#!/usr/bin/env bash

FILE=input
read -r -a INPUT_ARRAY <<< "$( sed -E 's/.*X[\+\=]([0-9]+), Y[\+\=]([0-9]+)/\1 \2 /g' < "$FILE" | paste -s -d " " )"
#printf "%s\n" "${INPUT_ARRAY[@]}" >&2
INPUT_LEN=${#INPUT_ARRAY[@]}

TOTAL_TOKEN=0
for (( i=0 ; i < INPUT_LEN; i+=6 ))
do
  A=${INPUT_ARRAY[i]}
  C=${INPUT_ARRAY[i+1]}
  B=${INPUT_ARRAY[i+2]}
  D=${INPUT_ARRAY[i+3]}
  X=$(( 10000000000000 + ${INPUT_ARRAY[i+4]} ))
  Y=$(( 10000000000000 + ${INPUT_ARRAY[i+5]} ))

  # Check if moduluses are eq 0 before proceeding
  I_MODULUS=$(( (B*Y - D*X) % (B*C - D*A) ))
  echo "I_MODULUS: $I_MODULUS"
  if [[ $I_MODULUS -eq 0 ]]
  then
    I=$(( ( B*Y - D*X ) / ( B*C - D*A ) )) # Button A
  else
    continue
  fi
  J_MODULUS=$(( ( X - A*I ) % B ))
  echo "J_MODULUS: $J_MODULUS"
  if [[ $J_MODULUS -eq 0 ]]
  then
    J=$(( ( X - A*I ) / B )) # Button b
  else
    continue
  fi

  # Numbers have to be positive ints
  if [[ $I -lt 1 ]] || [[ $J -lt 1 ]]
  then
    continue
  fi

  {
    echo "( $B*$Y - $D*$X ) / ( $B*$C - $D*$A )" >&2 # Button A
    echo "( $X - $A*$I ) / $B )" >&2  # Button B
    printf "Answer: I= %s, J= %s\n" "$I" "$J"
    printf "Verify answer : %s to %s, %s to %s\n" "$(( A*I + B*J ))" "$X" "$(( C*I + D*J ))" "$Y"
    printf "Total cost: %s\n" "$(( I*3 + J*1 ))"
  } >&2

  TOKEN=$(( I*3 + J*1 )) # Calculate token cost

  # Verify numbers with results for positions
  if ! [[ $(( A*I + B*J )) -eq $X ]] # X position
  then
    continue
  elif ! [[ $(( C*I + D*J )) -eq $Y ]] # Y position
  then
    continue
  else
    (( TOTAL_TOKEN+=TOKEN ))
  fi
done
printf "Total token: %s\n" "$TOTAL_TOKEN"