/**
 * Copyright (C) 2010-2017 Structr GmbH
 *
 * This file is part of Structr <http://structr.org>.
 *
 * Structr is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * Structr is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Structr.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.structr.core.function;

import java.util.Map;
import org.structr.common.SecurityContext;
import org.structr.common.error.FrameworkException;
import org.structr.core.GraphObject;
import org.structr.core.app.Query;
import org.structr.core.app.StructrApp;
import org.structr.core.converter.PropertyConverter;
import org.structr.core.property.PropertyKey;
import org.structr.core.property.PropertyMap;
import org.structr.schema.ConfigurationProvider;
import org.structr.schema.action.ActionContext;
import org.structr.schema.action.Function;

public class PrivilegedFindFunction extends Function<Object, Object> {

    public static final String ERROR_MESSAGE_PRIVILEGEDFIND = "Usage: ${find_privileged(type, key, value)}. Example: ${find_privileged(\"User\", \"email\", \"tester@test.com\"}";

    @Override
    public Object apply(final ActionContext ctx, final Object caller, Object[] sources) throws FrameworkException {

		if (sources != null) {

			final SecurityContext securityContext = SecurityContext.getSuperUserInstance();
			final ConfigurationProvider config = StructrApp.getConfiguration();
			final Query query = StructrApp.getInstance(securityContext).nodeQuery().sort(GraphObject.createdDate).order(false);

			// the type to query for
			Class type = null;

			if (sources.length >= 1 && sources[0] != null) {

				final String typeString = sources[0].toString();
				type = config.getNodeEntityClass(typeString);

				if (type != null) {

					query.andTypes(type);

				} else {

					logger.warn("Error in find_privileged(): type \"{}\" not found.", typeString);
					return "Error in find_privileged(): type " + typeString + " not found.";

				}
			}

			// exit gracefully instead of crashing..
			if (type == null) {
				logger.warn("Error in find_privileged(): no type specified. Parameters: {}", getParametersAsString(sources));
				return "Error in find_privileged(): no type specified.";
			}

			// experimental: disable result count, prevents instantiation
			// of large collections just for counting all the objects..
			securityContext.ignoreResultCount(true);

			// extension for native javascript objects
			if (sources.length == 2 && sources[1] instanceof Map) {

				query.and(PropertyMap.inputTypeToJavaType(securityContext, type, (Map)sources[1]));

			} else if (sources.length == 2) {

				if (sources[1] == null) {

					throw new IllegalArgumentException();
				}

				// special case: second parameter is a UUID
				final PropertyKey key = config.getPropertyKeyForJSONName(type, "id");

				query.and(key, sources[1].toString());

				final int resultCount = query.getResult().size();

				switch (resultCount) {
					case 1:
						return query.getFirst();
					case 0:
						return null;
					default:
						throw new FrameworkException(400, "Multiple Objects found for id! [" + sources[1].toString() + "]");
				}

			} else {

				final Integer parameter_count = sources.length;

				if (parameter_count % 2 == 0) {

					throw new FrameworkException(400, "Invalid number of parameters: " + parameter_count + ". Should be uneven: " + ERROR_MESSAGE_PRIVILEGEDFIND);
				}

				for (Integer c = 1; c < parameter_count; c += 2) {

					final PropertyKey key = config.getPropertyKeyForJSONName(type, sources[c].toString());

					if (key != null) {

						final PropertyConverter inputConverter = key.inputConverter(securityContext);
						Object value = sources[c + 1];

						if (inputConverter != null) {

							value = inputConverter.convert(value);
						}

						query.and(key, value);
					}
				}
			}

			return query.getAsList();
		}

		return "";
    }

    @Override
    public String usage(boolean inJavaScriptContext) {
        return ERROR_MESSAGE_PRIVILEGEDFIND;
    }

    @Override
    public String shortDescription() {
        return "Returns a collection of entities of the given type from the database, takes optional key/value pairs. Executed in a super user context.";
    }

    @Override
    public String getName() {
        return("find_privileged()");
    }

}