#!/usr/bin/env bash

TOWEL_FILE=$1
DESIGN_FILE=$2
TOWEL_ITER=10

read -r -a TOWELS <<< "$( < "$TOWEL_FILE" tr ',' ' ' | paste -s -d " " )"
read -r -a DESIGNS <<< "$( < "$DESIGN_FILE" paste -s -d " " )"

#printf "Towel %s\n" "${TOWELS[@]}"
#printf "Design %s\n" "${DESIGNS[@]}"

# Check if towel is a viable match
match_towel () {
  TOWEL=$1
  MATCH=$2
  FULL_DESIGN=$3

  TO_MATCH="$MATCH$TOWEL"
  PARTIAL_DESIGN=${FULL_DESIGN::${#TO_MATCH}}
  if [[ $PARTIAL_DESIGN == "$TO_MATCH" ]]
  then
    return 0
  else
    return 1
  fi
}

TOTAL_VALID=0
declare -A UNMATCHED_TOWEL_LIST
for DESIGN in "${DESIGNS[@]}"
do
  printf "Starting design : %s\n" "$DESIGN"
  declare -A MATCH_LIST
  # Get all viable starting matches
  for TOWEL_IDX in "${!TOWELS[@]}"
  do
    TOWEL=${TOWELS[$TOWEL_IDX]}
    #printf "Testing towel: %s\n" "$TOWEL"

    if match_towel "$TOWEL" "" "$DESIGN"
    then
      #printf "Starting match found. towel : %s\n" "$TOWEL"
      # Copy towel list and remove the starting towel
      read -r -a TOWEL_LIST <<< "$( printf "%s " "${TOWELS[@]}" )"
      unset "TOWEL_LIST[$TOWEL_IDX]"
      # Add to combinations
      MATCH_LIST["$TOWEL"]=$( printf "%s " "${TOWEL_LIST[@]}" )
      unset "TOWEL_LIST"
    fi
  done
  if [[ ${#MATCH_LIST[@]} -eq 0 ]] ; then printf "No available starting matches.\n" ; continue ; fi
  # Now iterate over starting matches
  LOOP_COUNT=${#TOWELS[@]}
  while [[ $LOOP_COUNT -gt 0 ]]
  do
    for TOWEL_MATCH in "${!MATCH_LIST[@]}"
    do
      read -r -a TOWEL_LIST <<< "${MATCH_LIST[$TOWEL_MATCH]}"
      # Iterate over towels and find subsequent match
      for TOWEL_IDX in "${!TOWEL_LIST[@]}"
      do
        TOWEL=${TOWELS[$TOWEL_IDX]}
        if match_towel "$TOWEL" "$TOWEL_MATCH" "$DESIGN"
        then
          #printf "Match found for %s towel : %s\n" "${TOWEL_MATCH}" "$TOWEL"
          unset "TOWEL_LIST[$TOWEL_IDX]"
          # Add to combinations
          MATCH_LIST["$TOWEL_MATCH$TOWEL"]=$( printf "%s " "${TOWEL_LIST[@]}" )
          unset "MATCH_LIST[$TOWEL_MATCH]"
        fi
      done
    done
    (( LOOP_COUNT-- ))
  done

  # Calculate proper matches
  for MATCH in "${!MATCH_LIST[@]}"
  do
    if [[ $MATCH == "$DESIGN" ]]
    then
      printf "Match found for design %s\n" "$DESIGN"
      (( TOTAL_VALID++ ))
    fi
  done

  # Remove matches
  unset MATCH_LIST
done
printf "Total valid designs: %s\n" "$TOTAL_VALID"