#!/usr/bin/env bash

FILE=test-input-1
read -r -a MAP_ARRAY <<< "$( < "$FILE" paste -s -d "" | sed -E 's/(.)/\1\ /g' )"
MAP_LEN=${#MAP_ARRAY[@]}
MAP_WIDTH=$(( $( head -1 "$FILE" | wc -c ) -1 ))
MAP_HEIGHT=$( < "$FILE" wc -l )
printf "Len: %s Width: %s Height: %s\n" "$MAP_LEN" "$MAP_WIDTH" "$MAP_HEIGHT"

# Check if tiles are adjacent and do not violate bounds
check_adjacent () {

  # Check for out of map bounds
  if [[ $2 -lt 0 ]] || [[ $2 -gt $MAP_LEN ]]
  then
    return 1
  fi

  DIFF=$(( $2 - $1 ))
  # Valid adjacent distances
  case "$DIFF" in
    1|-1|"${MAP_WIDTH}"|-"${MAP_WIDTH}")
      :
      ;;
    *)
      return 1
      ;;
  esac

  # Check for left/right bounds
  if [[ $DIFF -eq 1 ]] && [[ $(( $2 % MAP_WIDTH )) -eq 0 ]]
  then
    return 1
  fi
  if [[ $DIFF -eq -1 ]] && [[ $(( $1 % MAP_WIDTH )) -eq 0 ]]
  then
    return 1
  fi

  return 0
}

# Basically recurse over mapping and "consume" all adjacent tiles
check_and_unset () {

  IDX=$1
  local KV_I=${IDX%% *} # Remove trailing whitespace
  if [[ -v KV_CACHE[$KV_I] ]] # Check if tile has been "taken"
  then 
    (( AREA++ ))
    VALUE=${KV_CACHE[$IDX]}
    printf "max: %s peri: %s area: %s key: %s val: %s\n" "$MAX_PERI" "$PERI_NUM" "$AREA" "$1" "$VALUE" >&2

    (( PERI_NUM+=MAX_PERI ))
    unset IFS; read -r -a VAL_ARRAY <<< "$VALUE"
    for VAL in "${VAL_ARRAY[@]}"
    do
      (( PERI_NUM-- ))
      check_and_unset "$VAL"
    done

    unset "KV_CACHE[$KV_I]" # "Take" it
  fi
}

while read -r CHAR
do
  # Get all indexes for a plant
  read -r -a CHAR_ARRAY <<< "$(
    for (( i=0; i<MAP_LEN; i++ ))
    do
      if [[ ${MAP_ARRAY[$i]} == "$CHAR" ]]
      then
        printf "%s " "$i"
      fi
    done
  )"

  { 
    printf "For char %s \n" "$CHAR"
    printf "%s " "${CHAR_ARRAY[@]}"
    printf "\n" 
  } >&2

  declare -A KV_CACHE
   
  IFS=':'; while read -r VAR1 VAR2
  do
    KV_CACHE[$VAR1]=$VAR2
  done <<< "$(
  
    # Find all adjacent tiles
    for (( i=0; i<${#CHAR_ARRAY[@]}; i++ ))
    do
      NUM_ADJ=0
      printf "%s:" "${CHAR_ARRAY[i]}"
      for (( j=i+1; j<i+MAP_WIDTH; j++ )) # There can only be MAP_WIDTH number of elements within valid range
      do
        if check_adjacent "${CHAR_ARRAY[i]}" "${CHAR_ARRAY[j]}"
        then
          printf "%s " "${CHAR_ARRAY[j]}"
          (( NUM_ADJ++ ))
        fi
      done
      printf "\n"
      #printf "Num adj for %s idx %s is %s\n" "$CHAR" "${CHAR_ARRAY[$i]}" "$NUM_ADJ" >&2
    done
  )"

  # Iterate through
  for CHAR in "${CHAR_ARRAY[@]}"
  do
    MAX_PERI=3
    PERI_NUM=1 # Special head case
    AREA=0
    check_and_unset "$CHAR"
    printf "max: %s peri: %s area: %s\n" "$MAX_PERI" "$PERI_NUM" "$AREA" >&2
    printf "%s\n" "$(( PERI_NUM * AREA ))"
  done
# Get all plants
done <<< "$( < "$FILE" grep -o '[A-Z]' | sort -u | grep -o '[A-Z]*' )" |
  paste -s -d "+" | bc