install

#!/usr/bin/env bash
# ----------------------------------------------------------------------------------------------------------------------
# ls-git - https://github.com/eth-p/ls-git/ | MIT License | Copyright (C) 2018 Ethan P. (eth-p)
# ----------------------------------------------------------------------------------------------------------------------
# Copyright (c) 2018 Ethan P. (eth-p)
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
# ----------------------------------------------------------------------------------------------------------------------
HERE="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
INSTALL_CACHE="${HERE}/.installed"
# ----------------------------------------------------------------------------------------------------------------------
A_ERR="\x1B[31m"
A_MSG="\x1B[35m"
A_RST="\x1B[0m"
A_AMEND="\x1B[A\x1B[J"
A_ALT_ENTER="\x1B[?1049h\x1B[2J\x1B[H"
A_ALT_EXIT="\x1B[?1049l"
# ----------------------------------------------------------------------------------------------------------------------
# Arguments:

arg_to="$([ -f "$INSTALL_CACHE" ] && cat "$INSTALL_CACHE" || echo "$HOME/.bin")"
arg_update=false
arg_deps=false
arg_minify=false
arg_depcheck=true
argv=()
argv_original=("$@")

# Argument Parser:
argparse_key=''
argparse_val=''
for argparse in "$@" ''; do
	[ "$argparse_key" = '--' ] && { argv+=("$argparse"); continue; };
	case "$argparse" in
		'--')      argparse_key='--'; continue;;
		'--'*'='*) argparse_key="$(sed 's/=.*$//' <<< "$argparse")"; argparse_val="$(sed 's/^.*=//' <<< "$argparse")";;
		'--'*)     argparse_key="$argparse";;
		*)         argparse_val="$argparse";;
	esac

	case "$argparse_key" in
		'')              argv+=("$argparse_val");;
		'--to')          [ "$argparse" != "$argparse_key" ] && arg_to="$argparse_val";;
		'--deps')        arg_deps=true;      argparse_key='';;
		'--update')      arg_update=true;    argparse_key='';;
		'--minify')      arg_minify=true;    argparse_key='';;
		'--no-depcheck') arg_depcheck=false; argparse_key='';;
		*)               printf "${A_ERR}Illegal argument: %s${A_RST}\n" "$argparse_key";;
	esac

	[ "$argparse" != "$argparse_key" ] && argparse_key=''
done

# ----------------------------------------------------------------------------------------------------------------------
# Utility Functions:

start() {
	printf "${A_MSG}%s${A_RST}\n" "$1" 1>&2
}

err() {
	printf "%$(tput cols)s" '' | tr ' ' '-' 1>&2
	printf "${A_ERR}ERROR: %s${A_RST}\n" "$1" 1>&2
}

fatal() {
	printf "%$(tput cols)s" '' | tr ' ' '-' 1>&2
	printf "${A_ERR}FATAL: %s${A_RST}\n" "$1" 1>&2
	exit 1
}

contains() {
	local search="$1"
	local element
	for element in "${@:2}"; do
		[ "$element" = "$search" ] && return 0
	done
	return 1
}

abspath() {
	python -c "import os,sys; print os.path.abspath(sys.argv[1])" "$1" || realpath "$1" || {
		fatal "Please install python to use this installer."
		exit 2
	}
}

# ----------------------------------------------------------------------------------------------------------------------
# Dependency Check Functions:

__cache_depcheck_perl=()
__cache_depcheck=()

depcheck_perl() {
	local module="$1"

	contains "$module" "${__cache_depcheck_perl[@]}" && return 0
	__cache_depcheck_perl+=("$module")

	# Check if the module can be loaded in Perl.
	printf "Checking for module %-30s " "'$module'..."
	if echo "use $module;" | perl &>/dev/null; then
		echo "OK"
		return 0
	else
		echo "Missing"
	fi

	# Check if the module can't be installed by the script.
	[ "$arg_deps" = "true" ] || fatal "Missing module."

	# Attempt to install the module.
	printf "${A_ALT_ENTER}"
	start "Installing module: ${module}"
	[ -d "${HERE}/.install-logs" ] || mkdir -p "${HERE}/.install-logs"
	PERL_MM_USE_DEFAULT=1 cpan install -T "$module" | tee "${HERE}/.install-logs/${module}";

	if [ "$?" -ne 0 ]; then
		err "Install failed."
		read -s
		printf "${A_ALT_EXIT}"
		exit 1
	fi

	printf "${A_ALT_EXIT}"
	printf "${A_AMEND}"
	printf "Checking for module %-30s Installed\n" "'$module'..."
}

depcheck() {
	local program="$1"

	contains "$program" "${__cache_depcheck[@]}" && return 0
	__cache_depcheck+=("$program")

	# Check if the program exists in the path.
	printf "Checking for dependency %-26s " "'$program'..."
	if command -v "$1" &>/dev/null; then
		echo "OK"
		return 0
	fi

	# Fail.
	echo "Missing"
	fatal "Missing dependency."
	exit 1
}

# ----------------------------------------------------------------------------------------------------------------------
# Preproccessing:

__cache__preprocess_included=()

preprocess() {
	local srcfile="$(abspath "$1")"
	local srcdir="$(abspath "$2")"

	# Don't include twice.
	contains "$srcfile" "${__cache__preprocess_included[@]}" && return 0
	__cache__preprocess_included+=("$srcfile")

	# Preprocess.
	while IFS='' read -r line; do
		case "$line" in
			'#!'*) {
				# Shebang comment.
				echo "$line"
			};;

			'#@'*) {
				# Copyright comment.
				echo "#${line:2}"
			};;

			'#'*) {
				# Regular comment.
				:
			};;

			'use FindBin;');;

			'require'*) {
				# Use directive.
				file="${srcdir}/$(sed "s/^require *(\{0,1\}['\"]\\\$FindBin::RealBin\/\([A-Za-z0-9\\/\.\\-]\{1,\}\).*\$/\1/" <<< "$line")"
				echo "- Embedding: $file" 1>&2
				if [ -f "$file" ]; then

					echo "# <PREPROCESSOR> INCLUDE: $file"
					preprocess "$file" "$srcdir"
					echo "# <PREPROCESSOR> END:     $file"
					continue
				else
					fatal "Failed to embed file: $file"
				fi
			};;

			*) {
				# Regular line.
				echo "$line"
			};;
		esac
	done < "$srcfile"
}

# ----------------------------------------------------------------------------------------------------------------------
# Update:

if [ "$arg_update" = "true" ]; then
	start "Updating..."
	git -C "$HERE" remote update >/dev/null
	if [ "$(git -C "$HERE" rev-parse @)" != "$(git -C "$HERE" rev-parse '@{u}')" ] && [ "$(git -C "$HERE" rev-parse @)" = "$(git -C "$HERE" merge-base @ '@{u}')" ]; then
		start "Update found."
		exec bash "${BASH_SOURCE[0]}" "${argv_original[@]}"
		return $?
	fi
fi

# ----------------------------------------------------------------------------------------------------------------------
# Install:
INSTALL="$arg_to"
SOURCE="${HERE}/src/main.pl"
echo "$INSTALL" > "$INSTALL_CACHE"

[ -z "$arg_to" ] && fatal "Invalid usage of '--to' argument."

# Preprocessing.
start "Preprocessing..."
tempfile="$(mktemp "$(mktemp -d)"/'ls-git.XXXXXX')"
preprocess "$SOURCE" "$(dirname "$SOURCE")" > "$tempfile"

# Command dependencies.
start "Checking dependencies..."
depcheck 'cpan'
depcheck 'git'
depcheck 'perl'
depcheck 'tput'

# Module dependencies.
while read -r module; do
	depcheck_perl "$module"
done < <(grep "^use [A-Z][A-Za-z\:]\{1,\}" "$tempfile" | sed 's/use \([A-Za-z\:]\{1,\}\).*/\1/' | sort -r )

# Install.
start "Installing..."
echo "Installing to: $INSTALL"
if [ "$arg_minify" = "true" ] && command -v perltidy &>/dev/null; then
	# Install minified.
	perltidy --mangle --delete-all-comments "$tempfile" -o "$INSTALL"
else
	# Install normal.
	cp "$tempfile" "$INSTALL"
fi

chmod 755 "$INSTALL"