mCreated = date;
+    }
+
+    /**
+     * @return The message text.
+     */
+    public String getMessage() {
+        return mMessage;
+    }
+
+    /**
+     * Set the message text.
+     * @param text The message text.
+     */
+    public void setMessage(String text) {
+        mMessage = text;
+    }
+}
diff --git a/src/com/p4square/grow/model/MessageThread.java b/src/com/p4square/grow/model/MessageThread.java
new file mode 100644
index 0000000..f93ec13
--- /dev/null
+++ b/src/com/p4square/grow/model/MessageThread.java
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.model;
+
+import java.util.UUID;
+
+/**
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public class MessageThread {
+    private String mId;
+
+    /**
+     * Create a new thread with a probably unique id.
+     *
+     * @return the new thread.
+     */
+    public static MessageThread createNew() {
+        MessageThread t = new MessageThread();
+        t.setId(String.format("%x-%s", System.currentTimeMillis(), UUID.randomUUID().toString()));
+
+        return t;
+    }
+
+    /**
+     * @return The id the message.
+     */
+    public String getId() {
+        return mId;
+    }
+
+    /**
+     * Set the id of the message.
+     * @param id The new message id.
+     */
+    public void setId(String id) {
+        mId = id;
+    }
+
+}
diff --git a/src/com/p4square/grow/provider/CollectionProvider.java b/src/com/p4square/grow/provider/CollectionProvider.java
new file mode 100644
index 0000000..e4e9040
--- /dev/null
+++ b/src/com/p4square/grow/provider/CollectionProvider.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.provider;
+
+import java.io.IOException;
+import java.util.Map;
+
+/**
+ * ListProvider is the logical extension of Provider for dealing with lists of
+ * items.
+ *
+ * @param C The type of the collection key.
+ * @param K The type of the item key.
+ * @param V The type of the value.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public interface CollectionProvider<C, K, V> {
+    /**
+     * Retrieve a specific object from the collection.
+     *
+     * @param collection The collection key.
+     * @param key The key for the object in the collection.
+     * @return The object or null if not found.
+     */
+    V get(C collection, K key) throws IOException;
+
+    /**
+     * Retrieve a collection.
+     *
+     * The returned map will never be null.
+     *
+     * @param collection The collection key.
+     * @return A Map of keys to values.
+     */
+    Map<K, V> query(C collection) throws IOException;
+
+    /**
+     * Retrieve a portion of a collection.
+     *
+     * The returned map will never be null.
+     *
+     * @param collection The collection key.
+     * @param limit Max number of items to return.
+     * @return A Map of keys to values.
+     */
+    Map<K, V> query(C collection, int limit) throws IOException;
+
+    /**
+     * Persist the object with the given key.
+     *
+     * @param collection The collection key.
+     * @param key The key for the object in the collection.
+     * @param obj The object to persist.
+     */
+    void put(C collection, K key, V obj) throws IOException;
+}