/*******************************************************************************
 * Copyright (c) 2000, 2018 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.test.internal.performance.results.db;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.eclipse.core.runtime.SubMonitor;
import org.eclipse.test.internal.performance.results.utils.Util;

/**
 * Class to handle performance results of an eclipse component
 * (for example 'org.eclipse.jdt.core').
 *
 * It gives access to results for each scenario run for this component.
 *
 * @see ScenarioResults
 */
public class ComponentResults extends AbstractResults {

    public ComponentResults(AbstractResults parent, String name) {
	super(parent, name);
	this.printStream = parent.printStream;
}

Set<String> getAllBuildNames() {
	Set<String> buildNames = new HashSet<>();
	int size = size();
	for (int i=0; i<size; i++) {
		ScenarioResults scenarioResults = (ScenarioResults) this.children.get(i);
		Set<String> builds = scenarioResults.getAllBuildNames();
		buildNames.addAll(builds);
	}
	return buildNames;
}

/**
 * Return all the build names for this component sorted by ascending order.
 *
 * @return An array of names
 */
public String[] getAllSortedBuildNames() {
	return getAllSortedBuildNames(false/*ascending order*/);
}

String[] getAllSortedBuildNames(final boolean reverse) {
	Set<String> allBuildNames = getAllBuildNames();
	String[] sortedNames = new String[allBuildNames.size()];
	allBuildNames.toArray(sortedNames);
	Arrays.sort(sortedNames, (o1, o2) -> {
  	String s1 = reverse ? o2 : o1;
  	String s2 = reverse ? o1 : o2;
  	return Util.getBuildDate(s1).compareTo(Util.getBuildDate(s2));
    });
	return sortedNames;
}

@Override
ComponentResults getComponentResults() {
	return this;
}

/**
 * Get all results numbers for a given machine of the current component.
 *
 * @param configName The name of the configuration to get numbers
 * @param fingerprints Set whether only fingerprints scenario should be taken into account
 * @return A list of lines. Each line represent a build and is a list of either strings or values.
  * 	Values are an array of double:
 * 	<ul>
 * 		<li>{@link #BUILD_VALUE_INDEX}: the build value in milliseconds</li>
 * 		<li>{@link #BASELINE_VALUE_INDEX}: the baseline value in milliseconds</li>
 * 		<li>{@link #DELTA_VALUE_INDEX}: the difference between the build value and its more recent baseline</li>
 * 		<li>{@link #DELTA_ERROR_INDEX}: the error made while computing the difference</li>
 * 		<li>{@link #BUILD_ERROR_INDEX}: the error made while measuring the build value</li>
 * 		<li>{@link #BASELINE_ERROR_INDEX}: the error made while measuring the baseline value</li>
 * 	</ul>
*/
public List<List<Object>> getConfigNumbers(String configName, boolean fingerprints, List<List<Object>> differences) {

	// Initialize lists
	AbstractResults[] scenarios = getChildren();
	int length = scenarios.length;

	// Print scenario names line
	List<Object> firstLine = new ArrayList<>();
	for (int i=0; i<length; i++) {
		ScenarioResults scenarioResults = (ScenarioResults) scenarios[i];
		if (!fingerprints || scenarioResults.hasSummary()) {
			firstLine.add(scenarioResults.getName());
		}
	}

	// Print each build line
	String[] builds = getAllSortedBuildNames(true/*descending order*/);
//	int milestoneIndex = 0;
//	String milestoneDate = Util.getMilestoneDate(milestoneIndex);
	String currentBuildName = null;
	int buildsLength= builds.length;
	firstLine.add(0, Integer.valueOf(buildsLength));
	differences.add(firstLine);
	for (int i=0; i<buildsLength; i++) {
		List<Object> line = new ArrayList<>();
		String buildName = builds[i];
		line.add(buildName);
		if (!buildName.startsWith(DB_Results.getDbBaselinePrefix())) {
			for (int j=0; j<length; j++) {
				ScenarioResults scenarioResults = (ScenarioResults) scenarios[j];
				if (!fingerprints || scenarioResults.hasSummary()) {
					ConfigResults configResults = scenarioResults.getConfigResults(configName);
					BuildResults buildResults = configResults == null ? null : configResults.getBuildResults(buildName);
					if (buildResults == null) {
						// no result for this scenario in this build
						line.add(NO_BUILD_RESULTS);
					} else {
					    if (configResults == null) {
					        throw new RuntimeException("configResults was unexpectedly null. Check input data?");
					    }
						line.add(configResults.getNumbers(buildResults, configResults.getBaselineBuildResults(buildName)));
					}
				}
			}
			differences.add(line);
			if (currentBuildName != null && currentBuildName.charAt(0) != 'N') {
            }
			currentBuildName = buildName;
		}
//		if (milestoneDate != null) { // update previous builds
//			int dateComparison = milestoneDate.compareTo(Util.getBuildDate(buildName));
//			if (dateComparison <= 0) {
//				if (dateComparison == 0) {
//                }
//				if (++milestoneIndex == Util.MILESTONES.length) {
//					milestoneDate = null;
//				} else {
//					milestoneDate = Util.getMilestoneDate(milestoneIndex);
//				}
//			}
//		}
	}

	// Write differences lines
	int last = buildsLength-1;
	String lastBuildName = builds[last];
	while (last > 0 && lastBuildName.startsWith(DB_Results.getDbBaselinePrefix())) {
		lastBuildName = builds[--last];
	}
//	appendDifferences(lastBuildName, configName, previousMilestoneName, differences, fingerprints);
//	appendDifferences(lastBuildName, configName, previousBuildName, differences, fingerprints);

	// Return the computed differences
	return differences;
}

/*
double[] getConfigNumbers(BuildResults buildResults, BuildResults baselineResults) {
	if (baselineResults == null) {
		return INVALID_RESULTS;
	}
	double[] values = new double[NUMBERS_LENGTH];
	for (int i=0 ;i<NUMBERS_LENGTH; i++) {
		values[i] = Double.NaN;
	}
	double buildValue = buildResults.getValue();
	values[BUILD_VALUE_INDEX] = buildValue;
	double baselineValue = baselineResults.getValue();
	values[BASELINE_VALUE_INDEX] = baselineValue;
	double delta = (baselineValue - buildValue) / baselineValue;
	values[DELTA_VALUE_INDEX] = delta;
	if (Double.isNaN(delta)) {
		return values;
	}
	long baselineCount = baselineResults.getCount();
	long currentCount = buildResults.getCount();
	if (baselineCount > 1 && currentCount > 1) {
		double baselineError = baselineResults.getError();
		double currentError = buildResults.getError();
		values[BASELINE_ERROR_INDEX] = baselineError;
		values[BUILD_ERROR_INDEX] = currentError;
		values[DELTA_ERROR_INDEX] = Double.isNaN(baselineError)
				? currentError / baselineValue
				: Math.sqrt(baselineError*baselineError + currentError*currentError) / baselineValue;
	}
	return values;
}
*/

private ScenarioResults getScenarioResults(List<ScenarioResults> scenarios, int searchedId) {
	int size = scenarios.size();
	for (int i=0; i<size; i++) {
		ScenarioResults scenarioResults = scenarios.get(i);
		if (scenarioResults.id == searchedId) {
			return scenarioResults;
		}
	}
	return null;
}

/**
 * Returns a list of scenario results which have a summary
 *
 * @param global Indicates whether the summary must be global or not.
 * @param config Configuration name
 * @return A list of {@link ScenarioResults scenario results} which have a summary
 */
public List<ScenarioResults> getSummaryScenarios(boolean global, String config) {
	int size= size();
	List<ScenarioResults> scenarios = new ArrayList<>(size);
	for (int i=0; i<size; i++) {
		ScenarioResults scenarioResults = (ScenarioResults) this.children.get(i);
		ConfigResults configResults = scenarioResults.getConfigResults(config);
		if (configResults != null) {
			BuildResults buildResults = configResults.getCurrentBuildResults();
			if ((global && buildResults.summaryKind == 1) || (!global && buildResults.summaryKind >= 0)) {
				scenarios.add(scenarioResults);
			}
		}
	}
	return scenarios;
}

private String lastBuildName(int kind) {
	String[] builds = getAllSortedBuildNames();
	int idx = builds.length-1;
	String lastBuildName = builds[idx--];
	switch (kind) {
		case 1: // no ref
			while (lastBuildName.startsWith(DB_Results.getDbBaselinePrefix())) {
				lastBuildName = builds[idx--];
			}
			break;
		case 2: // only I-build or M-build
			char ch = lastBuildName.charAt(0);
			while (ch != 'I' && ch != 'M') {
				lastBuildName = builds[idx--];
				ch = lastBuildName.charAt(0);
			}
			break;
		default:
			break;
	}
	return lastBuildName;
}

/*
 * Read local file contents and populate the results model with the collected
 * information.
 */
String readLocalFile(File dir, List<ScenarioResults> scenarios) throws FileNotFoundException {
//	if (!dir.exists()) return null;
	File dataFile = new File(dir, getName()+".dat");	//$NON-NLS-1$
	if (!dataFile.exists()) throw new FileNotFoundException();
	try (DataInputStream stream = new DataInputStream(new BufferedInputStream(new FileInputStream(dataFile)));) {
		// Read local file info

		print(" - read local files info"); //$NON-NLS-1$
		String lastBuildName = stream.readUTF(); // first string is the build name

		// Next field is the number of scenarios for the component
		int size = stream.readInt();

		// Then follows all the scenario information
		for (int i=0; i<size; i++) {
			// ... which starts with the scenario id
			int scenario_id = stream.readInt();
			ScenarioResults scenarioResults = scenarios == null ? null : getScenarioResults(scenarios, scenario_id);
			if (scenarioResults == null) {
				// this can happen if scenario pattern does not cover all those stored in local data file
				// hence, creates a fake scenario to read the numbers and skip to the next scenario
				// Note: we put a fake name and decription here since in some logging cases, it requires a name.
				// TODO: should work though the issues and make a "NullScenarioResult" work everywhere.
				scenarioResults = new ScenarioResults(-1, "org.eclipse.unexplained", "Place holder scenerio that does not appear to fit in?");
//				scenarioResults.parent = this;
//				scenarioResults.readData(stream);
				// Should no longer occur as we get all scenarios from database now
//				throw new RuntimeException("Unexpected unfound scenario!"); //$NON-NLS-1$
			}
			scenarioResults.parent = this;
			scenarioResults.printStream = this.printStream;
			scenarioResults.readData(stream);
			addChild(scenarioResults, true);
			if (this.printStream != null) this.printStream.print('.');
		}
		println();
		println("	=> "+size+" scenarios data were read from file "+dataFile); //$NON-NLS-1$ //$NON-NLS-2$

		// Return last build name stored in the local files
		return lastBuildName;
	} catch (IOException ioe) {
		println("	!!! "+dataFile+" should be deleted as it contained invalid data !!!"); //$NON-NLS-1$ //$NON-NLS-2$
	}
	return null;
}

/*
 * Read the database values for a build name and a list of scenarios.
 * The database is read only if the components does not already knows the
 * given build (i.e. if it has not been already read) or if the force arguments is set.
 */
void updateBuild(String buildName, List<ScenarioResults> scenarios, boolean force, File dataDir, SubMonitor subMonitor, PerformanceResults.RemainingTimeGuess timeGuess) {

	// Read all variations
	println("Component '"+this.name+"':"); //$NON-NLS-1$ //$NON-NLS-2$

	// manage monitor
	int size = scenarios.size();
	subMonitor.setWorkRemaining(size+1);
	StringBuffer buffer = new StringBuffer("Component "); //$NON-NLS-1$
	buffer.append(this.name);
	buffer.append("..."); //$NON-NLS-1$
	String title = buffer.toString();
	subMonitor.subTask(title+timeGuess.display());
	timeGuess.count++;
	subMonitor.worked(1);
	if (subMonitor.isCanceled()) return;

	// Read new values for the local result
	boolean dirty = false;
	long readTime = System.currentTimeMillis();
	String log = " - read scenarios from DB:"; //$NON-NLS-1$
	if (size > 0) {
		for (int i=0; i<size; i++) {

			// manage monitor
			subMonitor.subTask(title+timeGuess.display());
			timeGuess.count++;
			if (log != null) {
				println(log);
				log = null;
			}

			// read results
			ScenarioResults nextScenarioResults= scenarios.get(i);
			ScenarioResults scenarioResults = (ScenarioResults) getResults(nextScenarioResults.id);
			if (scenarioResults == null) {
				// Scenario is not known yet, force an update
				scenarioResults = nextScenarioResults;
				scenarioResults.parent = this;
				scenarioResults.printStream = this.printStream;
				scenarioResults.updateBuild(buildName, true);
				dirty = true;
				addChild(scenarioResults, true);
			} else {
				if (scenarioResults.updateBuild(buildName, force)) {
					dirty = true;
				}
			}
			if (dataDir != null && dirty && (System.currentTimeMillis() - readTime) > 300000) { // save every 5mn
				writeData(buildName, dataDir, true, true);
				dirty = false;
				readTime = System.currentTimeMillis();
			}

			// manage monitor
			subMonitor.worked(1);
			if (subMonitor.isCanceled()) return;
		}
	}

	// Write local files
	if (dataDir != null) {
		writeData(buildName, dataDir, false, dirty);
	}

	// Print global time
	printGlobalTime(readTime);

}

/*
 * Write the component results data to the file '<component name>.dat' in the given directory.
 */
void writeData(String buildName, File dir, boolean temp, boolean dirty) {
    if (DO_NOT_WRITE_DATA) {
        return;
    }
//	if (!dir.exists() && !dir.mkdirs()) {
//		System.err.println("can't create directory "+dir); //$NON-NLS-1$
//	}
	File tmpFile = new File(dir, getName()+".tmp"); //$NON-NLS-1$
	File dataFile = new File(dir, getName()+".dat"); //$NON-NLS-1$
	if (!dirty) { // only possible on final write
		if (tmpFile.exists()) {
			if (dataFile.exists()) dataFile.delete();
			tmpFile.renameTo(dataFile);
			println("	=> rename temporary file to "+dataFile); //$NON-NLS-1$
		}
		return;
	}
	if (tmpFile.exists()) {
		tmpFile.delete();
	}
	File file;
	if (temp) {
		file = tmpFile;
	} else {
		if (dataFile.exists()) {
			dataFile.delete();
		}
		file = dataFile;
	}

		try (DataOutputStream stream = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(file)))){
			int size = this.children.size();
			stream.writeUTF(lastBuildName(0));
			stream.writeInt(size);
			for (int i=0; i<size; i++) {
				ScenarioResults scenarioResults = (ScenarioResults) this.children.get(i);
				scenarioResults.write(stream);
			}

	} catch (FileNotFoundException e) {
		System.err.println("can't create output file"+file); //$NON-NLS-1$
	} catch (IOException e) {
		e.printStackTrace();
	} finally {
    println(" => extracted data "+(temp?"temporarily ":"")+"written in file "+file); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
  }
}

}