#!/bin/bash

#
# Find files or directories specific to techniques
# Features:
# - can list files by types
# - can list only directory
# - can list all versions or only the last one
# - can filter file list with a command
# - knows about .placeholder files
#

# safemode
set -euo pipefail

# parameters
LAST=0
HELP=0
DIR_ONLY=0
INCLUDE_INITIAL=0
PATTERN=""
FILTER=""
PLACEHOLDER=1

# parameter parsing
while getopts "hldif:s:p" opt
do
  case ${opt} in
    h)
      HELP=1
      ;;
    l)
      LAST=1
      ;;
    d)
      DIR_ONLY=1
      ;;
    i)
      INCLUDE_INITIAL=1
      ;;
    f)
      [ -n "${PATTERN}" ] && PATTERN="${PATTERN} -o "
      PATTERN="${PATTERN}-wholename *${OPTARG}*"
      ;;
    s)
      FILTER="${OPTARG}"
      ;;
    p)
      PLACEHOLDER=0
      ;;
    h)
      HELP=1
      ;;
    \?)
      HELP=1
      ;;
  esac
done
shift $((OPTIND-1))
[ -n "${PATTERN}" ] && PATTERN="( ${PATTERN} )"


# usage
if [ ${HELP} -eq 1 -o $# -eq 0 ]
then
  echo "Usage $0 [-p] [-l] [-d] [-i] [-f <pattern> [-f <pattern>] ...] <technique directory> [<technique directory> ...]"
  echo "  Find and filter files or directories for techniques under a specified directory"
  echo ""
  echo "  <technique directory> : specify the root of technique directories"
  echo "  -p : force including placeholder versions (default is to ignore them)"
  echo "  -l : list last version of each technique only"
  echo "  -d : list only base directories of techniques"
  echo "  -i : list 'special' files in initial-promises root (promises.cf, failsafe.cf, ...)"
  echo "  -f <pattern> : list files matching a pattern (may be repeated for multiple patterns)"
  echo "  -s '<command line>' : command to filter results, {} will be replaced by the file name"
  echo "     example : $0 -d -f '*.cf' -s 'grep edit_line {}' techniques"
  echo "               will list directories having .cf files that match edit_line"
  exit 1
fi

# find version directories of techniques
find_directories() {
  directory_regex='.*/[[:digit:]]+\.[[:digit:]]+'

  # indentation is important here for readability, be careful with pipes '|'
  find "${directory}" -not -wholename "*/.git/*" -type d -regextype posix-egrep -regex "${directory_regex}" |
    if [ "${PLACEHOLDER}" -eq 1 ]
    then
      xargs -r -n1 -I{} bash -c "test -f {}/.placeholder || echo {}"
    else
      cat
    fi |

      if [ "${LAST}" -eq 1 ]
      then
        perl -pe 's|(.*)/(\d+)\.(\d+)|$1 $2 $3|' |
          sort -k 1,1d -k 2,2nr -k 3,3nr | 
          perl -ne '/(.*) (\d+) (\d+)/;print "$1/$2.$3\n" unless($n eq $1);$n=$1'
      else
        cat
      fi
}

# find extra 'special' files in initial-promises root (promises.cf, failsafe.cf, ...)
find_initial() {
  if [ ${INCLUDE_INITIAL} -eq 1 ]; then
    find "${directory}" -not -wholename "*/.git/*" -type d -name "node-server" |
      xargs -r -n1 -I{} find "{}" -maxdepth 1 -not -wholename "*/.git/*" -type f
  fi
}

# main script
for directory in "$@"
do
  if [ ! -d "${directory}" ]
  then
    echo "No such directory ${directory}"
    exit 2
  fi
  
  if [ "${FILTER}" != "" ]
  then
    if [ ${DIR_ONLY} -eq 1 ]
    then
      # filter but keep only directory names
      find $(find_directories) -type f ${PATTERN} -exec /bin/bash -c "${FILTER} > /dev/null && echo {}" \; | xargs -r -n1 dirname | sort -u
    else
      # filter and show all file names
      find $(find_directories) $(find_initial) -type f ${PATTERN} -exec /bin/bash -c "${FILTER} > /dev/null && echo {}" \; | sort -u
    fi
  else
    if [ ${DIR_ONLY} -eq 1 ]
    then
      # just list directories
      find_directories
    else
      # list files within directories
      find $(find_directories) $(find_initial) -type f ${PATTERN}
    fi
  fi
done