package edu.uw.cs.cse461.SNet;

import java.io.File;

import org.json.JSONObject;

import edu.uw.cs.cse461.DB461.DB461.DB461Exception;
import edu.uw.cs.cse461.Net.Base.NetBase;
import edu.uw.cs.cse461.Net.DDNS.DDNSFullName;
import edu.uw.cs.cse461.Net.DDNS.DDNSFullNameInterface;
import edu.uw.cs.cse461.Net.RPC.RPCService;
import edu.uw.cs.cse461.SNet.SNetDB461.CommunityRecord;
import edu.uw.cs.cse461.util.Log;


/**
 * Handles UI-independent operations on SNetDB
 * 
 * @author zahorjan
 *
 */
public class SNetController {
	private static final String TAG="SNetController";
	
	/**
	 * A full path name to the sqlite database.
	 */
	private String mDBName;
	
	/**
	 * IMPLEMENTED: Returns the full path name of the DB file.
	 */
	public String DBName() {
		return mDBName;
	}
	
	/**
	 * IMPLEMENTED: Ensures that the root member and the member whose name is the argument
	 * (usually the host name of this node) both have entries in the community table.
	 * @param user A user name
	 * @throws DB461Exception Some unanticipated exception occurred.
	 */
	public void registerBaseUsers(DDNSFullName user) throws DB461Exception {
		SNetDB461 db = null;
		try {
			db = new SNetDB461(mDBName);
			db.registerMember( user );
			db.registerMember( new DDNSFullName("") );  // and the root
		} catch (Exception e) {
			Log.e(TAG, "registerBaseUsers caught exception: " + e.getMessage());
			throw new DB461Exception("registerUser caught exception: " + e.getMessage());
		}
		finally {
			if ( db != null ) db.discard();
		}
	}

	/**
	 * IMPLEMENTED: Helper function that returns a string representing the community table record in the database
	 * for the user whose name is the node's hostname.
	 * @return The community table row, as a String.
	 */
	synchronized public String getStatusMsg() {
		SNetDB461 db = null;
		StringBuilder sb = new StringBuilder();
		try {
			sb.append("Host: ").append(NetBase.theNetBase().hostname()).append("\n");
			RPCService rpcService = (RPCService)NetBase.theNetBase().getService("rpc");
			sb.append("Location: ").append(rpcService.localIP()).append(":").append(rpcService.localPort()).append("\n");
			db = new SNetDB461(mDBName);
			String memberName = new DDNSFullName(NetBase.theNetBase().hostname()).toString();
			CommunityRecord member = db.COMMUNITYTABLE.readOne(memberName);
			if ( member != null ) sb.append(member.toString());
			else sb.append("No data for member '" + memberName + "'");
		} catch (Exception e) {
			Log.e(TAG, "getStatusMsg: caught exception: " + e.getMessage());
		}
		finally {
			if ( db != null ) db.discard();
		}
		return sb.toString();
	}
	
	/**
	 * Implemented: Checks db for consistency violations and tries to fix  them.
	 * Consistency requirements:
	 * <ul>
	 * <li> Every photo hash in community table should have a photo table entry
	 * <li> Ref counts should be correct
	 * <li> If a photo table entry has a file name, the file should exist, and the file's hash should correspond to the photo record key
	 * </ul>
	 * @param galleryDir A File object representing the gallery directory
	 */
	synchronized public void fixDB(File galleryDir) throws DB461Exception {
		SNetDB461 db = null;
		try {
			db = new SNetDB461(mDBName);
			db.checkAndFixDB(galleryDir);
		} catch (Exception e) {
			throw new DB461Exception("fixDB caught exception: "+ e.getMessage());
		}
		finally {
			if ( db != null ) db.discard();
		}
	}
	
	
	//////////////////////////////////////////////////////////////////////////////////////
	// Below here the methods may need implementation, completion, or customization.
	//////////////////////////////////////////////////////////////////////////////////////
	
	public SNetController(String dbDirName) {
		mDBName = dbDirName + "/" + new DDNSFullName(NetBase.theNetBase().hostname()) + "snet.db";
	}
	
	/**
	 * OPTIONAL: Provides a web interface displaying status of SNet database.
	 * @param uriVec The parsed URI argument.  (See HTTPProviderInterface.java.)
	 * @return Text to return to the browser.
	 */
	public String httpServe(String[] uriVec) throws DB461Exception {
		return "Not implemented";
	}
	
	/**
	 * Assign a photo that exists as a local file as a member's chosen photo.
	 * Decrement reference count on any existing chosen photo and delete underyling file if appropriate.
	 * @param memberName Name of member
	 * @param filename Full path name to new chosen photo file
	 * @param galleryDir File object representing the gallery directory
	 * @throws DB461Exception
	 */
	synchronized public void setChosenPhoto(DDNSFullNameInterface memberName, String filename, File galleryDir) throws DB461Exception {
	}

	/**
	 * This method supports the manual setting of a user's generation number.  It is probably not useful
	 * in building the SNet application per se, but can be useful in debugging tools you might write.
	 * @param memberName Name of the member whose generation number you want to set
	 * @param gen The value the generation number should be set to.
	 * @return The old value of the member's generation number
	 * @throws DB461Exception  Member doesn't exist in community db, or some unanticipated exception occurred.
	 */
	synchronized public int setGenerationNumber(DDNSFullNameInterface memberName, int gen) throws DB461Exception {
		return -1;
	}

	/**
	 * Sets friend status of a member.  The member must already be in the DB.
	 * @param friend  Name of member whose friend status should be set.
	 * @param isfriend true to make a friend; false to unfriend.
	 * @throws DB461Exception The member is not in the community table in the DB, or some unanticipated exception occurs.
	 */
	synchronized public void setFriend(DDNSFullNameInterface friend, boolean isfriend) throws DB461Exception {
	}
	
	/**
	 * Registers a photo as the "my" photo for a given member.
	 * Decrements the reference count of any existing my photo for that member, and deletes the underyling file for it
	 * as appropriate.
	 * @param memberName Member name
	 * @param filename  Full path name to new my photo file
	 * @param galleryDir File object describing directory in which gallery photos live
	 * @throws DB461Exception  Can't find member in community table, or some unanticipated exception occurs.
	 */
	synchronized public void newMyPhoto(DDNSFullNameInterface memberName, String filename, File galleryDir) throws DB461Exception {
	}
	
	/**
	 * The caller side of fetchUpdates.
	 * @param friend The friend to be contacted
	 * @param galleryDir The path name to the gallery directory
	 * @throws DB461Exception Something went wrong...
	 */
	synchronized public void fetchUpdatesCaller( String friend, File galleryDir) throws DB461Exception {
	}
	
	/**
	 * The callee side of fetchUpdates - invoked via RPC.
	 * @param args JSONObject containing commmunity JSONObject and needphotos JSONArray (described in assignment)
	 * @return JSONObject containing communityupdates JSONObject and photoupdates JSONArray (described in assignment)
	 */
	synchronized public JSONObject fetchUpdatesCallee(JSONObject args) throws Exception {
		return null;
	}	
	
	/**
	 * Callee side of fetchPhoto (fetch one photo).  To fetch an image file, call this
	 * method repeatedly, starting at offset 0 and incrementing by the returned length each
	 * subsequent call.  Repeat until a length of 0 comes back.
	 * @param args {photoHash: int, maxlength: int, offset: int}
	 * @return {photoHash: int, photodata: String (base64 encoded byte[]), length: int, offset: int}.  The photodata field may
	 *     not exist if the length is 0.
	 * @throws Exception
	 */
	synchronized public JSONObject fetchPhotoCallee(JSONObject args) throws Exception {
		return null;
	}
	
}