package com.example.connector;

import com.google.enterprise.connector.spi.AuthenticationIdentity;
import com.google.enterprise.connector.spi.AuthenticationManager;
import com.google.enterprise.connector.spi.AuthenticationResponse;
import com.google.enterprise.connector.spi.AuthorizationManager;
import com.google.enterprise.connector.spi.AuthorizationResponse;
import com.google.enterprise.connector.spi.Connector;
import com.google.enterprise.connector.spi.Document;
import com.google.enterprise.connector.spi.DocumentList;
import com.google.enterprise.connector.spi.Property;
import com.google.enterprise.connector.spi.RepositoryException;
import com.google.enterprise.connector.spi.Session;
import com.google.enterprise.connector.spi.SimpleDocument;
import com.google.enterprise.connector.spi.SpiConstants;
import com.google.enterprise.connector.spi.TraversalManager;
import com.google.enterprise.connector.spi.Value;

import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

public class HelloWorldConnector implements Connector {

  public Session login() {
    return new HelloSession();
  }

  public class HelloSession implements Session {
    public AuthenticationManager getAuthenticationManager() {
      return new HelloAuthenticationManager();
    }

    public AuthorizationManager getAuthorizationManager() {
      return new HelloAuthorizationManager();
    }

    public TraversalManager getTraversalManager() {
      return new HelloTraversalManager();
    }
  }

  public class HelloTraversalManager implements TraversalManager {
    private static final int MAX_DOCID = 1000;
    private int batchHint = 10;

    public void setBatchHint(int hint) {
      batchHint = hint;
    }

    public DocumentList startTraversal() {
      return traverse("0");
    }

    public DocumentList resumeTraversal(String checkpoint) {
      return traverse(checkpoint);
    }

    /**
     * Utility method to produce a {@code DocumentList} containing
     * the next batch of {@code Document} from the checkpoint.
     *
     * @param checkpoint a String representing the last document
     *        number processed.
     */
    private DocumentList traverse(String checkpoint) {
      int startDocId = Integer.parseInt(checkpoint) + 1;
      if (startDocId > MAX_DOCID) {
        return null;  // No more documents.
      }

      Calendar cal = Calendar.getInstance();

      List<Document> docList = new ArrayList<Document>(batchHint);

      int endDocId = Math.min(startDocId + batchHint - 1, MAX_DOCID);

      for (int i = startDocId; i <= endDocId; i++) {
        cal.setTimeInMillis(10 * 1000); // Each doc has the curretn timestamp
        Map<String, List<Value>>properties;
        properties = new HashMap<String, List<Value>>();

        properties.put(SpiConstants.PROPNAME_DOCID,
            asList(Value.getStringValue(Integer.toString(i))));

        properties.put(SpiConstants.PROPNAME_LASTMODIFIED,
            asList(Value.getDateValue(cal)));

        properties.put(SpiConstants.PROPNAME_DISPLAYURL,
            asList(Value.getStringValue("http://www.example.com/?docid=" + i)));

        properties.put(SpiConstants.PROPNAME_CONTENT,
            asList(Value.getBinaryValue("Hello World!".getBytes())));

        docList.add(new SimpleDocument(properties));
      }

      return new HelloWorldDocumentList(docList);
    }

    private List<Value> asList(Value value) {
      List<Value> list = new LinkedList<Value>();
      list.add(value);
      return list;
    }
  }

  class HelloWorldDocumentList implements DocumentList {
    private Iterator<Document> iterator;
    private Document document;

    public HelloWorldDocumentList(List<Document> documents) {
      this.iterator = documents.iterator();
      this.document = null;
    }

    public Document nextDocument() {
      if (iterator.hasNext()) {
        document = iterator.next();
        return document;
      }
      return null;
    }

    public String checkpoint() throws RepositoryException {
      if (document != null) {
        Property docId =
            document.findProperty(SpiConstants.PROPNAME_DOCID);
        return docId.nextValue().toString();
      }
      return null;
    }
  }

  class HelloAuthenticationManager implements AuthenticationManager {
    public AuthenticationResponse authenticate(AuthenticationIdentity id) {
      return new AuthenticationResponse(true, null);
    }
  }

  class HelloAuthorizationManager implements AuthorizationManager {
    public Collection<AuthorizationResponse> authorizeDocids(
         Collection<String> docIds, AuthenticationIdentity id) {
      ArrayList<AuthorizationResponse> authorized =
          new ArrayList<AuthorizationResponse>(docIds.size());
      for (String docId : docIds) {
        authorized.add(new AuthorizationResponse(true, docId));
      }
      return authorized;
    }
  }
}