package org.gcube.data.access.storagehub.services;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import javax.inject.Inject;
import javax.servlet.ServletContext;
import javax.ws.rs.DELETE;
import javax.ws.rs.FormParam;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;

import org.apache.jackrabbit.api.JackrabbitSession;
import org.apache.jackrabbit.api.security.user.Authorizable;
import org.apache.jackrabbit.api.security.user.Group;
import org.apache.jackrabbit.api.security.user.Query;
import org.apache.jackrabbit.api.security.user.QueryBuilder;
import org.apache.jackrabbit.api.security.user.User;
import org.gcube.common.authorization.control.annotations.AuthorizationControl;
import org.gcube.common.gxrest.response.outbound.GXOutboundErrorResponse;
import org.gcube.common.storagehub.model.exceptions.BackendGenericError;
import org.gcube.data.access.storagehub.exception.MyAuthException;
import org.gcube.data.access.storagehub.handlers.CredentialHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Path("groups")
public class GroupManager {

	@Context ServletContext context;

	private static final Logger log = LoggerFactory.getLogger(GroupManager.class);
	
	@Inject 
	RepositoryInitializer repository;
	
	@GET
	@Path("")
	@Produces(MediaType.APPLICATION_JSON)
	@AuthorizationControl(allowed={"lucio.lelii"}, exception=MyAuthException.class)
	public List<String> getGroups(){

		JackrabbitSession session = null;
		List<String> groups= new ArrayList<>();
		try {
			session = (JackrabbitSession) repository.getRepository().login(CredentialHandler.getAdminCredentials(context));

			Iterator<Authorizable> result = session.getUserManager().findAuthorizables(new Query() {

				@Override
				public <T> void build(QueryBuilder<T> builder) {
					builder.setSelector(Group.class);
				}
			});

			while (result.hasNext()) {
				Authorizable group = result.next();
				log.info("group {} found",group.getPrincipal().getName());
				groups.add(group.getPrincipal().getName());
			}
		}catch(Exception e) {
			log.error("jcr error getting users", e);
			GXOutboundErrorResponse.throwException(new BackendGenericError(e));
		} finally {
			if (session!=null)
				session.logout();
		}
		return groups;
	}

	@POST
	@Path("")
	@AuthorizationControl(allowed={"lucio.lelii"}, exception=MyAuthException.class)
	public String createGroup(@FormParam("group") String group){

		JackrabbitSession session = null;
		String groupId = null;
		try {
			session = (JackrabbitSession) repository.getRepository().login(CredentialHandler.getAdminCredentials(context));

			org.apache.jackrabbit.api.security.user.UserManager usrManager = session.getUserManager();

			Group createdGroup = usrManager.createGroup(group);
			groupId = createdGroup.getID();
			session.save();
		}catch(Exception e) {
			log.error("jcr error creating group {}", group, e);
			GXOutboundErrorResponse.throwException(new BackendGenericError(e));
		} finally {
			if (session!=null)
				session.logout();
		}
		
		return groupId;
	}
	
	@DELETE
	@Path("{id}")
	@AuthorizationControl(allowed={"lucio.lelii"}, exception=MyAuthException.class)
	public String deleteGroup(@PathParam("id") String id){

		JackrabbitSession session = null;
		String userId = null;
		try {
			session = (JackrabbitSession) repository.getRepository().login(CredentialHandler.getAdminCredentials(context));

			org.apache.jackrabbit.api.security.user.UserManager usrManager = session.getUserManager();

			Authorizable authorizable = usrManager.getAuthorizable(id);
			if (authorizable.isGroup())
				authorizable.remove();
			session.save();
		}catch(Exception e) {
			log.error("jcr error getting users", e);
			GXOutboundErrorResponse.throwException(new BackendGenericError(e));
		} finally {
			if (session!=null)
				session.logout();
		}
		
		return userId;
	}
	
	@PUT
	@Path("{id}")
	@AuthorizationControl(allowed={"lucio.lelii"}, exception=MyAuthException.class)
	public boolean addUserToGroup(@PathParam("id") String groupId, @FormParam("userId") String userId){

		JackrabbitSession session = null;
		boolean success = false;
		try {
			session = (JackrabbitSession) repository.getRepository().login(CredentialHandler.getAdminCredentials(context));

			org.apache.jackrabbit.api.security.user.UserManager usrManager = session.getUserManager();

			Group group = (Group)usrManager.getAuthorizable(groupId);
			User user = (User)usrManager.getAuthorizable(userId);
			
			success = group.addMember(user);
			
			session.save();
		}catch(Exception e) {
			log.error("jcr error adding user {} to group {}", userId, groupId, e);
			GXOutboundErrorResponse.throwException(new BackendGenericError(e));
		} finally {
			if (session!=null)
				session.logout();
		}
		
		return success;
	}
	
	@DELETE
	@Path("{groupId}/users/{userId}")
	@AuthorizationControl(allowed={"lucio.lelii"}, exception=MyAuthException.class)
	public boolean removeUserFromGroup(@PathParam("groupId") String groupId, @PathParam("userId") String userId){

		JackrabbitSession session = null;
		boolean success = false;
		try {
			session = (JackrabbitSession) repository.getRepository().login(CredentialHandler.getAdminCredentials(context));

			org.apache.jackrabbit.api.security.user.UserManager usrManager = session.getUserManager();

			Group group = (Group)usrManager.getAuthorizable(groupId);
			User user = (User)usrManager.getAuthorizable(userId);
			
			success = group.removeMember(user);
			
			session.save();
		}catch(Exception e) {
			log.error("jcr error adding user {} to group {}", userId, groupId, e);
			GXOutboundErrorResponse.throwException(new BackendGenericError(e));
		} finally {
			if (session!=null)
				session.logout();
		}
		
		return success;
	}
	
	@GET
	@Path("{groupId}/users")
	@AuthorizationControl(allowed={"lucio.lelii"}, exception=MyAuthException.class)
	public List<String> getUsersOfGroup(@PathParam("groupId") String groupId){

		JackrabbitSession session = null;
		List<String> users = new ArrayList<>();
		try {
			session = (JackrabbitSession) repository.getRepository().login(CredentialHandler.getAdminCredentials(context));

			org.apache.jackrabbit.api.security.user.UserManager usrManager = session.getUserManager();

			Group group = (Group)usrManager.getAuthorizable(groupId);
			
			Iterator<Authorizable> it = group.getMembers();
			
			while (it.hasNext()) {
				Authorizable user = it.next();
				users.add(user.getPrincipal().getName());
			}
			
			
		}catch(Exception e) {
			log.error("jcr error getting users of group {}", groupId, e);
			GXOutboundErrorResponse.throwException(new BackendGenericError(e));
		} finally {
			if (session!=null)
				session.logout();
		}
		
		return users;
	}
	
}