#!/usr/bin/env bash

function show_contents {
  local file="${2/#~/$HOME}"
  if [ -f "$file" ]; then
    echo "$1 gitignore: $2" && cat "$file"
  else
    echo "There is no $1 .gitignore yet"
  fi
}

function show_global {
  show_contents Global `git config --global core.excludesfile`
}

function add_global {
  local global_gitignore=$(git config --global core.excludesfile)
  if [ -z "$global_gitignore" ]; then
    echo "Can't find global .gitignore."
    echo ""
    echo "Use 'git config --global --add core.excludesfile ~/.gitignore-global' to set the path to your global gitignore file to '~/.gitignore-global'."
    echo ""
  else
    add_patterns `git config --global core.excludesfile` "$@"
  fi
}

function show_local {
  cd "$(git root)"
  show_contents Local .gitignore
}

function add_local {
  cd "$(git root)"
  add_patterns .gitignore "$@"
}

function add_patterns {
  echo "Adding pattern(s) to: $1"
  local file="${1/#~/$HOME}"
  for pattern in "${@:2}"; do
    echo "... adding '$pattern'"
    (test -f "$file" && test "$pattern" && grep -q -F -x -- "$pattern" "$file") || echo "$pattern" >> "$file"
  done
}

if test $# -eq 0; then
   show_global
   echo "---------------------------------"
   show_local
else
  case "$1" in
    -l|--local)
      test $# -gt 1 && add_local "${@:2}" && echo
      show_local
      ;;
    -g|--global)
      test $# -gt 1 && add_global "${@:2}" && echo
      show_global
      ;;
    *)
      add_local "$@"
      ;;
  esac
fi