package com.amfine.mdi.web.export;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.time.LocalDateTime;
import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.FlushModeType;
import javax.persistence.NoResultException;
import javax.persistence.TypedQuery;

import org.mdi.common.enums.PriceSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.opencsv.CSVWriter;

import com.amfine.mdi.domain.HistoricalPrice;
import com.amfine.mdi.service.HistoricalPriceService;

public class BloombergExport {

  private final char             cellSeparator;

  private final char             quoteChar;

  private HistoricalPriceService service;

  private static Logger          logger  = LoggerFactory.getLogger(BloombergExport.class);

  private EntityManagerFactory   emFactory;

  private final String[]         headers = new String[] {
    "instrumentId",
    "date",
    "instrumentData",
    "instrumentDividend",
    "currency"
  };

  public BloombergExport(
  final char cellSeparator,
  final char quoteChar,
  final HistoricalPriceService service,
  final EntityManagerFactory emFactory) {
    this.cellSeparator = cellSeparator;
    this.quoteChar = quoteChar;
    this.service = service;
    this.emFactory = emFactory;
  }

  public InputStream exportToStream(Long length, LocalDateTime sincePriceDate) throws IOException {

    File tmpFile = File.createTempFile("bloomberg-temporary", ".tmp");
    CSVWriter writer = new CSVWriter(new FileWriter(tmpFile), cellSeparator, quoteChar, '\'', "\n");
    writer.writeNext(headers);

    int lineCount = 0;
    String[] line;
    int col = 0;

    final String request = "select p from HistoricalPrice p where p.source = :priceSource AND p.writeDate >= :priceDate order by p.id";
    final int pageSize = 2;
    EntityManager eMgr = emFactory.createEntityManager();

    eMgr.setFlushMode(FlushModeType.COMMIT);
    EntityTransaction tx = eMgr.getTransaction();
    TypedQuery<HistoricalPrice> tq = eMgr.createQuery(request, HistoricalPrice.class);
    tq.setMaxResults(pageSize);
    tq.setParameter("priceSource", PriceSource.BLOOMBERG);
    tq.setParameter("priceDate", sincePriceDate);
    int startAt = 0;
    List<HistoricalPrice> pagedResults = null;
    do {
      tx.begin();
      tq.setFirstResult(startAt);
      pagedResults = tq.getResultList();
      try {
        System.out.println("startAt " + startAt);
        for (HistoricalPrice price : pagedResults) {

          line = new String[headers.length];
          col = 0;
          line[col++] = price.getInstrument().getInstrumentId();
          line[col++] = price.getPriceDate().toString();
          line[col++] = price.getClosePrice().toString();
          // in bloomberg case, we never export dividends so we skip the field..
          col++;
          if (price.getCurrency() != null) {
            line[col++] = price.getCurrency().toString();
          } else {
            line[col++] = null;
          }
          writer.writeNext(line);
          lineCount++;
          if (lineCount % pageSize == 0) {
            logger.info("Exported {} Bloomberg prices from EPR.", lineCount);
            writer.flush();
          }
          // System.out.println(price.getId() + "-" + price.getSource());
        }
      } catch (NoResultException e) {
        pagedResults = null;
      }
      eMgr.flush();
      eMgr.clear();
      tx.rollback();
      startAt += pageSize;
    } while ((pagedResults != null) && (!pagedResults.isEmpty()));
    eMgr.close();

    writer.close();
    InputStream targetStream = new FileInputStream(tmpFile);
    length = tmpFile.length();
    return targetStream;

  }

  public InputStream exportToStreamWithoutEM(Long length, LocalDateTime sincePriceDate) throws IOException {

    File tmpFile = File.createTempFile("bloomberg-temporary", ".tmp");
    CSVWriter writer = new CSVWriter(new FileWriter(tmpFile), cellSeparator, quoteChar, '\'', "\n");
    writer.writeNext(headers);

    List<HistoricalPrice> prices;
    prices = service.findBySourceSince(PriceSource.BLOOMBERG, sincePriceDate);

    int lineCount = 0;
    String[] line;
    int col = 0;

    for (HistoricalPrice p : prices) {
      line = new String[headers.length];
      col = 0;
      line[col++] = p.getInstrument().getInstrumentId();
      line[col++] = p.getPriceDate().toString();
      line[col++] = p.getClosePrice().toString();
      // in bloomberg case, we never export dividends so we skip the field..
      col++;
      if (p.getCurrency() != null) {
        line[col++] = p.getCurrency().toString();
      } else {
        line[col++] = null;
      }
      writer.writeNext(line);
      lineCount++;
      if (lineCount % 100 == 0) {
        logger.info("Exported {} Bloomberg prices from EPR.", lineCount);
        writer.flush();
      }
    }

    writer.close();
    InputStream targetStream = new FileInputStream(tmpFile);
    length = tmpFile.length();
    return targetStream;
  }

}