#!/bin/bash

set -euf -o pipefail

top="#TOP#"
shadow_top="#SHADOW_TOP#"

orig_ar="#ORIG_TOOL#"
shadow_ar="#SHADOW_TOOL#"

errors=()
warnings=()
skips=()

orig_out=()
shadow_out=()
orig_input=()
shadow_input=()
orig_opts=()
shadow_opts=()

dump_log ()
{
    (
    set +u
    IFS=";"
    cat <<EOF
errors=(${errors[@]})
warnings=(${warnings[@]})
skips=(${skips[@]})
orig_out=(${orig_out[@]})
shadow_out=(${shadow_out[@]})
orig_input=(${orig_input[@]})
shadow_input=(${shadow_input[@]})
orig_opts=($0 ${orig_opts[@]})
shadow_opts=(${shadow_opts[@]})

EOF
    )
}

report_errors () {
    res=$?
    if [ $res != 0 ]; then
	errors+=("wrapper failed with $res")
    fi
    if [ ${#errors[@]} != 0 ] \
	   || [ ${#warnings[@]} != 0 ] \
	   || [ ${#skips[@]} != 0 ]; then
	(
	    /usr/bin/flock -e 9

	    if [ ${#errors[@]} != 0 ]; then
		log=$shadow_top.errors
	    elif [ ${#warnings[@]} != 0 ]; then
		log=$shadow_top.warnings
	    else
		log=$shadow_top.skips
	    fi
	    dump_log >>$log
	) 9>>$shadow_top.lock
    fi
}

trap report_errors EXIT

if [ "$#" -gt 0 ] && [ ${#orig_opts[@]} = 0 ]; then
    opt="$1"
    shift

    orig_opts+=("$opt")

    case "$opt" in
	"-M") skips+=("mri-script unsupported") ;;
	"c"*) ;;
	*) errors+=("orig expecting: crsPD, cqsL, etc.; got: $opt") ;;
    esac
else
    errors+=("orig missing: action")
fi

while [ "$#" -gt 0 ]; do
    opt="$1"
    shift

    orig_opts+=("$opt")

    case "$opt" in
	"-"*)
	    ;;
	*)
	    if [ ${#orig_out[@]} = 0 ]; then
		orig_out+=("$opt")
	    else
		orig_input+=("$opt")
	    fi
	    ;;
    esac
done

# orig_out is used only if command is not skipped
if [ "${#orig_out[@]}" = 0 ] && [ ${#skips[@]} = 0 ]; then
    errors+=("orig missing: orig_out")
fi

print_shadow_path ()
{
    local path="$1"
    local prefix="${2-}"

    case "$path" in
	"/dev/null") echo "$path"; return ;;
	"/"*) errors+=("Absolute path: $path") ;;
    esac

    # Check that we are under $top
    case "$(pwd -P | sed -e "s#^$top##")" in
	"/"*) errors+=("Running outside of $top") ;;
    esac

    echo "$(pwd -P)/$path" | sed -e "s#$top#$shadow_top${prefix}#"
}

generate_shadow_rsp ()
{
    local orig_rsp="$1"

    local shadow_rsp orig_file shadow_file

    shadow_rsp=$(print_shadow_path "$orig_rsp")
    mkdir -p "$(dirname "$shadow_rsp")"
    rm -f "$shadow_rsp"

    if [ "$(stat --format=%s "$orig_rsp")" = 0 ]; then
	touch "$shadow_rsp"
    else
	local quote delim=""
	while read -d '' -r orig_file; do
            # unquote orig
            case "$orig_file" in
                \'*\') quote="'"; orig_file=${orig_file:1:-1} ;;
                *) quote="" ;;
            esac
	    shadow_file=$(print_shadow_path "$orig_file")
	    if ! [ -e "$shadow_file" ]; then
		shadow_file="$orig_file"
	    fi
            # quote shadow
	    echo -ne "$delim$quote$shadow_file$quote" >> "$shadow_rsp"
	    delim=" "
	done < <({ cat "$orig_rsp"; echo; } | xargs printf '%s\0')
    fi

    echo "$shadow_rsp"
}

make_shadow_opts ()
{
    local opt
    local shadow_file

    if [ "$#" -gt 0 ] && [ ${#shadow_opts[@]} = 0 ]; then
	opt="$1"
	shift

	shadow_opts+=("$opt")

	case "$opt" in
	    "c"*) ;;
	    *) errors+=("shadow expecting: crsPD, cqsL, etc.; got: $opt") ;;
	esac
    else
	errors+=("shadow missing: action")
    fi

    while [ "$#" -gt 0 ]; do
	opt="$1"
	shift

	case "$opt" in
	    "-"*) ;;
	    "@"*".rsp")
		opt="${opt#@}"
		if [ x"$(basename "$opt" .rsp)" = x"$(basename "${orig_out[*]}")" ]; then
		    opt=$(generate_shadow_rsp "$opt")
		else
		    errors+=("RSP file $opt does not match orig_out ${orig_out[*]}")
		fi
		opt="@$opt"
		;;
	    "@"*)
		errors+=("Unexpected option: $opt")
		opt="${opt#@}"
		# shellcheck disable=SC2046
		make_shadow_opts $(cat "$opt")
		continue
		;;
	    *)
		shadow_file=$(print_shadow_path "$opt")
		if [ ${#shadow_out[@]} = 0 ]; then
		    opt="$shadow_file"
		    shadow_out+=("$shadow_file")
		elif [ -e "$shadow_file" ]; then
		    opt="$shadow_file"
		    shadow_input+=("$shadow_file")
		fi
		;;
	esac
	shadow_opts+=("$opt")
    done
}

if [ ${#errors[@]} = 0 ] && [ ${#skips[@]} = 0 ]; then
    make_shadow_opts "${orig_opts[@]}"
fi

if [ ${#errors[@]} = 0 ] && [ ${#skips[@]} = 0 ]; then
    shadow_log=$(print_shadow_path "${orig_out[*]}" "-logs")

    mkdir -p "$(dirname "${shadow_out[*]}")"
    mkdir -p "$(dirname "$shadow_log")"

    dump_log > "$shadow_log"
    echo "$shadow_ar" "${shadow_opts[@]}" >> "$shadow_log"
    "$shadow_ar" "${shadow_opts[@]}" >> "$shadow_log" 2>&1 &
    shadow_res=0 && wait $! || shadow_res=$?

    if [ $shadow_res != 0 ]; then
	errors+=("shadow_ar failed with $shadow_res")
    elif ! [ -e "${shadow_out[*]}" ]; then
	errors+=("shadow_ar failed to generate output")
    else
	shadow_link=$(IFS=""; print_shadow_path "${orig_out[*]}" "-default-A")
	mkdir -p "$(dirname "$shadow_link")"
	ln -s -f "${shadow_out[*]}" "$shadow_link"
    fi
fi

"$orig_ar" "${orig_opts[@]}" < /dev/stdin &
orig_res=0 && wait $! || orig_res=$?

if [ $orig_res != 0 ]; then
    errors+=("orig_ar failed with $orig_res")
fi

exit $orig_res