package org.apache.maven.artifact.repository;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.util.Hashtable;

import java.util.StringTokenizer;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import javax.xml.parsers.ParserConfigurationException;

import org.xml.sax.SAXException;

import org.w3c.dom.*;

public class MavenJPackageDepmap {

	private static class ArtifactDefinition {

		String groupId = null;

		String artifactId = null;

		String version = null;

	}

	private static  MavenJPackageDepmap instance;

	private static Hashtable<String, String> jppArtifactMap;

	private MavenJPackageDepmap() {

		jppArtifactMap = new Hashtable<String,String>();

		buildJppArtifactMap();

	}

	public static MavenJPackageDepmap getInstance() {

		if (instance == null) {

			instance = new MavenJPackageDepmap();

		}

		return instance;

	}

	public Hashtable<String, String> getMappedInfo(Hashtable<String, String> mavenDep) {

		return getMappedInfo((String) mavenDep.get("group"),

				(String) mavenDep.get("artifact"),

				(String) mavenDep.get("version"));

	}

	public Hashtable<String, String> getMappedInfo(String groupId, String artifactId, String version) {

		Hashtable<String, String> jppDep;

		String idToCheck, jppCombination;

		if (System.getProperty("maven.ignore.versions") == null && System.getProperty("maven.local.mode") == null) {

			idToCheck = groupId+","+artifactId+","+version;

		} else {

			idToCheck = groupId+","+artifactId;

		}

		jppCombination = (String) jppArtifactMap.get(idToCheck);

		//System.err.println("*** " + groupId+","+artifactId+","+version + " => " + jppCombination);

		jppDep = new Hashtable<String, String>();

		if (jppCombination != null && jppCombination != "") {

			StringTokenizer st = new StringTokenizer(jppCombination, ",");

			jppDep.put("group", st.nextToken());

			jppDep.put("artifact",st.nextToken());

			jppDep.put("version",st.nextToken());

		} else {

			jppDep.put("group", groupId);

			jppDep.put("artifact", artifactId);

			jppDep.put("version", version);

		}

		return jppDep;

	}

	/**

	 *	Returns whether or not the given dependency should be dropped.

	 */

	public boolean shouldEliminate(String groupId, String artifactId, String version) {

		String idToCheck;

		if (System.getProperty("maven.ignore.versions") == null && System.getProperty("maven.local.mode") == null) {

			idToCheck = groupId+","+artifactId+","+version;

		} else {

			idToCheck = groupId+","+artifactId;

		}

		return jppArtifactMap.get(idToCheck) != null && jppArtifactMap.get(idToCheck).equals("");

	}

	private static void buildJppArtifactMap() {

		if (System.getProperty("maven.ignore.versions") != null || System.getProperty("maven.local.mode") != null) {

			debug("Processing file: /usr/share/java-utils/xml/maven2-versionless-depmap.xml");

			processDepmapFile("/etc/maven/maven2-versionless-depmap.xml");

		}

		debug("Processing file: /usr/share/java-utils/xml/maven2-depmap.xml");

		processDepmapFile("/etc/maven/maven2-depmap.xml");

		String customFileName = System.getProperty("maven.local.depmap.file", null);

		if (customFileName != null) {

			debug("Processing file: " + customFileName);

			processDepmapFile(customFileName);

		}

	}

	private static void processDepmapFile(String fileName) {

		Document mapDocument;

		debug("Loading depmap file: " + fileName);

		try {

			DocumentBuilderFactory fact = DocumentBuilderFactory.newInstance();

			fact.setNamespaceAware(true);

			DocumentBuilder builder = fact.newDocumentBuilder();

			mapDocument = builder.parse(fileName);

		} catch (FileNotFoundException fnfe) {

			System.err.println("ERROR: Unable to find map file: " + fileName);

			fnfe.printStackTrace();

			return;

		} catch (IOException ioe) {

			System.err.println("ERROR: I/O exception occured when opening map file");

			ioe.printStackTrace();

			return;

		} catch (ParserConfigurationException pce) {

			System.err.println("ERROR: Parsing of depmap file failed - configuration");

			pce.printStackTrace();

			return;

		} catch (SAXException se) {

			System.err.println("ERROR: Parsing of depmap file failed");

			se.printStackTrace();

			return;

		}

		NodeList depNodes = (NodeList) mapDocument.getElementsByTagName("dependency");

		for (int i = 0; i < depNodes.getLength(); i++) {

			Element depNode = (Element) depNodes.item(i);

			NodeList mavenNodeList = (NodeList) depNode.getElementsByTagName("maven");

			if (mavenNodeList.getLength() != 1) {

				debug("Number of maven sub-elements is not 1. Bailing from depmap generation");

				debug("Maven node: " + depNode.getTextContent());

				return;

			}

			ArtifactDefinition mavenAD = getArtifactDefinition((Element) mavenNodeList.item(0));

			ArtifactDefinition jppAD = null;

			NodeList jppNodeList = (NodeList) depNode.getElementsByTagName("jpp");

			if (jppNodeList.getLength() == 1) {

				jppAD = getArtifactDefinition((Element) jppNodeList.item(0));

				if (System.getProperty("maven.ignore.versions") == null && System.getProperty("maven.local.mode") == null) {

					debug("*** Adding: " + mavenAD.groupId + "," + mavenAD.artifactId + "," + mavenAD.version + " => "

							+  jppAD.groupId + "," + jppAD.artifactId + "," + jppAD.version + " to map...");

					jppArtifactMap.put(mavenAD.groupId + "," + mavenAD.artifactId + "," + mavenAD.version,

							jppAD.groupId + "," + jppAD.artifactId + "," + jppAD.version);

				} else {

					debug("*** Adding: " + mavenAD.groupId+"," + mavenAD.artifactId + " => " 

							+  jppAD.groupId + "," + jppAD.artifactId + "," + jppAD.version + " to map...");

					jppArtifactMap.put(mavenAD.groupId+","+mavenAD.artifactId, 

							jppAD.groupId + "," + jppAD.artifactId + "," + jppAD.version);

				}

			} else {

				debug("Number of jpp sub-elements is not 1. Dropping dependency");

				debug("*** Adding: " + mavenAD.groupId+","+mavenAD.artifactId+"," + " => " +  "JPP/maven2,empty-dep,"+mavenAD.version + " to map...");

				jppArtifactMap.put(mavenAD.groupId+","+mavenAD.artifactId, "JPP/maven2,empty-dep,"+mavenAD.version);

			}

		} 

	}

	private static ArtifactDefinition getArtifactDefinition(Element element) {

		ArtifactDefinition ad = new ArtifactDefinition();

		NodeList nodes = element.getElementsByTagName("groupId");

		if (nodes.getLength() != 1) {

			debug("groupId definition not found in depmap");

			return null;

		}

		ad.groupId = nodes.item(0).getTextContent();

		nodes = element.getElementsByTagName("artifactId");

		if (nodes.getLength() != 1) {

			debug("artifactId definition not found in depmap");

			return null;

		}

		ad.artifactId = nodes.item(0).getTextContent();

		nodes = element.getElementsByTagName("version");

		if (nodes.getLength() != 1) {

			ad.version = "DUMMY_VER";

		} else {

			ad.version = nodes.item(0).getTextContent();

		}

		return ad;

	}

	public static void debug(String msg) {

		if (System.getProperty("maven.local.debug") != null)

			System.err.println(msg);

	}

}