#!/bin/sh
set -eu


escape_name() {
	printf '%s' "$1" |
		sed 's|"|\\"|g' |
		printf '(load "%s")\n' "$(cat -)"
}


IMPLEMENTATIONS='
abcl
allegro
clasp
clisp
clozure
cmucl
ecl
jscl
mkcl
sbcl
'

usage() {
	cat <<-'EOF'
		Usage:
		  cl [-e EXP] [-f FILE] [-p] [-M IMAGE] [-I IMPL] [-n] [-v] [FILE...] [-- LISP_OPTIONS]
		  cl -l
		  cl -h
	EOF
}

help() {
	cat <<-'EOF'


		Options:
		  -e EXP          an sexp to be evaluated (can be given more than once)
		  -E EXP          an sexp to be executed as a script
		  -f FILE         a file to be evaluated (can be given more than once)
		  -p              print the value of the last given expression
		  -M IMAGE        load the given Lisp image
		  -I IMPL         use the given implementation (default: $LISP_CLI_IMPL)
		  -n              skip loading the implementation's init file
		  -v              verbose mode
		  -l              list the known types of implementations
		  -h, --help      show this message

		  FILE            the file to be executed as a script
		  LISP_OPTIONS    options to be forwarrded to the underlying Lisp command


		Lauch the desired Lisp implementation, properly adapting the given
		CLI options.

		When the implementation is not explicited on the command line, and
		the $LISP_CLI_IMPL environment variable in unset, implementations are
		searched for alphabetically in $PATH, untill one is found, otherwise
		an error is emitted.

		The supported implementations are:
	EOF


	for i in $IMPLEMENTATIONS; do
		printf -- '- %s\n' "$i"
	done

	cat <<-'EOF'


		Examples:

		  Launch CLISP REPL, when $LISP_CLI_IMPL is set to 'clisp':

		    $ cl


		  Lauch SBCL REPL, with the given Lisp image loaded, skipping the
		  loading of the '.sbclrc' file:

		    $ cl -n -Isbcl sbcl.image


		  Run file1.lisp with ABCL:

		    $ cl -Iabcl file1.lisp


		  Process STDIN:

		    $ cat <<-EOS > process.lisp

		    EOS
		    $ cat f1.txt f2.txt | cl -p process.lisp


		  Print a value on all types of implementations:

		    $ for i in `cl -l`; do cl -I$i -pe 'call-arguments-list'; done
	EOF
}


for flag in "$@"; do
	case "$flag" in
		--)
			break
			;;
		--help)
			usage
			help
			exit
			;;
		*)
			;;
	esac
done

SCRIPT="$(mkstemp)"
trap 'rm -f "$SCRIPT"' EXIT

NO_RC=false
LISP_CLI_RC="${XDG_CONFIG_HOME:-$HOME/.config}/lisp-cli/init.lisp"
VERBOSE=false
IMAGE=''
IMPL="${LISP_CLI_IMPL:-}"
INTERACTIVE=true
while getopts 'e:E:f:pM:I:nvlh' flag; do
	case "$flag" in
		e)
			printf '%s\n' "$OPTARG" >> "$SCRIPT"
			;;
		E)
			printf '%s\n' "$OPTARG" >> "$SCRIPT"
			INTERACTIVE=false
			;;
		f)
			escape_name "$OPTARG" >> "$SCRIPT"
			;;
		M)
			IMAGE="$OPTARG"
			;;
		I)
			IMPL="$OPTARG"
			;;
		n)
			NO_RC=true
			;;
		v)
			VERBOSE=true
			;;
		l)
			for i in $IMPLEMENTATIONS; do
				printf '%s\n' "$i"
			done
			exit
			;;
		h)
			usage
			help
			exit
			;;
		*)
			usage >&2
			exit 2
			;;
	esac
done

shift $((OPTIND - 2))
if [ "$1" != '--' ]; then
	shift
fi

PRESERVE_ARGS=false
for f in "$@"; do
	if [ "$f" = '--' ]; then
		PRESERVE_ARGS=true
		shift
		break
	fi
	INTERACTIVE=false
	escape_name "$f" >> "$SCRIPT"
done

if [ "$PRESERVE_ARGS" = false ]; then
	set --
fi

MAIN="$(mkstemp)"
trap 'rm -f "$MAIN"' EXIT
if [ "$NO_RC" = false ] && [ -e "$LISP_CLI_RC" ]; then
	escape_name "$LISP_CLI_RC" > "$MAIN"
fi

if [ "$INTERACTIVE" = true ]; then
	escape_name "$SCRIPT" >> "$MAIN"
else
	cat <<-EOF >> "$MAIN"
		(handler-case
		  (progn
		    (load "$SCRIPT"
		          :verbose nil
		          :print nil)
		    (uiop:quit 0))
		  (error (e)
		    (format *error-output* "~&~%error: ~a~%" e)
		    (uiop:quit 1)))
	EOF
fi

if [ -z "$IMPL" ]; then
	for i in $IMPLEMENTATIONS; do
		if command -v "$i" > /dev/null; then
			IMPL="$i"
			break
		fi
	done
	if [ -z "$IMPL" ]; then
		printf "Could not find any implementation in \$PATH.\n" >&2
		exit 2
	fi
fi


case "$IMPL" in
	abcl)
		exit 4
		;;
	allegro)
		exit 4
		;;
	clasp)
		exit 4
		;;
	clisp)
		set -- -ansi -i "$MAIN" "$@"
		if [ -n "$IMAGE" ]; then
			set -- -M "$IMAGE" "$@"
		fi
		if [ "$NO_RC" = true ]; then
			set -- -norc "$@"
		fi
		if [ "$VERBOSE" = false ]; then
			set -- -q -q "$@"
		else
			set -x
		fi
		clisp "$@"
		;;
	clozure)
		set -- -l "$MAIN" "$@"
		if [ -n "$IMAGE" ]; then
			set -- -I "$IMAGE" "$@"
		fi
		if [ "$NO_RC" = true ]; then
			set -- -n "$@"
		fi
		if [ "$VERBOSE" = false ]; then
			set -- -Q "$@"
		else
			set -x
		fi
		ccl "$@"
		;;
	cmucl)
		exit 4
		;;
	ecl)
		exit 4
		;;
	jscl)
		exit 4
		;;
	mkcl)
		exit 4
		;;
	sbcl)
		set -- --load "$MAIN" "$@"
		if [ -n "$IMAGE" ]; then
			# The '--core' "C runtime option" must appear before the
			# other "Lisp options", such as '--load'.
			set -- --core "$IMAGE" "$@"
		fi
		if [ "$NO_RC" = true ]; then
			set -- --no-sysinit --no-userinit "$@"
		fi
		if [ "$VERBOSE" = false ]; then
			set -- --noinform "$@"
		else
			set -x
		fi
		sbcl "$@"
		;;
	*)
		printf 'Unsupported implementation: "%s".\n\n' "$IMPL" >&2
		usage >&2
		exit 2
		;;
esac