#!/bin/bash
#
# Copyright, the authors of the Linux man-pages project
# SPDX-License-Identifier: GPL-3.0-or-later

set -Eefuo pipefail;
trap 'exit 2;' ERR;


# Defaults:
A='';
B='';
C='';
c='';
h='-H';
i='';
l='';
m='';
n='';
t='';
x='c';


grepc_err()
{
	>&2 printf '%s\n' "$(basename "$0"): error: $*";
	exit 2;
}


while getopts "A:B:C:chilm:nt:x:" opt; do
	case "$opt" in
	A)	A="-A$OPTARG";		;;
	B)	B="-B$OPTARG";		;;
	C)	C="-C$OPTARG";		;;
	c)	c='-c';			;;
	h)	h='-h';			;;
	i)	i='-i';			;;
	l)	l='-l';			;;
	m)	m="-m$OPTARG";		;;
	n)	n='-n';			;;
	t)	t="$t -t$OPTARG";	;;
	x)	x="$OPTARG";		;;
	\? | *)	exit 2;			;;
	esac;
done;
shift $((OPTIND-1));

if test $# -lt 1; then
	grepc_err "Missing identifier.";
fi;
identifier="$1";
shift;


patterns="$(mktemp -t grepc.patterns.XXXXXX)";


# shellcheck disable=SC2086  # $t may contain zero or more flags
"grepc_$x" $t "$identifier" >"$patterns";


export opts="$A $B $C $c $h $i $l -M $m $n";


if test -z "$*"; then
	# shellcheck disable=SC2086  # $opts may contain zero or more flags
	pcre2grep $opts -f "$patterns" || test $? -eq 1;
else
	find "$@" -type f -print0 \
	| if test -z "$c"; then
		xargs -0 sh -c 'grep -lZPI $i -e "$0" -- "$@" || test $? -eq 1;' "$identifier";
	else
		cat;
	fi \
	| xargs -0 sh -c 'pcre2grep $opts -f "$0" -- "$@" || test $? -eq 1;' "$patterns";
fi;