aoc/5/2/solution.sh

#!/usr/bin/env bash

# INCOMPLETE

set -o errexit
set -o nounset
set -o pipefail
if [[ "${TRACE-0}" == "1" ]]; then
  set -o xtrace
fi

INPUT_FILE="$1"

gen_maps ()
{
  local map_count paragraph_num lines name
  map_count=$(awk -v RS= 'END {print NR}' "${INPUT_FILE}")
  map_count=$((map_count-1)) # one paragraph in file is seeds
  for ((i=1; i<=map_count; i++)); do
    paragraph_num=$((i+1)) # number of paragraph in input file
    lines="$(awk -v RS= "{if(NR == ${paragraph_num}) print}" "${INPUT_FILE}"| tail -n +2)"
    name="$(awk -v RS= "{if(NR == ${paragraph_num}) print}" "${INPUT_FILE}" | head -n 1 | cut -d ' ' -f 1 | tr - _)"
    declare -n array="${name}"
    while read -r line; do
      array+=("${line}")
    done <<< "${lines}"
    maps+=("${name}")
  done
}

gen_seed_pairs ()
{
  local seed_count pair_count i_start i_length start length end
  IFS=" " read -r -a seeds <<< "$(grep seeds "${INPUT_FILE}" | cut -d ' ' -f 2-)"
  seed_count="${#seeds[@]}"
  pair_count=$((seed_count/2))
  for ((i=0; i<pair_count; i++)); do
    i_start=$((i*2))
    i_length=$((i*2+1))
    start=${seeds[${i_start}]}
    length=${seeds[${i_length}]}
    end=$((start+length-1))
    seed_pairs+=("${start},${end}")
  done
}

get_lowest ()
{
  local dest_start source_start length dest_end source_end
  for n in "${maps[@]}"; do
    declare -a new_pairs=()
    declare -n map="${n}"
    for line in "${map[@]}"; do
      dest_start="$(cut -d ' ' -f 1 <<< "${line}")"
      source_start="$(cut -d ' ' -f 2 <<< "${line}")"
      length="$(cut -d ' ' -f 3 <<< "${line}")"
      dest_end=$((dest_start+length-1))
      source_end=$((source_start+length-1))
      if [[ ${#new_pairs[@]} -eq 0 ]]; then
        declare -n source_pairs="seed_pairs"
      else
        declare -n source_pairs="new_pairs"
      fi
      for ((i=0; i<${#source_pairs[@]}; i++)); do
        interim_pairs+=(source)
        seed_start="$(cut -d ',' -f 1 <<< "${source_pairs[${i}]}")"
        seed_end="$(cut -d ',' -f 2 <<< "${source_pairs[${i}]}")"
      done
    done
  done
  declare -a new_pairs
  seed_pairs=("${new_pairs[@]}")
}

main ()
{
  declare -a maps=()
  declare -a seed_pairs=() # start,end
  gen_maps
  gen_seed_pairs
  get_lowest

  echo "${#seed_pairs[@]}"
  for i in "${seed_pairs[@]}"; do
    echo "$i"
  done

#  for map in "${maps[@]}"; do
#    declare -n array="${map}"
#    echo "printing ${map} ${#array[@]}"
#    for ((i=0; i<${#array[@]}; i++)); do
#      echo "${array[${i}]}"
#    done
#  done
}

main