package org.gcube.accounting.datamodel.validations.validators;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FilenameFilter;
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.gcube.accounting.aggregator.RegexRulesAggregator;
import org.gcube.accounting.datamodel.aggregation.AggregatedServiceUsageRecord;
import org.gcube.accounting.datamodel.usagerecords.ServiceUsageRecord;
import org.gcube.documentstore.exception.NotAggregatableRecordsExceptions;
import org.gcube.documentstore.records.DSMapper;
import org.gcube.testutility.ContextTest;
import org.gcube.testutility.TestUsageRecord;
import org.junit.Assert;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.databind.ObjectMapper;

public class TestRules extends ContextTest {
	
	private static final Logger logger = LoggerFactory.getLogger(TestRules.class);
	
	public File getRulesDirectory() throws Exception {
		URL logbackFileURL = TestRules.class.getClassLoader().getResource("logback-test.xml");
		File logbackFile = new File(logbackFileURL.toURI());
		File resourcesDirectory = logbackFile.getParentFile();
		return new File(resourcesDirectory, "rules");
	}
	
	protected long durationWeightedAverage(int numberA, long durationA, int numberB, long durationB) {
		return ((numberA * durationA) + (numberB * durationB)) / (numberA + numberB);
	}
	
	public List<File> allRules() throws Exception {
		File rulesDirectory = getRulesDirectory();
		FilenameFilter filenameFilter = new FilenameFilter() {
			@Override
			public boolean accept(File dir, String name) {
				return name.endsWith(".json");
			}
		};
		
		List<File> rulesFiles = new ArrayList<>();
		for(File dir : rulesDirectory.listFiles()) {
			if(!dir.isDirectory()) {
				continue;
			}
			rulesFiles.addAll(Arrays.asList(dir.listFiles(filenameFilter)));
			RegexRulesAggregator regexRulesAggregator = RegexRulesAggregator.getInstance();
			for(File rulesFile : rulesFiles) {
				ObjectMapper mapper = DSMapper.getObjectMapper();
				MatcherReplace matcherReplace = mapper.readValue(rulesFile, MatcherReplace.class);
				regexRulesAggregator.addMatcherReplace(matcherReplace);
			}
			
		}
		
		return rulesFiles;
	}
	
	public void testRule(File rulesFile) throws Exception {
		logger.info(
				"-----------------------------------------------------------------------------------------------------");
		logger.info("Analisyng rule from file {}\n", rulesFile.getAbsolutePath());
		File rulesDirectory = rulesFile.getParentFile();
		
		ObjectMapper mapper = DSMapper.getObjectMapper();
		MatcherReplace matcherReplace = mapper.readValue(rulesFile, MatcherReplace.class);
		Replace replacementRegex = matcherReplace.getReplacementRegex();
		
		Map<String,AggregatedServiceUsageRecord> aggregatedMap = new HashMap<>();
		
		AggregatedServiceUsageRecord aggregated;
		
		// it indicates that the rules can create multiple calledMethod because the replacement is based on
		// Named Capture Group  
		
		final String requiredMatchesFileName = rulesFile.getName().replaceAll(".json", ".csv");
		File elaborationFile = new File(rulesDirectory, requiredMatchesFileName);
		try(BufferedReader br = new BufferedReader(new FileReader(elaborationFile))) {
			for(String line; (line = br.readLine()) != null;) {
				String[] splittedLine = line.split(",");
				
				String serviceClass = splittedLine[0];
				String serviceName = splittedLine[1];
				String calledMethod = splittedLine[2];
				
				Replace replace = matcherReplace.check(serviceClass, serviceName, calledMethod);
				if(replace != null) {
					logger.info("{} --> {},{},{}", line, replace.getServiceClass(), replace.getServiceName(),
							replace.getCalledMethod());
				} else {
					logger.error("{} does not match {}. This MUST not occur.", line,
							matcherReplace.getMultiMatcher().toString());
					throw new Exception();
				}
				
				String obtainedTriple = replace.getServiceClass() + "+++" + replace.getServiceName() + "+++"
						+ replace.getCalledMethod();
				if(aggregatedMap.containsKey(obtainedTriple)) {
					aggregated = aggregatedMap.get(obtainedTriple);
				} else {
					ServiceUsageRecord serviceUsageRecord = TestUsageRecord.createTestServiceUsageRecord();
					serviceUsageRecord.setServiceClass(replace.getServiceClass());
					serviceUsageRecord.setServiceName(replace.getServiceName());
					serviceUsageRecord.setCalledMethod(replace.getCalledMethod());
					serviceUsageRecord.validate();
					aggregated = new AggregatedServiceUsageRecord(serviceUsageRecord);
					aggregatedMap.put(obtainedTriple, aggregated);
				}
				
				ServiceUsageRecord sur = TestUsageRecord.createTestServiceUsageRecord();
				sur.setServiceClass(serviceClass);
				sur.setServiceName(serviceName);
				sur.setCalledMethod(calledMethod);
				sur.validate();
				// logger.trace("To Be aggregated ServiceUsageRecord {}", sur);
				
				long oldMinInvocationTime = aggregated.getMinInvocationTime();
				long oldMaxInvocationTime = aggregated.getMaxInvocationTime();
				int oldOperationCount = aggregated.getOperationCount();
				long oldDuration = aggregated.getDuration();
				
				long surDuration = sur.getDuration();
				
				aggregated.aggregate(sur);
				//logger.debug("Resulting Aggregated ServiceUsageRecord: {}", aggregated);
				
				long avgDuration = durationWeightedAverage(oldOperationCount, oldDuration, 1, surDuration);
				Assert.assertTrue(aggregated.getDuration() == (avgDuration));
				Assert.assertTrue(aggregated.getOperationCount() == ++oldOperationCount);
				
				if(oldMinInvocationTime >= surDuration) {
					Assert.assertTrue(aggregated.getMinInvocationTime() == surDuration);
				} else {
					Assert.assertTrue(aggregated.getMinInvocationTime() == oldMinInvocationTime);
				}
				
				if(oldMaxInvocationTime >= surDuration) {
					Assert.assertTrue(aggregated.getMaxInvocationTime() == oldMaxInvocationTime);
				} else {
					Assert.assertTrue(aggregated.getMaxInvocationTime() == surDuration);
				}
				
			}
		} catch(Exception e) {
			throw e;
		}
		
		FilenameFilter filenameFilter = new FilenameFilter() {
			@Override
			public boolean accept(File dir, String name) {
				boolean accept = name.endsWith(".csv");
				return name.compareTo(requiredMatchesFileName) != 0 && accept;
			}
		};
		
		for(File dir : rulesDirectory.listFiles()) {
			if(!dir.isDirectory()) {
				continue;
			}
			File[] elaborationFilesNoMatch = dir.listFiles(filenameFilter);
			
			for(File elaborationFileNoMatch : elaborationFilesNoMatch) {
				logger.info("Comparing examples which must not match from file {}", elaborationFileNoMatch.getName());
				try(BufferedReader br = new BufferedReader(new FileReader(elaborationFileNoMatch))) {
					for(String line; (line = br.readLine()) != null;) {
						String[] splittedLine = line.split(",");
						String serviceClass = splittedLine[0];
						String serviceName = splittedLine[1];
						String calledMethod = splittedLine[2];
						Replace replace = matcherReplace.check(serviceClass, serviceName, calledMethod);
						if(replace != null) {
							logger.error("{} match {} but it should NOT. This MUST not occur.", line,
									matcherReplace.getMultiMatcher().toString());
							throw new Exception();
						} else {
							logger.trace("{} does NOT match as requested", line, replacementRegex.getServiceClass(),
									replacementRegex.getServiceName(), replacementRegex.getCalledMethod());
						}
						
						ServiceUsageRecord sur = TestUsageRecord.createTestServiceUsageRecord();
						sur.setServiceClass(serviceClass);
						sur.setServiceName(serviceName);
						sur.setCalledMethod(calledMethod);
						sur.validate();
						//logger.trace("Should not be aggregated ServiceUsageRecord {}", sur);
						for(AggregatedServiceUsageRecord asur : aggregatedMap.values()) {
							try {
								asur.aggregate(sur);
								throw new Exception("The record has been aggregated and it should NOT");
								
							} catch(NotAggregatableRecordsExceptions e) {
								//logger.trace("{} is not aggragable as expected", sur);
							}
						}
					}
				} catch(Exception e) {
					throw e;
				}
			}
		}
		logger.info(
				"-----------------------------------------------------------------------------------------------------\n\n\n");
	}
	
	@Test
	public void testSingleRule() throws Exception {
		allRules();
		File rulesDirectory = getRulesDirectory();
		File rulesDirFile = new File(rulesDirectory, "Thredds");
		File rulesFile = new File(rulesDirFile, "Thredds_METADATA::OTHER.json");
		testRule(rulesFile);
	}
	
	@Test
	public void testAllRules() throws Exception {
		List<File> rulesFiles = allRules();
		
		for(File rulesFile : rulesFiles) {
			testRule(rulesFile);
		}
	}
	
}