/*-
 * ========================LICENSE_START=================================
 * O-RAN-SC
 * %%
 * Copyright (C) 2019 Nordix 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.
 * ========================LICENSE_END===================================
 */

package org.oransc.policyagent.configuration;

import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Properties;
import java.util.Set;

import javax.validation.constraints.NotNull;

import org.immutables.gson.Gson;
import org.immutables.value.Value;
import org.onap.dmaap.mr.test.clients.ProtocolTypeConstants;
import org.oransc.policyagent.exceptions.ServiceException;
import org.springframework.http.MediaType;

/**
 * Parser for the Json representing of the component configuration.
 */
public class ApplicationConfigParser {

    private static final String CONFIG = "config";
    private static final String CONTROLLER = "controller";

    @Value.Immutable
    @Gson.TypeAdapters
    public interface ConfigParserResult {
        List<RicConfig> ricConfigs();

        Properties dmaapPublisherConfig();

        Properties dmaapConsumerConfig();

        Map<String, ControllerConfig> controllerConfigs();
    }

    public ConfigParserResult parse(JsonObject root) throws ServiceException {

        Properties dmaapPublisherConfig = new Properties();
        Properties dmaapConsumerConfig = new Properties();

        JsonObject agentConfigJson = root.getAsJsonObject(CONFIG);

        if (agentConfigJson == null) {
            throw new ServiceException("Missing root configuration \"" + CONFIG + "\" in JSON: " + root);
        }

        JsonObject json = agentConfigJson.getAsJsonObject("streams_publishes");
        if (json != null) {
            dmaapPublisherConfig = parseDmaapConfig(json);
        }

        json = agentConfigJson.getAsJsonObject("streams_subscribes");
        if (json != null) {
            dmaapConsumerConfig = parseDmaapConfig(json);
        }

        List<RicConfig> ricConfigs = parseRics(agentConfigJson);
        Map<String, ControllerConfig> controllerConfigs = parseControllerConfigs(agentConfigJson);
        checkConfigurationConsistency(ricConfigs, controllerConfigs);

        return ImmutableConfigParserResult.builder() //
            .dmaapConsumerConfig(dmaapConsumerConfig) //
            .dmaapPublisherConfig(dmaapPublisherConfig) //
            .ricConfigs(ricConfigs) //
            .controllerConfigs(controllerConfigs) //
            .build();
    }

    private void checkConfigurationConsistency(List<RicConfig> ricConfigs,
        Map<String, ControllerConfig> controllerConfigs) throws ServiceException {
        Set<String> ricUrls = new HashSet<>();
        Set<String> ricNames = new HashSet<>();
        for (RicConfig ric : ricConfigs) {
            if (!ricUrls.add(ric.baseUrl())) {
                throw new ServiceException("Configuration error, more than one RIC URL: " + ric.baseUrl());
            }
            if (!ricNames.add(ric.name())) {
                throw new ServiceException("Configuration error, more than one RIC with name: " + ric.name());
            }
            if (!ric.controllerName().isEmpty() && controllerConfigs.get(ric.controllerName()) == null) {
                throw new ServiceException(
                    "Configuration error, controller configuration not found: " + ric.controllerName());
            }

        }

    }

    private List<RicConfig> parseRics(JsonObject config) throws ServiceException {
        List<RicConfig> result = new ArrayList<>();
        for (JsonElement ricElem : getAsJsonArray(config, "ric")) {
            JsonObject ricAsJson = ricElem.getAsJsonObject();
            JsonElement controllerNameElement = ricAsJson.get(CONTROLLER);
            ImmutableRicConfig ricConfig = ImmutableRicConfig.builder() //
                .name(get(ricAsJson, "name").getAsString()) //
                .baseUrl(get(ricAsJson, "baseUrl").getAsString()) //
                .managedElementIds(parseManagedElementIds(get(ricAsJson, "managedElementIds").getAsJsonArray())) //
                .controllerName(controllerNameElement != null ? controllerNameElement.getAsString() : "") //
                .build();
            result.add(ricConfig);
        }
        return result;
    }

    Map<String, ControllerConfig> parseControllerConfigs(JsonObject config) throws ServiceException {
        if (config.get(CONTROLLER) == null) {
            return new HashMap<>();
        }
        Map<String, ControllerConfig> result = new HashMap<>();
        for (JsonElement element : getAsJsonArray(config, CONTROLLER)) {
            JsonObject controllerAsJson = element.getAsJsonObject();
            ImmutableControllerConfig controllerConfig = ImmutableControllerConfig.builder() //
                .name(get(controllerAsJson, "name").getAsString()) //
                .baseUrl(get(controllerAsJson, "baseUrl").getAsString()) //
                .password(get(controllerAsJson, "password").getAsString()) //
                .userName(get(controllerAsJson, "userName").getAsString()) // )
                .build();

            if (result.put(controllerConfig.name(), controllerConfig) != null) {
                throw new ServiceException(
                    "Configuration error, more than one controller with name: " + controllerConfig.name());
            }
        }
        return result;
    }

    private List<String> parseManagedElementIds(JsonArray asJsonObject) {
        Iterator<JsonElement> iterator = asJsonObject.iterator();
        List<String> managedElementIds = new ArrayList<>();
        while (iterator.hasNext()) {
            managedElementIds.add(iterator.next().getAsString());

        }
        return managedElementIds;
    }

    private static JsonElement get(JsonObject obj, String memberName) throws ServiceException {
        JsonElement elem = obj.get(memberName);
        if (elem == null) {
            throw new ServiceException("Could not find member: '" + memberName + "' in: " + obj);
        }
        return elem;
    }

    private JsonArray getAsJsonArray(JsonObject obj, String memberName) throws ServiceException {
        return get(obj, memberName).getAsJsonArray();
    }

    private Properties parseDmaapConfig(JsonObject streamCfg) throws ServiceException {
        Set<Entry<String, JsonElement>> streamConfigEntries = streamCfg.entrySet();
        if (streamConfigEntries.size() != 1) {
            throw new ServiceException(
                "Invalid configuration. Number of streams must be one, config: " + streamConfigEntries);
        }
        JsonObject streamConfigEntry = streamConfigEntries.iterator().next().getValue().getAsJsonObject();
        JsonObject dmaapInfo = get(streamConfigEntry, "dmaap_info").getAsJsonObject();
        String topicUrl = getAsString(dmaapInfo, "topic_url");

        try {
            Properties dmaapProps = new Properties();
            URL url = new URL(topicUrl);
            String passwd = "";
            String userName = "";
            if (url.getUserInfo() != null) {
                String[] userInfo = url.getUserInfo().split(":");
                userName = userInfo[0];
                passwd = userInfo[1];
            }
            String urlPath = url.getPath();
            DmaapUrlPath path = parseDmaapUrlPath(urlPath);

            dmaapProps.put("ServiceName", url.getHost() + ":" + url.getPort() + "/events");
            dmaapProps.put("topic", path.dmaapTopicName);
            dmaapProps.put("host", url.getHost() + ":" + url.getPort());
            dmaapProps.put("contenttype", MediaType.APPLICATION_JSON.toString());
            dmaapProps.put("userName", userName);
            dmaapProps.put("password", passwd);
            dmaapProps.put("group", path.consumerGroup);
            dmaapProps.put("id", path.consumerId);
            dmaapProps.put("TransportType", ProtocolTypeConstants.HTTPNOAUTH.toString());
            dmaapProps.put("timeout", "15000");
            dmaapProps.put("limit", "100");
            dmaapProps.put("maxBatchSize", "10");
            dmaapProps.put("maxAgeMs", "10000");
            dmaapProps.put("compress", true);
            dmaapProps.put("MessageSentThreadOccurance", "2");
            return dmaapProps;
        } catch (MalformedURLException e) {
            throw new ServiceException("Could not parse the URL", e);
        }
    }

    private static @NotNull String getAsString(JsonObject obj, String memberName) throws ServiceException {
        return get(obj, memberName).getAsString();
    }

    private class DmaapUrlPath {
        final String dmaapTopicName;
        final String consumerGroup;
        final String consumerId;

        DmaapUrlPath(String dmaapTopicName, String consumerGroup, String consumerId) {
            this.dmaapTopicName = dmaapTopicName;
            this.consumerGroup = consumerGroup;
            this.consumerId = consumerId;
        }
    }

    private DmaapUrlPath parseDmaapUrlPath(String urlPath) throws ServiceException {
        String[] tokens = urlPath.split("/"); // /events/A1-P/users/sdnc1
        if (!(tokens.length == 3 ^ tokens.length == 5)) {
            throw new ServiceException("The path has incorrect syntax: " + urlPath);
        }

        final String dmaapTopicName = tokens[2]; // /events/A1-P
        String consumerGroup = ""; // users
        String consumerId = ""; // sdnc1
        if (tokens.length == 5) {
            consumerGroup = tokens[3];
            consumerId = tokens[4];
        }
        return new DmaapUrlPath(dmaapTopicName, consumerGroup, consumerId);
    }
}