Document.java

/*
   Copyright 2007 Fourspaces Consulting, LLC

   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.fourspaces.couchdb;

import java.io.IOException;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import com.fourspaces.couchdb.util.JSONUtils;
import net.sf.json.*;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;


/**
 * Everything in CouchDB is a Document.  In this case, the document is an object backed by a 
 * JSONObject.  The Document is also aware of the database that it is connected to.  This allows
 * the Document to reload it's properties when needed.  The only special fields are "_id", "_rev", 
 * "_revisions", and "_view_*".
 * <p>
 * All document have an _id and a _rev.  If this is a new document those fields are populated when
 * they are saved to the CouchDB server.
 * <p>
 * _revisions is only populated if the document has been retrieved via database.getDocumentWithRevisions();
 * So, if this document wasn't, then when you call document.getRevisions(), it will go back to the server
 * to reload itself via database.getDocumentWithRevisions().
 * <p>
 * The Document can be treated like a JSONObject, eventhough it doesn't extend JSONObject (it's final).
 * <p>
 * You can also get/set values by calling document.get(key), document.put(key,value), just like a Map.
 * <p>
 * You can get a handle on the backing JSONObject by calling document.getJSONObject();  If this hasn't
 * been loaded yet, it will load the data itself using the given database connection.
 * <p>
 * If you got this Document from a view, you are likely missing elements.  To load them you can call
 * document.load().
 * 
 * @author mbreese
 *
 */
@SuppressWarnings("unchecked")
public class Document implements Map {
	Log log = LogFactory.getLog(Document.class);

  public static final String REVISION_HISTORY_PROP = "_revisions";

	protected Database database=null;
	protected JSONObject object;
	
	boolean loaded = false;
	
	/**
	 * Create a new Document
	 *
	 */
	public Document () {
		this.object = new JSONObject();
	}
	/**
	 * Create a new Document from a JSONObject
	 * @param obj
	 */
	public Document (JSONObject obj) {
		this.object = obj;
		loaded=true;
	}

  /**
	 * Load data into this document from a differing JSONObject 
	 * <p>
	 * This is mainly for reloading data for an object that was retrieved from a view.  This version
	 * doesn't overwrite any unsaved data that is currently present in this object.
	 * 
	 * @param object2
	 */	
	protected void load(JSONObject object2) {
		if (!loaded) {
			object.putAll(object2);
			loaded=true;
		}
	}
	
	/**
	 * This document's id (if saved)
	 * @return
	 */
	public String getId() {
	  if (StringUtils.isNotBlank(object.optString("_id"))) {
	    return object.optString("_id");
	  } else {	
	    return object.optString("id");
	  }
	}
	public void setId(String id)  {
		object.put("_id",id);
	}

	/**
	 * This strips _design from the document id
	 */
	public String getViewDocumentId() {
		String id = getId();
		int pos = id.lastIndexOf("/");
		if (pos == -1) {
			return id;
		} else {
			return id.substring(pos+1);
		}
	}

	/**
	 * This document's Revision (if saved)
	 * @return
	 */
	public String getRev()  {
    if (StringUtils.isNotBlank(object.optString("_rev"))) {
      return object.optString("_rev");
    } else {
      return object.optString("rev");
    }
	}
	public void setRev(String rev)  {
		object.put("_rev", rev);
	}
	
	/**
	 * A list of the revision numbers that this document has.  If this hasn't been 
	 * populated with a "full=true" query, then the database will be re-queried
	 * @return
	 */
	public String[] getRevisions() throws IOException {
		String[] revs = null;
		if (!object.has("_revs")) {
			populateRevisions();
		} 
		//System.out.println(object);
		JSONArray ar = object.getJSONObject(REVISION_HISTORY_PROP).getJSONArray("ids");
		if (ar!=null) {
			revs = new String[ar.size()];
			for (int i=0 ; i< ar.size(); i++) {
				revs[i]=ar.getString(i);
			}
		}
		return revs;
	}
	
	/**
	 * Get a named view that is stored in the document.
	 * @param name
	 * @return
	 */
	public View getView(String name) {
		if (object.has("views")) {
			JSONObject views = object.getJSONObject("views");
			if (views.has(name)) {
				return new View(this,name);
			}
		}
		return null;
    }
	
	/**
	 * Add a view to this document.  If a view function already exists with the given viewName
	 * it is overwritten.
	 * <p>
	 * This isn't persisted until the document is saved.
	 * 
	 * @param designDoc document name
	 * @param viewName
	 * @param function
	 * @return
	 */
	public View addView(String designDoc, String viewName, String function) {
		object.put("_id", "_design/"+ designDoc); //Not sure if _id or id should be used
		object.put("language", "javascript"); //FIXME specify language

    JSONObject funcs = new JSONObject();
//    System.err.println("JSON String: " + JSONUtils.stringSerializedFunction(function));
//    funcs.put("map", JSONUtils.stringSerializedFunction(function));
    funcs.accumulate("map", JSONUtils.stringSerializedFunction(function));

    System.err.println("FUNCS: " + funcs.toString());

		JSONObject viewMap = new JSONObject();
		viewMap.put(viewName, funcs);

		object.put("views", viewMap);

		return new View(this, viewName, function);

	}
	
	/**
	 * Removes a view from this document.
	 * <p>
	 * This isn't persisted until the document is saved.
	 * @param viewName
	 */
	public void deleteView(String viewName) {
		object.remove("_design/"+viewName);
	}
	
	void setDatabase(Database database) {
		this.database=database;
	}
	
	/**
	 * Loads data from the server for this document.  Actually requests a new copy of data from the 
	 * server and uses that to populate this document.  This doesn't overwrite any unsaved data.
	 */
	public void refresh() throws IOException {
		if (database!=null) {
			Document doc = database.getDocument(getId());
			log.info("Loading: "+doc.getJSONObject());
			load(doc.getJSONObject());
		}
	}
	
	protected void populateRevisions() throws IOException {
		if (database!=null) {
			Document doc = database.getDocumentWithRevisions(getId());
			log.info("Loading: "+doc.getJSONObject());
			load(doc.getJSONObject());
		}
	}
	
	/**
	 * Retrieves the backing JSONObject
	 * @return
	 */
	public JSONObject getJSONObject() {
		if (!loaded && database!=null && getId()!=null && !getId().equals("")) {
			try {
        refresh();
      } catch (IOException e) {
        throw new RuntimeException("error in refreshing Document", e);
      }
		}
		return object;
	}
	
	public String toString() {
		return object.toString();
	}
	
	/*
	 * Delegate methods to the JSON Object.
	 */	
	public JSONObject accumulate(String arg0, boolean arg1) {
		return getJSONObject().accumulate(arg0, arg1);
	}
	public JSONObject accumulate(String arg0, double arg1) {
		return getJSONObject().accumulate(arg0, arg1);
	}
	public JSONObject accumulate(String arg0, int arg1) {
		return getJSONObject().accumulate(arg0, arg1);
	}
	public JSONObject accumulate(String arg0, long arg1) {
		return getJSONObject().accumulate(arg0, arg1);
	}
	public JSONObject accumulate(String arg0, Object arg1) {
		return getJSONObject().accumulate(arg0, arg1);
	}
	public void accumulateAll(Map arg0) {
		getJSONObject().accumulateAll(arg0);
	}
	public void clear() {
		getJSONObject().clear();
	}
	public boolean containsKey(Object arg0) {
		return getJSONObject().containsKey(arg0);
	}
	public boolean containsValue(Object arg0) {
		return getJSONObject().containsValue(arg0);
	}
	public JSONObject element(String arg0, boolean arg1) {
		return getJSONObject().element(arg0, arg1);
	}
	public JSONObject element(String arg0, Collection arg1) {
		return getJSONObject().element(arg0, arg1);
	}
	public JSONObject element(String arg0, double arg1) {
		return getJSONObject().element(arg0, arg1);
	}
	public JSONObject element(String arg0, int arg1) {
		return getJSONObject().element(arg0, arg1);
	}
	public JSONObject element(String arg0, long arg1) {
		return getJSONObject().element(arg0, arg1);
	}
	public JSONObject element(String arg0, Map arg1) {
		return getJSONObject().element(arg0, arg1);
	}
	public JSONObject element(String arg0, Object arg1) {
		return getJSONObject().element(arg0, arg1);
	}
	public JSONObject elementOpt(String arg0, Object arg1) {
		return getJSONObject().elementOpt(arg0, arg1);
	}
	public Set entrySet() {
		return getJSONObject().entrySet();
	}
	public Object get(Object arg0) {
		return getJSONObject().get(arg0);
	}
	public Object get(String arg0) {
		return getJSONObject().get(arg0);
	}
	public boolean getBoolean(String arg0) {
		return getJSONObject().getBoolean(arg0);
	}
	public double getDouble(String arg0) {
		return getJSONObject().getDouble(arg0);
	}
	public int getInt(String arg0) {
		return getJSONObject().getInt(arg0);
	}
	public JSONArray getJSONArray(String arg0) {
		return getJSONObject().getJSONArray(arg0);
	}
	public JSONObject getJSONObject(String arg0) {
		return getJSONObject().getJSONObject(arg0);
	}
	public long getLong(String arg0) {
		return getJSONObject().getLong(arg0);
	}
	public String getString(String arg0) {
		return getJSONObject().getString(arg0);
	}
	public boolean has(String arg0) {
		return getJSONObject().has(arg0);
	}
	public Iterator keys() {
		return getJSONObject().keys();
	}
	public Set keySet() {
		return getJSONObject().keySet();
	}
	public JSONArray names() {
		return getJSONObject().names();
	}
	public Object opt(String arg0) {
		return getJSONObject().opt(arg0);
	}
	public boolean optBoolean(String arg0, boolean arg1) {
		return getJSONObject().optBoolean(arg0, arg1);
	}
	public boolean optBoolean(String arg0) {
		return getJSONObject().optBoolean(arg0);
	}
	public double optDouble(String arg0, double arg1) {
		return getJSONObject().optDouble(arg0, arg1);
	}
	public double optDouble(String arg0) {
		return getJSONObject().optDouble(arg0);
	}
	public int optInt(String arg0, int arg1) {
		return getJSONObject().optInt(arg0, arg1);
	}
	public int optInt(String arg0) {
		return getJSONObject().optInt(arg0);
	}
	public JSONArray optJSONArray(String arg0) {
		return getJSONObject().optJSONArray(arg0);
	}
	public JSONObject optJSONObject(String arg0) {
		return getJSONObject().optJSONObject(arg0);
	}
	public long optLong(String arg0, long arg1) {
		return getJSONObject().optLong(arg0, arg1);
	}
	public long optLong(String arg0) {
		return getJSONObject().optLong(arg0);
	}
	public String optString(String arg0, String arg1) {
		return getJSONObject().optString(arg0, arg1);
	}
	public String optString(String arg0) {
		return getJSONObject().optString(arg0);
	}
	public Object put(Object arg0, Object arg1) {
		return getJSONObject().put(arg0, arg1);
	}
	public void putAll(Map arg0) {
		getJSONObject().putAll(arg0);
	}
	public Object remove(Object arg0) {
		return getJSONObject().remove(arg0);
	}
	public Object remove(String arg0) {
		return getJSONObject().remove(arg0);
	}
	public int size() {
		return getJSONObject().size();
	}
	public Collection values() {
		return getJSONObject().values();
	}
	public boolean isEmpty() {
		return getJSONObject().isEmpty();
	}
}