/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.ranger.plugin.contextenricher;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Map;
import java.util.Properties;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.ranger.authorization.hadoop.config.RangerPluginConfig;
import org.apache.ranger.plugin.model.RangerServiceDef;
import org.apache.ranger.plugin.model.RangerServiceDef.RangerContextEnricherDef;
import org.apache.ranger.plugin.policyengine.RangerAccessRequest;
import org.apache.ranger.plugin.policyengine.RangerPluginContext;
import org.apache.ranger.plugin.service.RangerAuthContext;


public abstract class RangerAbstractContextEnricher implements RangerContextEnricher {
	private static final Log LOG = LogFactory.getLog(RangerAbstractContextEnricher.class);

	protected RangerContextEnricherDef enricherDef;
	protected String                   serviceName;
	protected String                   appId;
	protected RangerServiceDef         serviceDef;
	private   RangerPluginContext      pluginContext;

	@Override
	public void setEnricherDef(RangerContextEnricherDef enricherDef) {
		this.enricherDef = enricherDef;
	}

	@Override
	public void setServiceName(String serviceName) {
		this.serviceName = serviceName;
	}

	@Override
	public void setServiceDef(RangerServiceDef serviceDef) {
		this.serviceDef = serviceDef;
	}

	@Override
	public void setAppId(String appId) {
		this.appId = appId;
	}

	@Override
	public void init() {
		if(LOG.isDebugEnabled()) {
			LOG.debug("==> RangerAbstractContextEnricher.init(" + enricherDef + ")");
		}

		RangerAuthContext authContext = getAuthContext();

		if (authContext != null) {
			authContext.addOrReplaceRequestContextEnricher(this, null);
		} else {
			if (LOG.isDebugEnabled()) {
				LOG.debug("authContext is null. This context-enricher is not added to authContext");
			}
		}

		if(LOG.isDebugEnabled()) {
			LOG.debug("<== RangerAbstractContextEnricher.init(" + enricherDef + ")");
		}
	}

	@Override
	public void enrich(RangerAccessRequest request, Object dataStore) {
		enrich(request);
	}

	@Override
	public boolean preCleanup() {
		if(LOG.isDebugEnabled()) {
			LOG.debug("==> RangerAbstractContextEnricher.preCleanup(" + enricherDef + ")");
		}

		RangerAuthContext authContext = getAuthContext();

		if (authContext != null) {
			authContext.cleanupRequestContextEnricher(this);
		} else {
			if (LOG.isDebugEnabled()) {
				LOG.debug("authContext is null. AuthContext need not be cleaned.");
			}
		}

		if(LOG.isDebugEnabled()) {
			LOG.debug("<== RangerAbstractContextEnricher.preCleanup(" + enricherDef + ")");
		}

		return true;
	}

	@Override
	public void cleanup() {
		preCleanup();
	}

	@Override
	protected void finalize() throws Throwable {
		try {
			cleanup();
		}
		finally {
			super.finalize();
		}
	}

	@Override
	public String getName() {
		return enricherDef == null ? null : enricherDef.getName();
	}

	public RangerContextEnricherDef getEnricherDef() {
		return enricherDef;
	}

	public String getServiceName() {
		return serviceName;
	}

	public RangerServiceDef getServiceDef() {
		return serviceDef;
	}

	public String getAppId() {
		return appId;
	}

	public String getOption(String name) {
		String ret = null;

		Map<String, String> options = enricherDef != null ? enricherDef.getEnricherOptions() : null;

		if(options != null && name != null) {
			ret = options.get(name);
		}

		return ret;
	}

	public RangerAuthContext getAuthContext() {
		RangerPluginContext pluginContext = this.pluginContext;

		return pluginContext != null ? pluginContext.getAuthContext() : null;
	}

	final public void setPluginContext(RangerPluginContext pluginContext) {
		this.pluginContext = pluginContext;
	}

	public RangerPluginConfig getPluginConfig() {
		RangerPluginContext pluginContext = this.pluginContext;

		return pluginContext != null ? pluginContext.getConfig() : null;
	}

	public void notifyAuthContextChanged() {
		RangerPluginContext pluginContext = this.pluginContext;

		if (pluginContext != null) {
			pluginContext.notifyAuthContextChanged();
		}
	}

	public String getConfig(String configName, String defaultValue) {
		RangerPluginContext pluginContext = this.pluginContext;
		String              ret           = defaultValue;
		Configuration       config        = pluginContext != null ? pluginContext.getConfig() : null;

		if (config != null) {
			ret = config.get(configName, defaultValue);
		}

		return ret;
	}

	public int getIntConfig(String configName, int defaultValue) {
		RangerPluginContext pluginContext = this.pluginContext;
		int                 ret           = defaultValue;
		Configuration       config        = pluginContext != null ? pluginContext.getConfig() : null;

		if (config != null) {
			ret = config.getInt(configName, defaultValue);
		}

		return ret;
	}

	public boolean getBooleanConfig(String configName, boolean defaultValue) {
		RangerPluginContext pluginContext = this.pluginContext;
		boolean             ret           = defaultValue;
		Configuration       config        = pluginContext != null ? pluginContext.getConfig() : null;

		if (config != null) {
			ret = config.getBoolean(configName, defaultValue);
		}

		return ret;
	}

	public String getOption(String name, String defaultValue) {
		String ret = defaultValue;
		String val = getOption(name);

		if(val != null) {
			ret = val;
		}

		return ret;
	}

	public boolean getBooleanOption(String name, boolean defaultValue) {
		boolean ret = defaultValue;
		String  val = getOption(name);

		if(val != null) {
			ret = Boolean.parseBoolean(val);
		}

		return ret;
	}

	public char getCharOption(String name, char defaultValue) {
		char   ret = defaultValue;
		String val = getOption(name);

		if(! StringUtils.isEmpty(val)) {
			ret = val.charAt(0);
		}

		return ret;
	}

	public long getLongOption(String name, long defaultValue) {
		long   ret = defaultValue;
		String val = getOption(name);

		if(val != null) {
			ret = Long.parseLong(val);
		}

		return ret;
	}

	public Properties readProperties(String fileName) {
		Properties  ret     = null;
		InputStream inStr   = null;
		URL         fileURL = null;
		File        f       = new File(fileName);

		if (f.exists() && f.isFile() && f.canRead()) {
			try {
				inStr   = new FileInputStream(f);
				fileURL = f.toURI().toURL();
			} catch (FileNotFoundException exception) {
				LOG.error("Error processing input file:" + fileName + " or no privilege for reading file " + fileName, exception);
			} catch (MalformedURLException malformedException) {
				LOG.error("Error processing input file:" + fileName + " cannot be converted to URL " + fileName, malformedException);
			}
		} else {
			fileURL = getClass().getResource(fileName);

			if (fileURL == null && !fileName.startsWith("/")) {
				fileURL = getClass().getResource("/" + fileName);
			}

			if (fileURL == null) {
				fileURL = ClassLoader.getSystemClassLoader().getResource(fileName);

				if (fileURL == null && !fileName.startsWith("/")) {
					fileURL = ClassLoader.getSystemClassLoader().getResource("/" + fileName);
				}
			}
		}

		if (fileURL != null) {
			try {
				inStr = fileURL.openStream();

				Properties prop = new Properties();

				prop.load(inStr);

				ret = prop;
			} catch (Exception excp) {
				LOG.error("failed to load properties from file '" + fileName + "'", excp);
			} finally {
				if (inStr != null) {
					try {
						inStr.close();
					} catch (Exception excp) {
						// ignore
					}
				}
			}
		}

		return ret;
	}
}