#!/bin/bash

# Check if two arguments (input and output files) are provided
if [ "$#" -ne 2 ]; then
  echo "Usage: $0 input_file.csv output_file.csv"
  exit 1
fi

input_file="$1"    # First script parameter: input CSV file
output_file="$2"   # Second script parameter: output CSV file

rm -f "$output_file"

# Initialize an associative array to store the pairs and their corresponding last two numbers
declare -A pair_map

# Read the input file line by line
while IFS=, read -r first second third fourth fifth sixth seventh eighth; do
  # Create a unique key for the pair (first,second)
  key="$first,$second"
  reverse_key="$second,$first"
  
  # If the reverse key already exists in the array, compare the last two numbers
  if [[ -n "${pair_map[$reverse_key]}" ]]; then
    # Get the values stored for the reverse pair
    reverse_line="${pair_map[$reverse_key]}"
    reverse_seventh=$(echo "$reverse_line" | cut -d',' -f7)
    reverse_eighth=$(echo "$reverse_line" | cut -d',' -f8)
    
    # Compare the last two numbers and keep the line with the larger of the two
    if (( $(echo "$seventh > $reverse_seventh" | awk '{print ($1 > $2)}') )) && \
       (( $(echo "$eighth > $reverse_eighth" | awk '{print ($1 > $2)}') )); then
      echo "$first,$second,$third,$fourth,$fifth,$sixth,$seventh,$eighth" >> "$output_file"
    else
      echo "$reverse_line" >> "$output_file"
    fi
    
    # Remove the reverse_key from the array, as it has already been handled
    unset pair_map["$reverse_key"]
  else
    # Store the current line in the array
    pair_map["$key"]="$first,$second,$third,$fourth,$fifth,$sixth,$seventh,$eighth"
  fi
done < "$input_file"

# Optional: Output a message indicating the completion of the script
echo "Processing completed. Check $output_file for results."