package org.gcube.data.access.storagehub;

import javax.inject.Inject;
import javax.jcr.Node;
import javax.jcr.RepositoryException;
import javax.jcr.Session;
import javax.jcr.security.AccessControlEntry;
import javax.jcr.security.Privilege;

import org.apache.jackrabbit.api.JackrabbitSession;
import org.apache.jackrabbit.api.security.JackrabbitAccessControlList;
import org.apache.jackrabbit.api.security.user.Authorizable;
import org.apache.jackrabbit.api.security.user.Group;
import org.apache.jackrabbit.commons.jackrabbit.authorization.AccessControlUtils;
import org.gcube.common.authorization.library.provider.AuthorizationProvider;
import org.gcube.common.authorization.library.provider.ClientInfo;
import org.gcube.common.storagehub.model.Excludes;
import org.gcube.common.storagehub.model.acls.AccessType;
import org.gcube.common.storagehub.model.exceptions.BackendGenericError;
import org.gcube.common.storagehub.model.exceptions.InvalidCallParameters;
import org.gcube.common.storagehub.model.exceptions.UserNotAuthorizedException;
import org.gcube.common.storagehub.model.items.FolderItem;
import org.gcube.common.storagehub.model.items.Item;
import org.gcube.common.storagehub.model.items.SharedFolder;
import org.gcube.common.storagehub.model.items.TrashItem;
import org.gcube.data.access.storagehub.handlers.items.Node2ItemConverter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 
 * 
 * the caller must be authorized, so i'm not passing the login also if it works on behalf of an user
 * 
 *
 */
public class AuthorizationChecker {

	private static Logger log = LoggerFactory.getLogger(AuthorizationChecker.class);

	@Inject
	Node2ItemConverter node2Item;
	
	@Inject
	PathUtil pathUtil;
	
	String userToCheck;
	
	public AuthorizationChecker(){
		ClientInfo client = AuthorizationProvider.instance.get().getClient();
		this.userToCheck = client.getId();
	}
	
	public AuthorizationChecker(String userToCheck){
		this.userToCheck = userToCheck;
	}

	public String getUserToCheck() {
		return userToCheck;
	}
	
	public void setUserToCheck(String user) {
		this.userToCheck = user;
	}

	public void checkReadAuthorizationControl(Session session,  String id) throws UserNotAuthorizedException , BackendGenericError, RepositoryException{
		
		Node node = session.getNodeByIdentifier(id);

		Item item  = node2Item.getItem(node, Excludes.ALL);

		if (item==null) throw new UserNotAuthorizedException("Insufficent Privileges for user "+userToCheck+" to read node with id "+id+": it's  not a valid StorageHub node");

		//checking if the item is in the owner trash folder 
		if(item instanceof TrashItem && item.getParentPath().equals(pathUtil.getOldTrashPath(userToCheck).toPath())) 
			return;
		
		
		if (!item.isShared() && item.getOwner()!=null && item.getOwner().equals(userToCheck)) return;

		if (hasParentPublicFolder(session, item)) return;
							
		
		if (item.isShared()) {
			SharedFolder parentShared = node2Item.getItem(retrieveSharedFolderParent(node, session), Excludes.EXCLUDE_ACCOUNTING);

			if (parentShared.getUsers().getMap().keySet().contains(userToCheck)) return;

			//CHECKING ACL FOR VREFOLDER AND SHARED FOLDER
			JackrabbitAccessControlList accessControlList = AccessControlUtils.getAccessControlList(session, parentShared.getPath());
			AccessControlEntry[] entries = accessControlList.getAccessControlEntries();
			Authorizable userAuthorizable = ((JackrabbitSession) session).getUserManager().getAuthorizable(userToCheck);
			for (AccessControlEntry entry: entries) {
				log.debug("checking access right for {} with compared with {}",userToCheck, entry.getPrincipal());
				Authorizable authorizable = ((JackrabbitSession) session).getUserManager().getAuthorizable(entry.getPrincipal());

				if (authorizable==null) {
					log.warn("{} doesn't have a correspondant auhtorizable object, check it ", entry.getPrincipal());
					continue;
				}

				try {
					if (!authorizable.isGroup() && entry.getPrincipal().getName().equals(userToCheck)) return;
					if (authorizable.isGroup() && ((Group) authorizable).isMember(userAuthorizable)) return;
				}catch (Throwable e) {
					log.warn("someting went wrong checking authorizations",e);
				}
			}
			throw new UserNotAuthorizedException("Insufficent Privileges for user "+userToCheck+" to read node with id "+id);

		} 

		throw new UserNotAuthorizedException("Insufficent Privileges for user "+userToCheck+" to read node with id "+id);

	}

	
	private boolean hasParentPublicFolder(Session session, Item item) {
		if (item.getParentPath().replaceAll("/Home/[^/]*/"+Constants.WORKSPACE_ROOT_FOLDER_NAME,"").isEmpty() || item.getParentPath().replaceAll(Constants.SHARED_FOLDER_PATH, "").isEmpty()) {
			if (item instanceof FolderItem)
				return ((FolderItem) item).isPublicItem();
			else return false;
		} else { 
			if (item instanceof FolderItem)
				try {
					return ((FolderItem) item).isPublicItem() || hasParentPublicFolder(session, node2Item.getItem(item.getParentId(), session, Excludes.ALL));
				}catch (Throwable e) {
					log.warn("error checking public parents",e);
					return false;
				}
			else 
				try {
					return hasParentPublicFolder(session, node2Item.getItem(item.getParentId(), session, Excludes.ALL));
				}catch (Throwable e) {
					log.warn("error checking public parents",e);
					return false;
				}
		}
	}

	private Node retrieveSharedFolderParent(Node node, Session session) throws BackendGenericError, RepositoryException{
		if (node2Item.checkNodeType(node, SharedFolder.class)) return node;
		else 
			return retrieveSharedFolderParent(node.getParent(), session);

	}

	//newItem means that a new item will be created and id is the destination directory
	public void checkWriteAuthorizationControl(Session session, Item item, Node node,  boolean isNewItem) throws UserNotAuthorizedException, BackendGenericError, RepositoryException {
		if (item==null) throw new UserNotAuthorizedException("Not valid StorageHub node");
		
		if (Constants.WRITE_PROTECTED_FOLDER.contains(item.getName()) || Constants.WRITE_PROTECTED_FOLDER.contains(item.getTitle()))
			throw new UserNotAuthorizedException("Insufficent Privileges for user "+userToCheck+" to write into node with id "+item.getId()+": it's  a protected folder");
		
		/*
		if (item.isTrashed())
			throw new UserNotAuthorizedException("Trashed item cannot be written");*/
		
		if (item.isShared()) {
			Node parentSharedNode = retrieveSharedFolderParent(node, session);
			JackrabbitAccessControlList accessControlList = AccessControlUtils.getAccessControlList(session, parentSharedNode.getPath());
			AccessControlEntry[] entries = accessControlList.getAccessControlEntries();
			Authorizable UserAuthorizable = ((JackrabbitSession) session).getUserManager().getAuthorizable(userToCheck);
			//put it in a different method
			for (AccessControlEntry entry: entries) {
				Authorizable authorizable = ((JackrabbitSession) session).getUserManager().getAuthorizable(entry.getPrincipal());
				if ((!authorizable.isGroup() && entry.getPrincipal().getName().equals(userToCheck)) || (authorizable.isGroup() && ((Group) authorizable).isMember(UserAuthorizable))){
					for (Privilege privilege : entry.getPrivileges()){
						AccessType access = AccessType.fromValue(privilege.getName());
						if (isNewItem && access!=AccessType.READ_ONLY)
							return;
						else 
							if (!isNewItem && 
									(access==AccessType.ADMINISTRATOR || access==AccessType.WRITE_ALL || (access==AccessType.WRITE_OWNER && item.getOwner().equals(userToCheck)))) 
								return;

					}

				}
			}
		} else 
			if(item.getOwner().equals(userToCheck))
				return;
		throw new UserNotAuthorizedException("Insufficent Privileges for user "+userToCheck+" to write into node with id "+item.getId());
	}

	//newItem means that a new item will be created and id is the destination directory
	public void checkWriteAuthorizationControl(Session session, String id, boolean isNewItem) throws UserNotAuthorizedException, BackendGenericError, RepositoryException {
		//in case of newItem the id is the parent otherwise the old node to replace
		Node node = session.getNodeByIdentifier(id);
		Item item  = node2Item.getItem(node, Excludes.ALL);
		checkWriteAuthorizationControl(session, item, node, isNewItem);
	}


	public void checkMoveOpsForProtectedFolders(Session session, String id) throws InvalidCallParameters, BackendGenericError, RepositoryException {
		Node node = session.getNodeByIdentifier(id);
		Item item  = node2Item.getItem(node, Excludes.ALL);
		
		if (Constants.PROTECTED_FOLDER.contains(item.getName()) || Constants.PROTECTED_FOLDER.contains(item.getTitle()))
			throw new InvalidCallParameters("protected folder cannot be moved or deleted");
	}


	public void checkAdministratorControl(Session session, SharedFolder item) throws UserNotAuthorizedException, BackendGenericError, RepositoryException {
		
		if (item==null) throw new UserNotAuthorizedException("Insufficent Privileges for user "+userToCheck+": it's  not a valid StorageHub node");

		Node node = session.getNodeByIdentifier(item.getId());

		if (item.isShared()) {
			Node parentSharedNode = retrieveSharedFolderParent(node, session);
			JackrabbitAccessControlList accessControlList = AccessControlUtils.getAccessControlList(session, parentSharedNode.getPath());
			AccessControlEntry[] entries = accessControlList.getAccessControlEntries();
			//put it in a different method

			SharedFolder parentShared = node2Item.getItem(parentSharedNode, Excludes.EXCLUDE_ACCOUNTING);					
			for (AccessControlEntry entry: entries) {
				if (entry.getPrincipal().getName().equals(userToCheck) || (parentShared.isVreFolder() && entry.getPrincipal().getName().equals(parentShared.getTitle()))) {
					for (Privilege privilege : entry.getPrivileges()){
						AccessType access = AccessType.fromValue(privilege.getName());
						if (access==AccessType.ADMINISTRATOR) 
							return;

					}
					//throw new UserNotAuthorizedException("The user "+login+" is not an administrator of node with id "+item.getId());
				}
			}

		}  //else should never happen

		throw new UserNotAuthorizedException("The user "+userToCheck+" is not an administrator of node with id "+item.getId());

	}


	/*
	private String retrieveOwner(Node node) {
		Node nodeOwner;
		//get Owner
		try{
			return node.getProperty(NodeProperty.PORTAL_LOGIN.toString()).getString();
		}catch (Exception e) {
			try {
				nodeOwner = node.getNode(NodeProperty.OWNER.toString());
				return nodeOwner.getProperty(NodeProperty.PORTAL_LOGIN.toString()).getString();
				//				this.userId = nodeOwner.getProperty(USER_ID).getString();
				//				this.portalLogin = nodeOwner.getProperty(PORTAL_LOGIN).getString();
				//				node.getSession().save();
			} catch (Exception e1) {
				throw new RuntimeException(e1);
			}

		}	
	}
	 */
}