package de.aikiit.bilanzanalyser.reader;
   
   import de.aikiit.bilanzanalyser.entity.BilanzRow;
   import lombok.AllArgsConstructor;
   import lombok.Data;
   import lombok.extern.log4j.Log4j2;
   import org.odftoolkit.odfdom.doc.OdfSpreadsheetDocument;
   import org.odftoolkit.odfdom.doc.table.OdfTable;
   import org.odftoolkit.odfdom.doc.table.OdfTableCell;
  import org.odftoolkit.odfdom.doc.table.OdfTableRow;
  
  import java.io.File;
  import java.io.IOException;
  import java.nio.file.Path;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Optional;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import static de.aikiit.bilanzanalyser.reader.BilanzRowParser.fromOdfTableRow;
  
  @Data
  @AllArgsConstructor
  @Log4j2
  public final class BilanzOdsReader {
  
      private String tableName;
      private Path source;
  
      /**
       * Parses the given tableName in the configured ODS file.
       *
       * @return result object.
       * @throws IOException in case of general I/O errors as parsing errors are transformed into skipped rows.
       */
      public BilanzRowParserResult extractData() throws IOException {
          try {
              BilanzRowParserResult result = BilanzRowParserResult.empty();
  
              OdfTable table = readTable();
              if (table == null) {
                  return result;
              }
  
              // ODS default is 1048576 albeit it's only empty rows
              log.info("Given table '{}' has {} rows", this.tableName, table.getRowCount());
  
              List<BilanzRow> rows = new ArrayList<>();
              AtomicInteger counter = new AtomicInteger(0);
              AtomicInteger readRows = new AtomicInteger(0);
              AtomicInteger rowsWithParsingErrors = new AtomicInteger(0);
  
              for (int rowCount = 0; rowCount < table.getRowCount(); rowCount++) {
                  OdfTableRow row = table.getRowByIndex(rowCount);
  
                  // only allow 5 empty rows in a row
                  if (counter.get() == 5) {
                      log.info("STOPPING due to too many empty lines after having read {} non-empty rows.", readRows.get());
                      break;
                  }
  
                  OdfTableCell cell = row.getCellByIndex(0);
                  if (cell.getStringValue().isEmpty()) {
                      counter.incrementAndGet();
                      // skip empty rows
                  } else {
                      counter.set(0);
                      readRows.incrementAndGet();
                      result = result.withRow();
  
                      Optional<BilanzRow> br = fromOdfTableRow(row);
                      if (br.isPresent()) {
                          rows.add(br.get());
                      } else {
                          rowsWithParsingErrors.incrementAndGet();
                          result = result.withError();
                      }
                  }
              }
  
              log.info("Extracted {} rows successfully, while skipping {} not well formatted rows.", rows.size(), rowsWithParsingErrors.get());
              return result.withRows(rows);
          } catch (Exception e) {
              throw new IOException(e);
          }
      }
  
      private OdfTable readTable() throws Exception {
          try (OdfSpreadsheetDocument document = OdfSpreadsheetDocument.loadDocument(source.toFile())) {
              return document.getTableByName(this.tableName);
          }
      }
  }