/*
 * Copyright 2021-present Open Networking Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.onosproject.kubevirtnetworking.util;

import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.net.util.SubnetUtils;
import org.onlab.packet.IpAddress;
import org.onosproject.cfg.ConfigProperty;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * An utility that used in KubeVirt networking app.
 */
public final class KubevirtNetworkingUtil {

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

    private static final int PORT_NAME_MAX_LENGTH = 15;

    /**
     * Prevents object installation from external.
     */
    private KubevirtNetworkingUtil() {
    }

    /**
     * Obtains the boolean property value with specified property key name.
     *
     * @param properties    a collection of properties
     * @param name          key name
     * @return mapping value
     */
    public static boolean getPropertyValueAsBoolean(Set<ConfigProperty> properties,
                                                    String name) {
        Optional<ConfigProperty> property =
                properties.stream().filter(p -> p.name().equals(name)).findFirst();

        return property.map(ConfigProperty::asBoolean).orElse(false);
    }

    /**
     * Re-structures the OVS port name.
     * The length of OVS port name should be not large than 15.
     *
     * @param portName  original port name
     * @return re-structured OVS port name
     */
    public static String structurePortName(String portName) {

        // The size of OVS port name should not be larger than 15
        if (portName.length() > PORT_NAME_MAX_LENGTH) {
            return StringUtils.substring(portName, 0, PORT_NAME_MAX_LENGTH);
        }

        return portName;
    }

    /**
     * Generates string format based on the given string length list.
     *
     * @param stringLengths a list of string lengths
     * @return string format (e.g., %-28s%-15s%-24s%-20s%-15s)
     */
    public static String genFormatString(List<Integer> stringLengths) {
        StringBuilder fsb = new StringBuilder();
        stringLengths.forEach(length -> {
            fsb.append("%-");
            fsb.append(length);
            fsb.append("s");
        });
        return fsb.toString();
    }

    /**
     * Prints out the JSON string in pretty format.
     *
     * @param mapper        Object mapper
     * @param jsonString    JSON string
     * @return pretty formatted JSON string
     */
    public static String prettyJson(ObjectMapper mapper, String jsonString) {
        try {
            Object jsonObject = mapper.readValue(jsonString, Object.class);
            return mapper.writerWithDefaultPrettyPrinter().writeValueAsString(jsonObject);
        } catch (IOException e) {
            log.debug("Json string parsing exception caused by {}", e);
        }
        return null;
    }

    /**
     * Obtains valid IP addresses of the given subnet.
     *
     * @param cidr CIDR
     * @return set of IP addresses
     */
    public static Set<IpAddress> getSubnetIps(String cidr) {
        SubnetUtils utils = new SubnetUtils(cidr);
        utils.setInclusiveHostCount(false);
        SubnetUtils.SubnetInfo info = utils.getInfo();
        Set<String> allAddresses =
                new HashSet<>(Arrays.asList(info.getAllAddresses()));

        if (allAddresses.size() > 2) {
            allAddresses.remove(info.getLowAddress());
            allAddresses.remove(info.getHighAddress());
        }

        return allAddresses.stream()
                .map(IpAddress::valueOf).collect(Collectors.toSet());
    }

    /**
     * Calculate the broadcast address from given IP address and subnet prefix length.
     *
     * @param ipAddr        IP address
     * @param prefixLength  subnet prefix length
     * @return broadcast address
     */
    public static String getBroadcastAddr(String ipAddr, int prefixLength) {
        String subnet = ipAddr + "/" + prefixLength;
        SubnetUtils utils = new SubnetUtils(subnet);
        return utils.getInfo().getBroadcastAddress();
    }
}