package org.gcube.dataharvest.harvester;

import static org.gcube.resources.discovery.icclient.ICFactory.clientFor;
import static org.gcube.resources.discovery.icclient.ICFactory.queryFor;

import java.io.IOException;
import java.io.StringReader;
import java.security.GeneralSecurityException;
import java.time.Instant;
import java.time.LocalDate;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.HashMap;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.gcube.accounting.accounting.summary.access.model.ScopeDescriptor;
import org.gcube.accounting.accounting.summary.access.model.update.AccountingRecord;
import org.gcube.common.authorization.client.exceptions.ObjectNotFound;
import org.gcube.common.encryption.encrypter.StringEncrypter;
import org.gcube.common.resources.gcore.GenericResource;
import org.gcube.common.resources.gcore.ServiceEndpoint;
import org.gcube.common.resources.gcore.ServiceEndpoint.AccessPoint;
import org.gcube.common.resources.gcore.ServiceEndpoint.Property;
import org.gcube.common.resources.gcore.utils.Group;
import org.gcube.common.resources.gcore.utils.XPathHelper;
import org.gcube.common.scope.api.ScopeProvider;
import org.gcube.common.scope.impl.ScopeBean;
import org.gcube.dataharvest.datamodel.AnalyticsReportCredentials;
import org.gcube.dataharvest.datamodel.CatalogueAccessesReportRow;
import org.gcube.dataharvest.datamodel.HarvestedDataKey;
import org.gcube.resources.discovery.client.api.DiscoveryClient;
import org.gcube.resources.discovery.client.queries.api.SimpleQuery;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Node;
import org.xml.sax.InputSource;

import com.google.analytics.data.v1beta.BetaAnalyticsDataClient;
import com.google.analytics.data.v1beta.BetaAnalyticsDataSettings;
import com.google.analytics.data.v1beta.DateRange;
import com.google.analytics.data.v1beta.DateRange.Builder;
import com.google.analytics.data.v1beta.Dimension;
import com.google.analytics.data.v1beta.Metric;
import com.google.analytics.data.v1beta.Row;
import com.google.analytics.data.v1beta.RunReportRequest;
import com.google.analytics.data.v1beta.RunReportResponse;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.gax.core.FixedCredentialsProvider;
import com.google.auth.oauth2.ServiceAccountCredentials;


public class CatalogueAccessesHarvester extends BasicHarvester {

	private static Logger logger = LoggerFactory.getLogger(CatalogueAccessesHarvester.class);

	private static final JsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();


	private static final String MAPPING_RESOURCE_CATEGORY = "BigGAnalyticsMapping";
	private static final String SERVICE_ENDPOINT_CATEGORY = "OnlineService";
	private static final String SERVICE_ENDPOINT_NAME = "GA4AnalyticsDataService";
	private static final String AP_CATALOGUE_PAGEVIEWS_PROPERTY = "catalogue-pageviews";
	private static final String AP_CLIENT_PROPERTY = "client_id";
	private static final String AP_PRIVATEKEY_PROPERTY = "private_key_id";

	private static final String REGEX_CATALOGUE_ACCESSES = "^\\/$";
	private static final String REGEX_CATALOGUE_DATASET_LIST_ACCESSES = "^\\/dataset(\\?([a-zA-Z0-9_.-]*.+))*";
	private static final String REGEX_CATALOGUE_DATASET_ACCESSES = "^\\/dataset\\/[a-zA-Z0-9_.-]+$";
	private static final String REGEX_CATALOGUE_RESOURCE_ACCESSES = "^\\/dataset\\/[a-zA-Z0-9_.-]+\\/resource\\/[a-zA-Z0-9_.-]+$";

	private  HashMap<String, List<CatalogueAccessesReportRow>> catalogueAccesses;

	public CatalogueAccessesHarvester(Date start, Date end) throws Exception {
		super(start, end);
		catalogueAccesses = getAllAccesses(start, end);
	}

	@Override
	public List<AccountingRecord> getAccountingRecords() throws Exception {
		try {
			ArrayList<AccountingRecord> accountingRecords = new ArrayList<AccountingRecord>();	
			for (String dashboardContext : catalogueAccesses.keySet()) {
				int catalogueTotalAccesses = 0;
				int catalogueDatasetListAccesses = 0;
				int catalogueDatasetAccesses = 0;
				int catalogueResourceAccesses = 0;
				logger.debug("Catalogue accesses for {} ", dashboardContext);
				for(CatalogueAccessesReportRow row : catalogueAccesses.get(dashboardContext)) {
					//					String pagePath = row.getPagePath();
					switch (row.getKey()) {
					case CATALOGUE_ACCESSES:
						catalogueTotalAccesses += row.getVisitNumber();
						break;
					case CATALOGUE_DATASET_LIST_ACCESSES:
						catalogueDatasetListAccesses += row.getVisitNumber();
						break;
					case CATALOGUE_DATASET_ACCESSES:
						catalogueDatasetAccesses += row.getVisitNumber();
						break;
					case CATALOGUE_RESOURCE_ACCESSES:
						catalogueResourceAccesses += row.getVisitNumber();
						break;
					default:
						break;
					}
				}
				ScopeDescriptor scopeDescriptor = new ScopeDescriptor();
				
				try {
					ScopeBean scopeBean = new ScopeBean(dashboardContext);
					scopeDescriptor.setId(dashboardContext);
					scopeDescriptor.setName(scopeBean.name());

					AccountingRecord ar1 = new AccountingRecord(scopeDescriptor, instant, getDimension(HarvestedDataKey.CATALOGUE_ACCESSES), (long) catalogueTotalAccesses);
					AccountingRecord ar2 = new AccountingRecord(scopeDescriptor, instant, getDimension(HarvestedDataKey.CATALOGUE_DATASET_LIST_ACCESSES), (long) catalogueDatasetListAccesses);
					AccountingRecord ar3 = new AccountingRecord(scopeDescriptor, instant, getDimension(HarvestedDataKey.CATALOGUE_DATASET_ACCESSES), (long) catalogueDatasetAccesses);
					AccountingRecord ar4 = new AccountingRecord(scopeDescriptor, instant, getDimension(HarvestedDataKey.CATALOGUE_RESOURCE_ACCESSES), (long) catalogueResourceAccesses);
					logger.debug("{} : {}", ar1.getDimension().getId(), ar1.getMeasure());
					accountingRecords.add(ar1);
					logger.debug("{} : {}", ar2.getDimension().getId(), ar2.getMeasure());
					accountingRecords.add(ar2);
					logger.debug("{} : {}", ar3.getDimension().getId(), ar3.getMeasure());
					accountingRecords.add(ar3);
					logger.debug("{} : {}", ar4.getDimension().getId(), ar4.getMeasure());
					accountingRecords.add(ar4);
				} catch (NullPointerException e) {
					logger.warn("I found no correspondance in the Genereric Resource for a PropertyId you should check this, type: BigGAnalyticsMapping name: AccountingDashboardMapping");
					e.printStackTrace();
				}

			}
			logger.debug("Returning  {} accountingRecords ", accountingRecords.size());
			return accountingRecords;

		} catch(Exception e) {
			throw e;
		}
	}

	/**
	 * 
	 */
	private static HashMap<String, List<CatalogueAccessesReportRow>> getAllAccesses(Date start, Date end) throws Exception {
		Builder dateRangeBuilder = getDateRangeBuilderForAnalytics(start, end);
		logger.debug("Getting Catalogue accesses in this time range {}", dateRangeBuilder.toString());

		AnalyticsReportCredentials credentialsFromD4S = getAuthorisedApplicationInfoFromIs();

		logger.debug("Getting credentials credentialsFromD4S");

		BetaAnalyticsDataSettings serviceSettings = initializeAnalyticsReporting(credentialsFromD4S);

		logger.debug("initializeAnalyticsReporting service settings");


		HashMap<String,List<RunReportResponse>> responses = getReportResponses(serviceSettings, credentialsFromD4S.getViewIds(), dateRangeBuilder);
		HashMap<String, List<CatalogueAccessesReportRow>> toReturn = new HashMap<>();

		for(String view : responses.keySet()) {
			String dashboardContext = getAccountingDashboardContextGivenGAViewID(view);
			logger.info("\n\n****************   Parsing responses for this catalogue view, which corresponds to Dashboard Context: " + dashboardContext);
			List<CatalogueAccessesReportRow> viewReport = parseResponse(view, responses.get(view), dashboardContext);
			logger.trace("Got {} entries from view id={}", viewReport.size(), view);
			toReturn.put(dashboardContext, viewReport);
		}
		return toReturn;
	}

	/**
	 * Initializes an Google Analytics Data API service object.
	 *
	 * @return An authorized Google Analytics Data API 
	 * @throws IOException
	 * @throws GeneralSecurityException
	 */
	private static BetaAnalyticsDataSettings initializeAnalyticsReporting(AnalyticsReportCredentials cred) throws IOException {
		return BetaAnalyticsDataSettings.newBuilder()
				.setCredentialsProvider(FixedCredentialsProvider.create(
						ServiceAccountCredentials.fromPkcs8(cred.getClientId(), cred.getClientEmail(), cred.getPrivateKeyPem(), cred.getPrivateKeyId(), null)))
				.build();
	}

	/**
	 * Queries Analytics Data API service 
	 *
	 * @param service Analytics Data API service  service settings.
	 * @return Row Analytics Data API service 
	 * @throws IOException
	 */
	private static HashMap<String,List<RunReportResponse>> getReportResponses(BetaAnalyticsDataSettings betaAnalyticsDataSettings,
			List<String> viewIDs, Builder dateRangeBuilder) throws IOException {

		HashMap<String,List<RunReportResponse>> reports = new HashMap<>();

		try (BetaAnalyticsDataClient analyticsData = BetaAnalyticsDataClient.create(betaAnalyticsDataSettings)) {

			for(String propertyId : viewIDs) {
				List<RunReportResponse> gReportResponses = new ArrayList<>();
				logger.debug("Getting data from Analytics Data API for propertyId: " + propertyId);
				RunReportRequest request =
						RunReportRequest.newBuilder()
						.setProperty("properties/" + propertyId)
						.addDimensions(Dimension.newBuilder().setName("pagePath"))
						.addMetrics(Metric.newBuilder().setName("screenPageViews"))
						.addDateRanges(dateRangeBuilder)
						.build();

				// Make the request.
				RunReportResponse response = analyticsData.runReport(request);
				gReportResponses.add(response);
				// Iterate through every row of the API response.
				//				for (Row row : response.getRowsList()) {
				//					System.out.printf(
				//							"%s, %s%n", row.getDimensionValues(0).getValue(), row.getMetricValues(0).getValue());
				//				}				
				reports.put(propertyId, gReportResponses);
			}
		}
		return reports;
	}

	/**
	 * Parses and prints the Analytics Data API service respose
	 *
	 * @param dashboardContext 
	 */
	private static List<CatalogueAccessesReportRow> parseResponse(String viewId,  List<RunReportResponse> responses, String dashboardContext) {
		logger.debug("parsing Response for " + viewId);

		List<CatalogueAccessesReportRow> toReturn = new ArrayList<>();
		for (RunReportResponse response : responses) {
			for (Row row: response.getRowsList()) {
				String dimension = row.getDimensionValues(0).getValue();
				String metric = row.getMetricValues(0).getValue();
				CatalogueAccessesReportRow var = new CatalogueAccessesReportRow();
				boolean validEntry = false;
				String pagePath = dimension;
				logger.trace("parsing pagepath {}: value: {}", pagePath, Integer.parseInt(metric)); 
				if (pagePath.matches(REGEX_CATALOGUE_RESOURCE_ACCESSES)) {
					var.setKey(HarvestedDataKey.CATALOGUE_RESOURCE_ACCESSES);
					validEntry = true;
				}
				else if (pagePath.matches(REGEX_CATALOGUE_DATASET_ACCESSES)) {
					var.setKey(HarvestedDataKey.CATALOGUE_DATASET_ACCESSES);
					validEntry = true;
				}
				else if (pagePath.matches(REGEX_CATALOGUE_DATASET_LIST_ACCESSES)) {
					var.setKey(HarvestedDataKey.CATALOGUE_DATASET_LIST_ACCESSES);
					validEntry = true;
				}
				else if (pagePath.matches(REGEX_CATALOGUE_ACCESSES)) {
					var.setKey(HarvestedDataKey.CATALOGUE_ACCESSES);
					validEntry = true;
				}
				if (validEntry) {
					var.setDashboardContext(dashboardContext);
					var.setPagePath(dimension);
					var.setVisitNumber(Integer.parseInt(metric));
					toReturn.add(var);
				}
			}
		}
		return toReturn;
	}


	private static List<ServiceEndpoint> getAnalyticsReportingConfigurationFromIS(String infrastructureScope)
			throws Exception {
		String scope = infrastructureScope;
		String currScope = ScopeProvider.instance.get();
		ScopeProvider.instance.set(scope);
		SimpleQuery query = queryFor(ServiceEndpoint.class);
		query.addCondition("$resource/Profile/Category/text() eq '" + SERVICE_ENDPOINT_CATEGORY + "'");
		query.addCondition("$resource/Profile/Name/text() eq '" + SERVICE_ENDPOINT_NAME + "'");
		DiscoveryClient<ServiceEndpoint> client = clientFor(ServiceEndpoint.class);
		List<ServiceEndpoint> toReturn = client.submit(query);
		ScopeProvider.instance.set(currScope);
		return toReturn;
	}

	/**
	 * This method look up in the IS the Gateway which corresponds to a given Google Analytics viewId
	 * @param viewID
	 * @return the gateway name, e.g. "Blue-Cloud Gateway" or null if no correspondance was found
	 * @throws Exception 
	 * @throws ObjectNotFound 
	 */
	private static String getAccountingDashboardContextGivenGAViewID(String viewID) throws ObjectNotFound, Exception {
		String toReturn = null;
		String context = org.gcube.dataharvest.utils.Utils.getCurrentContext();
		String currScope = ScopeProvider.instance.get();
		ScopeProvider.instance.set(context);
		SimpleQuery query = queryFor(GenericResource.class);
		query.addCondition("$resource/Profile/SecondaryType/text() eq '" + MAPPING_RESOURCE_CATEGORY + "'");
		query.addCondition("$resource/Profile/Body/Property/viewID/text() eq '" + viewID + "'");
		DiscoveryClient<GenericResource> client = clientFor(GenericResource.class);
		List<GenericResource> list = client.submit(query);
		if(list.size() > 1) {
			logger.error("Too many Generic Resources having GA viewID " + viewID
					+ " in this scope having SecondaryType " + MAPPING_RESOURCE_CATEGORY);
		} else if(list.size() == 0) {
			logger.warn("There is no Generic Resources having GA viewID " + viewID + " and SecondaryType "
					+ MAPPING_RESOURCE_CATEGORY + " in this context: " + context);
		} else {			
			GenericResource found = list.get(0);
			String elem = new StringBuilder("<body>").append(found.profile().bodyAsString()).append("</body>").toString();
			DocumentBuilder docBuilder =  DocumentBuilderFactory.newInstance().newDocumentBuilder();
			Node node = docBuilder.parse(new InputSource(new StringReader(elem))).getDocumentElement();
			XPathHelper helper = new XPathHelper(node);
			List<String> currValue = helper.evaluate("//Property/viewID/text()");
			if (currValue != null && currValue.size() > 0) {
				List<String> contexts = currValue;
				for (int i = 0; i < contexts.size(); i++) {
					if (currValue.get(i).trim().compareTo(viewID) == 0) {								
						toReturn = helper.evaluate("//Property/DashboardContext/text()").get(i);
						break;
					}						
				}		
			}			
			logger.debug("Found DashboardContext for viewId {} : {} ", viewID, toReturn);
		}		
		ScopeProvider.instance.set(currScope);
		return toReturn;
	}

	/**
	 * @throws Exception 
	 */
	private static AnalyticsReportCredentials getAuthorisedApplicationInfoFromIs() throws Exception {
		AnalyticsReportCredentials reportCredentials = new AnalyticsReportCredentials();

		String context = org.gcube.dataharvest.utils.Utils.getCurrentContext();
		try {
			List<ServiceEndpoint> list = getAnalyticsReportingConfigurationFromIS(context);
			if(list.size() > 1) {
				logger.error("Too many Service Endpoints having name " + SERVICE_ENDPOINT_NAME
						+ " in this scope having Category " + SERVICE_ENDPOINT_CATEGORY);
			} else if(list.size() == 0) {
				logger.warn("There is no Service Endpoint having name " + SERVICE_ENDPOINT_NAME + " and Category "
						+ SERVICE_ENDPOINT_CATEGORY + " in this context: " + context);
			} else {

				for(ServiceEndpoint res : list) {
					Group<AccessPoint> apGroup = res.profile().accessPoints();
					AccessPoint[] accessPoints = (AccessPoint[]) apGroup.toArray(new AccessPoint[apGroup.size()]);
					AccessPoint found = accessPoints[0];
					reportCredentials.setClientEmail(found.username());
					String decryptedPrivateKey = StringEncrypter.getEncrypter().decrypt(found.password());
					reportCredentials.setPrivateKeyPem(decryptedPrivateKey.trim());

					for(Property prop : found.properties()) {
						if(prop.name().compareTo(AP_CATALOGUE_PAGEVIEWS_PROPERTY) == 0) {
							String decryptedValue = StringEncrypter.getEncrypter().decrypt(prop.value());
							String[] views = decryptedValue.split(";");
							reportCredentials.setViewIds(Arrays.asList(views));
						}
						if(prop.name().compareTo(AP_CLIENT_PROPERTY) == 0) {
							String decryptedValue = StringEncrypter.getEncrypter().decrypt(prop.value());
							reportCredentials.setClientId(decryptedValue);
						}
						if(prop.name().compareTo(AP_PRIVATEKEY_PROPERTY) == 0) {
							String decryptedValue = StringEncrypter.getEncrypter().decrypt(prop.value());
							reportCredentials.setPrivateKeyId(decryptedValue);
						}
					}
				}
			}
		} catch(Exception e) {
			e.printStackTrace();
			return null;
		}
		return reportCredentials;
	}

	private static LocalDate asLocalDate(Date date) {
		return Instant.ofEpochMilli(date.getTime()).atZone(ZoneId.systemDefault()).toLocalDate();
	}

	private static Builder getDateRangeBuilderForAnalytics(Date start, Date end) {
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd"); //required by Analytics
		String startDate = asLocalDate(start).format(formatter);
		String endDate = asLocalDate(end).format(formatter);
		Builder dateRangeBuilder = DateRange.newBuilder().setStartDate(startDate).setEndDate(endDate);

		return dateRangeBuilder;
	}

}