package de.fhdw.wtf.context.core;
   
   import java.math.BigInteger;
   import java.util.Collection;
   import java.util.HashMap;
   import java.util.Iterator;
   import java.util.Map;
   import java.util.Vector;
   
  import de.fhdw.wtf.context.exception.FrameworkException;
  import de.fhdw.wtf.persistence.facade.IDManager;
  import de.fhdw.wtf.persistence.facade.TypeManager;
  import de.fhdw.wtf.persistence.facade.TypeManagerImplementation;
  import de.fhdw.wtf.persistence.meta.IntegerValue;
  import de.fhdw.wtf.persistence.meta.Link;
  import de.fhdw.wtf.persistence.meta.MapLink;
  import de.fhdw.wtf.persistence.meta.Object;
  import de.fhdw.wtf.persistence.meta.StringValue;
  import de.fhdw.wtf.persistence.meta.UnidirectionalLink;
  import de.fhdw.wtf.persistence.meta.UserObject;
  import de.fhdw.wtf.persistence.meta.UserType;
  import de.fhdw.wtf.persistence.utils.Tuple;
  
  /**
   * An implementation of a Context, which can be used in Test cases. It partly simulates the behavior of the persistence
   * layer, so model classes can be tested without needing the database.
   * 
   */
  public class TestCaseContext extends Context {
  	
  	/**
  	 * The IDManager which is used to collect Type information. It has to be filled before either from the database or
  	 * from a file.
  	 */
  	private final IDManager manager = IDManager.instance();
  	
  	/**
  	 * The instance Item id will be synthetically created.
  	 */
  	private static long instanceItemId = 0;
  	
  	/**
  	 * This cache is used to store objects stored via {@link #set} operations.
  	 */
  	private final Map<UserObject, Map<String, Collection<Tuple<UnidirectionalLink, Object>>>> cache;
  	
  	/**
  	 * The model prefix of the types.
  	 */
  	private final String modelPrefix;
  	
  	/**
  	 * Creates a TestCaseContext.
  	 * 
  	 * @param modelPrefix
  	 *            The model prefix of the types.
  	 */
  	public TestCaseContext(final String modelPrefix) {
  		this.cache = new HashMap<>();
  		this.modelPrefix = modelPrefix;
  	}
  	
  	/**
  	 * Returns the next available unique identifier.
  	 * 
  	 * @return The next available unique identifier.
  	 */
  	protected static long getInstanceItemId() {
  		final long result = instanceItemId;
  		instanceItemId++;
  		return result;
  	}
  	
  	@Override
  	public Collection<UserObject> find(final String associationName, final String value) {
  		throw new FrameworkException("A find method for String objects is not yet implemented");
  	}
  	
  	@Override
  	public Collection<UserObject> find(final String associationName, final BigInteger value) {
  		throw new FrameworkException("A find method for Integer objects is not yet implemented");
  	}
  	
  	@Override
  	public Collection<Tuple<UnidirectionalLink, UserObject>> inverseGet(final String associationName,
  			final UserObject object) {
  		throw new FrameworkException("An inverse get method is not yet implemented");
  	}
  	
  	@Override
  	public Collection<Tuple<UnidirectionalLink, Object>> get(final UserObject object, final String associationName) {
  		return this.cache.get(object).get(associationName);
  	}
  	
  	@Override
  	public Collection<Tuple<MapLink, Object>> get(final UserObject object,
  			final String associationName,
  			final String key) {
  		// TODO Auto-generated method stub
 		return null;
 	}
 	
 	@Override
 	public Collection<Tuple<MapLink, Object>> get(final UserObject object,
 			final String associationName,
 			final BigInteger key) {
 		// TODO Auto-generated method stub
 		return null;
 	}
 	
 	@Override
 	public Collection<Tuple<MapLink, Object>> get(final UserObject object,
 			final String associationName,
 			final UserObject key) {
 		// TODO Auto-generated method stub
 		return null;
 	}
 	
 	@Override
 	public UserObject create(final String typeName) {
 		return UserObject.init(
 				getInstanceItemId(),
 				new UserType(this.manager.findIdForType(typeName.substring(this.modelPrefix.length() + 1)), null,
 						false, false));
 	}
 	
 	@Override
 	public UnidirectionalLink set(final UserObject object, final String associationName, final String val) {
 		final UnidirectionalLink result =
 				new UnidirectionalLink(getInstanceItemId(), object, new StringValue(val), null);
 		this.put(object, associationName, result);
 		return result;
 	}
 	
 	/**
 	 * Stores an object/association/link relation in the cache.
 	 * 
 	 * @param object
 	 *            The owner.
 	 * @param associationName
 	 *            The name of the association.
 	 * @param result
 	 *            The link.
 	 */
 	private void put(final UserObject object, final String associationName, final UnidirectionalLink result) {
 		if (!this.cache.containsKey(object)) {
 			this.cache.put(object, new HashMap<String, Collection<Tuple<UnidirectionalLink, Object>>>());
 		}
 		this.putInner(this.cache.get(object), associationName, result);
 	}
 	
 	/**
 	 * Stores an object/association/link relation in a map that is part of the cache.
 	 * 
 	 * @param map
 	 *            The map for some owner object.
 	 * @param associationName
 	 *            The name of the association.
 	 * @param result
 	 *            The link.
 	 */
 	private void putInner(final Map<String, Collection<Tuple<UnidirectionalLink, Object>>> map,
 			final String associationName,
 			final UnidirectionalLink result) {
 		if (!map.containsKey(associationName)) {
 			map.put(associationName, new Vector<Tuple<UnidirectionalLink, Object>>());
 		}
 		map.get(associationName).add(new Tuple<>(result, result.getTarget()));
 	}
 	
 	@Override
 	public UnidirectionalLink set(final UserObject object, final String associationName, final BigInteger val) {
 		final UnidirectionalLink result =
 				new UnidirectionalLink(getInstanceItemId(), object, new IntegerValue(val), null);
 		this.put(object, associationName, result);
 		return result;
 	}
 	
 	@Override
 	public UnidirectionalLink set(final UserObject object, final String associationName, final UserObject target) {
 		final UnidirectionalLink result = new UnidirectionalLink(getInstanceItemId(), object, target, null);
 		this.put(object, associationName, result);
 		return result;
 	}
 	
 	@Override
 	public MapLink put(final UserObject owner, final String associationName, final UserObject target, final String key) {
 		// TODO Auto-generated method stub
 		return null;
 	}
 	
 	@Override
 	public MapLink put(final UserObject owner, final String associationName, final BigInteger target, final String key) {
 		// TODO Auto-generated method stub
 		return null;
 	}
 	
 	@Override
 	public MapLink put(final UserObject owner, final String associationName, final String target, final String key) {
 		// TODO Auto-generated method stub
 		return null;
 	}
 	
 	@Override
 	public MapLink put(final UserObject owner,
 			final String associationName,
 			final UserObject target,
 			final BigInteger key) {
 		// TODO Auto-generated method stub
 		return null;
 	}
 	
 	@Override
 	public MapLink put(final UserObject owner,
 			final String associationName,
 			final BigInteger target,
 			final BigInteger key) {
 		// TODO Auto-generated method stub
 		return null;
 	}
 	
 	@Override
 	public MapLink put(final UserObject owner, final String associationName, final String target, final BigInteger key) {
 		// TODO Auto-generated method stub
 		return null;
 	}
 	
 	@Override
 	public MapLink put(final UserObject owner,
 			final String associationName,
 			final UserObject target,
 			final UserObject key) {
 		// TODO Auto-generated method stub
 		return null;
 	}
 	
 	@Override
 	public MapLink put(final UserObject owner,
 			final String associationName,
 			final BigInteger target,
 			final UserObject key) {
 		// TODO Auto-generated method stub
 		return null;
 	}
 	
 	@Override
 	public MapLink put(final UserObject owner, final String associationName, final String target, final UserObject key) {
 		// TODO Auto-generated method stub
 		return null;
 	}
 	
 	@Override
 	public void commit() {
 		// nothing to do
 	}
 	
 	@Override
 	public void rollback() {
 		// nothing to do
 	}
 	
 	@Override
 	public void savePoint() {
 		// nothing to do
 	}
 	
 	@Override
 	public void rollbackToSavePoint() {
 		// nothing to do
 	}
 	
 	@Override
 	public void unset(final Link toUnset) {
 		final Iterator<Collection<Tuple<UnidirectionalLink, Object>>> iterator =
 				this.cache.get(toUnset.getOwner()).values().iterator();
 		while (iterator.hasNext()) {
 			final Collection<Tuple<UnidirectionalLink, Object>> current = iterator.next();
 			final Iterator<Tuple<UnidirectionalLink, Object>> innerIterator = current.iterator();
 			while (innerIterator.hasNext()) {
 				final Tuple<UnidirectionalLink, Object> innerCurrent = innerIterator.next();
 				if (innerCurrent.getFirst().equals(toUnset)) {
 					innerIterator.remove();
 				}
 			}
 		}
 	}
 	
 	@Override
 	public TypeManager getTypeManager() {
 		return TypeManagerImplementation.getInstance();
 	}
 	
 	@Override
 	public Collection<UserObject> getObjectsByType(final String typeName) {
 		// TODO Auto-generated method stub
 		return null;
 	}
 	
 	@Override
 	public UserObject checkout(final long object) {
 		// TODO Auto-generated method stub
 		return null;
 	}
 	
 }