package org.xmlsh.aws;

import java.io.IOException;
import java.util.List;
import javax.xml.stream.XMLStreamException;
import org.xmlsh.aws.util.AWSDDBCommand;
import org.xmlsh.core.CoreException;
import org.xmlsh.core.Options;
import org.xmlsh.core.UnexpectedException;
import org.xmlsh.core.XValue;
import com.amazonaws.AmazonClientException;
import com.amazonaws.services.dynamodbv2.model.ListTablesRequest;
import com.amazonaws.services.dynamodbv2.model.ListTablesResult;
import net.sf.saxon.s9api.SaxonApiException;

public class ddbListTables extends AWSDDBCommand {

  private int kLIMIT = 100;

  /**
   * @param args
   * @throws IOException
   */
  @Override
  public int run(List<XValue> args) throws Exception {

    Options opts = getOptions("limit:,exclusive-start-table=last-table:");
    parseOptions(opts, args);

    setSerializeOpts(this.getSerializeOpts(opts));
    args = opts.getRemainingArgs();

    if(args.size() != 0) {
      usage();
      return 1;
    }

    try {
      getDDBClient(opts);
    } catch (UnexpectedException e) {
      usage(e.getLocalizedMessage());
      return 1;

    }

    int ret = -1;
    ret = list(opts);

    return ret;

  }

  private int list(Options opts) throws IOException, XMLStreamException,
      SaxonApiException, CoreException {

    traceCall("listTables");

    int userLimit = opts.getOptInt("limit", 0);
    ListTablesRequest listTablesRequest = new ListTablesRequest();
    if(userLimit > 0)
      listTablesRequest.setLimit(Math.min(userLimit, kLIMIT));

    String lastTable = opts.getOptString("exclusive-start-table", null);
    boolean bStarted = false;

    int nlist = 0;
    do {
      if(lastTable != null)
        listTablesRequest.setExclusiveStartTableName(lastTable);
      ListTablesResult result = null;
      try {
        result = getAWSClient().listTables(listTablesRequest);
      } catch (AmazonClientException e) {
        return handleException(e);
      } finally {
        if(bStarted)
          endResult();
      }

      if(!bStarted)
        bStarted = startResult();
      int n = result.getTableNames().size();
      if(n <= 0)
        break;
      writeTables(result.getTableNames());
      nlist += n;
      if(userLimit > 0 && nlist >= userLimit)
        break;
      lastTable = result.getLastEvaluatedTableName();
    } while(lastTable != null);

    endResult();

    return 0;

  }

  private void writeTables(List<String> tableNames) throws XMLStreamException {
    for(String t : tableNames) {
      startElement("table");
      attribute("name", t);
      endElement();
    }
  }

}