/*-
 * ============LICENSE_START=======================================================
 * ONAP-XACML
 * ================================================================================
 * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * 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.
 * ============LICENSE_END=========================================================
 */
package org.onap.policy.xacml.std.pap;

import org.onap.policy.common.logging.eelf.PolicyLogger;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.Serializable;
import java.net.URI;
import java.net.URL;
import java.util.ArrayList;
import java.util.Properties;

import oasis.names.tc.xacml._3_0.core.schema.wd_17.PolicySetType;
import oasis.names.tc.xacml._3_0.core.schema.wd_17.PolicyType;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.onap.policy.xacml.util.XACMLPolicyScanner;

import com.att.research.xacml.api.pap.PAPException;
import com.att.research.xacml.api.pap.PDPPolicy;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.google.common.base.Splitter;
import com.google.common.collect.Lists;


public class StdPDPPolicy implements PDPPolicy, Serializable {
	private static final long serialVersionUID = 1L;
	private static Log	logger	= LogFactory.getLog(StdPDPPolicy.class);
	
	private String id = null;
	
	private String name = null;

	private String policyId = null;
	
	private String description = null;
	
	private int[]	version = null;

	private boolean isRoot = false;
	
	private boolean isValid = false;
	
	private URI location = null;
	

	public StdPDPPolicy(String id, boolean isRoot) {
		this.id = id;
		this.isRoot = isRoot;
	}

	public StdPDPPolicy(String id, boolean isRoot, String name) {
		this(id, isRoot);
		this.name = name;
	}

	
	public StdPDPPolicy(String id, boolean isRoot, String name, URI location) throws IOException {
		this(id, isRoot);
		this.name = name;
		this.location = location;
		
		//
		// Read the policy data
		//		
		String theID = this.readPolicyData();

		if (this.id == null) {
			logger.debug("id is null so we are calling readPolicyData() to get the policyID");
			this.id = theID;
		}
		
		logger.debug("The final outcome of the constructor returned the following:  id = " + id + 
						", location = " + location + ", name = " + name);
		
	}
	
	public StdPDPPolicy(String id, boolean isRoot, String name, URI location, boolean isValid, String policyId, 
							String description, String version) throws IOException {
		this(id, isRoot);
		this.name = name;
		this.location = location;
		this.policyId = policyId;
		this.description = description;
		this.version = versionStringToArray(version);
		this.isValid = isValid;
		
		logger.debug("The final outcome of the constructor returned the following:  id = " + id + 
						", location = " + location + ", name = " + name + ", policyId = " + policyId +
							", description = " + description + ", Version = " + version);
		
	}
	
	public StdPDPPolicy(String id, boolean isRoot, String name, URI location, boolean isFromAPI) throws IOException {
		this(id, isRoot);
		this.name = name;
		this.location = location;
		this.isValid = isFromAPI;
		
		logger.debug("The final outcome of the constructor returned the following:  id = " + id + 
						", location = " + location + ", name = " + name);
		
	}

	public StdPDPPolicy(String id, boolean isRoot, URI location, Properties properties) throws IOException {
		this(id, isRoot);
		this.location = location;
		//
		// Read the policy data
		//
		this.readPolicyData();
		//
		// See if there's a name
		//
		for (Object key : properties.keySet()) {
			if (key.toString().equals(id + ".name")) {
				this.name = properties.getProperty(key.toString());
				break;
			}
		}
	}
	
	
	private String readPolicyData() throws IOException {
		//
		// Extract XACML policy information
		//
		URL url = this.location.toURL();
		Object rootElement = XACMLPolicyScanner.readPolicy(url.openStream());
		if (rootElement == null ||
			(
				! (rootElement instanceof PolicySetType) &&
				! (rootElement instanceof PolicyType)
			)	) {
			logger.warn("No root policy element in URI: " + this.location.toString() + " : " + rootElement);
			this.isValid = false;
		} else {
			this.version = versionStringToArray(XACMLPolicyScanner.getVersion(rootElement));
			if (rootElement instanceof PolicySetType) {
				this.policyId = ((PolicySetType)rootElement).getPolicySetId();
				this.description = ((PolicySetType)rootElement).getDescription();
				this.isValid = true;
				this.version = versionStringToArray(((PolicySetType)rootElement).getVersion());
			} else if (rootElement instanceof PolicyType) {
				this.policyId = ((PolicyType)rootElement).getPolicyId();
				this.description = ((PolicyType)rootElement).getDescription();
				this.version = versionStringToArray(((PolicyType)rootElement).getVersion());
				this.isValid = true;
			} else {
				PolicyLogger.error("Unknown root element: " + rootElement.getClass().getCanonicalName());
			}
		}
		if (this.policyId != null) {
			ArrayList<String> foo = Lists.newArrayList(Splitter.on(':').split(this.policyId));
			if (foo.isEmpty() == false) {
				return foo.get(foo.size() - 1);
			}
		}
		return null;
	}
	
	@Override
	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	@Override
	public String getName() {
		return this.name;
	}
	
	public void setName(String name) {
		this.name = name;
	}

	@Override
	public String getPolicyId() {
		return this.policyId;
	}
	
	@Override
	public String getDescription() {
		return this.description;
	}
	
	@Override
	public String getVersion() {
		return versionArrayToString(this.version);
	}
	
	@Override
	@JsonIgnore
	public int[] getVersionInts() {
		return version;
	}

	@Override
	public boolean isRoot() {
		return this.isRoot;
	}

	@Override
	public boolean isValid()
	{
		return this.isValid;
	}

	@Override
	@JsonIgnore
	public InputStream getStream() throws PAPException, IOException {
		try {
			if (this.location != null) {
				URL url = this.location.toURL();
				return url.openStream();
			}
			return null;
		} catch (FileNotFoundException e) {
			throw new PAPException(e);
		}
	}

	@Override
	public URI getLocation() throws PAPException {
		return this.location;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((id == null) ? 0 : id.hashCode());
		result = prime * result
				+ ((policyId == null) ? 0 : policyId.hashCode());
		result = prime * result;
		if (version != null) {
			for (int i = 0; i < version.length; i++) {
				result += version[i];
			}
		}
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		StdPDPPolicy other = (StdPDPPolicy) obj;
		if (id == null) {
			if (other.id != null)
				return false;
		} else if (!id.equals(other.id))
			return false;
		if (policyId == null) {
			if (other.policyId != null)
				return false;
		} else if (!policyId.equals(other.policyId))
			return false;
		if (version != other.version)
			return false;
		return true;
	}

	@Override
	public String toString() {
		return "StdPDPPolicy [id=" + id + ", name=" + name + ", policyId="
				+ policyId + ", description=" + description + ", version="
				+ this.getVersion() + ", isRoot=" + isRoot + ", isValid=" + isValid
				+ ", location=" + location + "]";
	}
	
	
	/**
	 * Given a version string consisting of integers with dots between them, convert it into an array of ints.
	 * 
	 * @param version
	 * @return
	 * @throws NumberFormatException
	 */
	public static int[] versionStringToArray(String version) throws NumberFormatException {
		if (version == null || version.length() == 0) {
			return new int[0];
		}
		String[] stringArray = version.split("\\.");
		int[] resultArray = new int[stringArray.length];
		for (int i = 0; i < stringArray.length; i++) {
			resultArray[i] = Integer.parseInt(stringArray[i]);
		}
		return resultArray;
	}
	
	/**
	 * Given an array representing a version, create the corresponding dot-separated string.
	 * 
	 * @param array
	 * @return
	 */
	public static String versionArrayToString(int[] array) {
		if (array == null || array.length == 0) {
			return "";
		}
		String versionString = "";
		if (array.length > 0) {
			versionString = "" + array[0];
			for (int i = 1; i < array.length; i++) {
				versionString += "." + array[i];
			}
		}
		return versionString;
	}
	

	
	//
	// Methods needed for JSON Deserialization
	//
	public StdPDPPolicy() {}
	
	public void setPolicyId(String policyId) {
		this.policyId = policyId;
	}
	public void setDescription(String description) {
		this.description = description;
	}
	public void setVersion(String version) {
		this.version = versionStringToArray(version);
	}
	public void setRoot(boolean isRoot) {
		this.isRoot = isRoot;
	}
	public void setValid(boolean isValid) {
		this.isValid = isValid;
	}
	public void setLocation(URI location) {
		this.location = location;
	}
	
}