#!/bin/sh
# git-annex compute remote program that uses wasmedge to run WASM binaries
# from the git-annex repository.
# 
# Copyright 2025 Joey Hess; licenced under the GNU GPL version 3 or higher.
set -e

if [ -z "$1" ]; then
	echo "Usage: file.wasm [inputs] -- [outputs] -- [options]" >&2
	echo "Example: concat.wasm foo bar -- baz --" >&2
	exit 1
fi

stage=1
wasm=""
while [ -n "$1" ]; do
	if [ "$1" = "--" ]; then
		stage=$((stage+1))
		shift 1
	else
		if [ "$stage" = 1 ]; then
			echo "INPUT $1"
			read input
			if [ -n "$input" ]; then
				p="./$1"
				mkdir -p "$(dirname "$p")"
				ln -s $(realpath "$input") "$p"
				if [ -z "$wasm" ]; then
					wasm="$p"
				fi
			fi
			shift 1
		elif [ "$stage" = 2 ]; then
			echo "OUTPUT $1"
			read output
			shift 1
		else
			break
		fi
	fi
done

if [ -n "$wasm" ]; then
	# Use --force-interpreter to avoid wasmedge running AOT native
	# instructions, which is insecure if the WASM binary comes from
	# an untrusted source.
	#
	# Avoid displaying output from the WASM binary, since it is
	# untrusted, and could contain harmful terminal escape sequences,
	# for example.
	wasmedge --dir "/:`pwd`" --force-interpreter -- "$wasm" "$@" \
		>/dev/null 2>/dev/null </dev/null
fi