#!/usr/bin/env bash
#===============================================================================
#
#          FILE: setup.sh
#         USAGE: ./setup.sh 
#   DESCRIPTION: after pulling/cloning dotfiles repo, this script will check/create
#                symlinks for for dotfiles.  It checks for the presence of installed
#                software (i.e. won't symlink a dotfile for applications that aren't
#                installed) and will remove links for applications that are no longer
#                installed.  Safe to run after every git pull
#       OPTIONS: 
#  REQUIREMENTS: This script replies on the 'command' command.  Basically, it will run
#                `command -v <dotfile>` and if there is no output, it assumes the app
#                isn't installed.  So this won't work for apps that aren't in your $PATH
#                reference: http://www.cyberciti.biz/faq/unix-linux-shell-find-out-posixcommand-exists-or-not/
#         NOTES: 
#        AUTHOR: C Hawley
#       CREATED: 2015-10
#      REVISION: Tue 10 Oct 2017 04:37:37 PM EDT
#
#===============================================================================

set -o nounset                               # Treat unset variables as an error

# specify where your dotfiles live
dotfiledir="$HOME/dotfiles-vim"

# function to handle checking for existings links/files and updating
link() {
	echo "symlinking ${1}"
	# check for existing symlinks
	if [ -h "${HOME}"/"${1}" ]; then
		echo " - There's already a symlink named ${1}.  Diff'ing."
		# If there's an existing sylink, check if it's different than the dotfile
		if [[ $(diff --brief "${HOME}"/"${1}" "${dotfiledir}"/"${1}") ]]; then
			# If the links are different, ask if it should be replaced
			echo " - Old link and new link are different:"
			echo -n " - Replace existing symlink "${1}"? [Y/N] "
			read replace
			if [ "${replace}" = "Y" ] || [ "${replace}" = "y" ]; then
				# If yes, unlink the old file and link the new one and exit
				echo " - Unlinking old file and linking new file"
				unlink "${HOME}"/"${1}"
				ln -s "${dotfiledir}"/"${1}" "${HOME}"/"${1}"
			fi
		else
			# If the link is the same, just exit function
			echo " - Old link and new link are the same."
		fi
	# check for existing file/directory
	elif [ -f "${HOME}"/"${1}" ] || [ -d "${HOME}"/"${1}" ]; then
		echo " - There's already a file or directory named ${1}.  Diff'ing."
		if [[ $(diff --brief "${HOME}"/"${1}" "${dotfiledir}"/"${1}") ]]; then
			echo " - Old file/dir and new link are different:"
			echo -n " - Rename "${1}" and create new link? [Y/N] "
			read replace
			if [ "${replace}" = "Y" ] || [ "${replace}" = "y" ]; then
				echo " - Renaming old file/dir and linking new file"
				mv "${HOME}"/"${1}" "${HOME}"/"${1}"_original
				ln -s "${dotfiledir}"/"${1}" "${HOME}"/"${1}"
			fi
		fi
	else
		# If there is no existing file, create one and exit
		echo " - Creating link for ${1}"
		ln -s "${dotfiledir}"/"${1}" "${HOME}"/"${1}"
	fi
}

clear

echo "------------------------------------------"
echo "       .vim/.vimrc repo setup script      "
echo "------------------------------------------"
echo "          Setting up symlinks             "
echo "------------------------------------------"
echo ""

# link .vimrc
#-------------------------------------------------------------------------------
if [ $(command -v vim) ]; then
	link .vim
	link .vimrc
else
    echo "... vim not installed"
fi

echo ""
echo "------------------------------------------"
echo "Done.                                     "
echo "------------------------------------------"