package org.greenstone.gsdl3.gs3build;

import java.util.Date;
import java.util.Calendar;
import java.util.List;
import java.util.ArrayList;
import java.util.Map;
import java.util.HashMap;
import java.util.Iterator;
import java.util.GregorianCalendar;

import java.io.File;
import java.io.IOException;
import java.io.FileOutputStream;
import java.io.BufferedWriter;
import java.io.OutputStreamWriter;

import java.net.URL;
import java.net.URLEncoder;

import javax.xml.parsers.*;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;

import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

import org.greenstone.gsdl3.gs3build.collection.*;
import org.greenstone.gsdl3.gs3build.classifier.*;
import org.greenstone.gsdl3.gs3build.indexers.*;

import org.greenstone.gsdl3.gs3build.util.GS3SQLConnection;
import org.greenstone.gsdl3.gs3build.util.GS3SQLConnectionFactory;
import org.greenstone.gsdl3.gs3build.util.DOMUtils;
import org.greenstone.gsdl3.gs3build.util.URLTools;

import org.greenstone.gsdl3.util.GSFile;
import org.greenstone.gsdl3.util.GSXML;
import org.greenstone.gsdl3.util.XMLConverter;

/**
 *  Store and hold collection-level configuration information for a collection.
 *  This should be used by BuildManager to work out which classes, etc. to load
 *  at build time, and as a repository for the collection-level metadata, and
 *  a means of loading and saving the same to a file or database, as is seen
 *  fit in the final development of gs3.
 */

public class CollectionManager
{
  GregorianCalendar  lastBuildDate;  // pretty obvious
  String             adminEmail;     // the email address of the administrator of the
		                     // collection
  int                buildDocNo;     // used to generate document identifiers
  CollectionMetadata metadata;       // collection-level metadata
  GS3SQLConnection   database;       // the database to store everything in
  String             collectionHome;
  String             siteHome;
  String             collectionName;
  String             qualifiedCollectionName; // used as the database name 

  BuildManager       buildManager;
   
  class CollectionClassifier
  { URL    file;
    String type;
    List fields;
    String sort;
    String className;

    public CollectionClassifier(URL parentURL, String type, String className, Node node)
    { this.type = type;
      this.className = className;
      this.fields = new ArrayList();

      NodeList children = node.getChildNodes();
      for (int c = 0; c < children.getLength(); c ++) {
	Node child = children.item(c);

	if (child.getNodeType() == org.w3c.dom.Node.ELEMENT_NODE) {
	  String name = child.getNodeName();
	  
	  if (name.equals("file")) {
	    NamedNodeMap atts = children.item(c).getAttributes();
	    Node attribute = atts.getNamedItem("URL");
	    String urlString = attribute.getNodeValue();
	    if (urlString == null)
	      continue;

	    System.out.println("Path is" + parentURL.getPath());
	    System.out.println("Host is" + parentURL.getHost());
	    System.out.println(urlString);

	    try {
	      URL url = new URL(parentURL, urlString);
	      this.file = url;
	      System.out.println(url);
	    }
	    catch (java.net.MalformedURLException malEx) {
	      System.out.println(malEx);
	    }
	  }
	  else if (name.equals("field")) {
	    String fieldName = DOMUtils.getNodeChildText(children.item(c));
	    this.fields.add(fieldName.toString());
	  }
	  else if (name.equals("sort")) {
	    String sortName = DOMUtils.getNodeChildText(children.item(c));
	    this.sort = sortName;
	  }
	}
      }
    }

    public ClassifierInterface getClassifier()
    { ClassifierInterface classifier = null;

      if (this.type == null) {
	return null;
      }
      System.out.println(this.type.toLowerCase());
      
      if (this.type.toLowerCase().equals("hierarchy")) {
	System.out.println(this.file);
	classifier = new HierarchyClassifier(this.className, this.file, this.fields, this.sort);
      }
      else if (this.type.toLowerCase().equals("azlist")) {
	classifier = new AZListClassifier(this.className, this.fields);
      }

      return classifier;
    }
  }
   
  /**
   *  Create the collection manager for a given collection
   *
   * @param site the name of the site
   *  @param collection <code>String</code> the name of the collection
   */
  public CollectionManager(String site, String collection) {
    
    String gsdl3Root = System.getProperty("GSDL3HOME");
    if (gsdl3Root == null) {
      System.out.println("Error: Unable to locate GSDL3HOME");
      System.exit(1);
      //return;
    }
    
    this.siteHome = GSFile.siteHome(gsdl3Root, site);
    File site_dir = new File(this.siteHome);
    System.out.println(site_dir);
    if (!site_dir.exists()) {
      System.out.println("Error: Non-existant site ("+site+") specified");
      System.exit(1);
    }
    site_dir = null;
    this.collectionHome = GSFile.collectionBaseDir(this.siteHome, collection);
    
    File collect_dir = new File(this.collectionHome);
    if (!collect_dir.exists()) {
      System.out.println("Error: Non-existant collection ("+collection+") specified in site "+site);
      System.exit(1);
    }
    collect_dir = null;

    this.collectionName = collection;
    this.qualifiedCollectionName = site+"_"+collection;

    this.database = GS3SQLConnectionFactory.createConnection(this.qualifiedCollectionName);
    /*    if (this.database != null) {
      this.database.clearCollection(collection);
      this.database = null;
    }
    */
    if (this.database == null) {
      this.database = GS3SQLConnectionFactory.createConnection("test");
      this.database.initCollection(this.qualifiedCollectionName);
    }

    this.metadata = new CollectionMetadata();

    File buildDirectory = new File(GSFile.collectionBuildDir(this.collectionHome));
    if (!buildDirectory.exists()) {
      buildDirectory.mkdir();
    }

    File archiveDirectory = new File(GSFile.collectionArchiveDir(this.collectionHome));
    if (!archiveDirectory.exists()) {
      archiveDirectory.mkdir();
    }

    this.buildDocNo = 1;
  }

  public void setBuildManager(BuildManager build_man) 
  { this.buildManager = build_man;
  }

  private void configureBrowsers(Node node, File etcFile)
  { CollectionClassifier classifier = null;
    URL etcURL = null;

    etcURL = URLTools.getFileURL(etcFile);

    NodeList children = node.getChildNodes();
    for (int c = 0; c < children.getLength(); c ++)
    { // assume that non-element children are irrelevant
      if (children.item(c).getNodeType() != org.w3c.dom.Node.ELEMENT_NODE)
      { continue;
      }

      String name = children.item(c).getNodeName();
      System.out.println(name);

      if (name.equals(GSXML.CLASSIFIER_ELEM))
      { NamedNodeMap atts = children.item(c).getAttributes();

        // get the type attribute
	Node attribute = atts.getNamedItem(GSXML.TYPE_ATT);
	if (attribute == null) {
	  continue;
	}
	String type = attribute.getNodeValue();

        // get the type attribute
	attribute = atts.getNamedItem(GSXML.NAME_ATT);
	if (attribute == null) {
	  continue;
	}
	String className = attribute.getNodeValue();

	classifier = new CollectionClassifier(etcURL, type, className, children.item(c));
	
	System.out.println("Found classifier " + type);
	
	// attach the classifier
	ClassifierInterface classify = classifier.getClassifier();
	this.buildManager.getClassifierManager().addClassifier(classify);
      }  
    }
  }

  public void configureCollection()
  { File collectionConfig = new File(GSFile.collectionConfigFile(this.collectionHome));
    
    // get the File and read it in
    try
    {
      DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
      DocumentBuilder builder = factory.newDocumentBuilder();
      Document document = builder.parse(collectionConfig);

      // TODO: report an error
      if (document == null)
      {	
      }

      // now parse the manager file...
      Element rootElement = document.getDocumentElement();

      if (rootElement.getTagName() != GSXML.COLLECTION_CONFIG_ELEM)
      {	// TODO: throw exception
      }

      System.out.println("Configuring collection");

      NodeList children = rootElement.getChildNodes();
      for (int c = 0; c < children.getLength(); c ++)
      {	// assume that non-element children are irrelevant
	if (children.item(c).getNodeType() != org.w3c.dom.Node.ELEMENT_NODE)
	{ continue;
	}

	String name = children.item(c).getNodeName();

	// the name is a plugin element

	if (name.equals("doctype")) {
	  System.out.println("document type");
	  NamedNodeMap typeAttributes = children.item(c).getAttributes();
	  Node typeAttribute = typeAttributes.getNamedItem("type");
	  String documentType = null;

	  NodeList childNodes = children.item(c).getChildNodes();
	  for (int n = 0; n < childNodes.getLength(); n ++)
	  { if (childNodes.item(n).getNodeType() == org.w3c.dom.Node.TEXT_NODE)
	    { String label = childNodes.item(n).getNodeValue();
              label.trim();
	      if (label.length() > 0) {
		documentType = label;
		System.out.println("Document type " + documentType);
	      }
	    }
	  }
	}
	else if (name.equals(GSXML.SEARCH_ELEM)) {
	  // pick up attributes from the <search> tag now...
	  NamedNodeMap searchAttributes = children.item(c).getAttributes();
	  Node searchAttribute = searchAttributes.getNamedItem(GSXML.TYPE_ATT);
	  String searchType = null;
	  if (searchAttribute != null) {
	      searchType = searchAttribute.getNodeValue();
	  } else {
	      System.out.println("no "+GSXML.TYPE_ATT+" attribute found for the "+GSXML.SEARCH_ELEM+" element, assuming mg");
	      searchType = MGIndexer.MG_INDEX_TYPE;
	  }
	  
	  searchAttribute = searchAttributes.getNamedItem(GSXML.NAME_ATT);
	  String searchName = null;
	  if (searchAttribute != null) {
	      searchName = searchAttribute.getNodeValue();
	  }
	  if (searchName == null) {
	      searchName = "idx"; // need to modify this if we have two search elements with no names
	  }
	  // create the pertinent indexer...
	  IndexerInterface indexer = IndexerFactory.makeIndexer(searchType, searchName);

	  if (indexer == null) {
	    continue;
	  }

	  // configure the indexer
	  indexer.configure(children.item(c));

	  // install it into the build manager
	  this.buildManager.addIndexer(indexer);
	}
	else if (name.equals(GSXML.BROWSE_ELEM))
	{ this.configureBrowsers(children.item(c), collectionConfig);
	}
	// TODO: other elements - make a factory-method approach here...
	else
	{
	}
      }
    }
    catch (FactoryConfigurationError e) {
      System.out.println(e);
    }
    catch (ParserConfigurationException ex) {
      System.out.println(ex);
    }
    catch (SAXException ex) {
      System.out.println(ex);
    }
    catch (IOException ex)
    {
      System.out.println(ex);
    }

    System.out.println("<<<Obtaining database>>>>");
  }

  public String getEtcDirectory()
  
  { return GSFile.collectionEtcDir(this.collectionHome);
  }

  public String getImportDirectory()
  { return GSFile.collectionImportDir(this.collectionHome);
  }

  public String getBuildDirectory()
  { return GSFile.collectionBuildDir(this.collectionHome);
  }

  public String getArchiveDirectory()
  { return GSFile.collectionArchiveDir(this.collectionHome);
  }

  public GS3SQLConnection getDatabase()
  {
    return this.database;
  }

  public Date getBuildDate()
  { return this.lastBuildDate.getTime();
  }

  public void startBuild()
  { GregorianCalendar today = new GregorianCalendar();
  
    if (this.lastBuildDate != null)
    { // if the build date is different to the last build date, then reset the build
      // document number
      if (today.get(Calendar.YEAR) != this.lastBuildDate.get(Calendar.YEAR) ||
	  today.get(Calendar.MONTH) != this.lastBuildDate.get(Calendar.MONTH) ||
	  today.get(Calendar.DAY_OF_MONTH) != this.lastBuildDate.get(Calendar.DAY_OF_MONTH))
      { this.buildDocNo = 1;
      }
    }
    this.lastBuildDate = today;
  }

  public void endBuild()
  {
      // here we write out the build config file
      // create the xml for the buildConfig
      XMLConverter converter = new XMLConverter();
      Document doc = converter.newDOM();
      Element build_config = doc.createElement(GSXML.COLLECTION_BUILD_ELEM);
      Element meta_list = doc.createElement(GSXML.METADATA_ELEM + GSXML.LIST_MODIFIER);
      build_config.appendChild(meta_list);
      Element service_list = doc.createElement(GSXML.SERVICE_CLASS_ELEM+GSXML.LIST_MODIFIER);
      build_config.appendChild(service_list);

      // the document structure and metadata retrieval will use GS3REtrieve service, so add it in here
      Element base_retrieve_service = doc.createElement(GSXML.SERVICE_CLASS_ELEM);
      base_retrieve_service.setAttribute(GSXML.NAME_ATT, "GS3Retrieve");
      service_list.appendChild(base_retrieve_service);
      // ask the indexers to add stuff into the service rack list
      this.buildManager.getIndexerManager().addServiceDescriptions(service_list);
      this.buildManager.getClassifierManager().addServiceDescriptions(service_list);
      // get the String
      String build_config_string = converter.getString(build_config);
      // write it to the file
      try {
	  File build_config_file = new File(GSFile.collectionBuildConfigFileBuilding(this.collectionHome));
	  BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(build_config_file), "UTF-8"));
	  writer.write(build_config_string, 0, build_config_string.length());
	  writer.close();
      } catch (Exception e) {
	  System.err.println("CollectionManager.endBuild() Error while trying to output the buildConfig.xml file.");
	  System.err.println(e.getMessage());
      }
    Date startDate = this.lastBuildDate.getTime();
    Date date = new Date();

    long startTime = startDate.getTime();
    long endTime   = date.getTime();

    long difference = ((endTime - startTime) + 500) / 1000;

    System.out.println("Build completed");
    System.out.println("---------------");
    System.out.println("Total Documents: " + this.getCollectionMetadata("gsdl3", "documentCount"));
    System.out.println("Total Time :     " + (difference / 60) + " min. " + (difference % 60) + " secs.");
  }

  public String getNextDocumentID()
  { StringBuffer ID = new StringBuffer();

    int value;
    ID.append(lastBuildDate.get(Calendar.YEAR));

    // the use of month is a little odd, hence the following
    // code.  Calendar.MONTH yields 0 = January, 1 = February,
    // etc. hence there is a '+1' added to the month to make 
    // it into January = 1, etc., and the padding is altered
    // correspondingly.
    value = lastBuildDate.get(Calendar.MONTH);
    if (value < 9)
    { ID.append("0");
    }
    ID.append(value + 1);
    value = lastBuildDate.get(Calendar.DAY_OF_MONTH);
    if (value < 10)
      ID.append("0");
    ID.append(value);


    value = this.buildDocNo;
    this.buildDocNo ++;
    
    ID.append(":");
    ID.append(Integer.toString(value));
    return ID.toString();
  }
  
  public int getDocumentNumber()
  { this.buildDocNo ++;
    return this.buildDocNo - 1;
  }

  /**
   *  Get the collection metadata item in the given namespace
   *
   *  @param <code>String</code> the namespace
   *  @param <code>String</code> the label of the metadata
   */
  public String getCollectionMetadata(String namespace, String label)
  { return this.metadata.getCollectionMetadata(namespace, label).get(0).toString();
  }

  /**
   *  Set the collection metadata item in the given namespace
   *
   *  @param <code>String</code> the namespace
   *  @param <code>String</code> the label
   *  @param <code>String</code> the value
   */
  public void setCollectionMetadata(String namespace, String label, String value)
  { this.metadata.setCollectionMetadata(namespace, label, value);
  }
}