#! /usr/bin/env bash
# 2002: If we needed this to be performant, we wouldn't use bash. cat is fine.
# 2068: We want to resplit argument in this case.
# shellcheck disable=SC2002,2068

PROJECT_ID='W973564ED9F278A21F3E12037288412FBAF175F889'

PROJECT_HEADER="include/wtr/watcher.hpp"

# @todo This function doesn't work if the file doesn't end in a newline.
tool::hone() {
  USAGE="
  $0 < option > { option }

  option:
    --header-content-amalgam
    --header-content-raw
    --header-path-all
    --help

  example:
    tool/hone --header-content-amalgam > include/wtr/watcher.hpp"

  LAST_DIR="$PWD"

  cd "$(dirname "$0")/../devel" || return 1

  # Sanity checks
  while read -r H
  do if ! test -f "include/$H"
  then echo "Header file missing: 'include/$H'"; return 1; fi
  done <<< "$(\
    cat "$PROJECT_HEADER" \
      | grep -E '([ ]*)#([ ]*)include ' \
      | sed -E 's/(([ ]*)#([ ]*)include )|(["<>])//g')"

  # HEADER_INCLUDES_UNIQUE="$(\
  #   find include/detail include/wtr -name '*.hpp' -exec cat {} \; \
  #     | sed -E 's/(([ ]+)?#([ ]+)?include [<"][0-9a-zA-Z\-_\.\:;~`!@#$%^&\*\(\)'\'']+[">])|(.*)/\1/g' \
  #     | sort \
  #     | awk '!seen[$0]++')"

  HEADER_PATH_ALL="$(\
    while read -r H
    do echo "$PWD/include/$H" || return 1
    done <<< "$(\
      cat "$PROJECT_HEADER" \
        | grep -E '([ ]+)?#([ ]+)?include' \
        | sed -E 's/(([ ]+)?#([ ]+)?include )|(["<>])//g')"
  )"

  # cat the headers, replace our pragmas
  HEADER_CONTENT_RAW="$(\
    while read -r TOK
    do
      cat "$TOK" \
        | sed -E 's|(/\* )(@pragma/tool/hone/insert )(.+)( \*/)|\3 /\* @pragma/tool/hone/insert \*/|g' \
        | sed '/#pragma once/d' \
        | sed '/#include <detail\/wtr\/watcher\/.*/d' \
        | sed '/#include <wtr\/watcher.*/d' \
        | sed '/#include "detail\/wtr\/watcher\/.*/d' \
        | sed '/#include "wtr\/watcher.*/d'
    done <<< "$HEADER_PATH_ALL"
  )"

  # # cat the headers, remove includes.
  # # @todo this function is slow.
  # HEADER_CONTENT_SANS_INCLUDES="$(\
  #   while read -r H
  #   do
  #     echo "$H" \
  #       | sed -E '/#pragma once/d' \
  #       | sed -E '/([ ]+)?#([ ]+)?include/d'
  #   done <<< "$HEADER_CONTENT_RAW"
  # )"

  # give us the amalgamated header
  HEADER_CONTENT_AMALGAM="$(\
    echo "#ifndef $PROJECT_ID" \
      && echo "#define $PROJECT_ID" \
      && echo "$HEADER_CONTENT_RAW" \
      && echo "#endif /* $PROJECT_ID */"
  )"

  if test -n "$*"
  then
    if echo "$*" | grep -q -- --header-content-amalgam
    then echo "$HEADER_CONTENT_AMALGAM"; fi
    if echo "$*" | grep -q -- --header-content-raw
    then echo "$HEADER_CONTENT_RAW"; fi
    # if echo "$*" | grep -q -- --header-content-sans-includes
    # then echo "$HEADER_CONTENT_SANS_INCLUDES"; fi
    if echo "$*" | grep -q -- --header-path-all
    then echo "$HEADER_PATH_ALL"; fi
    if echo "$*" | grep -q -- --help
    then echo "$USAGE"; fi
  else
    AMALGAMATED_FILE=../$PROJECT_HEADER
    if ! diff <(echo "$HEADER_CONTENT_AMALGAM") "$AMALGAMATED_FILE" &> /dev/null
    then echo "$HEADER_CONTENT_AMALGAM" > "$AMALGAMATED_FILE"
    fi
  fi

  cd "$LAST_DIR" || return 1
}

tool::hone $@
exit $?