#!/usr/bin/env bash

set -x

if [ -z "$1" ]; then

  echo "Where config file?"

  exit 1

fi

cfg=$1

# Set host_os:

#   windows, linux, unknown

# host_distro:

#   cygwin, debian, unknown

check_platform() {

  case `uname -s` in

    CYGWIN_NT-*)

      host_os=windows

      host_distro=cygwin

      ;;

    MINGW64_NT-*)

      host_os=windows

      host_distro=mingw64

      ;;

    Linux)

      host_os=linux

      if [ -e /etc/debian_version ]; then

        host_distro=debian

      else

        host_distro=unknown

      fi

      ;;

    Darwin)

      host_os=darwin

      ;;

    *)

      host_os=unknown

      ;;

  esac

}

print_header() {

  echo

  echo ';; ================================================================'

  echo ";; ${FUNCNAME[1]}."

  echo

}

check_ispell() {

  command -v ispell >/dev/null && return 0 || return 1

}

check_aspell() {

  command -v aspell >/dev/null && return 0 || return 1

}

print_ispell() {

  echo '(setq-default ispell-program-name "ispell")'

  case $host_distro in

    debian)

      echo '(setq-default ispell-local-dictionary "american")'

      ;;

    unknown)

      echo '(setq-default ispell-local-dictionary "default")'

      ;;

  esac

}

print_aspell() {

  echo '(setq-default ispell-program-name "aspell")'

  echo '(setq-default ispell-local-dictionary "american")'

}

print_speller() {

  print_header

  check_ispell

  ispell_present=$?

  check_aspell

  aspell_present=$?

  case $host_os in

    windows|linux)

      if [ $aspell_present = 0 ]; then

          print_aspell

      elif [ $ispell_present = 0 ]; then

          print_ispell

      fi

      ;;

    darwin)

      print_aspell

      ;;

    *)

      :

      ;;

  esac

}

print_man() {

  print_header

  if man -a man >/dev/null 2>&1; then

    echo '(setq Man-switches "-a")'

  else

    echo '(setq Man-switches "")'

  fi

}

print_emacs_sources_dir() {

  print_header

  if [[ -d ~/devel/emacs/emacs/src ]]; then

    echo '(setq find-function-C-source-directory "~/devel/emacs/emacs/src")'

  else

    ls ~/devel/emacs/src/emacs.c ~/devel/emacs/emacs*/src/emacs.c 2>/dev/null | {

      read f

      printf '(setq find-function-C-source-directory "%s")' ${f%emacs.c}

    }

  fi

}

cat >$cfg <<EOF

;; -*- mode: emacs-lisp; coding: utf-8; fill-column: 78 -*-

;;

;; For load order see README.

EOF

check_platform

{

  print_speller

  print_man

  print_emacs_sources_dir

} >>$cfg