function generateTable() {
  var month = 8;
  var sheet = SpreadsheetApp.getActiveSheet();
  var lastRow = sheet.getDataRange().getLastRow();
  var fromRow = lastRow;
  if (lastRow != 1) {
     sheet.appendRow([' '])
     sheet.appendRow([' '])
     var fromRow = lastRow + 3
  }

  var tableLength = generateContent(month, fromRow, sheet)

  var toRow = fromRow + tableLength + 1;
  setDateNumbersFormat(fromRow, toRow, sheet);
  sheet.getRange(fromRow, 1, toRow - fromRow - 1, 7).setBorder(true, true, true, true, true, true)
  sheet.getRange(fromRow, 6, toRow - fromRow - 1).setFontWeight('bold').setFontLine('underline')
  sheet.getRange(fromRow + 1, 1, toRow - fromRow - 1, 7).setVerticalAlignment('middle').setHorizontalAlignment('center')
}

function isSunday(date) {
  return date.getDay() == 0;
}

function generateContent(month, firstRow, sheet) {
  var date =  new Date(month +'/1/2018');
  var monthStr = Utilities.formatDate(date, Session.getScriptTimeZone(), "MMMM");

  sheet.appendRow([monthStr]);
  sheet.setRowHeight(firstRow, 50)
  sheet.getRange(firstRow, 1, 1, 7).merge()
    .setBackgroundRGB(183, 225, 205)
    .setFontSize(18)
    .setFontWeight('bold')
    .setVerticalAlignment('middle');

  var count = 1;
  var skippedRowsCount = 0;
  var row = 0;
  var lastDayOfMonthInt;
  while (true) {
    var next = new Date(month +'/' + count + '/2018');
    if (next.getMonth() != month - 1) {
      lastDayOfMonthInt = count - 1
      break;
    }
    row = firstRow + count + skippedRowsCount;
    sheet.appendRow([next, '=TEXT(WEEKDAY(A' + row + '), "dddd")', '', '', '', '=D' + row + '-C' + row + '-E' + row]);

    var dateCells = sheet.getRange(row, 1, 1, 2)
    dateCells
      .setBackgroundRGB(183, 225, 205)
      .setFontWeight('bold')

    if (next.getDay() == 0 || next.getDay() == 6) {
      dateCells.setFontColor('#cc0000')
    }

    if (isSunday(next)){
      appendTotalForWeekRow(firstRow, row, sheet);
      skippedRowsCount++;
    }
    count++;
  }
  return count + skippedRowsCount + appendTotalForLastWeekRow(month, lastDayOfMonthInt, row, sheet);
}

function appendTotalForWeekRow(firstRow, row, sheet) {
   var mondayRow = row - 6;
   if (mondayRow < firstRow + 1) {
     mondayRow = firstRow + 1;
   }
   var workingDaysCount = row - mondayRow - 1
   sheet.appendRow(['', '', '', '', '', '=SUM(F' + mondayRow + ':F' + row + ')', '=F' + (row + 1) + '- TIME(4, 0, 0) * ' +  workingDaysCount])
   sheet.getRange(row + 1, 7)
      .setFontColor('#cc0000')
      .setFontWeight('bold')
   sheet.setRowHeight(row + 1, 35)
}

function appendTotalForLastWeekRow(month, lastDayOfMonthInt, lastRow, sheet) {
  if (!isSunday(new Date(month +'/' + lastDayOfMonthInt + '/2018'))) {
    var rowBeforeMonday = lastRow - 1
    while (true) {
      rowBeforeMonday--;
      lastDayOfMonthInt--;
      if (new Date(month +'/' + lastDayOfMonthInt + '/2018').getDay() == 1) {
        break
      }
    }
    if (lastRow - rowBeforeMonday == 6){
      rowBeforeMonday -= 1
    }
    else {
      rowBeforeMonday -= 2
    }
    appendTotalForWeekRow(rowBeforeMonday, lastRow, sheet)
    return 1
  }
  return 0
}

function setDateNumbersFormat(fromRow, toRow, sheet) {
  sheet.getRange(fromRow, 2, toRow - fromRow, 6).setNumberFormat('[h]:mm')
  sheet.getRange(fromRow, 1, toRow - fromRow).setNumberFormat('dd.MM')
}