/*
 * Copyright 2019 WeBank
 *
 * 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 com.webank.wedatasphere.linkis.cs.client.service;

import com.google.gson.Gson;
import com.webank.wedatasphere.linkis.common.exception.ErrorException;
import com.webank.wedatasphere.linkis.cs.client.ContextClient;
import com.webank.wedatasphere.linkis.cs.client.builder.ContextClientFactory;
import com.webank.wedatasphere.linkis.cs.common.entity.enumeration.ContextType;
import com.webank.wedatasphere.linkis.cs.common.entity.source.ContextID;
import com.webank.wedatasphere.linkis.cs.common.entity.source.ContextKey;
import com.webank.wedatasphere.linkis.cs.common.entity.source.ContextKeyValue;
import com.webank.wedatasphere.linkis.cs.common.entity.source.ContextValue;
import com.webank.wedatasphere.linkis.cs.common.exception.CSErrorException;
import com.webank.wedatasphere.linkis.cs.common.exception.ErrorCode;
import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @Author alexyang
 * @Date 2020/3/6
 */
public class DefaultSearchService implements SearchService {
    private static final Logger logger = LoggerFactory.getLogger(DefaultSearchService.class);
    private static final Gson gson = new Gson();
    private static SearchService searchService = null;

    private DefaultSearchService() {
    }

    @Override
    public <T> T getContextValue(ContextID contextID, ContextKey contextKey, Class<T> contextValueType) throws CSErrorException {
        ContextClient contextClient = ContextClientFactory.getOrCreateContextClient();
        ContextValue contextValue = null;
        ContextType contextType = contextKey.getContextType();
        try {
            contextValue = contextClient.getContextValue(contextID, contextKey);
        } catch (Exception e) {
            logger.error("Failed to get ContextValue: " + e.getMessage());
            throw new CSErrorException(ErrorCode.GET_CONTEXT_VALUE_ERROR, "Failed to get ContextValue: ", e);
        }

        if (null == contextValue || null == contextValue.getValue()) {
            return null;
        } else if (contextValueType.isInstance(contextValue.getValue())) {
            return (T) contextValue.getValue();
        } else {
            throw new CSErrorException(ErrorCode.INVALID_CONTEXT_VALUE_TYPE, "Invalid Context Type : " + contextType);
        }
    }

    @Override
    public <T> T searchContext(ContextID contextId, String keyword, String nodeName, Class<T> contextValueType) throws CSErrorException {
        if (null == contextId || StringUtils.isBlank(contextId.getContextId()) || StringUtils.isBlank(nodeName) || null == contextValueType) {
            logger.error("ContextID or nodeName or contextValueType cannot be null.");
            throw new CSErrorException(ErrorCode.INVALID_NULL_STRING, "ContextID or nodeName or contextValueType cannot be null.");
        }
        ContextClient contextClient = ContextClientFactory.getOrCreateContextClient();
        List<String> contains = new ArrayList<>();
        contains.add(keyword);
        List<Class> contextValueTypes = new ArrayList<>();
        contextValueTypes.add(contextValueType);
        List<ContextKeyValue> contextKeyValues = null;
        try {
            contextKeyValues = contextClient.search(contextId, null, null, contains, null, false, nodeName, 1, contextValueTypes);
        } catch (ErrorException e) {
            logger.error("Search context value error.");
            throw new CSErrorException(ErrorCode.GET_CONTEXT_VALUE_ERROR, "Search context value error: ", e);
        }
        if (CollectionUtils.isEmpty(contextKeyValues) || null == contextKeyValues.get(0).getContextValue()) {
            return null;
        }
        if (contextValueType.isInstance(contextKeyValues.get(0).getContextValue().getValue())) {
            return (T) contextKeyValues.get(0).getContextValue().getValue();
        } else {
            throw new CSErrorException(ErrorCode.SEARCH_CONTEXT_VALUE_ERROR, "Search value : " + gson.toJson(contextKeyValues.get(0)
                    + " is not instance of class : " + contextValueType.getName()));
        }
    }

    @Override
    public <T> List<T> searchUpstreamContext(ContextID contextID, String nodeName, int num, Class<T> contextValueType) throws CSErrorException {
        Map<ContextKey, T> contextMap = searchUpstreamContextMap(contextID, nodeName, num, contextValueType);
        if (null == contextMap || contextMap.size() < 1) {
            return null;
        }
        List<T> retValues = new ArrayList<>(contextMap.size());
        contextMap.entrySet().stream().filter(kv -> null != kv && null != kv.getValue()).map(kv -> kv.getValue()).forEach(retValues::add);
        return retValues;
    }

    @Override
    public <T> Map<ContextKey, T> searchUpstreamContextMap(ContextID contextID, String nodeName, int num, Class<T> contextValueType) throws CSErrorException {
        ContextClient contextClient = ContextClientFactory.getOrCreateContextClient();
        if (null == contextID || StringUtils.isBlank(contextID.getContextId())) {
            return null;
        }
        List<Class> contextValueTypes = new ArrayList<>();
        contextValueTypes.add(contextValueType);
        List<ContextKeyValue> contextKeyValueList = null;
        try {
            contextKeyValueList = contextClient.search(contextID, null, null, null, null, true, nodeName, num, contextValueTypes);
        } catch (ErrorException e) {
            throw new CSErrorException(ErrorCode.GET_CONTEXT_VALUE_ERROR, "searchUpstreamContextMap error ", e);
        }
        if (CollectionUtils.isEmpty(contextKeyValueList)) {
            return null;
        }
        Map<ContextKey, T> retValues = new HashMap<>(contextKeyValueList.size());
        contextKeyValueList.stream().filter(kv -> null != kv && null != kv.getContextValue()).forEach(kv -> retValues.put(kv.getContextKey(), (T) (kv.getContextValue().getValue())));
        return retValues;
    }

    @Override
    public <T> List<ContextKeyValue> searchUpstreamKeyValue(ContextID contextID, String nodeName, int num, Class<T> contextValueType) throws CSErrorException {
        ContextClient contextClient = ContextClientFactory.getOrCreateContextClient();
        if (null == contextID || StringUtils.isBlank(contextID.getContextId())) {
            return null;
        }
        List<Class> contextValueTypes = new ArrayList<>();
        contextValueTypes.add(contextValueType);
        List<ContextKeyValue> contextKeyValueList = null;
        try {
            contextKeyValueList = contextClient.search(contextID, null, null, null, null, true, nodeName, num, contextValueTypes);
        } catch (ErrorException e) {
            throw new CSErrorException(ErrorCode.GET_CONTEXT_VALUE_ERROR, "searchUpstreamKeyValue error ", e);
        }
        return contextKeyValueList;
    }

    public static SearchService getInstance() {
        if (null == searchService) {
            synchronized (DefaultSearchService.class) {
                if (null == searchService) {
                    searchService = new DefaultSearchService();
                }
            }
        }
        return searchService;
    }
}
