# Global variables
POS=~/.Point_Of_Sales
POS=POS.txt
export POS

confirm()
{
  echo -en "$@"
  read ans
  ans=`echo $ans | tr '[a-z]' '[A-Z]'`
  if [ "$ans" == "Y" ]; then
    return 0
  else
    return 1
  fi
}

num_lines()
{
  grep -i "$@" $POS|wc -l| awk '{ print $1 }'
}

find_lines()
{
  # Find lines matching $1
  res=-1
  if [ ! -z "$1" ]; then
    grep -i "$@" $POS
    res=$?
  fi
  return $res
}

list_items()
{
  # List items matching given search criteria
  if [ "$#" -eq "0" ]; then
    echo -en "Search for: (return to list all) "
    read search
    if [ -z "$search" ]; then
      search="."
    fi
    echo
  else
    search="$@"
  fi
  find_lines "${search}" | while read i
  do
    echo "$i" | tr ':' '\t'
  done
  echo -en "Matches found: "
  num_lines "$search"
}

add_item()
{
  echo "Add Item: You will be prompted for 3 items:"
  echo "- Item Description, Unit Price, Quantity Purchased -"
  echo
  echo -en "Item Description:"
  read product
  echo -en "Unit Price:"
  read Unit_Price
  echo -en "Quantity:"
  read Quantity
  Date_Purchased=$(date +"%d %b %Y")  
  

  echo "${product}:${Unit_Price}:${Quantity}:${Date_Purchased}" >> $POS
}

locate_single_item()
{
  echo -en "Item to search for: "
  read search
  n=`num_lines "$search"`
  if [ -z "$n" ]; then
    n=0
  fi
  while [ "${n}" -ne "1" ]; do
    #list_items "$search"
    echo -en "${n} matches found. Please choose a "
    case "$n" in 
      "0") echo "less" ;;
      "*") echo "more" ;;
    esac
    echo "specific search term (q to return to menu): "
    read search
    if [ "$search" == "q" ]; then
      return 0
    fi
    n=`num_lines "$search"`
  done
  return `grep -in $search $POS |cut -d":" -f1`
}

remove_item()
{
  locate_single_item
  search=`head -$? $POS | tail -1|tr ' ' '.'`
  if [ -z "${search}" ]; then
    return
  fi
  list_items "$search"
  confirm "Remove?"
  if [ "$?" -eq "0" ]; then
    grep -v "$search" $POS > ${POS}.tmp ; mv ${POS}.tmp ${POS}
  else
    echo "NOT REMOVING"
  fi
}

edit_item()
{
  locate_single_item
  search=`head -$? $POS | tail -1|tr ' ' '.'`
  if [ -z "${search}" ]; then
    return
  fi
  list_items "$search"
  thisline=`grep -i "$search" $POS`
  oldProduct=`echo $thisline|cut -d":" -f1`
  oldUnitPrice=`echo $thisline|cut -d":" -f2`
  oldQuanity=`echo $thisline|cut -d":" -f3`
  echo "SEARCH : $search"
  grep -v "$search" $POS > ${POS}.tmp ; mv ${POS}.tmp ${POS}
  echo -en "Item Description: [ $oldProduct ] "
  read Product
  echo -en "Unit Price[ $oldUnitPrice ] "
  read Unit_Price
  echo -en "Quanity [ $oldQuanity ] "
  read Quanity
  Date_Purchased=$(date +"%d %b %Y")  
  echo "${Product}:${Unit_Price}:${Quanity}:${Date_Purchased}" >> $POS
}
summary_items()
{
  #echo "- - - POS Summary Report - - -"
  #echo "---------------------------"
  #echo "Date       Total POS"
  #echo "---------------------------"
  print_dtotal
  #echo "---------------------------"
  #print_gtotal
  #echo "---------------------------"
  #echo -en "Best Selling Product: "
  #print_bestsell
  #echo -en "Product with Highest POS: "
  #print_phighPOS
  #echo -en "Date with Highest POS: "
  print_dtotal | sort -f4| while read z
    do
        echo $z | cut -f4 -d' '
        return 0
    done
  echo
  echo -en "Press Enter to continue..."
  read
}
print_dtotal()
{
  count=0
  grep -i : $POS | cut -d: -f4 | sort -u | while read i
    do
        dtotal=0
    grep -i "$i" $POS | while read x
        do
            count=`expr $count + 1`
            temp1=`echo $x | cut -d: -f2 | cut -c2-`
            temp2=`echo $x | cut -d: -f3`
            temp3=`calcu_m $temp1 $temp2`
                        dtotal=`calcu_a $dtotal $temp3`
            n=`num_lines "$i"`
               if [ "${n}" -eq "${count}" ]; then
                echo  $i"        $"$dtotal
              fi
        done
    done 

}
print_gtotal()
{
  gtotal=0
  grep -i : $POS | while read x
    do
        temp1=`echo $x | cut -d: -f2 | cut -c2-`
        temp2=`echo $x | cut -d: -f3`
        temp3=`calcu_m $temp1 $temp2`
                gtotal=`calcu_a $gtotal $temp3`
        n=`num_lines "$i"`
           if [ "${n}" -eq "${count}" ]; then
            echo  "Grand Total      $"$gtotal
          fi
        count=`expr $count + 1`
    done 

}
print_bestsell()
{
   grep -i : $POS | sort -k4 -r -t: | while read bs
    do
           echo $bs | cut -d: -f1
        return 0
    done
}
print_phighPOS()
{
      count=0
        phigh="0.0"
    grep -i : $POS | while read x
        do
            count=`expr $count + 1`
            temp1=`echo $x | cut -d: -f2 | cut -c2-`
            temp2=`echo $x | cut -d: -f3`
            temp3=`calcu_m $temp1 $temp2`
            comparex $temp3 $phigh
               if [ "$?" -eq "0" ]; then
                phigh=$temp3
                phighx=`echo $x | cut -d: -f1`
              fi
            n=`num_lines ":"`
               if [ "${n}" -eq "${count}" ]; then
                echo  $phighx
              fi
        done
}
comparex()        # compare 2 decimal numbers $1 $2 eg 1.20 and 3.60
{
    x1=`echo $1 | cut -d. -f1`
    x2=`echo $1 | cut -d. -f2`
    y1=`echo $2 | cut -d. -f1`
    y2=`echo $2 | cut -d. -f2`
    if [ "${x1}" -gt "${y1}" ]; then
        return 0
    elif [ "${x1}" -eq "${y1}" ]; then
        if [ "${x2}" -gt "${y2}" ]; then
            return 0
        fi
    fi
    return 1
}
calcu_a()        # add 2 decimal numbers $1 $2
{
    x1=`echo $1 | cut -d. -f1`
    x2=`echo $1 | cut -d. -f2`
    y1=`echo $2 | cut -d. -f1`
    y2=`echo $2 | cut -d. -f2`
    x1=`expr $x1 + $y1`
    x2=`expr $x2 + $y2`
    x3=`expr $x2 \/ 100`
    x1=`expr $x1 + $x3`
    x2=`expr $x2 \% 100`
    echo $x1"."$x2
}
calcu_m()        # multiply 2 decimal numbers $1 $2
{
    x1=`echo $1 | cut -d. -f1`
    x2=`echo $1 | cut -d. -f2`
    y=`echo $2`
    x1=`expr $x1 \* $y`
    x2=`expr $x2 \* $y`
    x3=`expr $x2 \/ 100`
    x1=`expr $x1 + $x3`
    x2=`expr $x2 \% 100`
    echo $x1"."$x2
}